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Publisher: John Wiley and Sons   (Total: 1589 journals)

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Showing 1 - 200 of 1589 Journals sorted alphabetically
Abacus     Hybrid Journal   (Followers: 12, SJR: 0.48, h-index: 22)
About Campus     Hybrid Journal   (Followers: 5)
Academic Emergency Medicine     Hybrid Journal   (Followers: 65, SJR: 1.385, h-index: 91)
Accounting & Finance     Hybrid Journal   (Followers: 47, SJR: 0.547, h-index: 30)
ACEP NOW     Free   (Followers: 1)
Acta Anaesthesiologica Scandinavica     Hybrid Journal   (Followers: 52, SJR: 1.02, h-index: 88)
Acta Archaeologica     Hybrid Journal   (Followers: 164, SJR: 0.101, h-index: 9)
Acta Geologica Sinica (English Edition)     Hybrid Journal   (Followers: 3, SJR: 0.552, h-index: 41)
Acta Neurologica Scandinavica     Hybrid Journal   (Followers: 5, SJR: 1.203, h-index: 74)
Acta Obstetricia et Gynecologica Scandinavica     Hybrid Journal   (Followers: 15, SJR: 1.197, h-index: 81)
Acta Ophthalmologica     Hybrid Journal   (Followers: 6, SJR: 0.112, h-index: 1)
Acta Paediatrica     Hybrid Journal   (Followers: 56, SJR: 0.794, h-index: 88)
Acta Physiologica     Hybrid Journal   (Followers: 6, SJR: 1.69, h-index: 88)
Acta Polymerica     Hybrid Journal   (Followers: 9)
Acta Psychiatrica Scandinavica     Hybrid Journal   (Followers: 35, SJR: 2.518, h-index: 113)
Acta Zoologica     Hybrid Journal   (Followers: 7, SJR: 0.459, h-index: 29)
Acute Medicine & Surgery     Hybrid Journal   (Followers: 4)
Addiction     Hybrid Journal   (Followers: 35, SJR: 2.086, h-index: 143)
Addiction Biology     Hybrid Journal   (Followers: 14, SJR: 2.091, h-index: 57)
Adultspan J.     Hybrid Journal   (SJR: 0.127, h-index: 4)
Advanced Energy Materials     Hybrid Journal   (Followers: 27, SJR: 6.411, h-index: 86)
Advanced Engineering Materials     Hybrid Journal   (Followers: 26, SJR: 0.81, h-index: 81)
Advanced Functional Materials     Hybrid Journal   (Followers: 51, SJR: 5.21, h-index: 203)
Advanced Healthcare Materials     Hybrid Journal   (Followers: 14, SJR: 0.232, h-index: 7)
Advanced Materials     Hybrid Journal   (Followers: 268, SJR: 9.021, h-index: 345)
Advanced Materials Interfaces     Hybrid Journal   (Followers: 6, SJR: 1.177, h-index: 10)
Advanced Optical Materials     Hybrid Journal   (Followers: 7, SJR: 2.488, h-index: 21)
Advanced Science     Open Access   (Followers: 5)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17, SJR: 2.729, h-index: 121)
Advances in Polymer Technology     Hybrid Journal   (Followers: 13, SJR: 0.344, h-index: 31)
Africa Confidential     Hybrid Journal   (Followers: 21)
Africa Research Bulletin: Economic, Financial and Technical Series     Hybrid Journal   (Followers: 13)
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 10)
African Development Review     Hybrid Journal   (Followers: 33, SJR: 0.275, h-index: 17)
African J. of Ecology     Hybrid Journal   (Followers: 16, SJR: 0.477, h-index: 39)
Aggressive Behavior     Hybrid Journal   (Followers: 15, SJR: 1.391, h-index: 66)
Aging Cell     Open Access   (Followers: 11, SJR: 4.374, h-index: 95)
Agribusiness : an Intl. J.     Hybrid Journal   (Followers: 3, SJR: 0.627, h-index: 14)
Agricultural and Forest Entomology     Hybrid Journal   (Followers: 16, SJR: 0.925, h-index: 43)
Agricultural Economics     Hybrid Journal   (Followers: 45, SJR: 1.099, h-index: 51)
AIChE J.     Hybrid Journal   (Followers: 32, SJR: 1.122, h-index: 120)
Alcoholism and Drug Abuse Weekly     Hybrid Journal   (Followers: 7)
Alcoholism Clinical and Experimental Research     Hybrid Journal   (Followers: 7, SJR: 1.416, h-index: 125)
Alimentary Pharmacology & Therapeutics     Hybrid Journal   (Followers: 33, SJR: 2.833, h-index: 138)
Alimentary Pharmacology & Therapeutics Symposium Series     Hybrid Journal   (Followers: 3)
Allergy     Hybrid Journal   (Followers: 51, SJR: 3.048, h-index: 129)
Alternatives to the High Cost of Litigation     Hybrid Journal   (Followers: 3)
American Anthropologist     Hybrid Journal   (Followers: 148, SJR: 0.951, h-index: 61)
American Business Law J.     Hybrid Journal   (Followers: 24, SJR: 0.205, h-index: 17)
American Ethnologist     Hybrid Journal   (Followers: 92, SJR: 2.325, h-index: 51)
American J. of Economics and Sociology     Hybrid Journal   (Followers: 29, SJR: 0.211, h-index: 26)
American J. of Hematology     Hybrid Journal   (Followers: 34, SJR: 1.761, h-index: 77)
American J. of Human Biology     Hybrid Journal   (Followers: 12, SJR: 1.018, h-index: 58)
American J. of Industrial Medicine     Hybrid Journal   (Followers: 16, SJR: 0.993, h-index: 85)
American J. of Medical Genetics Part A     Hybrid Journal   (Followers: 16, SJR: 1.115, h-index: 61)
American J. of Medical Genetics Part B: Neuropsychiatric Genetics     Hybrid Journal   (Followers: 4, SJR: 1.771, h-index: 107)
American J. of Medical Genetics Part C: Seminars in Medical Genetics     Partially Free   (Followers: 6, SJR: 2.315, h-index: 79)
American J. of Physical Anthropology     Hybrid Journal   (Followers: 37, SJR: 1.41, h-index: 88)
American J. of Political Science     Hybrid Journal   (Followers: 276, SJR: 5.101, h-index: 114)
American J. of Primatology     Hybrid Journal   (Followers: 15, SJR: 1.197, h-index: 63)
American J. of Reproductive Immunology     Hybrid Journal   (Followers: 3, SJR: 1.347, h-index: 75)
American J. of Transplantation     Hybrid Journal   (Followers: 17, SJR: 2.792, h-index: 140)
American J. on Addictions     Hybrid Journal   (Followers: 9, SJR: 0.843, h-index: 57)
Anaesthesia     Hybrid Journal   (Followers: 138, SJR: 1.404, h-index: 88)
Analyses of Social Issues and Public Policy     Hybrid Journal   (Followers: 9, SJR: 0.397, h-index: 18)
Analytic Philosophy     Hybrid Journal   (Followers: 18)
Anatomia, Histologia, Embryologia: J. of Veterinary Medicine Series C     Hybrid Journal   (Followers: 3, SJR: 0.295, h-index: 27)
Anatomical Sciences Education     Hybrid Journal   (Followers: 1, SJR: 0.633, h-index: 24)
Andrologia     Hybrid Journal   (Followers: 2, SJR: 0.528, h-index: 45)
Andrology     Hybrid Journal   (Followers: 2, SJR: 0.979, h-index: 14)
Angewandte Chemie     Hybrid Journal   (Followers: 220)
Angewandte Chemie Intl. Edition     Hybrid Journal   (Followers: 222, SJR: 6.229, h-index: 397)
Animal Conservation     Hybrid Journal   (Followers: 41, SJR: 1.576, h-index: 62)
Animal Genetics     Hybrid Journal   (Followers: 8, SJR: 0.957, h-index: 67)
Animal Science J.     Hybrid Journal   (Followers: 6, SJR: 0.569, h-index: 24)
Annalen der Physik     Hybrid Journal   (Followers: 5, SJR: 1.46, h-index: 40)
Annals of Anthropological Practice     Partially Free   (Followers: 2, SJR: 0.187, h-index: 5)
Annals of Applied Biology     Hybrid Journal   (Followers: 7, SJR: 0.816, h-index: 56)
Annals of Clinical and Translational Neurology     Open Access   (Followers: 1)
Annals of Human Genetics     Hybrid Journal   (Followers: 9, SJR: 1.191, h-index: 67)
Annals of Neurology     Hybrid Journal   (Followers: 47, SJR: 5.584, h-index: 241)
Annals of Noninvasive Electrocardiology     Hybrid Journal   (Followers: 1, SJR: 0.531, h-index: 38)
Annals of Public and Cooperative Economics     Hybrid Journal   (Followers: 8, SJR: 0.336, h-index: 23)
Annals of the New York Academy of Sciences     Hybrid Journal   (Followers: 5, SJR: 2.389, h-index: 189)
Annual Bulletin of Historical Literature     Hybrid Journal   (Followers: 13)
Annual Review of Information Science and Technology     Hybrid Journal   (Followers: 14)
Anthropology & Education Quarterly     Hybrid Journal   (Followers: 25, SJR: 0.72, h-index: 31)
Anthropology & Humanism     Hybrid Journal   (Followers: 17, SJR: 0.137, h-index: 3)
Anthropology News     Hybrid Journal   (Followers: 15)
Anthropology of Consciousness     Hybrid Journal   (Followers: 11, SJR: 0.172, h-index: 5)
Anthropology of Work Review     Hybrid Journal   (Followers: 11, SJR: 0.256, h-index: 5)
Anthropology Today     Hybrid Journal   (Followers: 89, SJR: 0.545, h-index: 15)
Antipode     Hybrid Journal   (Followers: 49, SJR: 2.212, h-index: 69)
Anz J. of Surgery     Hybrid Journal   (Followers: 8, SJR: 0.432, h-index: 59)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apmis     Hybrid Journal   (Followers: 1, SJR: 0.855, h-index: 73)
Applied Cognitive Psychology     Hybrid Journal   (Followers: 70, SJR: 0.754, h-index: 69)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7, SJR: 0.632, h-index: 58)
Applied Psychology     Hybrid Journal   (Followers: 206, SJR: 1.023, h-index: 64)
Applied Psychology: Health and Well-Being     Hybrid Journal   (Followers: 49, SJR: 0.868, h-index: 13)
Applied Stochastic Models in Business and Industry     Hybrid Journal   (Followers: 5, SJR: 0.613, h-index: 24)
Aquaculture Nutrition     Hybrid Journal   (Followers: 14, SJR: 1.025, h-index: 55)
Aquaculture Research     Hybrid Journal   (Followers: 31, SJR: 0.807, h-index: 60)
Aquatic Conservation Marine and Freshwater Ecosystems     Hybrid Journal   (Followers: 36, SJR: 1.047, h-index: 57)
Arabian Archaeology and Epigraphy     Hybrid Journal   (Followers: 11, SJR: 0.453, h-index: 11)
Archaeological Prospection     Hybrid Journal   (Followers: 12, SJR: 0.922, h-index: 21)
Archaeology in Oceania     Hybrid Journal   (Followers: 13, SJR: 0.745, h-index: 18)
Archaeometry     Hybrid Journal   (Followers: 27, SJR: 0.809, h-index: 48)
Archeological Papers of The American Anthropological Association     Hybrid Journal   (Followers: 15, SJR: 0.156, h-index: 2)
Architectural Design     Hybrid Journal   (Followers: 25, SJR: 0.261, h-index: 9)
Archiv der Pharmazie     Hybrid Journal   (Followers: 3, SJR: 0.628, h-index: 43)
Archives of Drug Information     Hybrid Journal   (Followers: 5)
Archives of Insect Biochemistry and Physiology     Hybrid Journal   (SJR: 0.768, h-index: 54)
Area     Hybrid Journal   (Followers: 12, SJR: 0.938, h-index: 57)
Art History     Hybrid Journal   (Followers: 245, SJR: 0.153, h-index: 13)
Arthritis & Rheumatology     Hybrid Journal   (Followers: 52, SJR: 1.984, h-index: 20)
Arthritis Care & Research     Hybrid Journal   (Followers: 27, SJR: 2.256, h-index: 114)
Artificial Organs     Hybrid Journal   (Followers: 1, SJR: 0.872, h-index: 60)
ASHE Higher Education Reports     Hybrid Journal   (Followers: 15)
Asia & the Pacific Policy Studies     Open Access   (Followers: 16)
Asia Pacific J. of Human Resources     Hybrid Journal   (Followers: 320, SJR: 0.494, h-index: 19)
Asia Pacific Viewpoint     Hybrid Journal   (Followers: 1, SJR: 0.616, h-index: 26)
Asia-Pacific J. of Chemical Engineering     Hybrid Journal   (Followers: 8, SJR: 0.345, h-index: 20)
Asia-pacific J. of Clinical Oncology     Hybrid Journal   (Followers: 6, SJR: 0.554, h-index: 14)
Asia-Pacific J. of Financial Studies     Hybrid Journal   (SJR: 0.241, h-index: 7)
Asia-Pacific Psychiatry     Hybrid Journal   (Followers: 4, SJR: 0.377, h-index: 7)
Asian Economic J.     Hybrid Journal   (Followers: 8, SJR: 0.234, h-index: 21)
Asian Economic Policy Review     Hybrid Journal   (Followers: 4, SJR: 0.196, h-index: 12)
Asian J. of Control     Hybrid Journal   (SJR: 0.862, h-index: 34)
Asian J. of Endoscopic Surgery     Hybrid Journal   (SJR: 0.394, h-index: 7)
Asian J. of Organic Chemistry     Hybrid Journal   (Followers: 6, SJR: 1.443, h-index: 19)
Asian J. of Social Psychology     Hybrid Journal   (Followers: 5, SJR: 0.665, h-index: 37)
Asian Politics and Policy     Hybrid Journal   (Followers: 12, SJR: 0.207, h-index: 7)
Asian Social Work and Policy Review     Hybrid Journal   (Followers: 5, SJR: 0.318, h-index: 5)
Asian-pacific Economic Literature     Hybrid Journal   (Followers: 5, SJR: 0.168, h-index: 15)
Assessment Update     Hybrid Journal   (Followers: 4)
Astronomische Nachrichten     Hybrid Journal   (Followers: 2, SJR: 0.701, h-index: 40)
Atmospheric Science Letters     Open Access   (Followers: 29, SJR: 1.332, h-index: 27)
Austral Ecology     Hybrid Journal   (Followers: 15, SJR: 1.095, h-index: 66)
Austral Entomology     Hybrid Journal   (Followers: 9, SJR: 0.524, h-index: 28)
Australasian J. of Dermatology     Hybrid Journal   (Followers: 8, SJR: 0.714, h-index: 40)
Australasian J. On Ageing     Hybrid Journal   (Followers: 6, SJR: 0.39, h-index: 22)
Australian & New Zealand J. of Statistics     Hybrid Journal   (Followers: 14, SJR: 0.275, h-index: 28)
Australian Accounting Review     Hybrid Journal   (Followers: 3, SJR: 0.709, h-index: 14)
Australian and New Zealand J. of Family Therapy (ANZJFT)     Hybrid Journal   (Followers: 3, SJR: 0.382, h-index: 12)
Australian and New Zealand J. of Obstetrics and Gynaecology     Hybrid Journal   (Followers: 47, SJR: 0.814, h-index: 49)
Australian and New Zealand J. of Public Health     Hybrid Journal   (Followers: 11, SJR: 0.82, h-index: 62)
Australian Dental J.     Hybrid Journal   (Followers: 7, SJR: 0.482, h-index: 46)
Australian Economic History Review     Hybrid Journal   (Followers: 5, SJR: 0.171, h-index: 12)
Australian Economic Papers     Hybrid Journal   (Followers: 31, SJR: 0.23, h-index: 9)
Australian Economic Review     Hybrid Journal   (Followers: 6, SJR: 0.357, h-index: 21)
Australian Endodontic J.     Hybrid Journal   (Followers: 3, SJR: 0.513, h-index: 24)
Australian J. of Agricultural and Resource Economics     Hybrid Journal   (Followers: 3, SJR: 0.765, h-index: 36)
Australian J. of Grape and Wine Research     Hybrid Journal   (Followers: 5, SJR: 0.879, h-index: 56)
Australian J. of Politics & History     Hybrid Journal   (Followers: 14, SJR: 0.203, h-index: 14)
Australian J. of Psychology     Hybrid Journal   (Followers: 18, SJR: 0.384, h-index: 30)
Australian J. of Public Administration     Hybrid Journal   (Followers: 406, SJR: 0.418, h-index: 29)
Australian J. of Rural Health     Hybrid Journal   (Followers: 5, SJR: 0.43, h-index: 34)
Australian Occupational Therapy J.     Hybrid Journal   (Followers: 72, SJR: 0.59, h-index: 29)
Australian Psychologist     Hybrid Journal   (Followers: 12, SJR: 0.331, h-index: 31)
Australian Veterinary J.     Hybrid Journal   (Followers: 21, SJR: 0.459, h-index: 45)
Autism Research     Hybrid Journal   (Followers: 36, SJR: 2.126, h-index: 39)
Autonomic & Autacoid Pharmacology     Hybrid Journal   (SJR: 0.371, h-index: 29)
Banks in Insurance Report     Hybrid Journal   (Followers: 1)
Basic & Clinical Pharmacology & Toxicology     Hybrid Journal   (Followers: 11, SJR: 0.539, h-index: 70)
Basic and Applied Pathology     Open Access   (Followers: 2, SJR: 0.113, h-index: 4)
Basin Research     Hybrid Journal   (Followers: 5, SJR: 1.54, h-index: 60)
Bauphysik     Hybrid Journal   (Followers: 2, SJR: 0.194, h-index: 5)
Bauregelliste A, Bauregelliste B Und Liste C     Hybrid Journal  
Bautechnik     Hybrid Journal   (Followers: 1, SJR: 0.321, h-index: 11)
Behavioral Interventions     Hybrid Journal   (Followers: 9, SJR: 0.297, h-index: 23)
Behavioral Sciences & the Law     Hybrid Journal   (Followers: 24, SJR: 0.736, h-index: 57)
Berichte Zur Wissenschaftsgeschichte     Hybrid Journal   (Followers: 10, SJR: 0.11, h-index: 5)
Beton- und Stahlbetonbau     Hybrid Journal   (Followers: 2, SJR: 0.493, h-index: 14)
Biochemistry and Molecular Biology Education     Hybrid Journal   (Followers: 6, SJR: 0.311, h-index: 26)
Bioelectromagnetics     Hybrid Journal   (Followers: 1, SJR: 0.568, h-index: 64)
Bioengineering & Translational Medicine     Open Access  
BioEssays     Hybrid Journal   (Followers: 10, SJR: 3.104, h-index: 155)
Bioethics     Hybrid Journal   (Followers: 14, SJR: 0.686, h-index: 39)
Biofuels, Bioproducts and Biorefining     Hybrid Journal   (Followers: 1, SJR: 1.725, h-index: 56)
Biological J. of the Linnean Society     Hybrid Journal   (Followers: 16, SJR: 1.172, h-index: 90)
Biological Reviews     Hybrid Journal   (Followers: 4, SJR: 6.469, h-index: 114)
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 41, SJR: 0.12, h-index: 1)
Biology of the Cell     Full-text available via subscription   (Followers: 9, SJR: 1.812, h-index: 69)
Biomedical Chromatography     Hybrid Journal   (Followers: 6, SJR: 0.572, h-index: 49)
Biometrical J.     Hybrid Journal   (Followers: 5, SJR: 0.784, h-index: 44)
Biometrics     Hybrid Journal   (Followers: 37, SJR: 1.906, h-index: 96)
Biopharmaceutics and Drug Disposition     Hybrid Journal   (Followers: 10, SJR: 0.715, h-index: 44)
Biopolymers     Hybrid Journal   (Followers: 18, SJR: 1.199, h-index: 104)
Biotechnology and Applied Biochemistry     Hybrid Journal   (Followers: 44, SJR: 0.415, h-index: 55)
Biotechnology and Bioengineering     Hybrid Journal   (Followers: 141, SJR: 1.633, h-index: 146)
Biotechnology J.     Hybrid Journal   (Followers: 14, SJR: 1.185, h-index: 51)
Biotechnology Progress     Hybrid Journal   (Followers: 39, SJR: 0.736, h-index: 101)
Biotropica     Hybrid Journal   (Followers: 20, SJR: 1.374, h-index: 71)
Bipolar Disorders     Hybrid Journal   (Followers: 9, SJR: 2.592, h-index: 100)
Birth     Hybrid Journal   (Followers: 38, SJR: 0.763, h-index: 64)
Birth Defects Research Part A : Clinical and Molecular Teratology     Hybrid Journal   (Followers: 2, SJR: 0.727, h-index: 77)
Birth Defects Research Part B: Developmental and Reproductive Toxicology     Hybrid Journal   (Followers: 6, SJR: 0.468, h-index: 47)
Birth Defects Research Part C : Embryo Today : Reviews     Hybrid Journal   (SJR: 1.513, h-index: 55)
BJOG : An Intl. J. of Obstetrics and Gynaecology     Partially Free   (Followers: 243, SJR: 2.083, h-index: 125)

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Journal Cover Advanced Materials Interfaces
  [SJR: 1.177]   [H-I: 10]   [6 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Online) 2196-7350
   Published by John Wiley and Sons Homepage  [1589 journals]
  • Passivation of Interfaces in Thin Film Solar Cells: Understanding the
           Effects of a Nanostructured Rear Point Contact Layer
    • Authors: Pedro M. P. Salomé; Bart Vermang, Rodrigo Ribeiro-Andrade, Jennifer P. Teixeira, José M. V. Cunha, Manuel J. Mendes, Sirazul Haque, Jêrome Borme, Hugo Águas, Elvira Fortunato, Rodrigo Martins, Juan C. González, Joaquim P. Leitão, Paulo A. Fernandes, Marika Edoff, Sascha Sadewasser
      Abstract: Thin film solar cells based in Cu(In,Ga)Se2 (CIGS) are among the most efficient polycrystalline solar cells, surpassing CdTe and even polycrystalline silicon solar cells. For further developments, the CIGS technology has to start incorporating different solar cell architectures and strategies that allow for very low interface recombination. In this work, ultrathin 350 nm CIGS solar cells with a rear interface passivation strategy are studied and characterized. The rear passivation is achieved using an Al2O3 nanopatterned point structure. Using the cell results, photoluminescence measurements, and detailed optical simulations based on the experimental results, it is shown that by including the nanopatterned point contact structure, the interface defect concentration lowers, which ultimately leads to an increase of solar cell electrical performance mostly by increase of the open circuit voltage. Gains to the short circuit current are distributed between an increased rear optical reflection and also due to electrical effects. The approach of mixing several techniques allows us to make a discussion considering the different passivation gains, which has not been done in detail in previous works. A solar cell with a nanopatterned rear contact and a 350 nm thick CIGS absorber provides an average power conversion efficiency close to 10%.In this work ultrathin 350 nm Cu(In,Ga)Se2 (CIGS) solar cells with passivated rear contact are studied and characterized. The rear interface passivation is achieved using an Al2O3 nanopatterned point structure and an average power conversion efficiency close to 10% is achieved due to chemical passivation and increased light trapping.
      PubDate: 2017-12-05T08:05:52.157642-05:
      DOI: 10.1002/admi.201701101
       
  • Achieving Totally Local Anticoagulation on Blood Contacting Devices
    • Authors: Rana Gbyli; Anna Mercaldi, Harihara Sundaram, Kagya A. Amoako
      Abstract: The recent years have witnessed an increased activity in biocompatibility research aimed at limiting biomaterial-induced blood coagulation. From 2008 to 2016, a total of $36 946 764.00 USD has been awarded in grants to 213 research proposals and as large as 50.4% ($18 627 854.00) of that award monies have been distributed to 101 proposals over the fiscal years of FY14 to FY16 alone. However, the complexity in blood responses to biomaterials, variability in blood function between individuals and animal species, and differences in medical device application and test setting all continue to pose difficulties in making a breakthrough in this field. This review focuses on the remaining challenges in the context of biomaterial surface interaction with blood, biomaterial properties and their influence on coagulation, old and new surface anticoagulation methods, main test systems (complement and platelet function) for evaluating those methods, limitations of modification techniques, and the current state of systemic anticoagulation usage as adjunctive therapy for controlling blood coagulation on biomaterials. Finally, ingredients necessary for advancing the field toward achieving totally local surface anticoagulation on blood contacting devices including standardization of in vitro and in-vivo test methods are proposed. Some highlights of recent forward-looking work and articles on local anticoagulation are also presented.Biomaterials have and continue to play an important role in how to support and treat patients with various diseases through their use in tissue and blood interacting medical devices and drug delivery systems. This review focuses on outstanding challenges and new directions of anticlotting biomaterials research.
      PubDate: 2017-12-04T11:31:28.471836-05:
      DOI: 10.1002/admi.201700954
       
  • Growth and Characterization of 3D Flower-Like β-NiS on Carbon Cloth: A
           Dexterous and Flexible Multifunctional Electrode for Supercapattery and
           Water-Splitting Applications
    • Authors: Subramani Surendran; Ramakrishnan Kalai Selvan
      Abstract: Evolution of 3D nanostructures is luring a great deal of importance owing to their eccentric structures that create plenty of rooms to grasp massive volume of charges. Here, a distinct multifunctional binder-free flexible electrode is developed by arrays of flower-like β-NiS nanostructures over flexible carbon cloth (β-NiS@CC) by the in situ hydrothermal method. It unveils an ultimate areal capacity of 1.654 C cm−2 (827 C g−1) at 1 mA cm−2, which seems to be the highest among the reported NiS so far. The fabricated flexible supercapattery gadget delivers a remarkable energy density of 38 µWh cm−2 at a power density of 800 µW cm−2. Due to immense mechanical strength and resilience of 3D flower-like morphology, it is further exposed as an economical bifunctional electrocatalyst. Both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) exhibit a significant burst of the enormous quantity of gas bubbles at the low overpotentials of 320 and 278 mV, respectively, to achieve a current density of 20 mA cm−2. Further, the developed laboratory scale water electrolyzer offers a low cell voltage of 1.65 V to accomplish a water-splitting current density of 10 mA cm−2. Henceforth, the multifunctional 3D flower-like β-NiS electrode is demonstrated by defining its potential use in real-world appliances.Flower-like β-NiS is a promising multifunctional electrode for the two most intriguing flexible, supercapattery and water-splitting, applications, and it renders a new direction to develop high-performance flexible energy storage and conversion system based on the binder-free NiS materials for various applications.
      PubDate: 2017-12-04T11:27:13.699777-05:
      DOI: 10.1002/admi.201701056
       
  • Controlling Wrinkle Propagation in the Bilayer System with
           Thickness-Gradient
    • Authors: Jongcheon Lim; Se-Jin Choi, Pilnam Kim
      Abstract: In this paper, a novel strategy to control the orientation of nanowrinkles by applying a thickness-gradient to a bilayer-system is presented. Surface modification by plasma treatment on ultraviolet light-curable polysiloxane-based resin applies biaxial compressive strain, resulting in the formation of randomly oriented nanowrinkles over a large-area. The thickness-gradient of the resin, given by the meniscus formed between the groove made with patterned polydimethylsiloxane (PDMS) after spin-coating of the resin, directed wrinkle propagation. Given the propagation orientation, nanowrinkles were well aligned over a large-area using a simple and accessible method.A strategy to align nanowrinkles on a large-area with simple steps is introduced. With the existence of thickness-gradient of the polymer substrate, critical strain for wrinkling varies with different thickness of substrate. When the surface is oxidated by the plasma treatment, nanowrinkles propagate with controlled orientation even though biaxial stress is applied in the process.
      PubDate: 2017-12-04T11:25:54.503683-05:
      DOI: 10.1002/admi.201701109
       
  • Laser Irradiation-Induced SiC@Graphene Sub-Microspheres: A Bioinspired
           Core–Shell Structure for Enhanced Tribology Properties
    • Authors: Ting Luo; Xinchun Chen, Ping Wang, Cuncheng Li, Bingqiang Cao, Haibo Zeng
      Abstract: Friction generally happening among all moving material interfaces wastes nearly one-third of total mechanical energy in the world each year, although different kinds of lubricants are adopted. Particle additives, like diamond, inorganic fullerene, and graphene, can enter tribological contacts to reduce friction and protect surfaces from wear. However, the growth of such additives with spherical morphology and high dispersibility in oil without molecular ligands is a major problem. Inspired by the impressive dispersion stability of Noctiluca scientillans in ocean, one novel core–shell composite constructed with superhard SiC sub-microsphere as core and exclusive floating flat-blade graphene sheet as shell (SiC@G) is designed. These core–shell SiC@G sub-micropheres are synthesized for the first time by in situ pulsed laser irradiating commercial SiC powders in liquid at ambient conditions. Both laser-stimulated surface tension energy release and photothermal decomposition involved in the laser irradiation process assure the reshaping of SiC particles and the formation of graphene sheets derived from SiC surface. Due to the synergistic effect of SiC spheres changing effectively sliding friction into rolling friction and flexible self-lubricating graphene forming a tribofilm easily, such composites as additives remain well dispersed in lubricating oil and exhibit enhanced antiwear and friction-reduction performance.SiC sub-microspheres decorated by floating flat-blade graphene nanosheets (SiC@G) are grown by a simple one-step laser irradiation method at ambient conditions. Due to the significant synergistic effect of superhard SiC spheres changing sliding friction into rolling friction and self-lubricating graphene preventing metal-to-metal direct contact, such core–shell SiC@G sub-microspheres as lubricant additives exhibit enhanced tribology properties.
      PubDate: 2017-12-04T08:01:06.805991-05:
      DOI: 10.1002/admi.201700839
       
  • A Combined Electrochemical-Microfluidic Strategy for the Microscale-Sized
           Selective Modification of Transparent Conductive Oxides
    • Authors: Francesco Lamberti; Stefano Salmaso, Alessandro Zambon, Laura Brigo, Alessio Malfanti, Teresa Gatti, Stefano Agnoli, Gaetano Granozzi, Giovanna Brusatin, Nicola Elvassore, Monica Giomo
      Abstract: Surface chemical functionalization of transparent conductive oxides (TCOs) is helpful for a wide range of technological applications, ranging from solar cells to biomedical devices, as it allows to tune the electrical, optical, and morphological properties of TCOs toward the desired goal. The electrochemical grafting technique is a surface modification methodology affording robust coatings with tuneable properties and has the potential to be exploited for modifying TCO surfaces. However, due to technical limitations, like the use of a 3-electrode cell and the need for low pH-solutions, this approach has not been recurrently applied. Here a novel electrochemical-microfluidic combined methodology is used where the use of a microchannel drives the spatially controlled covalent grafting of reagents on a TCO surface. To corroborate the validity of this approach in producing more complex chemical structures localized on selected microscale-sized areas, where a first electrochemical grafting step takes place, an electrochemical glucose biosensor is realized through a layer-by-layer approach that shows a remarkable limit of detection in the micromolar concentration range. The sensing mechanism is based on an efficient electron transfer from glucose to the functionalized TCO surface. Biosensor performance is conveniently tuned by acting on the number of enzymatic units loaded onto the biosensor-tree.An electrochemical-microfluidic combined methodology to modify transparent conductive oxides (TCOs) is proposed. The production of complex molecular structures, selectively localized in the microscale-sized areas where electrochemical grafting has taken place is demonstrated by realizing an electrochemical biosensor through a layer-by-layer approach. This strategy offers a method to produce customizable TCOs for different applications requiring defined patterning.
      PubDate: 2017-12-04T08:00:39.392642-05:
      DOI: 10.1002/admi.201701222
       
  • Octahedral Distortions at High-Temperature Superconducting La2CuO4
           Interfaces: Visualizing Jahn–Teller Effects
    • Authors: Y. Eren Suyolcu; Yi Wang, Wilfried Sigle, Federico Baiutti, Georg Cristiani, Gennady Logvenov, Joachim Maier, Peter A. Aken
      Abstract: Tuning the octahedral network represents a promising route for achieving new properties and functionalities in perovskite-based oxide heterostructures. One of the interface-mediated phenomena occurring in complex oxides is the Jahn—Teller (JT) effect. With the purpose of investigating octahedral distortions at interfaces showing high-temperature interface superconductivity, atomic layer-by-layer oxide molecular-beam epitaxy grown bilayers consisting of three unit cells, overdoped metallic La1.6M0.4CuO4, and three unit cells undoped insulating La2CuO4, where M represents a divalent dopant (namely, Ba2+, Sr2+, and Ca2+), are studied. The local crystal structure, chemistry, and dopant distribution are probed by analytical spherical-aberration-corrected scanning transmission electron microscopy. Here, the interrelation between the cationic size mismatch between dopant (M2+) and host La3+ ions and the local structure are reported, and the impact of the dopant distribution on the structural (CuO6 octahedra elongation) local properties is discussed. A clear correlation between dopant size and local lattice deformations is highlighted. Moreover, a relation between the nature of superconductivity (bulk vs interface) and JT distortions of the anionic sublattice is suggested.Scanning transmission electron microscopy-based quantitative investigations of octahedral distortions in atomic layer-by-layer oxide molecular beam epitaxy grown La1.6M0.4CuO4/La2CuO4 bilayers with M = Ba, Sr, and Ca are carried out. It is reported that the dopant distribution remarkably influences the apical OO distances (i.e., Jahn–Teller and anti-Jahn–Teller effects) and the superconducting properties of La2CuO4 systems.
      PubDate: 2017-12-04T07:11:10.690312-05:
      DOI: 10.1002/admi.201700737
       
  • Advances in Interfaces between Li Metal Anode and Electrolyte
    • Authors: Xue-Qiang Zhang; Xin-Bing Cheng, Qiang Zhang
      Abstract: Lithium metal has been considered as one of the most promising anode materials in high-energy-density rechargeable batteries due to its extremely high specific capacity and very low reduction potential of all possible candidates. However, the mysterious interfacial phenomena of lithium metal anode in long-term cycles, especially Li dendrite formation and low Coulombic efficiency, have greatly plagued the practical applications of Li metal in secondary batteries. The complex interface between Li metal and electrolyte plays a very important role in regulating Li deposition and enhancing the cycling stability of a full battery. In this review, recent advances in interfacial science and engineering are summarized to afford a fundamental understanding in Li deposition behavior and present design principles in constructing robust interface to stabilize Li metal anode in a working battery. Further investigations and directions are also included to promote the exploration of Li metal anodes. In particular, the rational combination of different Li metal protection strategies is strongly commended for practically applying Li metal anode in high-energy-density rechargeable batteries.The interfacial science and engineering of Li metal anode and electrolyte are summarized to afford a fundamental understanding in Li deposition behavior and present design principles in constructing robust interface to stabilize Li metal anode in a working battery. The rational combination of different Li metal protection strategies is strongly commended for their practical applications in high-energy-density batteries.
      PubDate: 2017-12-01T07:22:54.382673-05:
      DOI: 10.1002/admi.201701097
       
  • Strong SERS Performances of Ultrathin α-Co(OH)2 Nanosheets to the Toxic
           Organophosphorus Molecules and Hydrogen Bond-Induced Charge Transfer
           Mechanism
    • Authors: Qian Zhao; Guangqiang Liu, Hongwen Zhang, Yue Li, Weiping Cai
      Abstract: The ultrathin α-Co(OH)2 nanosheets are fabricated via homogeneous precipitation from the cobalt nitrate solution. The nanosheet-built film is used as the substrate for Raman detection of toxic organophosphorus molecules. Such nanosheets are of strong surface enhancement Raman scattering (SERS) effect to the molecules that can be captured by the hydroxyls on the nanosheets. The enhancement factor is up to 2.0 × 103. Typically, for the triphenylphosphine oxide (TPPPO) and 3,3-diethylthiatricarbocyanine iodide (DTTCI) which both can be used as hydrogen bond acceptors and form hydrogen bonds with α-Co(OH)2 on the nanosheets' surface, the detection are to 0.35 ppm. The Raman peak intensity shows a linear relation with logarithmic DTTCI concentration, due to Temkin adsorption of DTTCI molecules on the nanosheets, and exhibits a linear double logarithmic relation with TPPPO concentration, due to Freundlich-type adsorption. Further analysis reveal that such enhancement effect is attributed to the hydrogen bond-induced formation of new excited state in the test molecules, which induces the charge transfer and hence magnifies the test molecules' polarizability. This work not only provides an effective substrate for SERS-based detection of toxic organophosphorus molecules but also presents a new approach to design of the highly efficient nonmetal SERS-active materials.The ultrathin α-Co(OH)2 nanosheets are used as the substrate for Raman detection of organic molecules. It is found that such nanosheets are of strong surface enhancement Raman scattering effect to the toxic organophosphorus molecules, exhibiting a linear double logarithmic relation between Raman intensity and concentration, which is attributed to the hydrogen bond-induced charge transfer mechanism.
      PubDate: 2017-12-01T04:05:53.338262-05:
      DOI: 10.1002/admi.201700709
       
  • Cu-Decorated ZnO Nanorod Array Integrated Structured Catalysts for
           Low-Pressure CO2 Hydrogenation to Methanol
    • Authors: Shoucheng Du; Wenxiang Tang, Xingxu Lu, Sibo Wang, Yanbing Guo, Pu-Xian Gao
      Abstract: CO2 conversion into valuable chemicals and fuels, such as methanol, is one of the most practical routes for utilizing emitted CO2 and mitigating global warming. Herein, a 3D Cu-decorated ZnO nanorod array based structured catalysts for efficient thermochemical CO2 hydrogenation to methanol at relatively low pressures (
      PubDate: 2017-12-01T03:06:52.370789-05:
      DOI: 10.1002/admi.201700730
       
  • General Strategy for Synthesis of Pd3M (M = Co and Ni) Nanoassemblies as
           High-Performance Catalysts for Electrochemical Oxygen Reduction
    • Authors: Yifan Chen; Xian Jiang, Yueyang Li, Pei Li, Qicheng Liu, Gengtao Fu, Lin Xu, Dongmei Sun, Yawen Tang
      Abstract: Nanoassemblies have attracted considerable attention because of their unique structural advantages, such as the high porosity, abundant surface defects, and low-coordinated atomic steps, which are of importance to improve electrocatalytic activity and stability. However, developing effective and general synthetic methods for preparation of well-defined Pd-based nanoassemblies remains a challenge. Herein, a facile, effective, and general synthetic strategy for fabrication of high-quality Pd3M (M = Co and Ni) nanoassemblies is developed. It is identified that arginine is pivotal for control of the nucleation and growth process of nanocrystals, where there is strong self-assembly capacity between arginine molecules as well as effective coordination interaction between guanidine group of arginine with metal ions, endowing its unique dual-function for the structure-controllable synthesis of Pd3M alloy. The electrocatalytic performances of Pd3M nanoassemblies for the oxygen reduction reaction are studied through the rotating ring-disk electrode technique. As expected, both Pd3Co and Pd3Ni nanoassemblies exhibit the more positive onset reduced-overpotentials and the better catalytic stabilities compared to their counterparts. This work opens a new and general guideline for designing PdM alloy nanoassemblies with exclusive active sites for boosting energy electrocatalysis.Two kinds of Pd3M (M = Co and Ni) nanoassemblies by a facile, effective, and general synthetic strategy are reported, taking advantage of the unique coordination and self-assembly properties of arginine molecules. The resulting Pd3M catalysts exhibit excellent electrocatalytic activity and stability for the oxygen reduction reactions under alkaline media.
      PubDate: 2017-12-01T03:06:11.580335-05:
      DOI: 10.1002/admi.201701015
       
  • Flexible WS2@CNFs Membrane Electrode with Outstanding Lithium Storage
           Performance Derived from Capacitive Behavior
    • Authors: Chen Wu; Xiaohui Zeng, Pingge He, Libao Chen, Weifeng Wei
      Abstract: Flexible electrodes have recently elicited attention due to their potential to be woven into textiles as flexible power supplies for wearable electronic devices. However, contemporary flexible electrodes generally suffer from the limited reaction kinetics and inferior stability. Here, a flexible WS2@CNFs membrane electrode is facilely fabricated via hydrothermal method and subsequent electrospinning to embed WS2 nanosheets into interconnected framework of carbon nanofibers (CNFs). Benefitting from 3D porous architecture and good conductivity of CNFs, WS2@CNFs composites exhibit outstanding cycling stability and rate capability as self-supported binder-free anode for lithium-ion batteries. Especially, WS2@CNFs with 60.3 wt% of WS2 displays a discharge specific capacity as high as 545 mA h g−1 at 0.5 A g−1 after 800 cycles. Even at 2 A g−1, it maintains 62.4% of specific capacity at 0.1 A g−1, and stably cycles back at 0.1 A g−1. Kinetic analysis confirms that the capacitive mechanism is dominant in the Li-ion storage process, which is derived mainly from the structure evolution from WS2 nanosheets to WS2/W nanoparticles during extended cycling. The reduced nanoparticles also enhance electrochemical activity, conductivity, and reversibility of the conversion reaction, resulting in the increasing capacity with cycles.Flexible WS2@CNFs membrane electrode demonstrates a superior cycling performance as anode for lithium-ion batteries. Kinetic analysis confirms that the capacitive mechanism is dominant in the Li-ion storage process, which is derived mainly from the structure evolution from WS2 nanosheets to WS2/W nanoparticles. It also enhances electrochemical activity, conductivity, and reversibility of conversion reaction, resulting in the increasing capacity with cycles.
      PubDate: 2017-12-01T03:01:41.309314-05:
      DOI: 10.1002/admi.201701080
       
  • Combining Light-Gated and pH-Responsive Nanopore Based on PEG-Spiropyran
           Functionalization
    • Authors: Tianji Ma; Martin Walko, Mathilde Lepoitevin, Jean-Marc Janot, Emmanuel Balanzat, Armagan Kocer, Sebastien Balme
      Abstract: To mimic the selectivity and properties of biological channels and pumps, adaptive systems can be designed using artificial membranes. One big advantage of those membranes is that they are able to respond to several stimuli at the same time. Here, it is proposed to tailor conical nanopores by grafting polyethyleneglycol (PEG)-spiropyrans in order to combine both light- and pH-responsive properties. The study of the ionic transport reveals that after UV irradiation the nanopore is open while after visible irradiation, it is closed. This gating property is due to the self-assembly of PEG-spiropyran. The reversibility of the assembly inside the nanopore strongly depends on the solvent. Indeed, water blocks the photoswitchable molecule in its zwitterionic form, while ethanol favors the conformational switching. Under UV irradiation, the pH can control the nanopore selectivity. It is demonstrated that at acidic pH, the nanopore is selective to anion while at neutral pH the cation transport is favored.This work aims to tune original light-gated and pH response nanopore. To do so, PEG-spiropyrans is grafted inside conical nanopores. The study of the ionic transport shows that light irradiation permits to control the nanopore opening and its pH selectivity. However the reversibility depends on solvent polarity due to the presence of PEG chain.
      PubDate: 2017-12-01T03:01:12.088923-05:
      DOI: 10.1002/admi.201701051
       
  • Synthesis of Carbon Nanotube Incorporated Metal Oxides for the Fabrication
           of Printable, Flexible Nickel-Zinc Batteries
    • Authors: Zhiqian Wang; Xianyang Meng, Kun Chen, Somenath Mitra
      Abstract: The development of printable composite electrodes embedded with multiwalled carbon nanotubes (CNTs) for flexible nickel-zinc batteries is presented. The cathode and the anode comprised of Ni(OH)2-CNT and ZnO-CNT respectively are prepared by coprecipitation of the metal oxides on CNTs. High loading ratio of electroactive materials increases the amount of active materials in electrode, but causes a lower material utilization efficiency due to decrease in overall electrode conductivity. The direct loading of active materials onto CNTs enhances contact where the CNTs serve the pathways for electron transport leading to higher performance than physical mixing of active ingredients. The cells show good performance even under bending conditions and the overall technology is scalable by printing methods.Carbon nanotube incorporated metal oxides are synthesized by a coprecipitation method for the fabrication of flexible nickel-zinc batteries. Binders and additives are added to make inks for flexible electrodes. The cells show no performance drop under bending condition and the overall technology is scalable by printing methods.
      PubDate: 2017-12-01T03:00:49.559625-05:
      DOI: 10.1002/admi.201701036
       
  • Superamphiphilic Polyurethane Foams Synergized from Cellulose Nanowhiskers
           and Graphene Nanoplatelets
    • Authors: Xiaotan Zhang; Dongyan Liu, Guoxin Sui
      Abstract: Superamphiphilic materials are attracting significant attention because of their unique affinity to both water and oil. It is generally accepted that graphene-based assemblies are hydrophobic. Here, novel superamphiphilic polyurethane (PU) foams by the synergetic effect of cellulose nanowhiskers (CNWs) and graphene nanosheets (GNs) are reported. This process involves the creation of CNWs' base coating on the surface of PU network prior to GN coatings to obtain superamphiphilic surfaces by the simple dip-coating method. Wetting behaviors of the foams start to turn from hydrophobicity into superamphiphilicity by increasing the concentration of the CNWs up to 0.5 wt%. The hydrophobicity recovers when the concentration of CNWs reaches 1.0 wt%. The superamphiphilic foam (CNWs' concentration is 0.75 wt%) exhibits high storage capacity for water and various organic solvents up to 22–24 times of its own weight. Moreover, the coated foams can be reused for absorbing liquids for more than 20 cycles without losing their superamphiphilicity, exhibiting good reusability and durability. The discovery of this superamphiphilic foam is of great significance for the development of superwetting materials and finding their applications in oil emulsions purifying and catalyst anchoring fields.In this paper a novel superamphiphilic graphene-based material prepared through a simple dip-coating method, which is different from the conventionally coating graphene on polyurethane foams via reduction of graphene oxide is reported. Wetting behavior can be controlled by increasing the amount of cellulose nanowhiskers. The superamphiphilic foams can be reused for adsorbing liquids for more than 20 cycles without losing their superamphiphilicity.
      PubDate: 2017-12-01T02:58:01.902876-05:
      DOI: 10.1002/admi.201701094
       
  • Tuning Electrical Properties of 2D Materials by Self-Assembled Monolayers
    • Authors: Wi Hyoung Lee; Yeong Don Park
      Abstract: Tuning of electrical properties of 2D materials by self-assembled monolayers (SAMs) is reviewed in this article. When 2D materials such as graphene and transition metal dichalcogenides (TMDs) are in contact with SAMs, end functional group in SAMs governs dipole moment in SAMs, thereby affecting shift of Fermi level for instantaneous doping of 2D materials. Accordingly, carrier density, work function, and/or field-effect mobility of 2D materials are changed by the SAMs contact. Recent advances in the SAMs-induced changes of electrical properties in 2D materials are introduced by considering two types of 2D materials-SAMs contacts: 1) 2D materials on SAMs and 2) SAMs on 2D materials. 2D materials from graphene to TMDs are fully discussed in the context of SAMs-induced doping.Recent advances in the changes of electrical properties of 2D materials by self-assembled monolayers (SAMs) are reviewed in this paper. When 2D materials (i.e., graphene, transition metal dichalcogenides) are in contact with SAMs having different end groups, alkyl chain lengths, and linker groups, their electrical properties are changed.
      PubDate: 2017-12-01T02:56:40.863468-05:
      DOI: 10.1002/admi.201700316
       
  • A Novel Multiple Interface Structure with the Segregation of Dopants in
           Lead-Free Ferroelectric (K0.5Na0.5)NbO3 Thin Films
    • Authors: Chao Li; Lingyan Wang, Wen Chen, Lu Lu, Hu Nan, Dawei Wang, Yijun Zhang, Yaodong Yang, Chun-Lin Jia
      Abstract: Interfaces in oxides are found to possess different properties and can be engineered for modifying local structure and properties of nearby area. In this work, it is reported that the interfaces can be formed in Ba/Zr (BZ)-doped (K,Na)NbO3 (KNN) thin films by cycles of chemical solution deposition using same precursor solution. In the films, a novel and special cross-sectional structure is observed with periodic distribution of Ba-rich and Zr-rich layers. The Ba-rich and Zr-rich layers exhibit different strain, lattice parameters, and crystal structure, leading to an obvious effect on the general ferroelectric properties of the KNN-based thin films. Moreover, the self-polarization is also observed, which can be understood to originate from the formed built-in field by layered distribution of Ba and Zr in the KNN-BZ thin films.A novel multiple interface structure is characterized with periodic distribution of Ba-rich and Zr-rich layers in lead-free ferroelectric (K,Na)NbO3-Ba/Zr (KNN-BZ) thin films, which enhances the ferroelectricity of the KNN-BZ thin films. The interfaces can be realized by combining multiple cycles of chemical solution deposition with the long-range electrostatic potential effects of substrate.
      PubDate: 2017-12-01T02:51:34.651936-05:
      DOI: 10.1002/admi.201700972
       
  • Fabrication of α-Fe2O3@rGO/PAN Nanofiber Composite Membrane for
           Photocatalytic Degradation of Organic Dyes
    • Authors: Kai Sun; Lifang Wang, Chunzhi Wu, Jianping Deng, Kai Pan
      Abstract: The treatment of dye polluting water is one of the most important tasks that are concerned with water resources. Herein, a nanofiber composite membrane (NCM) is fabricated with an aim to effectively degrade organic dyes. First, α-Fe2O3 nanoparticles are loaded on the surface of graphene oxide (GO) sheets through hydrothermal method. Then the as-prepared α-Fe2O3@rGO sheets are deposited on polyacrylonitrile (PAN) nanofiber mat via vacuum filtration to obtain α-Fe2O3@rGO/PAN NCM. Thus, the NCM has a double-layer structure with α-Fe2O3@rGO as the upper layer and PAN nanofiber as the lower layer (support layer), providing structural advantages in photocatalytic degradation in solution. The composition, morphology, and structure of the NCM are characterized in detail. Photocatalytic experiments show that the NCM can effectively degrade a variety of organic dyes, among which the degradation rate of methylene blue is as high as 98.5% within 2 h. Moreover, the degradation rate still remains at high level after 5 cycles and the NCM remains intact, indicating the reusability of the NCM. It is in particular worth highlighting that high degradation efficiency is obtained even under natural sunlight, demonstrating great potential applications of the NCM in industrial dye wastewater treatment.The α-Fe2O3@reduced graphene oxide/polyacrylonitrile nanofiber composite membrane is obtained by hydrothermal method followed by vacuum filtration. Photocatalytic experiments show that the composite membrane can effectively degrade a variety of organic dyes and high degradation efficiency is obtained even under natural sunlight, demonstrating the great potential applications of the novel membranes in industrial dye wastewater treatment.
      PubDate: 2017-12-01T02:51:09.849507-05:
      DOI: 10.1002/admi.201700845
       
  • Anisotropic Raman-Enhancement Effect on Single-Walled Carbon Nanotube
           Arrays
    • Authors: Juanxia Wu; Shuchen Zhang, Dewu Lin, Bangjun Ma, Liangwei Yang, Shuqing Zhang, Lixing Kang, Nannan Mao, Na Zhang, Lianming Tong, Jin Zhang
      Abstract: The charge transfer between molecules and materials can modulate the polarizability tensor of the molecules and lead to an enhancement of the Raman scattering. Surface-enhanced Raman scattering on in-plane anisotropic layered materials has suggested the crystalline-axis-dependent charge interactions between molecules and materials. However, the full understanding of the anisotropic charge transfer process is still lacking. The rigorous anisotropic nature and structural diversity of single-walled carbon nanotube (SWNT) provide an ideal platform to systematically study the anisotropic charge transfer process. The present work reports the anisotropic Raman enhancement effect of molecules on horizontally aligned SWNT arrays and attribute it to the charge transfer efficiency that depends on the laser polarization direction and the resonance of SWNTs. The Raman signal of probe molecules on SWNT arrays is enhanced and reaches the maximum intensity when the incident laser is polarized along the SWNT axial direction, and the intensity is the minimum if they are perpendicular to each other. The different efficiencies of charge transfer are further confirmed by polarized optical absorption measurements and the energy alignment analysis. The present work provides a sensitive way to study the tunable charge interactions between molecules and anisotropic low-dimensional materials, which are also important for polarization-controlled optoelectronic applications.Anisotropic surface-enhanced Raman scattering on single-walled carbon nanotube (SWNT) arrays: The rigorous anisotropic structure and electronic structure of SWNT lead to the anisotropic charge interaction between SWNT and probe molecules, resulting in the anisotropic Raman enhancement, that is, Raman enhancement factor of molecules on SWNT arrays depends on the relative angle between laser polarization direction (ei) and SWNT axial direction.
      PubDate: 2017-12-01T02:50:48.388208-05:
      DOI: 10.1002/admi.201700941
       
  • Lithographically Designed Conical Microcarriers for Programed Release of
           Multiple Actives
    • Authors: Kwanghwi Je; Ju Hyeon Kim, Tae Soup Shim, Minhee Ku, Jaemoon Yang, Shin-Hyun Kim
      Abstract: The programed release of multiple ingredients is important in the therapeutics and pharmaceutical fields. A variety of core–shell microcarriers have been designed to fulfill the release function; however, encapsulating multiple actives in their own compartments and releasing them in a programed manner remains a challenge due to restrictions on the material sets that may be used to form the compartments. In this work, the development of lithographically featured core–shell microcarriers composed of double cones and a cap that encapsulate and release various combinations of multiactives in a predefined fashion is reported. Active-free caps are first prepared on a photomask using conventional photolithography. Onto each cap, sequentially, an active-loaded small cone and large cone in two steps of reaction–diffusion-mediated photolithography (RDP) are formed. The release kinetics of the actives stored in the inner and outer cones are controlled by tailoring the crosslinking density of the photocured polymers that composed each compartment. The cap prevents direct diffusion from the inner cone to the surrounding. The RDP-based lithographic means for creating core–shell microcarriers provides new opportunities for delivering synergistic combinations of drugs in pharmacotherapy.Conical microcarriers are lithographically prepared to have core–shell structures for encapsulation and release of multiple actives. Multisteps of lithography produces multicones on a cap, of which cones can load distinct actives. This lithographic approach allows the use of various combinations of materials and the control of permeability. Therefore, microcarriers can be designed to release multiple actives in a programed fashion.
      PubDate: 2017-12-01T02:47:41.967477-05:
      DOI: 10.1002/admi.201701163
       
  • Photovoltaic–Pyroelectric Coupled Effect Based Nanogenerators for
           Self-Powered Photodetector System
    • Authors: Jia Qi; Nan Ma, Ya Yang
      Abstract: Ferroelectric material BiFeO3 with narrow bandgap of 2.67 eV can be more suitable to fabricate photodetectors instead of solar energy harvesters because of low energy conversion efficiency. Herein, a BiFeO3 film-based self-powered photodetector is reported by using the photovoltaic–pyroelectric coupled effect to enable a fast sensing of 450 nm light illumination. Compared with photovoltaic effect, the photosensitivity parameters including photoconductive gain, responsivity, and specific detectivity can be enhanced by more than 9.7 times at light intensity of 0.86 mW cm−2 by utilizing light-induced photovoltaic–pyroelectric coupled effect. Moreover, a self-powered photodetector array system is achieved to detect 450 nm light by analyzing the real-time recorded output voltage signals as a mapping figure. In this work a new route to realize the performance enhancement of photodetector via photovoltaic–pyroelectric coupled effect on ferroelectric materials, which has great significance in extending the field of self-powered photodetectors is described.A self-powered photodetector by utilizing the light-induced photovoltaic–pyroelectric coupled effect in BiFeO3 is designed for detecting 450 nm light illumination, resulting in a dramatic enhancement of photosensitivity parameters by more than 9.7 times as compared with that of photovoltaic effect.
      PubDate: 2017-12-01T02:47:09.920566-05:
      DOI: 10.1002/admi.201701189
       
  • Detecting and Tuning the Interactions between Surfactants and Carbon
           Nanotubes for Their High-Efficiency Structure Separation
    • Authors: Xiang Zeng; Dehua Yang, Huaping Liu, Naigen Zhou, Yanchun Wang, Weiya Zhou, Sishen Xie, Hiromichi Kataura
      Abstract: The selective interaction is systematically explored between the surfactants (sodium deoxycholate (DOC), sodium dodecyl sulfate (SDS), and sodium cholate (SC)) and the single-wall carbon nanotubes (SWCNTs) by the gel chromatography technique. The results show that DOC preferentially interacts with small-diameter semiconducting SWCNTs (S-SWCNTs), exhibiting the strongest interaction strength for the SWCNTs, and the highest structural selectivity. The surfactant SC shows high selectivity toward the chiral angles of the SWCNTs. Its interaction strength and structural recognition ability are slightly higher than that of SDS but lower than that of DOC. Combining with the proved selectivity of SDS in the adsorption onto the S-SWCNTs with small CC bond curvature, it is discovered that the synergistic effect of the triple surfactants amplified the interaction difference among the different SWCNTs and the gel, and thus dramatically improved the separation efficiency and structural purity of the SWCNTs, achieving the separation of distinct (n, m) single-chirality species and their enantiomers in one step. This work not only provides deeper insights into the separation mechanism of SWCNTs with the surfactant sorting techniques, but also has a profound significance in studying the interaction between the SWCNTs and other small molecules.One-pot separation of single-chirality carbon nanotubes and their enantiomers is achieved by a cosurfactant system, in which the different selectivity of sodium cholate, sodium deoxycholate, and sodium dodecyl sulfate toward the chiral angles, diameters, and C-C bond curvatures of the nanotubes is used to synergistically enhance the structural recognition of the distinct (n, m) species.
      PubDate: 2017-12-01T02:46:46.834162-05:
      DOI: 10.1002/admi.201700727
       
  • MoSexOy-Coated 1D TiO2 Nanotube Layers: Efficient Interface for
           Light-Driven Applications
    • Authors: Siowwoon Ng; Milos Krbal, Raul Zazpe, Jan Prikryl, Jaroslav Charvot, Filip Dvořák, Lukas Strizik, Stanislav Slang, Hanna Sopha, Yuliia Kosto, Vladimir Matolin, Fong Kwong Yam, Filip Bures, Jan M. Macak
      Abstract: Ultrathin molybdenum oxyselenide (MoSexOy) coatings are made first ever by atomic layer deposition (ALD) within anodic 1D TiO2 nanotube layers for photoelectrochemical and photocatalytic applications. The coating thickness is controlled through varying ALD cycles from 5 to 50 cycles (corresponding to ≈1–10 nm). In the ultraviolet region, the coatings have enhanced up to four times the incident photon-to-current conversion efficiency (IPCE), and the highest IPCE is recorded at 32% at (at λ = 365 nm). The coatings notably extend the photoresponse to the visible spectral region and remarkable improvement of photocurrent densities up to ≈40 times is registered at λ = 470 nm. As a result, the MoSexOy-coated-TiO2 nanotube layers have shown to be an effective photocatalyst for methylene blue degradation, and the optimal performance is credited to a coating thickness between 2 and 5 nm (feasible only by ALD). The enhancement in photoactivities of the presented heterojunction is mainly associated with the passivation effect of MoSexOy on the TiO2 nanotube walls and the suitability of bandgap position between MoSexOy and TiO2 interface for an efficient charge transfer. In addition, MoSexOy possesses a narrow bandgap, which favors the photoactivity in the visible spectral region.Atomic layer deposition–synthesized oxyselenide coatings on 1D TiO2 nanotubes layers act as efficient co-photocatalyst. Increased light absorption, reduced optical bandgap, and formation of core-shell-like heterojunction due to ultrathin and uniform coatings within TiO2 nanotubes are accounted for enhanced photoelectrochemical activity of the resulting heterojunction and strongly enhanced photocatalytic activity in visible spectral region.
      PubDate: 2017-12-01T02:45:40.063365-05:
      DOI: 10.1002/admi.201701146
       
  • Room-Temperature Solid-State Grown WO3−δ Film on Plastic Substrate for
           Extremely Sensitive Flexible NO2 Gas Sensors
    • Authors: Venkateswarlu Annapureddy; Yonghun Kim, Geon-Tae Hwang, Ho Won Jang, Sung-Dae Kim, Jong-Jin Choi, Byungjin Cho, Jungho Ryu
      Abstract: Due to the increased world-wide threat to health from air pollution, as well as the need for personalized diagnostic and physiological monitoring of exhaled breath, flexible gas sensor nodes have become an emerging area of critical importance for wearable electronics applicable. In this study, WO3−δ films are prepared on flexible substrates at room temperature using a single-step, solid-state deposition, granule spray in vacuum (GSV) process. The GSV-WO3−δ films are successfully utilized to fabricate an ultrasensitive flexible gas sensor. The performance of the sensor can be enhanced by its increased surface area and large number of defect sites on the surface utilizing high-impulse hollow sphere granules. The gas sensor is extremely responsive and selective to low concentration of NO2. The gas-sensing responses are linear for the concentrations ranging from sub-ppm to tens of ppm with detection limit of 1.88 (±0.128) for NO2. The response time is on the order of few seconds for gas detection (17 s) and recovery (25 s). Beyond this sensing performance, the GSV-WO3−δ film is highly advantageous in terms of production cost and time for the realization of mass production of flexible sensing devices, compared to conventional gas sensors that require high-cost and time-consuming processes.A simple, scalable, time- and cost-efficient approach for enhancement of sensing capability of chemiresistive flexible gas sensors based on nonstoichiometric tungsten oxide (WO3–δ) created using the granule spray in vacuum technique at room temperature is demonstrated. A linear sensor response is achieved for gas concentrations of sub-ppm to tens of ppm for NO2 gas.
      PubDate: 2017-11-30T09:21:56.096533-05:
      DOI: 10.1002/admi.201700811
       
  • Direct Inkjet Printing of TIPS-Pentacene Single Crystals onto
           Interdigitated Electrodes by Chemical Confinement
    • Authors: Giulio Pipan; Marco Bogar, Andrea Ciavatti, Laura Basiricò, Tobias Cramer, Beatrice Fraboni, Alessandro Fraleoni-Morgera
      Abstract: Organic semiconducting single crystals (OSSCs) are very promising for low-cost electronics, being the highest performers among organic semiconductors in terms of charge transport, with carrier mobilities exceeding 10 cm2 V s−1. Here, it is demonstrated how it is possible to obtain millimeter-long single crystals of 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) onto gold interdigitated electrodes patterned onto flexible plastic substrates, via direct inkjet printing of precursor solutions. This result is enabled by a novel chemical confinement strategy that exploits fluorinated thiols as solvophobic “chemical fences”, able to avoid the printed solution spreading, thus promoting the formation of single crystals even on highly heterogeneous surfaces, without changing the chemical nature of the surface underlying the grown crystals. Electrical measurements demonstrate a good electrical contact with the electrodes. Moreover, their response UV-vis (Ultraviolet-visible) is among the highest up to now reported for organic UV–vis photodetectors, and their performance as direct X-ray detectors is satisfactory, confirming that the printed crystals have an effective electrical contact with the underlying electrodes. Since both the solvophobic fence and the TIPS crystals precursor solution are inkjet printed on flexible substrates, this work opens novel perspectives for the practical use of OSSCs in low cost, yet performing, flexible electronics.Millimeter-long bis(triisopropylsilylethynyl) pentacene single crystals grown from solutions directly inkjet-printed, thanks to a chemical confinement strategy, onto gold-interdigitated electrodes patterned onto flexible plastic substrates, are demonstrated. The crystals show a very strong response to UV–vis photons, and a good performance as direct X-ray detectors, opening promising perspectives for their use in low cost, yet performing, flexible electronics.
      PubDate: 2017-11-30T09:16:05.176833-05:
      DOI: 10.1002/admi.201700925
       
  • Electronic Transport and Ferroelectric Switching in Ion-Bombarded,
           Defect-Engineered BiFeO3 Thin Films
    • Authors: Sahar Saremi; Ruijuan Xu, Liv R. Dedon, Ran Gao, Anirban Ghosh, Arvind Dasgupta, Lane W. Martin
      Abstract: Despite continued interest in the multiferroic BiFeO3 for a diverse range of applications, use of this material is limited by its poor electrical leakage. This work demonstrates some of the most resistive BiFeO3 thin films reported to date via defect engineering achieved via high-energy ion bombardment. High leakage in as-grown BiFeO3 thin films is shown to be due to the presence of moderately shallow isolated trap states, which form during growth. Ion bombardment is shown to be an effective way to reduce this free carrier transport (by up to ≈4 orders of magnitude) by trapping the charge carriers in bombardment-induced, deep-lying defect complexes and clusters. The ion bombardment is also found to give rise to an increased resistance to switching as a result of an increase in defect concentration. This study demonstrates a systematic ion-dose-dependent increase in the coercivity, extension of the defect-related creep regime, increase in the pinning activation energy, decrease in the switching speed, and broadening of the field distribution of switching. Ultimately, the use of such defect-engineering routes to control materials will require identification of an optimum range of ion dosage to achieve maximum enhancement in resistivity with minimum impact on ferroelectric switching.Deterministic and dramatic enhancement of the properties including multiple orders of magnitude enhancement of resistivity arise from high-energy ion bombardment which tunes the type and concentration of intrinsic defects. The potential of this approach for systematic studies of defect–property relations (e.g., defect–polarization coupling in ferroelectrics) is also demonstrated.
      PubDate: 2017-11-30T09:15:40.888146-05:
      DOI: 10.1002/admi.201700991
       
  • Pt-Nanoparticle-Supported Carbon Electrocatalysts Functionalized with a
           Protic Ionic Liquid and Organic Salt
    • Authors: Reiko Izumi; Yu Yao, Tetsuya Tsuda, Tsukasa Torimoto, Susumu Kuwabata
      Abstract: Pt-nanoparticle-supported carbon catalysts for the electrochemical oxygen reduction reaction produced using a Pt-nanoparticle-monodispersed ionic liquid (IL) show better durability than a commercially available catalyst due to the small amount of IL between the Pt nanoparticles and the carbon support. In this study, to add further functionality to the catalysts prepared with the Pt-nanoparticle-monodispersed IL, a protic organic salt, diphenylammonium hydrogen sulfate ([DPA][HSO4]), and a protic ionic liquid, N,N-diethyl-N-methylammonium hydrogen sulfate ([DEMA][HSO4]), are employed for catalyst preparation. Interestingly, the mass activity and durability of the resulting catalyst are significantly enhanced by the addition of an electrochemically polymerizable [DPA][HSO4] to the Pt-nanoparticle-monodispersed [DEMA][HSO4] because of the formation of a conducting polymer, poly(diphenylamine), between the Pt nanoparticles and the carbon support during potential cycling.Pt-nanoparticle-supported carbon electrocatalysts are fabricated with a Pt-nanoparticle-dispersed protic ionic liquid (PIL) prepared by sputtering. The addition of a polymerizable protic organic salt to the PIL provides further enhancement of the mass activity of the electrocatalyst. This enhancement originates from the formation of a conducting polymer between the Pt nanoparticles and the carbon support during potential cycling test.
      PubDate: 2017-11-29T03:21:15.548503-05:
      DOI: 10.1002/admi.201701123
       
  • Exploration of Chirality and Achirality of Self-Assembled Monolayer Formed
           by Unsymmetrically Substituted Fluorenone Derivative at the Liquid/Solid
           Interface
    • Authors: Yi Hu; Kai Miao, Meiqiu Dong, Li Xu, Bao Zha, Xinrui Miao, Wenli Deng
      Abstract: The self-assemblies of 2-decyloxy-7-pentadecyloxy-9-fluorenone (DPF) are characterized by scanning tunneling microscopy at the liquid/solid interface. Achiral Dimer and chiral S-like structures are observed in 1-octanoic acid. The solvent molecule takes part in the self-assembly via forming COOH⋯OC and COOH⋯COOH hydrogen bonds. When 1-phenyloctane and n-tetradecane are used as the solvents, DPF self-assembles into chiral Z-like structure, which are classified into Types I–IV according to the packing styles. For the purpose of exploring the effect of solvent and the competition between these three structures, the self-assemblies of DPF in mixed solvents and on dry surface are investigated. The results show that S-like structure is preferred in mixed solvents, while the Z-like structure has priority when the function of solvent is excluded. DPF molecule shows polarity thus dipole−dipole interaction plays significant roles on forming stable adlayers by forming antiparallel dipole pairs. Furthermore, density functional theory calculation is performed to reveal the driving forces of hydrogen bonds and van der Waals interactions. In light of the popularity of studying chirality at the liquid/solid interface, it is believed that the findings will provide implications for designing chiral systems and will promote the exploration of self-assembly in the field of surface science.Induction and fabrication of chirality have received intense attention in natural science because chirality affects the performance of many chemical, physical, and biological systems. In this work asymmetrically substituted fluorenone derivative which possesses solvent-induced chiral and achiral self-assemblies at the liquid/solid interface, thus be potential to be used in nanoscience and nanotechnology are explored.
      PubDate: 2017-11-27T07:52:29.199622-05:
      DOI: 10.1002/admi.201700611
       
  • A Hybrid Piezoelectric and Triboelectric Nanogenerator with PVDF
           Nanoparticles and Leaf-Shaped Microstructure PTFE Film for Scavenging
           Mechanical Energy
    • Authors: Jianxiong Zhu; Yali Zhu, Xiaohu Wang
      Abstract: In this paper, a hybrid of piezoelectric polyvinylidene fluoride (PVDF)/polytetrafluoroethylene (PTFE) compound film and triboelectric leaf-shaped microstructure film for mechanical energy harvesting is first reported. The nanoparticles compound film is designed with PVDF particles and leaf-shaped PTFE. The triboelectric nanogenerator (TENG) is positioned at the upper side of the prototype and the piezoelectric nanogenerator (PENG) is placed at the lower side. It is found that the designed PENG could greatly enhance the harvested power by a coupling effect of PVDF nanoparticles and the compound PVDF/PTFE film than commercial film, and the leaf-shaped PTFE film could benefit the electric output for the TENG. The average output power density of TENG and PENG can achieve 2.75 and 0.15 mW m−2 with resistor 300 MΩ, respectively. It is found that with the increasing external accelerations on prototype, the maximum generated output voltage by this mechanic-electric conversion could obtain around 55 and −5.6 V by the two peak values, respectively. In the end, a random test using finger tap to light eight light-emitting diodes is demonstrated the mechanical energy conversion performance of the TENG and PENG with the generated peak voltage of TENG and PENG 25 and −5.2 V, respectively.A hybrid piezoelectric and triboelectric nanogenerator with polyvinylidene fluoride (PVDF) nanoparticles and leaf-shaped microstructure polytetrafluoroethylene (PTFE) film is developed for scavenging mechanical energy harvesting. The coupling effect of PVDF nanoparticles and the compound PVDF/PTFE film can greatly enhance the harvested power to piezoelectric nanogenerator (PENG), and the leaf-shaped PTFE film benefit the electric output from the triboelectric nanogenerator (TENG).
      PubDate: 2017-11-27T07:47:46.509915-05:
      DOI: 10.1002/admi.201700750
       
  • Epitaxial Stress-Free Growth of High Crystallinity Ferroelectric
           PbZr0.52Ti0.48O3 on GaN/AlGaN/Si(111) Substrate
    • Authors: Lin Li; Zhaoliang Liao, Nicolas Gauquelin, Minh Duc Nguyen, Raymond J. E. Hueting, Dirk J. Gravesteijn, Ivan Lobato, Evert P. Houwman, Sorin Lazar, Johan Verbeeck, Gertjan Koster, Guus Rijnders
      Abstract: Due to its physical properties gallium-nitride (GaN) is gaining a lot of attention as an emerging semiconductor material in the field of high-power and high-frequency electronics applications. Therefore, the improvement in the performance and/or perhaps even extension in functionality of GaN based devices would be highly desirable. The integration of ferroelectric materials such as lead–zirconate–titanate (PbZrxTi1-xO3) with GaN has a strong potential to offer such an improvement. However, the large lattice mismatch between PZT and GaN makes the epitaxial growth of Pb(Zr1-xTix)O3 on GaN a formidable challenge. This work discusses a novel strain relaxation mechanism observed when MgO is used as a buffer layer, with thicknesses down to a single unit cell, inducing epitaxial growth of high crystallinity Pb(Zr0.52Ti0.48)O3 (PZT) thin films. The epitaxial PZT films exhibit good ferroelectric properties, showing great promise for future GaN device applications.A one-monolayer MgO buffer layer enables epitaxial growth of highly crystalline, ferroelectric PbZr0.52Zr0.48O3 (PZT) on GaN/AlGaN/Si. This layer can completely overcome the lattice mismatch and is found to be not strained to the GaN allowing for the growth of epitaxial, functional PZT, paving a bright path toward oxide-GaN electronics.
      PubDate: 2017-11-27T07:46:13.071285-05:
      DOI: 10.1002/admi.201700921
       
  • Graphene Oxide Epoxy (GO-xy): GO as Epoxy Adhesive by Interfacial Reaction
           of Functionalities
    • Authors: Soumya Vinod; Chandra Sekhar Tiwary, Atanu Samanta, Sehmus Ozden, Tharangattu N. Narayanan, Robert Vajtai, Vipin Agarwal, Abhishek K. Singh, George John, Pulickel M. Ajayan
      Abstract: The unique combination of layered structure and chemical moieties grants very interesting physiochemical properties to graphene oxide (GO). Functional groups such as epoxide, hydroxyl, and carboxyl are abundantly distributed along the hexagonal lattice of carbon atoms. The superior properties of GO and increased interfacial interaction with other compounds make them excellent filler materials in polymers such as epoxies for creating multifunctional composites. Alternatively, the presence of epoxide group on GO opens up the possibility of using it as the major epoxy matrix constituent rather than just as a filler material. In this work, the formation of GO-xy (cross-linked GO via the epoxide functionality) resin is reported by reaction of GO with polymercaptan-based hardener by completely eliminating the need for conventional epoxy component. Substituting epoxy with GO marks notable advance in preparing adhesive materials with high temperature stability.Graphene oxide (GO) has epoxide groups which can essentially act as epoxy component in two part epoxy system. The epoxide ring opens and crosslinks with the highly nucleophilic SH group in polymercaptan-based hardener. Powdered GO when mixed with polymercaptan-based hardener and heated to 120 °C forms a resin that is named GO-xy.
      PubDate: 2017-11-27T07:45:44.780418-05:
      DOI: 10.1002/admi.201700657
       
  • Effect of UV Irradiation and Heat Treatment on the Surface Potential
           Distribution of Monolayer WS2 on SiO2/Si and Au Substrates
    • Authors: Weipeng Han; Junjie Qi, Feng Li, Minxuan Xu, Fan Bai, Youyin Fang, Xinxin Liu, Yue Zhang
      Abstract: The surface potential is relevant to work function and Fermi level of materials, which is of great significance to the research of charge transport, carrier concentration, and nanodevices design. Here the effect of UV illumination and heat treatment on the surface potential distribution of chemical vapor deposition grown monolayer WS2 on SiO2/Si and Au substrates is studied statistically. The experimental observation indicates that with the increase in light intensity, the surface potential of WS2 decreases on SiO2/Si substrate, while increases on Au substrate. Heat treatment is introduced to tuning the surface potential of monolayer WS2, resulting in the surface potential of WS2 on SiO2/Si substrate decrease and increase on Au substrate after annealing, respectively. The mechanism of the observed phenomenon is discussed in terms of the surface modification of the adsorption/desorption of charges on surface, photoinduced carriers, and charge transfer. This study provides a significant insight into the surface properties and can help optimize the performance of electronic and photonic devices.The effect of ultraviolet illumination and heat treatment on the surface potential of monolayer WS2 on SiO2/Si and Au substrates is investigated. With increasing light intensity, the surface potential of WS2 decreases on SiO2/Si substrate, while increase on Au substrate. Furthermore, the surface potential of WS2 decreases on SiO2/Si substrate and increases on Au substrate after annealing, respectively.
      PubDate: 2017-11-27T07:41:09.222161-05:
      DOI: 10.1002/admi.201701083
       
  • Masthead: (Adv. Mater. Interfaces 22/2017)
    • PubDate: 2017-11-27T07:34:34.696398-05:
      DOI: 10.1002/admi.201770117
       
  • Electrohydrodynamics: Triggering and Tracing Electro-Hydrodynamic
           Liquid-Metal Surface Convection with a Particle Raft (Adv. Mater.
           Interfaces 22/2017)
    • Authors: Jianbo Tang; Xi Zhao, Yuan Zhou, Jing Liu
      Abstract: Giant electrohydrodynamic instability of a partially immersed liquid-metal body is triggered by tiny copper particles, resulting in long-term surface convection and large-scale shape transformation of the liquid metal. In article number 1700939, Jianbo Tang, Jing Liu, and co-workers describe how complex flow patterns of the particle-driven surface convection are further captured by tracing the motions of the particles accompanying the flow.
      PubDate: 2017-11-27T07:34:34.641528-05:
      DOI: 10.1002/admi.201770118
       
  • Contents: (Adv. Mater. Interfaces 22/2017)
    • PubDate: 2017-11-27T07:34:33.530808-05:
      DOI: 10.1002/admi.201770115
       
  • Perovskites: Unlocking the Single-Domain Epitaxy of Halide Perovskites
           (Adv. Mater. Interfaces 22/2017)
    • Authors: Lili Wang; Pei Chen, Non Thongprong, Margaret Young, Padmanaban S. Kuttipillai, Chuanpeng Jiang, Pengpeng Zhang, Kai Sun, Phillip M. Duxbury, Richard R. Lunt
      Abstract: In article number 1701003, Richard R. Lunt and co-workers demonstrate the controllable epitaxial growth of single-crystal halide perovskites on low cost ionic crystal substrates investigated by in situ real-time diffraction. Such growth is achieved by reactive vapor-phase deposition enabling precise control for tuning epitaxial phases, demonstrating multilayer quantum wells, and providing a new route to uncover the full potential of halide perovskites.
      PubDate: 2017-11-27T07:34:33.473266-05:
      DOI: 10.1002/admi.201770114
       
  • Nanogenerators: Transparent, Flexible Cellulose Nanofibril–Phosphorene
           Hybrid Paper as Triboelectric Nanogenerator (Adv. Mater. Interfaces
           22/2017)
    • Authors: Peng Cui; Kaushik Parida, Meng-Fang Lin, Jiaqing Xiong, Guofa Cai, Pooi See Lee
      Abstract: A cellulose nanofibril-phosphorene hybrid paper is fabricated and used to configure a triboelectric energy nanogenerator in article number 1700651 by Pooi See Lee and co-workers. Phosphorene is successfully protected by the wrapping of cellulose nanofibrils against oxidation. The power density of the nanofibril-phosphorene hybrid paper based device is about 40 time higher than that of the pure cellulose nanofibril nanogenerator.
      PubDate: 2017-11-27T07:34:31.400895-05:
      DOI: 10.1002/admi.201770116
       
  • Colloidal Nanoparticles: Modulating the Spatial Electrostatic Potential
           for 1D Colloidal Nanoparticles Assembly (Adv. Mater. Interfaces 22/2017)
    • Authors: Jianmei Chen; Jing Huang, Andrea Toma, Liubiao Zhong, Zequn Cui, Weijing Shao, Ziyang Li, Wenkai Liang, Francesco De Angelis, Lin Jiang, Lifeng Chi
      Abstract: Lin Jiang, Lifeng Chi, and co-workers develop a novel strategy for precisely controlling the 1D assembly of sub-20 nm Au colloidal nanoparticles (CNPs) inside broad groove templates in article number 1700505. The lateral and bottom electrostatic potential of groove can be designed for the synergistic confinement of CNP assembly, which provide guidance for the further novel application with both fundamental and technological perspectives.
      PubDate: 2017-11-27T07:34:31.350506-05:
      DOI: 10.1002/admi.201770113
       
  • Graphdiyne Quantum Dots for Much Improved Stability and Efficiency of
           Perovskite Solar Cells
    • Authors: Xisheng Zhang; Qian Wang, Zhiwen Jin, Yanhuan Chen, Huibiao Liu, Jizheng Wang, Yuliang Li, Shengzhong (Frank) Liu
      Abstract: Comparing to other carbon materials, the general graphyne structure is much superior in terms of adaptable bandgap, uniformly distributed pores, more design flexibility, easier for chemical synthesis, pliable electronic properties, and smaller atomic density. Herein, novel γ-graphdiyne quantum dots (GD QDs) are used in perovskite solar cells as a surface modifier or dopant to TiO2, CH3NH3PbI3, and Spiro-OMeTAD to realize multiple advantageous effects, in hoping that it would form a more effective carrier transport channel for boosted solar cell performance. First, the presence of GD QDs on TiO2 surface increases perovskite grain size for higher current density and fill factor. Second, the GD QDs at each interface reduce the conduction band offset, passivate the surface for suppressed carrier recombination to attain higher open-circuit voltage. Third, it improves hydrophobicity and eliminates pinholes in the Spiro-OMeTAD film for enhanced solar cell stability. As a result, the optimized device shows>15% enhancement in power conversion efficiency (from 17.17 to 19.89%) comparing to the reference device. More significantly, the device stability was improved in harsh environment (moist air, UV irradiation, or thermal conditions). It is expected that GD QDs will find their applications in efficient and stable perovskite solar cells and optoelectronic devices.Controlling the morphology, surface passivation, and energy level in perovskite solar cells is paramount in obtaining optimal and stable optoelectronic properties. This study incorporates multifunctional γ-graphdiyne quantum dots in perovskite solar cells, which simultaneously induce an optimized morphology, surface passivation, conduction band offset, etc., resulting in enhancement of all photovoltaic parameters and stability in harsh environments.
      PubDate: 2017-11-24T09:39:34.051576-05:
      DOI: 10.1002/admi.201701117
       
  • Effects of W/Ir Top Electrode on Resistive Switching and Dopamine Sensing
           by Using Optimized TaOx-Based Memory Platform
    • Authors: Subhranu Samanta; Siddheswar Maikap, Anisha Roy, Surajit Jana, Jian-Tai Qiu
      Abstract: Resistive switching with best structural optimization by taking 100 devices of each structure including tungsten/iridium (W/Ir) top electrode effects and dopamine sensing by inserting 2 nm thick Al2O3 interfacial layer in TaOx-based memory platform are reported for the first time. Statistical analysis of device-to-device switching uniformity for the formation voltage, low resistance state, and high resistance state is executed at low current compliance of 30 μA by inserting 2 nm thick Al2O3 layer underneath of W electrode in W/Al2O3/TaOx/TiN structure. Incorporation of defective layer (TaOx) into Ta2O5 layer is clearly observed from the high-resolution transmission electron microscope image of stressed device. A long program/erase endurance of>108 cycles under low current of 30 μA with pulse width of 100 ns and retention of>900 h at 85 °C is obtained. Diode-like rectifying at 1 μA with higher ratio of>5000, nonlinearity factor of>300, and complementary resistive switching are achieved by using Ir electrode. Transport mechanism is dominated by Schottky conduction. Dopamine at a low concentration of 1 × 10−12m is detected through porous Ir in Ir/Al2O3/TaOx/TiN structure owing to oxidation at the Ir/Al2O3 interface for the first time, which will be useful for early diagnosis of human diseases.Resistive switching including tungsten/iridium top electrode effects, a long program/erase endurance of>108 cycles under low current operation of 30 µA with pulse width of 100 ns, and 1 × 10−12m dopamine sensing by optimized 2 nm thick Al2O3 interfacial layer in TaOx-based memory platform are reported for the first time.
      PubDate: 2017-11-24T09:37:57.625916-05:
      DOI: 10.1002/admi.201700959
       
  • Functionalized 2D Clay Derivative: Hybrid Nanosheets with Unique Lead
           Sorption Behaviors and Interface Structure
    • Authors: Zhaoli Yan; Liangjie Fu, Huaming Yang
      Abstract: Clay mineral and its derivatives can play an important role in stabilizing functional-groups and nanostructures. Here, a TP-SiNSs (TiSi2O5(OH)2·(OH2)2) nanocomposite, with highly dispersed and stabilized TiO2 precursor (TP, Ti(OH)4 gel) on template-free 2D silica nanosheets (SiNSs, Si2O3(OH)2), is presented, which is derived from kaolinite, a natural 2D layer mineral. Unique lead sorption behaviors are observed for balanced hydrophobicity–hydrophilicity, short sorption equilibrium time (within 5 min), large applied sorption capacities (≈38 000 kg polluted drinking water per kg TP-SiNSs, effluent Pb(II) contents
      PubDate: 2017-11-24T07:31:43.938906-05:
      DOI: 10.1002/admi.201700934
       
  • MoS2/WS2 Quantum Dots as High-Performance Lubricant Additive in
           Polyalkylene Glycol for Steel/Steel Contact at Elevated Temperature
    • Authors: Xinhu Wu; Kuiliang Gong, Gaiqing Zhao, Wenjing Lou, Xiaobo Wang, Weimin Liu
      Abstract: Herein, molybdenum disulfide (MoS2) and tungsten disulfide (WS2) quantum dots (QDs) are prepared by a facile and green technique, and characterized by microscopy and spectroscopy. The resulting products display exceptional stability in polyalkylene glycol (PAG) base oil, and are used for the first time as friction reducing and antiwear additives in PAG for steel/steel contact. Tribological measurements indicate that the stable dispersion consisting of PAG mixed with MoS2/WS2 QDs exhibits significant tribological properties compared with pure PAG and PAG containing MoS2/WS2 QDs nanosheets under different loads at elevated temperatures. The excellent tribological behaviors of MoS2/WS2 QDs are attributed to the formation of a boundary lubrication film, which can be generated not only by the physical entrapment of MoS2/WS2 QDs at the ball-disk contact surfaces, but also by tribochemical reaction between MoS2/WS2 and the iron atoms/iron oxide species.MoS2/WS2 quantum dots (QDs) is used for the first time as lubricating oil additive. Benefiting from the smaller particle size and higher special surface area, MoS2/WS2 QDs displays excellent dispersion stability in polyalkylene glycol (PAG). Tribological measurements indicate that MoS2/WS2 QDs added in PAG can significantly improve the friction reduction and antiwear properties of the base oil at elevated temperature.
      PubDate: 2017-11-23T09:40:09.811977-05:
      DOI: 10.1002/admi.201700859
       
  • A Facile Route to Fabricate Highly Anisotropic Thermally Conductive
           Elastomeric POE/NG Composites for Thermal Management
    • Authors: Chang-Ping Feng; Lu Bai, Yan Shao, Rui-Ying Bao, Zheng-Ying Liu, Ming-Bo Yang, Jun Chen, Hai-Ying Ni, Wei Yang
      Abstract: Highly anisotropic polyolefin elastomer (POE)/natural graphite (NG) composites with high through-plane thermal conductivity and excellent mechanical properties, in which NG sheet perfectly aligns along one direction, are prepared by two-roll milling, hot compression, and mechanical cutting. The through-plane thermal conductivity coefficient of POE/NG composites is markedly improved to be 13.27 W m−1 K−1 at an NG loading of 49.30 vol%. When the composite is used as a thermal management material, it shows excellent heat dissipating capability in the through-plane direction, which is very important for thermal management in electronic applications. This effective method is highly probable to be widely used for the facile fabrication of polymer-based thermal management materials.Highly through-plane thermally conductive polyolefin elastomer based composites filled with commercial nature graphite (NG) without any treatments are fabricated by a conventional melt-mixing method of a two-roll milling method. The as-fabricated composites with NG flakes perfectly vertically aligning in the matrix reveal high through-plane thermal conductivity (13.27 W m−1 K−1).
      PubDate: 2017-11-23T09:31:42.762731-05:
      DOI: 10.1002/admi.201700946
       
  • Favorable Face-on Orientation of a Conjugated Polymer on
           Roll-to-Roll-Transferred Graphene Interface
    • Authors: Sangmin Chae; Kuk Hyun Cho, Sejeong Won, Ahra Yi, Jiyeon Choi, Hyun Hwi Lee, Jae-Hyun Kim, Hyo Jung Kim
      Abstract: The use of dry transferred graphene as a templating layer to enhance face-to-face stacking in poly(3-hexylthiophene) (P3HT) systems which is widely used for organic optoelectronics is investigated. In contrast to conventional poly(methyl methacrylate) (PMMA) assisted wet transferred graphene, dry transferred graphene is found in the current work to be quite suitable for use in the roll-to-roll process due to its lack of PMMA residue, whose removal would require high-temperature annealing. Grazing-incidence wide-angle X-ray scattering (GIWAXS) is used to determine the percentages of P3HT molecules adopting a face-on orientation on the various substrates tested. When a P3HT film with a thickness of 30 nm is produced, the face-on populations of P3HT are prominent on both the dry and wet transferred graphene layers. As the film thickness is increased to 50 nm, the face-on population decreases on the wet transferred graphene surface, but retains high levels on the dry transferred graphene. GIWAXS, near-edge X-ray absorption fine structure, and atomic force microscopy data are combined to propose schematic models for the molecular stacking of P3HTs on the two differently transferred graphene surfaces.Roll-to-roll transferred graphene (dry graphene) is investigated as a templating layer for molecular template growth in poly(3-hexylthiophene) (P3HT) conjugated polymer systems. In contrast to conventional poly(methyl methacrylate)-assisted wet transferred graphene, dry graphene interface shows the superior π–π face-to-face interactions inducing a face-on orientation of P3HT, and the face-on orientation of P3HT is highly retained even in thick films.
      PubDate: 2017-11-23T09:19:31.286074-05:
      DOI: 10.1002/admi.201701099
       
  • Wetting Models and Working Mechanisms of Typical Surfaces Existing in
           Nature and Their Application on Superhydrophobic Surfaces: A Review
    • Authors: Jiaqiang E; Yu Jin, Yuanwang Deng, Wei Zuo, Xiaohuan Zhao, Dandan Han, Qingguo Peng, Zhiqing Zhang
      Abstract: Surfaces of plants and animals are evolved to optimal states to accommodate environments better after billions of years of natural selection. As the development of further study on bionics, surfaces with special wetting properties in nature are discovered, extremely related to the micro-/nanostructures on surface. The wetting models and wetting mechanism of several surfaces in nature are investigated, followed by lifting the veil of superhydrophobic field. Various facile, effective, and convenient methods for fabricating superhydrophobic surfaces are obtained and optimized in scientific research and practice. The possibility of wide application for superhydrophobic surface on production and life is improved via the promotion in fabrication ability. This paper is ranged from four main parts, including wetting models, wetting mechanism on various typical surfaces in nature, frequently used fabricating methods for superhydrophobic surfaces in recent years, and application of superhydrophobic material surfaces in three main aspects. It is really hoped that this review article can provide a useful guide for development of superhydrophobic surface in further study.Superhydrophobic surfaces have shown great potential value for future applications. For enhancing systematical understanding on superhydrophobic surfaces, classifications and summaries of classical wetting models, mechanism on typical surfaces in nature, frequently used fabricating methods for superhydrophobic surfaces in recent years, and applications of superhydrophobic material surfaces in three main aspects are presented as important issues.
      PubDate: 2017-11-10T10:05:23.758668-05:
      DOI: 10.1002/admi.201701052
       
  • Interface and Morphology Control of the Thermal Conductivity in
           Core–Shell Particle Colloidal Crystals
    • Authors: Pia Ruckdeschel; Markus Retsch
      Abstract: The thermal transport properties of nanostructured composite colloidal assemblies are investigated. These are of importance for future phase change material applications, which increasingly address the micrometer and sub-micrometer ranges. Polystyrene silica core–shell colloidal particles sizes of 270–480 nm and shell thicknesses of 15–42 nm are used as a structurally well-defined model system. This allows deducing precise structure property relationships with the lowest thermal conductivity being observed for particles with a large diameter, a thin shell thickness, and the highest polymer content. Importantly, clear evidence is found for polymer leakage through 15 nm silica shells when exceeding the glass transition temperature of the core polymer. This leads to a steady increase in thermal conductivity but also presents a lower limit for the silica shell thickness to contain the second phase. For a complete understanding, the findings are discussed in the light of colloidal crystals consisting of pure silica and polystyrene particles. Solid silica sphere colloidal crystals possess the highest thermal conductivity, and pure polymer beads the lowest. This demonstrates to which extent the thermal transport properties can be solely adjusted by the particle composition and morphology.The thermal transport properties of nanostructured composite materials depend on the particle morphology. Using polymer core–silica shell nanoparticles, a precise structure property relationship study is conducted, determining the influence of core size, particle diameter, and shell thickness, respectively. Polymer leakage, thermal conductivity tuning, and further effects relevant for future nanostructured phase change materials are investigated in detail.
      PubDate: 2017-11-10T10:01:31.048402-05:
      DOI: 10.1002/admi.201700963
       
  • Nanostructured, Highly Anisotropic, and Mechanically Robust Polymer
           Electrolyte Membranes via Holographic Polymerization
    • Authors: Derrick M. Smith; Qiwei Pan, Shan Cheng, Wenda Wang, Timothy J. Bunning, Christopher Y. Li
      Abstract: Solid polymer electrolytes have shown to be a promising solution to suppressing dendrite growth for safer and higher performance lithium batteries. This article reports the fabrication and characterization of a series of nanostructured polymer electrolyte membranes (PEMs) comprised of poly(ethylene glycol)/bis(trifluoromethane)sulfonimide lithium electrolyte and acrylate–thiol-ene crosslinked resin using a holographic polymerization (HP). Nanoscale long-range order is observed and this unique structure imposes intriguing mechanical and ion-conducting properties of the PEMs. The modulus of the holographically polymerized PEMs can be tuned to vary from 150 to 1300 MPa while room temperature conductivities of ≈2 × 10−5 S cm−1 and 90 °C conductivity of ≈5 × 10−4 S cm−1 are achieved. The HP nanostructure is also capable of directing ion transport either parallel or perpendicular to the membrane surface; an unprecedented ionic conductivity anisotropy as high as 3 × 105 is achieved. It is anticipated that these PEMs may be excellent candidates for lithium battery applications.Nanostructured solid polymer electrolytes are fabricated. The membranes show tunable mechanical properties from MPa to Gpa range. The membranes show an ionic conductivity anisotropy of ≈30 000.
      PubDate: 2017-11-09T12:42:53.495322-05:
      DOI: 10.1002/admi.201700861
       
  • Toward 5 V Lithium-Ion Battery: Exploring the Limit of Charge Cut-off
           Voltage of Li-Rich Layered Oxide Cathode and High-Voltage Interfacial
           Processes
    • Authors: Hieu Quang Pham; Eui-Hyung Hwang, Young-Gil Kwon, Seung-Wan Song
      Abstract: Increasing the capacity of Li-rich layered oxide (LMNC) cathode material for high-energy density lithium-ion batteries relies on the increase of charge cut-off voltage toward 5 V, under the utilization of anodically stable electrolyte component. The utilization of di-(2,2,2 trifluoroethyl)carbonate (DFDEC)-containing electrolyte permits significant improvement of anodic stability, cathode–electrolyte interface, and cycling stability of LMNC cathode, with respect to conventional electrolyte. In the present study, the limit of anodic stability of DFDEC under charging to 5.5 V versus Li is explored, and the interfacial processes of DFDEC-derived surface protection mechanism are investigated, utilizing charge cut-off voltage-dependent surface and structural analyses. The oxidative decomposition of DFDEC is found to begin at 4.7 V, producing metal fluorides and CF-containing organic compounds as the earliest surface species, passivating the cathode surface and reducing metal dissolution, structural transformation, and cathode degradation. The tolerable limit of charge cut-off voltage of a model electrolyte of 0.1 m LiPF6/DFDEC is determined to be 5.0 V, to which the cathode outperforms conventional electrolyte, delivering discharge capacities of 261–225 mAhg−1 with the capacity retention of 86% at the 50th cycle. The data give an insight into the principles of electrolyte design and high-voltage cathode–electrolyte interfacial stabilization toward advanced 5 V lithium-ion batteries.The limit of anodic stability of Li-rich layered oxide cathode with di-(2,2,2 trifluoroethyl)carbonate (DFDEC) under charging to 5.5 V versus Li is explored, and initial high-voltage cathode–electrolyte interfacial processes are investigated. DFDEC oxidation produces metal fluorides and CF-containing organic compounds as the earliest surface species, which passivates cathode surface and reduces metal dissolution, structural transformation, and degradation of cathode.
      PubDate: 2017-11-09T12:41:38.011074-05:
      DOI: 10.1002/admi.201700483
       
  • Precise Patterning of Large-Scale TFT Arrays Based on Solution-Processed
           Oxide Semiconductors: A Comparative Study of Additive and Subtractive
           Approaches
    • Authors: Minmin Li; Jiwen Zheng, Huihua Xu, Zhaogui Wang, Qian Wu, Bolong Huang, Hang Zhou, Chuan Liu
      Abstract: Precise patterning of solution-processed oxide semiconductors is critical for cost-effective, large-scale, and high throughput fabrication of circuits and display application. In this paper, demonstration and comparison are made using the additive and subtractive patterning strategies to precisely fabricate wafer-scale thin film transistor arrays (1600 devices), which are based on high-quality solution-processed indium zinc oxide (IZO) and indium gallium zinc oxide (IGZO). The IZO and IGZO TFTs exhibit field-effect mobility up to 8.0 and 5.2 cm2 V−1 s−1 when using the additive method, whereas the highest mobility of 24.2 and 13.7 cm2 V−1 s−1 for IZO and IGZO TFTs is achieved when using the subtractive method. The X-ray photoelectronic spectroscopy studies and quantitative 2D device simulations together reveal that good device performance is attributed to moderate shallow donor-like states (providing electrons) from oxygen vacancy and few accepter-like states (trapping electrons) resulted from the dense structural framework of MO bonds. After examining the uniformity and reliability of the devices, the solution-patterned inverters are demonstrated using negative-channel metal oxide semiconductors, which show full swing output transfer characteristics and thus provide a promising method for solution-based fabrications of circuits.A comparative study of additive and subtractive approaches are systematically analyzed with wafer-scale solution-processed InGaZnO and InZnO thin film transistor arrays. The X-ray photoelectron spectroscopy studies and quantitative 2D device simulations together reveal that the better device performance is attributed to moderate shallow donor-like states (providing electrons) from oxygen vacancy and few accepter-like states (trapping electrons) because of dense structural frame work of MO bonds.
      PubDate: 2017-11-09T12:37:49.49491-05:0
      DOI: 10.1002/admi.201700981
       
  • Electrooptical Synergy on Plasmon–Exciton-Codriven Surface Reduction
           Reactions
    • Authors: En Cao; Xiao Guo, Liqiang Zhang, Ying Shi, Weihua Lin, Xiaochun Liu, Yurui Fang, Liyan Zhou, Yinghui Sun, Yuzhi Song, Wenjie Liang, Mengtao Sun
      Abstract: The monolayer graphene–Ag nanoparticles hybrid system is fabricated as the electrooptical-coordinated controlled substrate for surface-enhanced Raman scattering spectroscopy. Plasmon–exciton interactions in this hybrid system are systemically investigated and applied in the field of surface catalytic reactions, manipulated by the electrooptical synergy. Experimental results demonstrate that the surface catalytic reactions can not only be controlled by plasmon–exciton coupling, but also be affected by the gate voltages and electric currents (or bias voltages). The gate voltage can tune the density of state of electrons, and electric current can make the hot electrons near the Fermi level with higher kinetic energy. Both of gate voltages and electric currents can significantly promote the efficiency and probability of plasmon–exciton-codriven surface catalytic reactions. The electrooptical device based on plasmon–exciton coupling can be potentially applied in the fields of sensor, catalysis, energy, and environment.An electrical-manipulated plasmon–exciton coupling device, based on monolayer graphene–Ag nanoparticles hybrid system, is fabricated as the surface-enhanced Raman scattering substrate. The gate voltage can increase density of state of hot electrons on the conduction band of graphene, and bias voltage can make hot electrons with higher kinetic energy. Both gate voltage and electrical currents can significantly promote plasmon–exciton-codriven surface catalytic reaction.
      PubDate: 2017-11-09T12:37:10.535896-05:
      DOI: 10.1002/admi.201700869
       
  • Controlled Selective CVD Growth of ZnO Nanowires Enabled by Mask-Free
           Fabrication Approach using Aqueous Fe Catalytic Inks
    • Authors: Dheyaa Alameri; Leonidas E. Ocola, Irma Kuljanshvili
      Abstract: Fabrication process that enables selective growth of vertically oriented zinc oxide (ZnO) nanowires (NWs) via chemical vapor deposition method and mask-free patterning approach is reported. It is shown that synthesis of high-quality ZnO nanowires in various architectures is achievable by optimizing the growth conditions and by precise patterning of catalytic ink precursors. Parallel direct-write patterning method is utilized to fabricate arrays of different architectures on Si/SiO2 substrates and directly on devices at preselected locations. The production of high-quality, crystalline ZnO NWs is demonstrated using aqueous iron catalytic inks. The composition of the ink and the lateral size of the patterns deposited on substrates are shown to affect the resulting nanowires and thus, allowing to control the geometry (length and diameter) of the individual ZnO NWs in the patterned assemblies. The results indicate that our protocols are tailored to the fabrication of ZnO NWs with specific surface geometries and interface functionalities for variety of targeted device applications.Selective synthesis of zinc oxide nanowires is demonstrated with controlled tunable morphologies via mask-free direct-write patterning of catalytic inks. Iron aqueous solutions have shown to be universally suitable for patterning on desired substrates and directly on devices, thus enabling direct assembly of targeted nanostructures with predefined interface functionalities.
      PubDate: 2017-11-09T12:36:14.03305-05:0
      DOI: 10.1002/admi.201700950
       
  • Gold Nanorods with Silica Shell and PAMAM Dendrimers for Efficient
           Photothermal Therapy and Low Toxic Codelivery of Anticancer Drug and siRNA
           
    • Authors: Qianyu Zhang; Li Wang, Yajun Jiang, Wei Gao, Yinsong Wang, Xiaoying Yang, Xinlin Yang, Zunfeng Liu
      Abstract: The multifunctional nanocomposites with grafting polyamidoamine dendrimers up to third generation (G3) are grown onto the surface of mesoporous silica-coated gold nanorods (AuNRs@SiO2) via a divergent technique. The resultant AuNRs@SiO2-G3 nanocomposites with uniform size and excellent stability not only enable their utilization as targeted contrast agents for photothermal cancer therapy but also serve as scaffolds for the intracellular delivery of anticancer drug and small interfering RNA (siRNA) to enhance the efficiency of cancer therapy. The controlled doxorubicin (DOX) release from AuNRs@SiO2-G3 nanocomposites is significantly improved under lower pH condition and near-infrared laser irradiation. The Bcl-2-targeted siRNA is transfected into tumor cells and induces knockdown of the protein expression, which is confirmed by western blot assays. Furthermore, the complementary effect of chemo- and gene therapy to MCF-7 cells for improved photothermal therapy is demonstrated by MTT assay. The DOX and siRNA coloaded AuNRs@SiO2-G3 nanocomposites show much lower cytotoxicity compared to the DOX, resulting in low toxicity to normal tissues. The multifunctional nanocomposites have potential application as nanoplatforms to integrate the photothermal-chemo-gene tumor therapy with high efficiency.The AuNRs@SiO2-G3 nanocomposites with uniform size and excellent stability are prepared by grafting polyamidoamine dendrimers up to third generation onto the surface of mesoporous silica-coated gold nanorods (AuNRs@SiO2) via a divergent technique. They show great potential to be used as a multifunctional nanoplatform to improve photothermal effect with the complement of gene silencing and chemotherapy, which may provide new possibilities for cancer treatment.
      PubDate: 2017-11-09T12:35:42.544532-05:
      DOI: 10.1002/admi.201701166
       
  • Surface Wrinkling and Porosity of Polymer Particles toward Biological and
           Biomedical Applications
    • Authors: Nikunjkumar R. Visaveliya; Christopher W. Leishman, Kara Ng, Nicolas Yehya, Nelson Tobar, Dorthe M. Eisele, Johann Michael Köhler
      Abstract: Polymer particles are promising particulate materials for renowned biomedical applications such as targeted drug delivery, tissue engineering, and biosensing. Surface properties of the polymer particles are of key importance for biomedical applications because they directly interact with biological systems. Particularly, wrinkled as well as porous surfaces possess an enhanced ability for cell attachment without any additional chemical modification. Therefore, a key objective is to fabricate the particles with desired degree of wrinkles and porosity. Many methods such as solvent evaporation, plasma treatment, emulsion instability, and electrospraying are being employed for the generation of porous, wrinkled and/or textured surfaces. Advantageously, an application of microfluidics can support the induction of surface instabilities on droplets in a case of droplet-based systems. Furthermore, microfluidics allows tuning of size and shape of the generated droplets as well as particles with desired surface textures. In this minireview article, surface characteristics (especially surface wrinkles and porosity) of the hydrophobic and hydrophilic polymer particles are presented for the potential applications toward biological as well as biomedical field. In addition, the impact of microfluidics is highlighted in order to produce the polymer particles of functional surface properties.Properties of polymer particles such as surface wrinkling and porosity present the larger surface area and allow excellent interactions with wide range of active objects. Particularly, these structured particulate materials are highly important for biomedical applications such as for high loading and controlled release of cargos in drug delivery, scaffolds for tissue engineering, and for the enhanced cell-material interfacial functions.
      PubDate: 2017-11-08T05:31:53.549151-05:
      DOI: 10.1002/admi.201700929
       
  • Mesoporous Thin Films for Fluid Manipulation
    • Authors: Magalí Mercuri; Claudio L. A. Berli, Martín G. Bellino
      Abstract: The ability to control nanoflows is critical to design and fabricate ever more versatile nanosystems. Scientists are currently interested in finding ways to handle fluid dynamics inside nanoporous networks, not only to increase our knowledge of fluidic behavior but also to develop novel nanodevices that have potential utility in applications ranging from diagnostics to the production of high-value chemicals. Here, we demonstrate how fluid motion can be manipulated by controlling the coexisting infiltration and evaporation phenomena in mesoporous films. A versatile actuation approach through liquid–vapor dynamic modulation was developed by integrating mesoporous substrates with a thermoelectric cell. This actuation resulted in fast and reversible fluid displacements through the mesoporous matrix, which was achieved with relatively small temperature variations by controlled voltage inputs. The versatility of the strategy is demonstrated by tunable cycling of fluid imbibition and switched nanofluidic connection of liquids into the substrate. This novel nanoflow manipulator could be the basis for smart nanofluidic devices toward exciting applications in actuators, controlled pattern formations and release systems.Mesoporous thin films to control nanofluidics with a thermoelectric cell can actively manipulate fluid transport through liquid–vapor dynamic modulation. The versatility of the strategy is demonstrated by tunable cycling of fluid imbibition and switched nanofluidic connection of liquids into the substrate. This dynamic fluid control can be used as a flexible tool in microscale transport, mixing and biotechnological areas.
      PubDate: 2017-11-08T05:31:07.987772-05:
      DOI: 10.1002/admi.201700970
       
  • Robust Hydrophobic Rare Earth Oxide Composite Electrodeposits
    • Authors: Jason Tam; Gino Palumbo, Uwe Erb, Gisele Azimi
      Abstract: Inspired by the lotus leaf, nonwetting surfaces have drawn widespread attention in the field of surface engineering due to their remarkable water repelling characteristics. There are many applications for these surfaces, for instance, self-cleaning walls and windows, anti-icing surfaces, or low drag microfluidic channels. However, the adoption of nonwetting surfaces in large scale industrial applications has been hampered by synthesis techniques that are not easily scalable and the limited long term stability and wear robustness of these surfaces in service. This study demonstrates a simple, low cost, and scalable electrochemical technique to produce robust composite coatings with tunable nonwetting properties. The composite coatings are composed of an ultrafine grain nickel matrix with embedded hydrophobic cerium oxide ceramic particles. A comprehensive characterization is performed, including wetting property measurements, electron microscopy, focused ion beam analysis, hardness measurements, and abrasive wear testing to establish the structure–property relationships for these materials. The ultrafine grain structure of the nickel matrix contributes to the high hardness of the composites. As a result of the bimodal CeO2 particle size, hierarchical roughness is present on the surface of the composite, leading to remarkable nonwetting properties, even after 720 m of abrasive wear.Here a simple and scalable electrochemical technique is demonstrated to produce robust composite coatings with tunable hydrophobicity. The coatings are composed of an ultra-fine grain Ni matrix with embedded hydrophobic CeO2 particles. It is demon­strated that these composite materials sustain their hydrophobicity even after prolonged abrasive wear; hence, it is expected that they find widespread applicability as robust hydrophobic materials.
      PubDate: 2017-11-07T11:47:12.192368-05:
      DOI: 10.1002/admi.201700850
       
  • Polyaniline Enriched Flexible Carbon Nanofibers with Core–Shell
           Structure for High-Performance Wearable Supercapacitors
    • Authors: Nousheen Iqbal; Xianfeng Wang, Aijaz Ahmed Babar, Jianhua Yan, Jianyong Yu, Soo-Jin Park, Bin Ding
      Abstract: High performance lightweight and flexible supercapacitors with superior electrochemical performance are in extremely high demand for wearable electronic device applications. Herein, a novel synthesis process is reported for developing highly flexible supercapacitor electrodes from carbon black doped carbon nanofiber/polyaniline core–shell nanofibers via electrospinning followed by carbonization and electrospray techniques. Resultant supercapacitor electrodes offer exceptional specific capacitance (SC) of 501.6 F g−1 at 0.5 A g−1, excellent capacitance retention of 91% even after 5000 cycles, demonstrating a long and stable life of the fabricated device. Moreover, solid state supercapacitor shows no obvious change in SC when subjected to various bending angles up to 180°. This simple three step (i.e., electrospinning, carbonization, and electrospray) fabrication technique paves new insights into the development of lightweight flexible supercapacitors.Polyaniline enriched flexible carbon nanofiber membrane with core–shell structure for high-performance wearable supercapacitor is developed, with exceptional specific capacitance (SC), excellent capacitance retention even after 5000 cycles, demonstrating longer and stable life of fabricated device. Moreover, synthesized supercapacitor shows no obvious change in SC when subjected to various bending angles up to 180°.
      PubDate: 2017-10-31T02:16:40.721201-05:
      DOI: 10.1002/admi.201700855
       
  • Conformal Carbon Nitride Coating as an Efficient Hole Extraction Layer for
           ZnO Nanowires-Based Photoelectrochemical Cells
    • Authors: Špela Hajduk; Sean P. Berglund, Matejka Podlogar, Goran Dražić, Fatwa F. Abdi, Zorica C. Orel, Menny Shalom
      Abstract: Charge transfer at the semiconductor–electrolyte junction is one of the main challenges for further improvement of photoelectrochemical (PEC) water splitting cells due to the poor surface catalytic properties of most semiconductors for the water oxidation reaction. Here it is shown, for the first time, that a conformal and thin carbon nitride (CN) layer can efficiently extract holes from ZnO nanowires (NWs), leading to a great enhancement of both PEC performance and stability in alkaline solution. The conformal CN coating is acquired by using a new synthetic method which involves the deposition of small supramolecular assemblies on ZnO-NWs as a seeding layer for the CN growth. Detailed PEC characterization reveals that the CN facilitates the hole transfer from the ZnO-NWs to the electrolyte and acts as a protective shell, resulting in 3.5 times higher current densities and high external quantum efficiencies at 1.23 V versus RHE compared to the pristine ZnO-NWs.Conformal carbon-nitride (CN) layer acts as an efficient hole extraction layer for ZnO nanowires (NWs)-based photoelectrochemical cells. The homogenous coating is acquired by the introduction of a new synthetic approach involving the deposition of small supramolecular-assembly seeds on ZnO-NWs prior the CN growth. The best device exhibits impressive current densities and external quantum efficiencies at 1.23 V versus reversible hydrogen electrode (RHE).
      PubDate: 2017-10-31T02:15:41.300244-05:
      DOI: 10.1002/admi.201700924
       
  • Smart Antibacterial Surfaces Established by One-Step Photo-Crosslinking
    • Authors: Yishi Dong; Peixi Wang, Ting Wei, Tao Zhou, Mengge Huangfu, Zhaoqiang Wu
      Abstract: Chemical modification of surfaces is recognized as efficient strategies to prevent bacterial contamination and the associated infection. Herein, a novel ionic liquid derivative 1-(((4-benzoylbenzoyl)oxy)methyl)-3-methyl-1H-imidazol-3-ium bromide (BMI) containing benzophenone moieties is developed to act as both a photoreactive cross-linker and an antibacterial agent. BMI can rapidly and efficiently form a “smart” antibacterial film on a variety of substrate surfaces in 2 min under mild UV irradiation. The modified surfaces show highly antibacterial activity, achieving more than 99% bacterial killing efficiency against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli using live/dead staining methods. In addition, the BMI-modified surfaces can release ≈97% of the killed bacteria via ion-exchange of hexametaphosphate (PP6−) anions and can regenerate bactericidal properties over three cycles. Moreover, in vitro cytocompatibility tests indicate that the BMI-modified surfaces have good biocompatibility. Thus, it can be concluded that cross-linked BMI layers provide a practical and convenient approach for the fabrication of “smart” antibacterial surfaces.The novel ionic liquid derivative (1-(((4-benzoylbenzoyl)oxy)methyl)-3-methyl-1H-imidazol-3-ium bromide) can rapidly and efficiently form a “smart” antibacterial film on a variety of substrate surfaces by one-step photo-crosslinking in 2 min under atmospheric conditions. The modified surfaces show highly antibacterial activity against both Gram-positive and Gram-negative bacteria and can be regenerated over three cycles.
      PubDate: 2017-10-31T02:10:46.478638-05:
      DOI: 10.1002/admi.201700953
       
  • Electron Microscopy Visualization of Vitronectin Adsorbed on COOH and NH2
           Functionalized Surfaces: Distinctive Spatial Alignment and Regulated
           Cellular Responses
    • Authors: Wenjia Hou; Yi Liu, Botao Zhang, Xiaoyan He, Hua Li
      Abstract: Adsorption of proteins associating with their conformational changes plays crucial roles in regulating biomaterial–cell interactions and consequent tissue responses to implanted biomaterials. This study reports direct visualization of typical serum protein, vitronectin, one of the key adhesive proteins that participate in mediating cell behaviors, upon adsorption on typically designed surfaces. Carbon films with their surfaces being plasma grafted functional groups COOH and NH2 are used as the model substrata for this study. Negative-staining electron microscopy technique is employed for visualizing the adsorbed protein and 2D image classification is made and interpreted. Results show that adsorbed vitronectin tends to form multimer aggregate on the COOH-grafted surfaces, exposing extensively its cell-binding RGD (arginine-glycine-aspartic acid) motif for enhanced cell adhesion. The adsorbed vitronectin on the NH2-grafted surface forms dimer aggregate with the binding sites being enwrapped. The COOH-grafting triggers enhanced expressions of ITGA5, ITGAV, ITGB1, and ITGB3 of the adhered cells and this is likely attributed to the special spatial alignment of vitronectin upon adsorption. The conformational information of adsorbed vitronectin gained from the single particle electron microscopy analyses would shed light on design and construction of appropriate biomaterials surfaces for desired cellular behaviors.Single-particle electron microscopy is employed for directly visualizing the spatial alignment of vitronectin after adsorption on material surface. The molecules tend to form multimer aggregates on COOH-grafted surface, exposing extensively their cell-binding domain RGD motif for regulated gene expression of adhered osteoblasts. The dimer aggregates formed on NH2-grafted surface show enwrapped binding sites, in turn suppressing adhesion of the cells.
      PubDate: 2017-10-27T03:00:42.586943-05:
      DOI: 10.1002/admi.201700958
       
  • Recent Advances in Spiro-MeOTAD Hole Transport Material and Its
           Applications in Organic–Inorganic Halide Perovskite Solar Cells
    • Authors: Zafer Hawash; Luis K. Ono, Yabing Qi
      Abstract: 2,2′,7,7′-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9′-spirobifluorene (spiro-MeOTAD) hole transport material (HTM) is a milestone in the history of perovskite solar cells (PSCs). Proper choice of HTMs is key factor for efficient charge extraction and stability in solar cells. Spiro-MeOTAD is proven to be the most suitable HTM for testing PSCs due to its facile implementation and high performance. Similarly, spiro-MeOTAD is receiving attention in other applications other than in solar cells due to its desirable properties. However, spiro-MeOTAD is under debate regarding the topics of cost-performance, long-term stability, degradation issues (induced by temperature, additives, film quality, and environmental conditions), coating technologies compatibility, reliance on additives, and hysteresis. In this review, the advent of spiro-MeOTAD, and related aforementioned issues about spiro-MeOTAD are discussed. In addition, spiro-MeOTAD properties, alternative and new additives, other applications, and new HTMs that is comparable or outperforms spiro-MeOTAD in PSCs are summarized. In the outlook, the future research directions based on reported results that warrant further investigations are outlined.Spiro-MeOTAD is the most commonly used hole transport material for perovskite solar cells. In this article, various aspects of spiro-MeOTAD including its properties, additives, stability, alternatives, its applications in perovskite solar cells as well as other applications are reviewed.
      PubDate: 2017-10-25T10:15:12.921146-05:
      DOI: 10.1002/admi.201700623
       
  • Laminated Free Standing PEDOT:PSS Electrode for Solution Processed
           Integrated Photocapacitors via Hydrogen-Bond Interaction
    • Authors: Yingzhi Jin; Zaifang Li, Leiqiang Qin, Xianjie Liu, Lin Mao, Yazhong Wang, Fei Qin, Yanfeng Liu, Yinhua Zhou, Fengling Zhang
      Abstract: In this work, a novel lamination method employing hydrogen-bond interaction to assemble a highly conductive free standing poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) film as a common electrode is demonstrated in a solution processed metal-free foldable integrated photocapacitor (IPC) composed of a monolithic organic solar cell (OSC) and a capacitor. The highlights of the work are: (1) micrometer free standing PEDOT:PSS electrode is successfully laminated onto a relatively large area (1 cm2) OSCs; (2) a free standing capacitor based on the PEDOT:PSS electrode is achieved; (3) the IPC demonstrates an overall efficiency of 2% and an energy storage efficiency of 58%, which is comparable with those of IPCs based on metallic common electrodes; (4) the novel lamination method for PEDOT:PSS electrode enables free standing PEDOT:PSS broad applications in solution processed flexible organic electronics, especially tandem or/and integrated organic electronic devices. Furthermore, the IPC is foldable with excellent cycling stability (no decay after 100 recycles at 1 mA cm−2). These results indicate that free standing PEDOT:PSS film is a promising candidate as common electrodes for IPCs to break the restrictions of metal electrodes. The demonstrated lamination method will greatly extend the applications of PEDOT:PSS electrodes to large area flexible organic electronic devices.A novel lamination method for free standing poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) electrode is developed and applied successfully onto large area metal-free organic solar cells and solution processed foldable integrated photocapacitors assisted by hydrogen-bond interaction. This novel lamination method for PEDOT:PSS electrode will greatly extend applications of PEDOT:PSS electrode in other kinds of large area flexible organic electronics.
      PubDate: 2017-10-25T10:13:21.711911-05:
      DOI: 10.1002/admi.201700704
       
  • X-Ray Absorption Spectroscopy of TiO2 Nanoparticles in Water Using a Holey
           Membrane-Based Flow Cell
    • Authors: Tristan Petit; Jian Ren, Sneha Choudhury, Ronny Golnak, Sreeju S. N. Lalithambika, Marc F. Tesch, Jie Xiao, Emad F. Aziz
      Abstract: Many applications of TiO2 nanoparticles, such as photocatalytic water splitting or water remediation, occur in aqueous environment. However, the impact of solvation on TiO2 electronic structure remains unclear because only few experimental methods are currently available to probe nanoparticle–water interface. Soft X-ray absorption spectroscopy has been extensively used to characterize the electronic structure of TiO2 materials, but so far only in vacuum conditions. Here, oxygen K edge and titanium L edge X-ray absorption spectroscopy characterization of TiO2 nanoparticles measured directly in aqueous dispersion is presented. For this purpose, a new method to probe nanomaterials in liquid using a holey membrane-based flow cell is introduced. With this approach, the X-ray transmission of the membrane is increased, especially in the water window, compared to solid membranes.TiO2 nanoparticles are characterized in situ in aqueous dispersions by soft X-ray absorption spectroscopy at the oxygen K edge and titanium L edge. For this purpose, a new flow cell method using a holey membrane to increase X-ray transmission of the membrane is introduced. The influence of hydration on the electronic structure of TiO2 nanoparticles is discussed.
      PubDate: 2017-10-25T10:13:06.418193-05:
      DOI: 10.1002/admi.201700755
       
  • Influence of Dopant Concentration and Steric Bulk on Interlayer Diffusion
           in OLEDs
    • Authors: Jake A. McEwan; Andrew J. Clulow, Andrew Nelson, Renjie Wang, Paul L. Burn, Ian R. Gentle
      Abstract: The performance of organic light-emitting diodes (OLEDs) can change when they are subjected to thermal stress after manufacture. The effect of heat on OLED film stacks is studied, in which the emissive layer (EML) comprises either a phosphorescent iridium(III) dopant blended in a host at different concentrations or materials with alkyl substituents to increase the steric bulk of the host and/or dopant. Neutron reflectometry with in situ photoluminescence measurements shows that interdiffusion between the emissive and hole transport layers within the films occurs on thermal annealing. Interdiffusion occurs independent of dopant concentration or steric bulk of the EML components. Importantly, when held at relatively low temperatures, the EML materials are found to only partially diffuse into an adjacent charge transport layer. The movement of materials is found to correlate with the change in luminescence from the hole transport material and an initial enhancement of the emission from the iridium(III) dopant. The results provide an explanation for the burn-in often observed for OLEDs as well as the need to change the driving characteristics over time to ensure that pixels can be held at the requisite brightness.Neutron reflectometry with in situ photoluminescence measurements shows that interdiffusion between organic light-emitting diode (OLED) emissive and hole transport layers occurs on thermal annealing. Interdiffusion occurs independent of dopant concentration or steric bulk of the emissive layer components and is correlated with the change in film luminescence. The results provide an explanation for the burn-in often observed for OLEDs.
      PubDate: 2017-10-25T10:12:52.937411-05:
      DOI: 10.1002/admi.201700872
       
  • Atomic Layered Titanium Sulfide Quantum Dots as Electrocatalysts for
           Enhanced Hydrogen Evolution Reaction
    • Authors: Yang Liu; Chenglu Liang, Jingjie Wu, Tiva Sharifi, Hui Xu, Yusuke Nakanishi, Yingchao Yang, Cristiano F. Woellne, Amir Aliyan, Angel A. Martí, Banghu Xie, Robert Vajtai, Wei Yang, Pulickel M. Ajayan
      Abstract: The overall electrocatalytic activity toward hydrogen evolution reaction for layered transition metal dichalcogenides is governed by their intrinsic activity, the corresponding density of active sites, and the electron transfer resistance. Here, nanoengineering strategies to scale down both the lateral size and thickness of layered 1T-TiS2 powder to quantum dots (QDs) by bath sonication and probing sonication incision are employed. Uniform lateral size of 3–6 nm in the resulting QDs enhances the density of edge sites while the atomic layer thickness (1–2 nm) facilitates the electron transfer from the substrate to the edge sites. The obtained TiS2 QDs exhibit superior hydrogen evolution reaction activity over TiS2 nanosheets and MoS2 QDs prepared by the same method. The turnover frequency of TiS2 QDs with a small loading of 0.7 ng cm−2 in an optimal deposition on electrode reached ≈2.0 s−1 at an overpotential of −0.2 V versus RHE, several orders of magnitude higher than TiS2 nanosheets (0.01 s−1) and MoS2 QDs (0.07 s−1).The nanoengineering of TiS2 to quantum dots (QDs) increases the active sites of electrocatalyst for hydrogen evolution reaction. Compared with TiS2 nanosheets and MoS2 QDs, more active sites and inherent metallicity of TiS2 QDs perform higher turnover frequency reaching to 2.01 s−1.
      PubDate: 2017-10-25T10:12:34.87368-05:0
      DOI: 10.1002/admi.201700895
       
  • Interface Strain Induced Hydrophobic Facet Suppression in Cellulose
           Nanocomposite Embedded with Highly Oxidized Monolayer Graphene Oxide
    • Authors: Qian Mao; Lei Yang, Xiumei Geng, Liao Chen, Bedanga Sapkota, Huijuan Zhao, Hongli Zhu
      Abstract: In nature, cellulose is a unique lightweight biopolymer with outstanding mechanical and optical properties that is readily available. Rigorous investigations have been conducted to use cellulose as an ingredient in the advanced functional composite design. In this work, a hybrid film composed of homogeneous cellulose nanocrystals (CNC) and high oxidation graphene oxide (GO) is obtained by sufficient blending and vacuum filtration. For the first time through the X-ray diffraction (XRD) spectrum, the suppression of the originally ordered hydrophobic (200) facet of CNC is observed with increasing concentrations of GO. Further, the originally ordered hydrophilic (110)/(1-10) facets of CNC remain intact. Through systematic molecular dynamics simulations of a set of simplified CNC–GO sandwich structures, the mechanism behind this hydrophilic/hydrophobic facets manipulation is revealed. The strain induced by the hydrogen bonding between the CNC hydroxyl groups and the oxidation types on GO is the dominant reason to cause the suppression of the hydrophobic facet of CNC in CNC–GO hybrid film. This strain induced mechanism provides an understanding for intrinsically manipulating cellulose–matrix interface and potentially engineering the cellulose based nanocomposite material properties for future advanced materials development.With the highly oxidized monolayer graphene oxide and cellulose crystal nanorod as building blocks, this work for the first time experimentally reveals the induced 200 facet suppression and computationally studies the underlying mechanism of crystalline structure alternation, providing a methodology to intrinsically manipulating cellulose–matrix interface and potentially engineering the cellulose-based nanocomposite material properties for future applications.
      PubDate: 2017-10-25T03:15:29.606785-05:
      DOI: 10.1002/admi.201700995
       
  • Exposing Metal Oxide with Intrinsic Catalytic Activity by Near-Infrared
           Pulsed Laser: Laser-Induced Selective Metallization on Polymer Materials
    • Authors: Jihai Zhang; Tao Zhou, Yi Xie, Liang Wen
      Abstract: In this work, a facile strategy is presented for the fabrication of precisely metallized patterns on polymer substrate based on the copper-free laser sensitizer through laser direct structuring (LDS) technology. A series of characterization methods are carried out to investigate the surface chemistry and morphology of polymer/antimony-doped tin oxide (ATO) composites after laser activation and selective metallization. X-ray photoelectron spectroscopy results show that a small part of Sn4+ and Sb5+ in ATO is reduced to Sn2+ and Sb3+, and it does not detect any Sn0 (elemental tin) after laser activation. This study confirms that ATO is a good copper-free laser sensitizer and an efficient catalyst for selective metallization. Furthermore, the obtained copper layer is anchoring into the substrate leading to a superior adhesion property (highest 5 B level after Scotch tape test) between the copper layer and polymer substrate. Meanwhile, the obtained copper circuit line exhibits high conductivity (1.26 × 107 Ω−1 m−1) and excellent stability over time. This study also provides a guideline to develop copper-free laser sensitizer for LDS technology.Approach for fabricating precisely metallized patterns on polymers based on the copper-free laser sensitizer through laser direct structuring (LDS) technology is proposed. After near-infrared pulsed laser activation, only 3% antimony-doped tin oxide (ATO) in polymer composites endows the polymer substrate with a good capacity of selective metallization. The role of laser activation is to expose ATO particles with the self-catalytic activity to the laser-irradiated surface.
      PubDate: 2017-10-23T03:20:59.668676-05:
      DOI: 10.1002/admi.201700937
       
  • Triggering and Tracing Electro-Hydrodynamic Liquid-Metal Surface
           Convection with a Particle Raft
    • Authors: Jianbo Tang; Xi Zhao, Yuan Zhou, Jing Liu
      Abstract: Microcopper particles are introduced to trigger and trace persistent surface convection of eutectic gallium indium (eGaIn) when the liquid-metal is partially immersed in shallow alkaline solution. It is found that the surface convection, which further induces large-scale shape transformation of the liquid-metal body, is driven by the surface-tension imbalance originated from the numerous tiny copper–eGaIn galvanic couples through the electrocapillary mechanism. Meanwhile, the particular configuration of particles binding to the liquid-metal surface and surfing with the flow also enables one to capture the flow patterns and visualize the flow field with the assistance of particle imaging velocimetry technology. This overcomes the difficulties in directly observing and quantifying the dynamic surface-flow behaviors of such nontransparent yet highly reflective liquid-metals. Characteristic flow regimes of the liquid–metal surface convection are revealed and their indications regarding the flow beneath the surface are also made.Giant electrohydrodynamic instability of a partially immersed liquid-metal body is triggered by tiny copper particles, resulting in long-term surface convection and large-scale shape transformation of the liquid metal. Complex flow patterns of the particle-driven surface convection are further captured by tracing the motions of the particles accompanying the flow.
      PubDate: 2017-10-04T05:17:28.845401-05:
      DOI: 10.1002/admi.201700939
       
  • Transparent, Flexible Cellulose Nanofibril–Phosphorene Hybrid Paper as
           Triboelectric Nanogenerator
    • Authors: Peng Cui; Kaushik Parida, Meng-Fang Lin, Jiaqing Xiong, Guofa Cai, Pooi See Lee
      Abstract: Few-layered phosphorene is exfoliated through a liquid phase exfoliation in ethanol, acting as an additive to mix with tempo-oxidized cellulose nanofibrils (CNF), forming a transparent, flexible nanogenerator paper. The gas barrier property of CNF protects phosphorene against oxidation in ambient condition. The phosphorene in the hybrid paper is stable over six months even with exposure to ambient condition (23 °C, 70% RH) in air. The hybrid paper is used as an active layer to construct a triboelectric energy nanogenerator (TENG). This hybrid paper shows an open-circuit voltage of 5.2 V with a current density of 1.8 µA cm−2, which is five and nine times higher than that of the pure CNF paper device, respectively. This work reveals the role of phosphorene in acting as a charge carrier in the hybrid paper and demonstrates a new way to attain stable functional phosphorene hybrids in ambient condition. The resultant phosphorene hybrid paper could be used as a building block for TENG with enhanced output performance.A cellulose nanofibril phosphorene hybrid paper can be fabricated into a triboelectric energy nanogenerator. The power density of the hybrid paper is about 40 times higher than that of the pure cellulose nanofibril paper.
      PubDate: 2017-09-29T12:00:34.242065-05:
      DOI: 10.1002/admi.201700651
       
  • Synergetic Enhancement in Photosensitivity and Flexibility of
           Photodetectors Based on Hybrid Nanobelt Network
    • Authors: Muhammad Shahid; Yuting Wang, Jun Yang, Tianjun Li, Jing Cheng, Mengfei Zhang, Yan Xing, Chunlei Wan, Wei Pan
      Abstract: High photosensitivity, transparency, flexibility, and facile assembly are the main important features of photodetectors, which extend their use for vast range of applications. In this study, a highly stable transparent flexible ultraviolet–visible (UV–vis) hybrid photodetectors, with enhanced photosensitivity and fast photoresponse speed (on/off switching) based on In2O3-ZnO hybrid nanobelts, is reported. A highly enhanced photosensitivity of about 4.7 × 105, fast photoresponse, and at the same time extended spectral range (UV to vis) have been achieved in these hybrid flexible photodetectors as compared to their pure counterparts In2O3 and ZnO. Furthermore, these photodetectors have shown excellent photoresponsivity of 18.5 A W−1 with an external quantum efficiency 7.4 × 103% and a high detectivity of 1.7 × 1012 Jones under the excitation wavelength of 308 nm. A facile, tunable, and cost-effective method has been employed to assemble these photodetectors by using well-aligned electrospun nanobelts. The prepared UV–vis photodetectors have shown a high transparency>90% under visible light (400–700 nm) which demonstrates their applications in fully light exposure required devices. These transparent electrospun nanobelts with high aspect ratios can also be transferred to multiple substrates, which shows their applications in different environment as a freestanding nanobelt network for UV–vis photodetectors.In this work, highly transparent and flexible photodetectors based on hybrid inorganic semiconductor oxides nanobelts are prepared via a facile assembly method. These photodetectors demonstrate superior optoelectronics and flexible properties. The prepared freestanding electrospun nanobelt networks with high transparency can be transferred to multiple substrates to prepare conformable and invisible photodetectors.
      PubDate: 2017-09-27T09:57:18.716458-05:
      DOI: 10.1002/admi.201700909
       
  • Solution Monolayer Epitaxy for Tunable Atomically Sharp Oxide Interfaces
    • Authors: Alon Ron; Amir Hevroni, Eran Maniv, Michael Mograbi, Lei Jin, Chun-Lin Jia, Knut W. Urban, Gil Markovich, Yoram Dagan
      Abstract: Interfaces play an important role in a variety of devices including transistors, solar cells, and memory components. Atomically sharp interfaces are essential to avoid charge traps that hamper efficient device operation. Sharp interfaces usually require thin-film fabrication techniques involving ultrahigh vacuum and high substrate temperatures. A new self-limiting wet chemical process for deposition of epitaxial layers from alkoxide precursors is presented. This method is fast, cheap, and yields perfect interfaces as validated by various analysis techniques. It allows the growth of heterostructures with half-unit-cell resolution. The method is demonstrated by designing a hole-type oxide interface SrTiO3/BaO/LaAlO3. It is shown that transport through this interface exhibits properties of mixed electron–hole contributions with hole mobility exceeding that of electrons.A self-limiting wet chemical process for deposition of epitaxial oxide monolayers is presented. This method is fast, cheap, and yields perfect interfaces. It allows the growth of oxide heterostructures with half-unit-cell resolution. It is demonstrated for a hole-type oxide interface SrTiO3/BaO/LaAlO3. The transport through this interface exhibits properties of mixed electron–hole contributions with hole mobility exceeding that of electrons.
      PubDate: 2017-09-27T09:56:29.084333-05:
      DOI: 10.1002/admi.201700688
       
  • Controlling Coffee Ring Formation during Drying of Inkjet Printed 2D Inks
    • Authors: Pei He; Brian Derby
      Abstract: The morphology of drops of graphene oxide (GO) inks produced by inkjet printing shows a distinctive coffee ring after drying when the mean diameter of the GO is below a critical size. Inks with larger diameter flakes do not show a coffee ring and the transition mean flake diameter decreases as the substrate temperature increases and when the printed drop size decreases. This behavior can be predicted with a model that compares the characteristic time for the agglomeration of high aspect ratio particles in suspension with the time scale for an evaporating liquid drop to begin receding during the drying process. The model is shown to accurately describe the transition from a coffee ring to a uniform dried deposit using a range of GO inks with mean flake size in the range 0.68–35.9 µm, drying temperatures of 20–60 °C, and drop sizes with contact diameter ranging from 30 to 800 µm.Coffee ring formation is suppressed during drying drops of 2D material inks, when the mean flake diameter is above a critical size. The mechanism for this behavior is related to the conditions for contact line pinning during drying. A simple model is presented that produces excellent agreement with experimental results.
      PubDate: 2017-09-25T05:22:25.217563-05:
      DOI: 10.1002/admi.201700944
       
  • Palladium-Loaded Hierarchical Flower-like Tin Dioxide Structure as
           Chemosensor Exhibiting High Ethanol Response in Humid Conditions
    • Authors: Cecilia A. Zito; Tarcísio M. Perfecto, Diogo P. Volanti
      Abstract: The impact of humidity is a crucial factor in the sensing performance of a chemiresistive gas sensor. Therefore, strategies for developing sensors with a small humidity dependence are required. Herein, the volatile organic compound (VOC)-sensing performance of palladium-loaded hierarchical flower-like tin dioxide structures (Pd/FL-SnO2) under humid conditions is reported. To prepare the Pd/FL-SnO2 heterostructures, FL-SnO2 is first synthesized using a microwave-assisted solvothermal method, followed by calcination, and then is loaded with Pd nanoparticles (NPs). VOC-sensing studies are conducted in dry and wet air with relative humidities (RHs) between 25% and 98%. FL-SnO2 and Pd/FL-SnO2 exhibit an enhanced response toward ethanol in comparison with other VOCs, including acetone, benzene, methanol, m-xylene, and toluene. However, FL-SnO2 with Pd NPs has a substantially decreased optimal working temperature, from 340 to 140 °C, and an improved selectivity. Furthermore, the ethanol response of the Pd/FL-SnO2 heterostructures is preserved under humid conditions, whereas the response of FL-SnO2 is significantly affected by humidity. The response to 100 ppm of ethanol under 98% RH is 3.1 and 8.0 for neat FL-SnO2 and 5% Pd/FL-SnO2 heterostructure, respectively. The ethanol-sensing performance enhancement under high humidity is attributed to the Pd/SnO2 heterointerface.Hierarchical flower-like SnO2 structures are prepared by a simple microwave-assisted solvothermal approach and decorated with well-dispersed Pd nanoparticles. Pd loading decreases the optimal operating temperature and improves the sensor selectivity. Pd-loaded SnO2 exhibits a high ethanol response under high-humidity conditions, and its excellent sensing performance is attributed to the Pd/SnO2 heterointerface.
      PubDate: 2017-09-22T01:57:45.898609-05:
      DOI: 10.1002/admi.201700847
       
  • Anti-Icing Performance of Superhydrophobic Texture Surfaces Depending on
           Reference Environments
    • Authors: Yizhou Shen; Guanyu Wang, Jie Tao, Chunling Zhu, Senyun Liu, Mingming Jin, Yuehan Xie, Zhong Chen
      Abstract: Materials decorated by the hierarchical micro-nanostructures similar to lotus leaf surface topographies are firmly considered to possess the substantial anti-icing functions, showing icing-delay and low ice adhesion. Here, the aim of this work is to verify the anti-icing capacity in the actual icing environment containing supercooled airflow. This study, therefore, develops both routes to fabricate the hierarchical micro-nanostructure and single nanostructure superhydrophobic surfaces, and first evaluates their anti-icing capacity based on the routine measuring strategies in laboratory. Also, the potential application environment is modeled and used to verify their anti-icing performance for further guiding rational design of surface structures of anti-icing materials. Due to the double-scale effect, the hierarchical micro-nanostructure can induce more air pockets to produce the higher hydrophobicity and anti-icing capacity based on the big reference droplets (diameter> 2 mm) and even static water. However, the verified results in the potential application environment demonstrate that the hierarchical micro-nanostructure exhibits the inferior anti-icing performance, comparing with the single nanostructure. The icing area on the single nanostructure surface is almost half of that on the hierarchical micro-nanostructure surface, also causing a reduction of ≈26 g in icing mass.Hierarchical micro-nanostructure superhydrophobic surfaces are widely considered to be ideal anti-icing materials due to the double-scale effect inducing to entrap more air pockets. However, the results in application environments show an inverse situation, because many supercooled microdroplets suspending in the environment (diameter of 20-40 μm) firstly rush into the micrometer structures to result in the rapid ice accumulation.
      PubDate: 2017-09-20T00:10:47.621932-05:
      DOI: 10.1002/admi.201700836
       
  • Decoration of Nanofibrous Paper Chemiresistors with Dendronized
           Nanoparticles toward Structurally Tunable Negative-Going Response
           Characteristics to Human Breathing and Sweating
    • Authors: Shan Yan; Xin Liu, Zakiya Skeete, Ning He, Zhi-Hui Xie, Wei Zhao, Jack P. Lombardi, Kai Liu, Ning Kang, Jin Luo, Benjamin S. Hsiao, Mark Poliks, Ivan Gitsov, Chuan-Jian Zhong
      Abstract: The development of wearable breath or sweat sensor arrays for human performance monitoring is increasingly important for providing personalized health information under various environmental conditions. A major challenge is the lack of sensing elements responsive uniquely to moisture-dominated breathing and sweating processes, which is critical for differentiating other chemical or biological species from the moisture-dominated environment. Here a novel class of nanofibrous paper chemiresistors decorated with dendronized nanoparticles that exhibit structurally tunable and negative-going responses to human breathing and sweating is reported. The nanocomposite device features flexible membrane-type scaffold derived from multilayered nanofibrous paper as a biocompatible matrix and dendronized gold nanoparticles with tunable sizes and shapes to enable structural diversity and molecular sensitivity. Key elements of novelty include the immobilization of poly(ether-ester) dendrons with oligoethylene glycol spacers on gold nanoparticles and the combination of hydrogen bonding and van der Waals interactions between partially interpenetrating dendrons, leading to tunable and unique response characteristics to breathing and sweating processes. The results demonstrate the first example of nanofibrous paper chemiresistors decorated with dendronized nanoparticles as a promising new strategy toward constructing sensing interfaces for wearable breath and sweat sensors.A nanostructured paper chemiresistor with negative-going response dominant characteristics to human breathing and sweating is demonstrated, which involves decoration of a nanofibrous membrane paper with dendronized gold nanoparticles to enable highly tunable sensitivity in moisture-dominant sensing environment and constitutes a promising new strategy to design sensing array elements for wearable breath and sweat sensors.
      PubDate: 2017-09-19T11:16:21.099368-05:
      DOI: 10.1002/admi.201700380
       
  • Decreasing Defect-State Density of Al2O3/GaxIn1−xAs Device
           Interfaces with InOx Structures
    • Authors: Jaakko Mäkelä; Marjukka Tuominen, Johnny Dahl, Sari Granroth, Muhammad Yasir, Juha-Pekka Lehtiö, Rami-Roope Uusitalo, Mikhail Kuzmin, Marko Punkkinen, Pekka Laukkanen, Kalevi Kokko, Roberto Félix, Mika Lastusaari, Ville Polojärvi, Jari Lyytikäinen, Antti Tukiainen, Mircea Guina
      Abstract: Control of defect densities at insulator/GaxIn1−xAs interfaces is essential for optimal operation of various devices like transistors and infrared detectors to suppress, for example, nonradiative recombination, Fermi-level pinning, and leakage currents. It is reported that a thin InOx interface layer is useful to limit the formation of these defects by showing effect of InOx on quantum efficiency of Ga0.45In0.55As detector and on photoluminescence of GaAs. A study of the Al2O3/GaAs interface via hard X-ray synchrotron photoelectron spectroscopy reveals chemical structure changes at the interface induced by this beneficial InOx incorporation: the InOx sheet acts as an O diffusion barrier that prevents oxidation of GaAs and concomitant As bond rupture.Novel crystalline oxide structure between GaAs(100) and atomic layer deposition grown Al2O3 is shown to result in improvement of practical IR detectors. Hard X-ray photoelectron spectroscopy analysis shows that different InOx structures can give rise to different charge carrier recombination mechanisms, but they are straightforwardly suppressed with an optimal amount of In in the interfacial layer.
      PubDate: 2017-09-19T11:15:31.912454-05:
      DOI: 10.1002/admi.201700722
       
  • Two-Step Synthesis of Hierarchical Dual Few-Layered Fe3O4/MoS2 Nanosheets
           and Their Synergistic Effects on Lithium-Storage Performance
    • Authors: Feifei Lu; Chunbo Xu, Fuchang Meng, Tian Xia, Ruihong Wang, Jingping Wang
      Abstract: Owing to unique lamellar nanostructures, 2D inorganic materials are considered as promising candidates in energy storage and conversion. In this paper, a facile two-step synthesis is developed to fabricate 3D hierarchical dual Fe3O4/MoS2 nanosheets (HD-FMNs), in which few-layered MoS2 nanosheets are anchored in 3D Fe3O4 nanosheet network to form the heterojunction structure. Furthermore, it is proved that the synergistic effects on both electron/lithium-ion transport kinetics and mechanical cycling stability benefit from Fe3O4/MoS2 nanosheet incorporation in 3D HD-FMN anode for lithium-ion batteries (LIBs), resulting in the dramatically enhanced performance. The Fe3O4 nanosheet incorporation effectively improves the electronic conductivity due to its half-metal characteristic, while the defect-rich structure in the MoS2 nanosheets can facilitate the lithium ion transport. When tested as potential anode materials, 3D HD-FMNs exhibit a high reversible capacity (650 mAh g−1) at current rate of 5 C (1 C = 1 A g−1) after superior long-term cycles (1000 times), as well as an excellent rate capability even at high current rates. The outstanding electrochemical property of 3D HD-FMNs allows their application in high-performance anode materials for next-generation LIBs. This strategy also opens a new way to design the novel 2D composite materials for electrochemical devices.Two-step synthesis route is developed to fabricate 3D hierarchical dual Fe3O4/MoS2 nanosheets, in which few-layered MoS2 nanosheets are anchored in 3D Fe3O4 nanosheet network to form the heterojunction structure. Their synergistic effects on lithium-storage performance are also presented.
      PubDate: 2017-09-18T11:37:50.808504-05:
      DOI: 10.1002/admi.201700639
       
  • 3D Highly Conductive Silver Nanowire@PEDOT:PSS Composite Sponges for
           
    • Authors: In Kyu Moon; Seonno Yoon, Jungwoo Oh
      Abstract: Although increasing attention has been paid to wearable electronic devices in recent years, flexible supercapacitors with high performance remain not readily available because of the limitations of flexible electrode types. A highly conductive 3D macroporous sponge is fabricated by coating poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/silver nanowires (AgNWs) on a commercial sponge using a simple and low-cost “immersion method.” The fabricated flexible 3D sponge conductor shows a high electrical conductivity of 3.94 × 10−4 S cm−1 with good stability in various environments and under bending deformation. To exploit the potential of the flexible 3D PEDOT:PSS/AgNW coating on the sponge as a current collector for energy-related applications, urchin-like Co(OH)F arrays are directly grown on PEDOT:PSS/AgNW-on-sponge conductors for all-solid-state supercapacitors. The resulting symmetric all-solid-state supercapacitor exhibits a mass-specific capacitance of 103.7 F g−1 at a current density of 1 A g−1, retaining 85.8% of the initial capacitance after 3000 cycles, and mechanical flexibility during bending. This fabrication of the 3D lightweight conductor can be easily scaled up for mass production and introduces new opportunities for flexible electronic applications.A new Co(OH)F nanowire array electrode on a flexible polyurethane sponge (PUS)/Ag nanowire (AgNW)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) conductor has been developed by combining hydrothermal growth with a wet-coating-processing material. This PUS/AgNW/PEDOT:PSS conductor is highly conductive and chemically stable. The all-solid-state Co(OH)F supercapacitor offers a new high-performance supercapacitor electrode design with significantly improved specific capacitance.
      PubDate: 2017-09-18T11:36:58.698745-05:
      DOI: 10.1002/admi.201700860
       
  • Nanoscale Ferromagnetic Cobalt-Doped ZnO Structures Formed by Deep-UV
           Direct-Patterning
    • Authors: Chun-Cheng Yeh; Silviu Colis, Philippe Fioux, Hsiao-Wen Zan, Dominique Berling, Olivier Soppera
      Abstract: Cobalt (II) acetate is mixed with zinc methacrylate (ZnMAA) to form a photopatternable Co-doped zinc oxide precursor. By using deep-UV (DUV) interference lithography, Co-doped ZnMAA precursor can be patterned as negative tone resist and transformed into ferromagnetic Co:ZnO films after thermal treatment. Moreover, Co:ZnO patterns as small as 300 nm line-width can be easily obtained. To have an in-depth understanding to the effect of DUV-patterning process as well as thermal annealing on Co:ZnO films derived from Co-doped ZnMAA precursor, optical, magnetic, and electrical characterizations are performed on Co:ZnO films prepared in different conditions. For the Co:ZnO film prepared without DUV-patterning, large zero-field-cooling (ZFC)–field-cooling (FC) irreversibility appears in superconducting quantum interference device measurements after vacuum annealing, indicating that Co clusters have formed inside the film. On the other hand, no ZFC–FC bifurcation can be observed for the DUV-patterned Co:ZnO film after the vacuum annealing, suggesting that the uniformity of Co ion distribution inside ZnO lattice is improved by DUV-patterning.With the use of deep-UV (DUV) interference patterning and photosensitive Co-doped zinc methacrylate (ZnMAA) precursor, nanoscale Co:ZnO patterns can be easily obtained. The effects of DUV-patterning as well as thermal annealing on the magnetic properties of Co:ZnO films derived from Co-doped ZnMAA precursor are investigated. The results indicate that the uniformity of Co ions in ZnO lattice is improved by DUV-patterning.
      PubDate: 2017-09-13T13:02:32.072353-05:
      DOI: 10.1002/admi.201700738
       
  • Nanoscale Distribution of Magnetic Anisotropies in Bimagnetic Soft
           Core–Hard Shell MnFe2O4@CoFe2O4 Nanoparticles
    • Authors: Niéli Daffé; Marcin Sikora, Mauro Rovezzi, Nadejda Bouldi, Véronica Gavrilov, Sophie Neveu, Fadi Choueikani, Philippe Ohresser, Vincent Dupuis, Dario Taverna, Alexandre Gloter, Marie-Anne Arrio, Philippe Sainctavit, Amélie Juhin
      Abstract: The nanoscale distribution of magnetic anisotropies is measured in core@shell MnFe2O4@CoFe2O4 7.0 nm particles using a combination of element selective magnetic spectroscopies with different probing depths. As this picture is not accessible by any other technique, emergent magnetic properties are revealed. The coercive field is not constant in a whole nanospinel. The very thin (0.5 nm) CoFe2O4 hard shell imposes a strong magnetic anisotropy to the otherwise very soft MnFe2O4 core: a large gradient in coercivity is measured inside the MnFe2O4 core with lower values close to the interface region, while the inner core presents a substantial coercive field (0.54 T) and a very high remnant magnetization (90% of the magnetization at saturation).The nanoscale distribution of magnetic anisotropies inside MnFe2O4@CoFe2O4 nanoparticles is measured using a unique combination of X-ray magnetic spectroscopies with different probing depths. Coercivity is not constant within a particle. The thin (0.5 nm) hard shell of CoFe2O4 imposes a strong magnetic anisotropy to the soft MnFe2O4 core, which presents a substantial coercive field and a very high remanent magnetization.
      PubDate: 2017-09-13T13:02:05.995899-05:
      DOI: 10.1002/admi.201700599
       
  • Unlocking the Single-Domain Epitaxy of Halide Perovskites
    • Authors: Lili Wang; Pei Chen, Non Thongprong, Margaret Young, Padmanaban S. Kuttipillai, Chuanpeng Jiang, Pengpeng Zhang, Kai Sun, Phillip M. Duxbury, Richard R. Lunt
      Abstract: The growth of epitaxial semiconductors and oxides has long since revolutionized the electronics and optics fields, and continues to be exploited to uncover new physics stemming from quantum interactions. While the recent emergence of halide perovskites offers exciting new opportunities for a range of thin-film electronics, the principles of epitaxy have yet to be applied to this new class of materials and the full potential of these materials is still not yet known. In this work, single-domain inorganic halide perovskite epitaxy is demonstrated. This is enabled by reactive vapor phase deposition onto single crystal metal halide substrates with congruent ionic interactions. For the archetypical halide perovskite, cesium tin bromide, two epitaxial phases, a cubic phase and tetragonal phase, are uncovered which emerge via stoichiometry control that are both stabilized with vastly differing lattice constants and accommodated via epitaxial rotation. This epitaxial growth is exploited to demonstrate multilayer 2D quantum wells of a halide-perovskite system. This work ultimately unlocks new routes to push halide perovskites to their full potential.Single-domain halide perovskite heteroepitaxy is demonstrated and multiple epitaxial phases of archetypical halide perovskite are uncovered via stiochiometry control. The epitaxial growth is further exploited to demonstrate multilayer 2D quantum wells of a halide-perovskite system and can ultimately enable their full potential in many emerging applications.
      PubDate: 2017-09-13T13:01:01.798551-05:
      DOI: 10.1002/admi.201701003
       
  • Solvent-Templated Block Ionomers for Base- and Acid-Gas Separations:
           Effect of Humidity on Ammonia and Carbon Dioxide Permeation
    • Authors: Luca Ansaloni; Zhongde Dai, Justin J. Ryan, Kenneth P. Mineart, Qiang Yu, Keara T. Saud, May-Britt Hägg, Richard J. Spontak, Liyuan Deng
      Abstract: As energy needs continue to drive the development of biogas and fossil-fuel technologies, methods by which to selectively remove basic (NH3) and acidic (CO2) gases are becoming increasingly important, especially in light of global climate change. Block copolymers are considered as suitable membrane candidates in gas separations due to the ability of such copolymers to microphase-separate and spontaneously form nanoscale morphologies that exhibit spatially modulated chemical specificity. Incorporation of charged moieties along the midblock of a thermoplastic elastomeric multiblock copolymer yields an amphiphilic block ionomer possessing a flexible molecular network stabilized by rigid endblocks. The presence of hydrophilic microdomains introduces an important consideration regulating molecular transport: humidity. In this study, solvent-templating paradigms are employed to control the morphologies of midblock-sulfonated pentablock ionomers, as discerned by electron microscopy and X-ray scattering. The effect of humidity on the permeation of NH3, CO2, and N2 is then investigated through the resulting membranes. As expected, NH3 permeates significantly faster than N2, especially under humid conditions. Although not as pronounced, similar behavior is observed for CO2, thereby establishing that this block ionomer is generally selective to humidified polar gases.A pentablock copolymer with charged moieties along the midblock displays promising separation performance for both basic and acidic gases under humidified conditions. The permeation of polar (NH3 and CO2) and non-polar (N2) penetrants through this amphiphilic copolymer has been measured by single- and mixed-gas methods to elucidate the influence of nanoscale morphology (controllably varied by solvent templating/annealing) and relative humidity.
      PubDate: 2017-09-13T13:00:40.284601-05:
      DOI: 10.1002/admi.201700854
       
  • Atomic Layer Deposition of Zinc Glutarate Thin Films
    • Authors: Leo D. Salmi; Miika Mattinen, Teemu Niemi, Mikko J. Heikkilä, Kenichiro Mizohata, Sanna Korhonen, Sami-Pekka Hirvonen, Jyrki Räisänen, Mikko Ritala
      Abstract: Deposition of zinc glutarate thin films by atomic layer deposition is studied at 200–250 °C using zinc acetate and glutaric acid as the precursors. The films are characterized by UV–vis spectrophotometry, X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, atomic force microscopy, and time-of-flight elastic recoil detection analysis. According to X-ray diffraction, the films deposited at 200 °C are crystalline with a crystal structure matching to zinc glutarate. The elastic recoil detection analysis shows that the composition of the films is a close match to zinc glutarate. Catalytic activity of the films is demonstrated using the copolymerization reaction of propylene oxide and CO2.Atomic layer deposition (ALD) of zinc glutarate (ZnGA) thin films is investigated. A well-controlled ALD process for ZnGA is presented and the films are characterized by various techniques including X-ray diffraction, time-of-flight elastic recoil detection analysis, infrared spectroscopy, and atomic force microscopy. The films are shown to be catalytically active in the copolymerization reaction of propylene oxide and CO2.
      PubDate: 2017-09-12T01:28:41.705922-05:
      DOI: 10.1002/admi.201700512
       
  • The Atomic Scale Electrochemical Lithiation and Delithiation Process of
           Silicon
    • Authors: Chuntian Cao; Hans-Georg Steinrück, Badri Shyam, Michael F. Toney
      Abstract: While silicon (Si) has tenfold capacity of commercially used graphite, its application is still limited due to its limited cyclability. In this in situ X-ray reflectivity study, a detailed mechanistic model of the first two (de)lithiation processes of a silicon wafer is presented, which sheds light onto the fundamental difference of the reaction of Li ions with crystalline and amorphous materials. Furthermore, this study provides insight into the formation and further evolution of the inorganic solid electrolyte interphase (SEI) layer on Si anodes. The results show that the lithiation of crystalline Si is a layer-by-layer, reaction limited two-phase process, but the delithiation of LixSi (resulting in amorphous Si) and the lithiation of amorphous Si are reaction-limited single-phase processes. Furthermore, the thickness-density product of the inorganic SEI layer increases during lithiation and decreases during delithiation, resembling a “breathing” behavior; the inorganic SEI layer thickness varies between 40 and 70 Å. Additionally, a low-electron-density “Li-dip” layer is found between the SEI and lithiated Si during the delithiation process, suggesting kinetically limited ion transport within the SEI, which is speculated to be one of the origins of battery's internal resistance. Several implications of the findings on battery performance in general are discussed.Illustration of the fit-derived models for the (de)lithiation process in silicon. In the 1st lithiation, crystalline-Si lithiates, forming LixSi; solid electrolyte interphase (SEI) layer starts to grow. In delithiation, the thickness of LixSi decreases, the electron density increases, and the final delithiation state is amorphous-Si (single-phase reaction); the SEI layer shrinks during delithiation. The second lithiation is the reverse of the delithiation process.
      PubDate: 2017-09-12T01:28:30.215076-05:
      DOI: 10.1002/admi.201700771
       
  • Mussel-Inspired Polyesters with Aliphatic Pendant Groups Demonstrate the
           Importance of Hydrophobicity in Underwater Adhesion
    • Authors: Ying Xu; Qianhui Liu, Amal Narayanan, Dharamdeep Jain, Ali Dhinojwala, Abraham Joy
      Abstract: Recognizing the potential for synthetic adhesives that can function in wet environments, elements of mussel foot proteins such as L-3,4-dihydroxyphenylalanine (DOPA) and phosphoserine have been incorporated into synthetic adhesives. Such adhesives have corroborated the advantage of surface active groups like DOPA, but have not yet demonstrated superior performance in wet or underwater environments, without using organic solvents. What has been conspicuously absent from such designs is the effect of hydrophobic components in the performance of underwater adhesives. Herein it is shown that incorporation of hydrophobic groups in low modulus polyester adhesives provides very high lap-shear strength and resistance to water penetration. In addition to the excellent performance in wet conditions, the designed adhesive can be applied underwater without any solvent, is biodegradable, and is designed from soybean oil, which is a readily available and renewable resource.Mussel-inspired polyesters designed with hydrophobic, catechol, and coumarin pendant groups can be applied underwater without a solvent. The catechol groups provide adhesive interactions while crosslinking through the coumarin groups provides cohesive bonds. The unsaturated aliphatic groups provide a hydrophobic environment that minimizes water penetration into the interface.
      PubDate: 2017-09-12T01:25:59.927521-05:
      DOI: 10.1002/admi.201700506
       
  • Fabrication of Shape-Controlled Palladium Nanoparticle-Decorated
           Electrospun Polypyrrole/Polyacrylonitrile Nanofibers for Hydrogen Peroxide
           Coalescing Detection
    • Authors: Wooyoung Kim; Dong Hoon Shin, Jaemoon Jun, Jae Hyun Kim, Jyongsik Jang
      Abstract: Shape-controlled palladium nanoparticle-decorated electrospun polypyrrole/polyacrylonitrile nanofibers (Pd_PPy/PAN NFs) are fabricated by electrospinning, vapor deposition polymerization (VDP), and electrodeposition. The electrospun PAN NFs are used as the framework for a composite nanomaterial. To make the material electrically conductive, the framework is coated with PPy by VDP. As-prepared PPy/PAN NFs are used as the working electrode during electrodeposition of Pd. During Pd introduction, the presence of sulfuric acid in the electrolyte influences the shape of the Pd nanoparticles. Sulfate ions prevent the growth of the Pd, resulting in nanoparticles with sharp features. The fabricated Pd_PPy/PAN NFs are then incorporated as the active element in an electrochemical hydrogen peroxide (H2O2) biosensor. Tailoring the morphology of the Pd nanoparticles enables a minimum detectable limit of 1 × 10−9m H2O2, which is sufficiently low for monitoring diseases related to H2O2 concentration, such as Parkinson's disease and Alzheimer's disease. The low detection limit is achieved by coalescing detection of Pd and PPy.Shape-controlled palladium nanoparticle-decorated electrospun polypyrrole/polyacrylonitrile nanofibers (Pd_PPy/PAN NFs) are fabricated by electrospinning, vapor phase deposition, and electrodeposition. The morphology of Pd is easily modified by controlling the sulfuric acid concentration in the electrolyte. The Pd_PPy/PAN NFs-based H2O2 sensor exhibits low minimum detectable limit of 1 × 10−9m.
      PubDate: 2017-09-12T01:23:28.678716-05:
      DOI: 10.1002/admi.201700573
       
  • Multimaterials 3D Printing for Free Assembly Manufacturing of Magnetic
           Driving Soft Actuator
    • Authors: Zhongying Ji; Changyou Yan, Bo Yu, Xiaolong Wang, Feng Zhou
      Abstract: Magnetic Fe3O4 nanoparticles are employed to develop digital light processing 3D printing resin, which is used to fabricate arbitrary-shape soft actuators with multimaterials printing in a free assembly manner. Various mechanical properties and printed morphology of curing resin with different Fe3O4 nanoparticles content are explored to demonstrate the feasibility and precision. By using magnetic and nonmagnetic resins as the magnetic and nonmagnetic segments, mulitple magnetic devices and actuators are prepared by digital light processing (DLP) 3D printing technology. Moreover, the interfacial binding strength between magnetic and nonmagnetic segments and deflection with different diameters of printed lattices and content of Fe3O4 nanoparticles are investigated. DLP 3D printing enables the free assembly manufacturing of actuators with complicated architectures to achieve bending, deformation, cargo transportation, and so on. As proof-of-concept, a flexible gripper is printed through integrating magnetic responsive and nonresponsive materials into one body. This approach with special material will be promising to extend the capability of 3D printing for applications in controllable delivery with remote magnetic control in biological, medical, and robotic fields.Arbitrary-shape magnetic driving soft actuators are prepared in free assembly manner by digital light processing 3D printing with multimaterials. The advantages combining computer-aid design, free assembly, and multimaterials will extend the capability of 3D printing for actuators for controllable delivery with remote control in biological, medical, and robotic fields.
      PubDate: 2017-09-12T01:11:49.107357-05:
      DOI: 10.1002/admi.201700629
       
  • Ultrafast Phase Transition Dynamics in Strained Vanadium Dioxide Films
    • Authors: Ryan J. Suess; Nicholas S. Bingham, Kristin M. Charipar, Heungsoo Kim, Scott A. Mathews, Alberto Piqué, Nicholas A. Charipar
      Abstract: An ultrafast insulator–metal–insulator phase transition cycle in epitaxially strained vanadium dioxide films is observed. The films are characterized by optoelectronic autocorrelation measurements that reveal a 400 fs transient change in response spanning two orders in magnitude. These findings suggest a predominantly electronic mechanism and demonstrate the promise of this material for optoelectronic applications requiring fast, high-contrast switching.An ultrafast insulator–metal–insulator phase transition cycle in epitaxially strained vanadium dioxide films is observed. The films are characterized by optoelectronic autocorrelation measurements that reveal a 400 fs transient change in response spanning two orders in magnitude. These findings suggest a predominantly electronic mechanism and demonstrate the promise of this material for optoelectronic applications requiring fast, high-contrast switching.
      PubDate: 2017-09-12T01:10:48.59794-05:0
      DOI: 10.1002/admi.201700810
       
  • A Highly Sensitive Nonenzymatic Sensor Based on Fe2O3 Nanoparticle Coated
           ZnO Nanorods for Electrochemical Detection of Nitrite
    • Authors: Rafiq Ahmad; Min-Sang Ahn, Yoon-Bong Hahn
      Abstract: Monitoring of nitrite is needed for the management of nitrite contamination and to ensure the welfare of environment and human health. Hence, it is important to develop high-performance sensors that precisely measure nitrite concentration. Herein, the fabrication of a highly sensitive nonenzymatic nitrite sensor based on Fe2O3 nanoparticle coated ZnO nanorods (Fe2O3 NP coated ZnO NRs) is demonstrated. The ZnO NRs are grown on a seeded silver electrode by a hydrothermal method and then coated under optimized conditions with Fe2O3 NPs using a dip-coating method. Detailed material characterizations and sensor fabrication process are reported. The electrochemical properties of a fabricated nonenzymatic nitrite sensor are tested with different concentrations of nitrite, which indicates that the coating of ZnO NRs with Fe2O3 NPs significantly enhances the electrocatalytic activity. The sensor responds linearly with increasing concentration of nitrite from 1 to 1250 × 10−6m with a high sensitivity (131.2 µA µM−1 cm−2) and low detection limit (0.015 × 10−6m). Moreover, excellent selectivity, stability, and reproducibility allow using these sensors for the determination of nitrite concentration in water with satisfactory results.A highly sensitive nonenzymatic nitrite sensor is successfully fabricated using Fe2O3 nanoparticle coated ZnO nanorods and employed for electrochemical detection of nitrite. The ZnO nanorod surface modification with Fe2O3 significantly improves the electrocatalytic activity for nitrite oxidation. As a result, enhanced sensing performance and potential application of fabricated sensor in real complex water samples are attained for nitrite detection.
      PubDate: 2017-09-11T01:22:01.453784-05:
      DOI: 10.1002/admi.201700691
       
  • “Three-in-One:” A New 3D Hybrid Structure of Li3V2(PO4)3 @ Biomorphic
           Carbon for High-Rate and Low-Temperature Lithium Ion Batteries
    • Authors: Yi Cheng; Kai Feng, Huaiqing Wang, Hongzhang Zhang, Xianfeng Li, Huamin Zhang
      Abstract: Li3V2(PO4)3 with high specific capacity and high operating potential has been considered as a promising cathode for the next generation lithium ion batteries (LIBs). But the low electronic conductivity restricts its practical applications. Here, a rational design of 3D hybrid structures of Li3V2(PO4)3 @ biomorphic carbon is presented. The 3D hybrid structures built from 0D, 1D, and 2D composites are carbonized from biomorphic carbon, namely, “three-in-one.” The synergistic effects of the carbon with different dimensions provide high electronic conductivity and good structural stability. In addition, abundant porous channels in the structure accelerate transfer of the Li+. This unique cathode material reaches the capacity retention up to 96% (relative to 1 C) when the rate increased to 50 C. When combines with Li4Ti5O12 to form a full battery, it delivers a capacity of 174 mAh g−1 at room temperature and retains 150 mAh g−1 when the temperature decreases to −40 °C. The excellent properties are attributed to the high electronic conductivity, fast ion transport channels, large electrode–electrolyte contact area, and robust structure stability of the 3D hybrid architecture. This work provides a new strategy for constructing 3D framework electrode materials for LIBs.A 3D hybrid structure built by 0D, 1D, and 2D carbon is carbonized from the biomorphic carbon, namely “three-in-one.” The synergistic effects of the carbon with different dimensions provide high electronic conductivity and good structural stability, which contribute to excellent rate performance and low-temperature performance.
      PubDate: 2017-09-11T01:20:50.963916-05:
      DOI: 10.1002/admi.201700686
       
  • Magnetic Wood as an Effective Induction Heating Material: Magnetocaloric
           Effect and Thermal Insulation
    • Authors: Wentao Gan; Likun Gao, Shaoliang Xiao, Runan Gao, Wenbo Zhang, Jian Li, Xianxu Zhan
      Abstract: An effective induction heating material composed of wood and magnetic Fe3O4 particles is prepared via a simple hydrothermal method. Fe3O4 particles deposit on the porous wood substrate provides excellent magnetic properties and high magnetothermal conversion resulting in rapid increase in the temperature at the wood substrate. Benefiting from the effective magnetocaloric effect of magnetic particles, the temperature of magnetic wood exhibits a noticeable rise (from 25.9 to 70.1 °C in 10 min) at low-frequency magnetic field. For simulating the real environment, the indoor temperature rise of magnetic wooden model also reveals the excellent heating performance of magnetic wood. Besides, the magnetic wood also serves as a thermal insulator to slow down the transport of thermal energy from the high temperature area to its surroundings due to its low thermal conductivity, which benefit the rational use of thermal energy in daily life. In view of highly scalable, simple operation, good durability, excellent magnetic properties, effective magnetocaloric effect, and thermal insulation, the novel magnetic wood composite demonstrated here is an attractive induction heating material for application in building, decoration, and massage furniture.Wood with excellent magnetic properties, effective magnetocaloric effect, and thermal insulation is an attractive induction heating material for application in building, decoration, and massage furniture.
      PubDate: 2017-09-11T01:16:30.002978-05:
      DOI: 10.1002/admi.201700777
       
  • Modulating the Spatial Electrostatic Potential for 1D Colloidal
           Nanoparticles Assembly
    • Authors: Jianmei Chen; Jing Huang, Andrea Toma, Liubiao Zhong, Zequn Cui, Weijing Shao, Ziyang Li, Wenkai Liang, Francesco De Angelis, Lin Jiang, Lifeng Chi
      Abstract: 1D nanoparticle arrangements have gained widespread attention because of their unique collective physical properties and potential applications in functional devices. To push the device integration toward its intrinsic limits, the precise positioning of colloidal nanoparticles into 1D layout is still a challenging task, especially for nanoparticles in the sub-20 nm range. In this work, a novel strategy based on the synergistic modulation of lateral and bottom electrostatic potential of grooves is applied, thus demonstrating a high-resolution confinement of 1D colloidal nanoparticle arrays. The mechanism of spatial potential modulation is elucidated in details, through the combination of quantitative theoretical modeling and consistent experimental results. A crystal-clear guide for the development of novel applications with both fundamental and technological perspectives is therefore provided.A novel strategy based on the synergistic modulation of lateral and bottom electrostatic potential of grooves is applied for the 1D array of the sub-20 nm colloidal nanoparticles with high resolution. The mechanism of spatial potential modulation is elucidated in detail by incorporation of quantitatively theoretical modeling and consistent experimental results.
      PubDate: 2017-07-25T01:33:42.971721-05:
      DOI: 10.1002/admi.201700505
       
 
 
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