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  Subjects -> CHEMISTRY (Total: 845 journals)
    - ANALYTICAL CHEMISTRY (51 journals)
    - CHEMISTRY (595 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (25 journals)
    - INORGANIC CHEMISTRY (41 journals)
    - ORGANIC CHEMISTRY (45 journals)
    - PHYSICAL CHEMISTRY (67 journals)

CHEMISTRY (595 journals)                  1 2 3 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 8)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 26)
ACS Catalysis     Full-text available via subscription   (Followers: 34)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 18)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 23)
ACS Macro Letters     Full-text available via subscription   (Followers: 24)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 39)
ACS Nano     Full-text available via subscription   (Followers: 245)
ACS Photonics     Full-text available via subscription   (Followers: 11)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 21)
Acta Chemica Iasi     Open Access   (Followers: 2)
Acta Chimica Sinica     Full-text available via subscription   (Followers: 1)
Acta Chimica Slovaca     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 8)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 5)
Advanced Functional Materials     Hybrid Journal   (Followers: 51)
Advanced Science Focus     Free   (Followers: 3)
Advances in Chemical Engineering and Science     Open Access   (Followers: 56)
Advances in Chemical Science     Open Access   (Followers: 13)
Advances in Chemistry     Open Access   (Followers: 15)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Enzyme Research     Open Access   (Followers: 9)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 9)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 21)
Advances in Nanoparticles     Open Access   (Followers: 15)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15)
Advances in Polymer Science     Hybrid Journal   (Followers: 41)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 17)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Science and Technology     Full-text available via subscription   (Followers: 12)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 2)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 67)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 14)
American Journal of Chemistry     Open Access   (Followers: 27)
American Journal of Plant Physiology     Open Access   (Followers: 14)
American Mineralogist     Hybrid Journal   (Followers: 14)
Analyst     Full-text available via subscription   (Followers: 40)
Angewandte Chemie     Hybrid Journal   (Followers: 192)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 218)
Annales UMCS, Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 4)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 8)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 15)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antiviral Chemistry and Chemotherapy     Hybrid Journal  
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7)
Applied Spectroscopy     Full-text available via subscription   (Followers: 23)
Applied Surface Science     Hybrid Journal   (Followers: 28)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 2)
Asian Journal of Biochemistry     Open Access   (Followers: 1)
Atomization and Sprays     Full-text available via subscription   (Followers: 4)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access   (Followers: 1)
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Full-text available via subscription   (Followers: 308)
Biochemistry Insights     Open Access   (Followers: 6)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 9)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 1)
Biomacromolecules     Full-text available via subscription   (Followers: 19)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 5)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 117)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 91)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 2)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 24)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 3)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 10)
Canadian Mineralogist     Full-text available via subscription   (Followers: 4)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 66)
Catalysis for Sustainable Energy     Open Access   (Followers: 7)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 7)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 8)
Cellulose     Hybrid Journal   (Followers: 7)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 1)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 14)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 72)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 24)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 20)
Chemical Reviews     Full-text available via subscription   (Followers: 181)
Chemical Science     Open Access   (Followers: 22)
Chemical Technology     Open Access   (Followers: 16)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemical Week     Full-text available via subscription   (Followers: 8)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 58)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 26)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 6)
Chemistry & Biology     Full-text available via subscription   (Followers: 30)
Chemistry & Industry     Hybrid Journal   (Followers: 5)
Chemistry - A European Journal     Hybrid Journal   (Followers: 147)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 15)
Chemistry and Materials Research     Open Access   (Followers: 20)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Hybrid Journal   (Followers: 2)
Chemistry Letters     Full-text available via subscription   (Followers: 44)
Chemistry of Materials     Full-text available via subscription   (Followers: 250)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry World     Full-text available via subscription   (Followers: 22)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 2)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 4)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 9)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 10)
Chromatographia     Hybrid Journal   (Followers: 24)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Cogent Chemistry     Open Access  
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 10)
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 7)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 18)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 2)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 9)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 3)
Copernican Letters     Open Access   (Followers: 1)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 5)
Crystal Structure Theory and Applications     Open Access   (Followers: 4)
CrystEngComm     Full-text available via subscription   (Followers: 13)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Metabolomics     Hybrid Journal   (Followers: 5)
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Opinion in Molecular Therapeutics     Full-text available via subscription   (Followers: 17)
Current Research in Chemistry     Open Access   (Followers: 8)
Current Science     Open Access   (Followers: 61)
Dalton Transactions     Full-text available via subscription   (Followers: 23)
Detection     Open Access   (Followers: 2)
Developments in Geochemistry     Full-text available via subscription   (Followers: 2)
Diamond and Related Materials     Hybrid Journal   (Followers: 12)
Dislocations in Solids     Full-text available via subscription  
Doklady Chemistry     Hybrid Journal  
Drying Technology: An International Journal     Hybrid Journal   (Followers: 4)
Eclética Química     Open Access   (Followers: 1)
Ecological Chemistry and Engineering S     Open Access   (Followers: 3)
Ecotoxicology and Environmental Contamination     Open Access  
Educación Química     Open Access   (Followers: 1)
Education for Chemical Engineers     Hybrid Journal   (Followers: 5)
EJNMMI Radiopharmacy and Chemistry     Open Access  
Elements     Full-text available via subscription   (Followers: 3)
Environmental Chemistry     Hybrid Journal   (Followers: 7)
Environmental Chemistry Letters     Hybrid Journal   (Followers: 4)
Environmental Science & Technology Letters     Full-text available via subscription   (Followers: 5)

        1 2 3 | Last

Journal Cover Advanced Functional Materials
  [SJR: 5.21]   [H-I: 203]   [51 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1616-301X - ISSN (Online) 1616-3028
   Published by John Wiley and Sons Homepage  [1579 journals]
  • A Unique Disintegration–Reassembly Route to Mesoporous Titania
           Nanocrystalline Hollow Spheres with Enhanced Photocatalytic Activity
    • Authors: Xin Wang; Licheng Bai, Hongyan Liu, Xuefeng Yu, Yadong Yin, Chuanbo Gao
      Abstract: A novel disintegration–reassembly route is reported for the synthesis of mesoporous TiO2 nanocrystalline hollow spheres with controlled crystallinity and enhanced photocatalytic activity. In this unique synthesis strategy, it is demonstrated that sol–gel-derived mesoporous TiO2 colloidal spheres can be disintegrated into discrete small nanoparticles that are uniformly embedded in the polymer (polystyrene, PS) matrix by surface-induced photocatalytic polymerization. Subsequent reassembly of these TiO2 nanoparticles can be induced by an annealing process after further coating of a resorcinol–formaldehyde (RF) resin, which forms self-supported hollow spheres of TiO2 at the PS/RF interface. The abundant phenolic groups on the RF resin serve as anchoring sites for the TiO2 nanoparticles, thus enable the reassembly of the TiO2 nanoparticles and prevent their sintering during the thermal crystallization process. This unique disintegration–reassembly process leads to the formation of self-supported TiO2 hollow spheres with relatively large surface area, high crystallinity, and superior photocatalytic activity in dye degradation under UV light irradiation.A novel disintegration–reassembly route is devised to synthesize mesoporous titania nanocrystalline shells starting from titania spheres. The resulting titania hollow spheres show high crystallinity, small grain size, and large surface area, which account for their superior photocatalytic activity in dye degradation under UV light irradiation, benchmarking against commercial P25.
      PubDate: 2017-11-17T09:20:48.848476-05:
      DOI: 10.1002/adfm.201704208
       
  • Tailoring Hybrid Layered Double Hydroxides for the Development of
           Innovative Applications
    • Authors: Christine Taviot-Guého; Vanessa Prévot, Claude Forano, Guillaume Renaudin, Christine Mousty, Fabrice Leroux
      Abstract: Hybrid materials based on layered double hydroxides (LDHs) exhibit great potential in diverse fields such as health care, polymer composites, environment, catalysis, and energy generation. Indeed, the compositional flexibility and the scalability of LDH structures, their low cost, and their ease of synthesis have made hybrid LDHs extremely attractive for constructing smart and high-performance multifunctional materials. This review provides a comprehensive and critical overview of the current research on multifunctional hybrid LDHs. Organic–inorganic hybrid LDHs, intercalated and surface-immobilized structures, are both specifically addressed. The new trends and strategies for hybrid LDH synthesis are first described, and then the potential of the latest hybrid LDHs, polymer LDH nanocomposites, and LDH bio-nanocomposites are presented. Significant achievements published from ≈2010, including authors' results, which employ hybrid LDH assemblies in materials science, medicine, polymer nanocomposites, cement chemistry, and environmental technologies, are specifically addressed. It is concluded with remarks on present challenges and future prospects.The concept of multifunctionality has exploded in materials science during the last decade, and this trend also applies to hybrid layered double hydroxides (LDHs). In this Feature Article, after a survey of the diverse approaches to hybrid LDH synthesis, significant achievements based on the use of hybrid LDH assemblies in materials science, medicine, polymer nanocomposites, cement chemistry, and environmental technologies are specifically addressed.
      PubDate: 2017-11-17T09:16:37.97248-05:0
      DOI: 10.1002/adfm.201703868
       
  • Surfactant-Free β-Galactosidase Micromotors for
           “On-The-Move” Lactose Hydrolysis
    • Authors: Roberto Maria-Hormigos; Beatriz Jurado-Sánchez, Alberto Escarpa
      Abstract: Surfactant-free β-galactosidase micromotors are explored here as moving biocatalyst for highly efficient lactose hydrolysis from raw milk. The coupling of the hydrolytic properties of such enzyme with the efficient movement of carbon nanotube tubular micromotors results in nearly 100% lactose hydrolysis and two fold removal efficiency as compared with static conditions and with free enzyme. The incorporation of an inner Ni layer allows its reusability to operate in batch mode. The rough micromotor surface area allows the immobilization of a high loading of β-galactosidase and results in an increase in the enzyme affinity toward lactose. The new micromotor concept opens new avenues for the use of micromotors as moving immobilized biocatalyst to improve the technological process not only in food industry but also in other fields.β-galactosidase functionalized micromotors are used as moving microcatalysts for highly efficient lactose hydrolysis. Dynamic micromotor movement results in quantitative lactose removal in 25 min. The incorporation of an inner Ni layer allows for its reusability to operate in batch mode. The concept opens new avenues for the use of micromotors to improve the biotechnological process in the alimentary industry.
      PubDate: 2017-11-17T09:15:42.274539-05:
      DOI: 10.1002/adfm.201704256
       
  • The Meeting Point of Carbonaceous Materials and Clays: Toward a New
           Generation of Functional Composites
    • Authors: Margarita Darder; Pilar Aranda, Cristina Ruiz-García, Francisco M. Fernandes, Eduardo Ruiz-Hitzky
      Abstract: Carbon and clays are worldwide-spread natural resources known and used for centuries by humans. In spite of their differences, both have been combined to produce diverse types of functional materials, from conventional pencil cores to advanced hybrid composites. The presence of highly conductive graphene and/or carbon nanotubes allows for their use in applications ranging from elements of electrochemical devices to additives for polymer nanocomposites, pollution adsorbents, or active catalysts. Both top-down and bottom-up strategies can be applied to conveniently assemble carbon and clay counterparts. Moreover, such synthetic strategies can be tailored to produce adequate nanostructured materials and/or associate other species. This critical review presents the latest advances on this topic, addressing aspects related to the possibility to produce hybrid materials based on their functionalization capacity.Carbon and clays are abundant natural resources that can be combined to produce functional materials from conventional pencil cores to advanced hybrid composites. Top-down and bottom-up strategies are suitable to conveniently assemble carbon and clay counterparts, whose functionalization capacity can be exploited to produce tailored hybrid materials for applications in energy, environmental remediation, nanocomposites, and catalysis.
      PubDate: 2017-11-17T09:11:25.061075-05:
      DOI: 10.1002/adfm.201704323
       
  • Ultra-Broadband Wide-Angle Terahertz Absorption Properties of 3D Graphene
           Foam
    • Authors: Zhiyu Huang; Honghui Chen, Yi Huang, Zhen Ge, Ying Zhou, Yang Yang, Peishuang Xiao, Jiajie Liang, Tengfei Zhang, Qian Shi, Guanghao Li, Yongsheng Chen
      Abstract: As a next generation of detection technology, terahertz technology is very promising. In this work, a highly efficient terahertz wave absorber based on 3D graphene foam (3DG) is first reported. Excellent terahertz absorption property at frequency ranging from 0.1 to 1.2 THz is obtained owing to faint surface reflection and enormous internal absorption. By precise control of the constant properties for 3DG, the reflection loss (RL) value of 19 dB is acquired and the qualified frequency bandwidth (with RL value over 10 dB) covers 95% of the entire measured bandwidth at normal incidence, which far surpasses most reported materials. More importantly, the terahertz absorption performance of 3DG enhances obviously with increasing the incidence while majority of materials become invalid at oblique incidence, instead. At the incidence of 45°, the maximum RL value increases 50% from 19 to 28.6 dB and the qualified frequency bandwidth covers 100% of the measured bandwidth. After considering all core indicators involving density, qualified bandwidth, and RL values, the specific average terahertz absorption (SATA) property is investigated. The SATA value of 3DG is over 3000 times higher than those of other materials in open literatures.The absorption performance of 3D graphene foam (3DG) is measured in the terahertz time-domain spectroscopy. The porous structure reduces surface reflection and the incident radiation quickly attenuates. Therefore, 3DG possesses the high reflection loss of −19 dB at 0.88 THz at normal incidence and −28.6 dB at 0.64 THz at oblique incidence and the qualified frequency bandwidth covers 100% of the measured bandwidth.
      PubDate: 2017-11-16T07:59:03.771848-05:
      DOI: 10.1002/adfm.201704363
       
  • Dynamically Gas-Phase Switchable Super(de)wetting States by Reversible
           Amphiphilic Functionalization: A Powerful Approach for Smart Fluid Gating
           Membranes
    • Authors: William S. Y. Wong; Thomas Gengenbach, Hieu T. Nguyen, Xiang Gao, Vincent S. J. Craig, Antonio Tricoli
      Abstract: In nature, cellular membranes perform critical functions such as endocytosis and exocytosis through smart fluid gating processes mediated by nonspecific amphiphilic interactions. Despite considerable progress, artificial fluid gating membranes still rely on laborious stimuli-responsive mechanisms and triggering systems. In this study, a room temperature gas-phase approach is presented for dynamically switching a porous material from a superhydrophobic to a superhydrophilic wetting state and back. This is realized by the reversible attachment of bipolar amphiphiles, which promote surface wetting. Application of this reversible amphiphilic functionalization to an impermeable nanofibrous membrane induces a temporary state of superhydrophilicity resulting in its pressure-less permeation. This mechanism allows for rapid smart fluid gating processes that can be triggered at room temperature by variations in the environment of the membrane. Owing to the universal adsorption of volatile amphiphiles on surfaces, this approach is applicable to a broad range of materials and geometries enabling facile fabrication of valve-less flow systems, fluid-erasable microfluidic arrays, and sophisticated microfluidic designs.Inspired by the spontaneous self-­assembly of simple amphiphilic hydro­carbons, a reversible amphiphilic functionalization concept for porous hierarchical material is presented. The gas-phase tuning of wettability for membranes is demonstrated, achieving cycles of superhydrophilicity and near-superhydrophobicity. Potential of the concept is showcased through valve-less fluid-gating and erasable microfluidic templates.
      PubDate: 2017-11-16T07:52:17.511107-05:
      DOI: 10.1002/adfm.201704423
       
  • Conductive Nanocrystalline Niobium Carbide as High-Efficiency Polysulfides
           Tamer for Lithium-Sulfur Batteries
    • Authors: Wenlong Cai; Gaoran Li, Kailong Zhang, Guannan Xiao, Can Wang, Kefen Ye, Zhongwei Chen, Yongchun Zhu, Yitai Qian
      Abstract: Rational design of functional interlayer is highly significant in pursuit of high-performance Li-S batteries. Herein, a nanocrystalline niobium carbide (NbC) is developed via a facile and scalable autoclave technology, which is, for the first time, employed as the advanced interlayer material for Li-S batteries. Combining the merits of strong polysulfides (PS) anchoring with high electric conductivity, the NbC-coated membrane enables efficiently tamed PS shuttling and fast sulfur electrochemistry, achieving outstanding cyclability with negligible capacity fading rate of 0.037% cycle−1 over 1500 cycles, superb rate capability up to 5 C, high areal capacity of 3.6 mA h cm−2 under raised sulfur loading, and reliable operation even in soft-package cells. This work offers a facile and effective method of promoting Li-S batteries for practical application.Nanocrystalline niobium carbide (NbC), combining the merits of strong polysulfides anchoring with high electric conductivity, is prepared via scalable autoclave technology. The application of a NbC-coated membrane enables prolonged lifespan and excellent rate capability for both thin and thick cathodes in coin cells, and reliable operation even in soft-package cells.
      PubDate: 2017-11-16T07:51:26.654219-05:
      DOI: 10.1002/adfm.201704865
       
  • Bioinspired Nanocomposites: Fatigue-Resistant Bioinspired Graphene-Based
           Nanocomposites (Adv. Funct. Mater. 43/2017)
    • Authors: Sijie Wan; Qunfeng Cheng
      Abstract: Natural nacre provides an inspiration for constructing fatigue-resistant graphene-based nanocomposites through interfacial interactions crosslinking and building blocks toughening, which could impede the crack growth through crack deflection, crack bridging, and plastic deformation. The resultant graphene-based nanocomposites, reviewed by Qunfeng Cheng and co-workers in article number 1703459, exhibit superior fatigue resistance and excellent electrical conductivity, showing a great potential for applications in flexible electronic devices.
      PubDate: 2017-11-15T08:04:54.614237-05:
      DOI: 10.1002/adfm.201770259
       
  • Contents: (Adv. Funct. Mater. 43/2017)
    • PubDate: 2017-11-15T08:04:54.486003-05:
      DOI: 10.1002/adfm.201770256
       
  • Porous Materials: Direct Laser Writing of Low-Density Interdigitated Foams
           for Plasma Drive Shaping (Adv. Funct. Mater. 43/2017)
    • Authors: James S. Oakdale; Raymond F. Smith, Jean-Baptiste Forien, William L. Smith, Suzanne J. Ali, Leonardus B. Bayu Aji, Trevor M. Willey, Jianchao Ye, Anthony W. van Buuren, Matthew A. Worthington, Shon T. Prisbrey, Hye-Sook Park, Peter A. Amendt, Theodore F. Baumann, Juergen Biener
      Abstract: James S. Oakdale, Juergen Biener, and co-workers report 3D-printing of low density foams with submicrometer features in article number 1702425. The foam is successfully applied in plasma drive shaping: A plasma shock wave travels through the foam before impinging upon and ramp compressing an aluminum sample to pressures of over 50 GPa. The 3D printed foam helps to smoothen and shape the plasma piston drive, thereby ensuring uniform compression.
      PubDate: 2017-11-15T08:04:54.095835-05:
      DOI: 10.1002/adfm.201770257
       
  • Masthead: (Adv. Funct. Mater. 43/2017)
    • PubDate: 2017-11-15T08:04:53.255015-05:
      DOI: 10.1002/adfm.201770255
       
  • Memory Devices: Low-Power Nonvolatile Charge Storage Memory Based on MoS2
           and an Ultrathin Polymer Tunneling Dielectric (Adv. Funct. Mater. 43/2017)
           
    • Authors: Myung Hun Woo; Byung Chul Jang, Junhwan Choi, Khang June Lee, Gwang Hyuk Shin, Hyejeong Seong, Sung Gap Im, Sung-Yool Choi
      Abstract: In article number 1703545, Sung-Yool Choi and co-workers describe MoS2-based low-power nonvolatile charge storage memory devices with a poly(1,3,5-trimethyl-1,3,5-trivinyl cyclotrisiloxane) (pV3D3) tunneling dielectric layer formed via a solvent-free initiated chemical vapor deposition (iCVD) process. The developed memory devices show excellent retention times (above 10 years), and a stable cycling endurance of more than 103 cycles at low operating voltage.
      PubDate: 2017-11-15T08:04:52.764057-05:
      DOI: 10.1002/adfm.201770254
       
  • Particles: Laser-Induced In-Fiber Fluid Dynamical Instabilities for
           Precise and Scalable Fabrication of Spherical Particles (Adv. Funct.
           Mater. 43/2017)
    • Authors: Jing Zhang; Kaiwei Li, Ting Zhang, Pio John S. Buenconsejo, Ming Chen, Zhe Wang, Mengying Zhang, Zhixun Wang, Lei Wei
      Abstract: A scalable and precisely controllable in-fiber fabrication method, described by Lei Wei and co-workers in article number 1703245, produces uniformly-sized, high-quality, and globally ordered spherical particles in a full spectrum of diameters from micro- to nano-scale. Harnessing a fluid instability phenomenon in fiber drawing achieves spherical particles from a variety of materials with disparate optical, electronic, and thermoelectric properties.
      PubDate: 2017-11-15T08:04:49.522381-05:
      DOI: 10.1002/adfm.201770258
       
  • Self-Established Rapid Magnesiation/De-Magnesiation Pathways in Binary
           Selenium–Copper Mixtures with Significantly Enhanced Mg-Ion Storage
           Reversibility
    • Authors: Zhonghua Zhang; Bingbing Chen, Huimin Xu, Zili Cui, Shanmu Dong, Aobing Du, Jun Ma, Qingfu Wang, Xinhong Zhou, Guanglei Cui
      Abstract: Rechargeable magnesium/sulfur (Mg/S) and magnesium/selenium (Mg/Se) batteries are characterized by high energy density, inherent safety, and economical effectiveness, and therefore, are of great scientific and technological interest. However, elusive challenges, including the limited charge storage capacity, low Coulombic efficiency, and short cycle life, have been encountered due to the sluggish electrochemical kinetics and severe shuttles of ploysulfides (polyselenide). Taking selenium as model paradigm, a new and reliable Mg-Se chemistry is proposed through designing binary selenium-copper (Se-Cu) cathodes. An intriguing effect of Cu powders on the electrochemical reaction pathways of the active Se microparticles is revealed in a way of forming Cu3Se2 intermediates, which induces an unconventional yet reversible two-stage magnesiation mechanism: Mg-ions first insert into Cu3Se2 phases; in a second step Cu-ions in the Mg2xCu3Se2 lattice exchange with Mg-ions. As expected, binary Se-Cu electrodes show significantly improved reversibility and elongated cycle life. More bracingly, Se/C nanostructures fabricated by facile blade coating Se nanorodes onto copper foils exhibit high output power and capacity (696.0 mAh g−1 at 67.9 mA g−1), which outperforms all previously reported Mg/Se batteries. This work envisions a facile and reliable strategy to achieve better reversibility and long-term durability of selenium (sulfur) electrodes.Binary microsized Se-Cu electrodes show an unconventional yet reversible process occurring in a way of two-stage magnesiation mechanism: one step is the Mg-ions inserting into the Cu3Se2 phases; in the second step Cu-ions in the Mg2xCu3Se2 lattice exchange with Mg-ions forming the final products of MgSe nanoparticles and metallic Cu nanowires, resulting in excellent Mg-ion storage properties.
      PubDate: 2017-11-14T02:27:10.394463-05:
      DOI: 10.1002/adfm.201701718
       
  • Wearable, Healable, and Adhesive Epidermal Sensors Assembled from
           Mussel-Inspired Conductive Hybrid Hydrogel Framework
    • Authors: Meihong Liao; Pengbo Wan, Jiangru Wen, Min Gong, Xiaoxuan Wu, Yonggang Wang, Rui Shi, Liqun Zhang
      Abstract: Healable, adhesive, wearable, and soft human-motion sensors for ultrasensitive human–machine interaction and healthcare monitoring are successfully assembled from conductive and human-friendly hybrid hydrogels with reliable self-healing capability and robust self-adhesiveness. The conductive, healable, and self-adhesive hybrid network hydrogels are prepared from the delicate conformal coating of conductive functionalized single-wall carbon nanotube (FSWCNT) networks by dynamic supramolecular cross-linking among FSWCNT, biocompatible polyvinyl alcohol, and polydopamine. They exhibit fast self-healing ability (within 2 s), high self-healing efficiency (99%), and robust adhesiveness, and can be assembled as healable, adhesive, and soft human-motion sensors with tunable conducting channels of pores for ions and framework for electrons for real time and accurate detection of both large-scale and tiny human activities (including bending and relaxing of fingers, walking, chewing, and pulse). Furthermore, the soft human-motion sensors can be enabled to wirelessly monitor the human activities by coupling to a wireless transmitter. Additionally, the in vitro cytotoxicity results suggest that the hydrogels show no cytotoxicity and can facilitate cell attachment and proliferation. Thus, the healable, adhesive, wearable, and soft human-motion sensors have promising potential in various wearable, wireless, and soft electronics for human–machine interfaces, human activity monitoring, personal healthcare diagnosis, and therapy.Flexible, wearable, healable, and adhesive soft strain sensors are successfully developed from a conductive and biocompatible hybrid hydrogel framework for ultrasensitive human–machine interaction and healthcare monitoring. They exhibit fast self-healing ability (within 2 s), highly self-healing efficiency (99%), robust self-adhesiveness, and a tunable conducting framework for real-time, wireless, and accurate detection in human–machine interfaces, human activity monitoring, personal healthcare diagnosis, and therapy.
      PubDate: 2017-11-14T02:26:33.272447-05:
      DOI: 10.1002/adfm.201703852
       
  • High-Performance Triboelectric Nanogenerators Based on Electrospun
           Polyvinylidene Fluoride–Silver Nanowire Composite Nanofibers
    • Authors: Siuk Cheon; Hyungseok Kang, Han Kim, Youngin Son, Jun Young Lee, Hyeon-Jin Shin, Sang-Woo Kim, Jeong Ho Cho
      Abstract: The preparation of ferroelectric polymer–metallic nanowire composite nanofiber triboelectric layers is described for use in high-performance triboelectric nanogenerators (TENGs). The electrospun polyvinylidene fluoride (PVDF)–silver nanowire (AgNW) composite and nylon nanofibers are utilized in the TENGs as the top and bottom triboelectric layers, respectively. The electrospinning process facilitates uniaxial stretching of the polymer chains, which enhances the formation of the highly oriented crystalline β-phase that forms the most polar crystalline phase of PVDF. The addition of AgNWs further promotes the β-phase crystal formation by introducing electrostatic interactions between the surface charges of the nanowires and the dipoles of the PVDF chains. The extent of β-phase formation and the resulting variations in the surface charge potential upon the addition of nanowires are systematically analyzed using X-ray diffraction (XRD) and Kelvin probe force microscopy techniques. The ability of trapping the induced tribocharges increases upon the addition of nanowires to the PVDF matrix. The enhanced surface charge potential and the charge trapping capabilities of the PVDF–AgNW composite nanofibers significantly enhance the TENG output performances. Finally, the mechanical stability of the electrospun nanofibers is dramatically enhanced while maintaining the TENG performances by applying thermal welding near the melting temperature of PVDF.High-performance triboelectric nanogenerators (TENG) are successfully demonstrated using electrospun polyvinylidene fluoride (PVDF)–silver nanowire (AgNW) composite nanofibers. It is found that an electrospinning process and the addition of AgNWs to the PVDF promote the effective formation of the polar crystalline β-phase. The enhanced surface charge potential and charge trapping properties of the PVDF–AgNW composite nanofibers significantly enhance the TENG performances.
      PubDate: 2017-11-14T02:25:53.715364-05:
      DOI: 10.1002/adfm.201703778
       
  • Electromagnetic Shielding Hybrid Nanogenerator for Health Monitoring and
           Protection
    • Authors: Qian Zhang; Qijie Liang, Zheng Zhang, Zhuo Kang, Qingliang Liao, Yi Ding, Mingyuan Ma, Fangfang Gao, Xuan Zhao, Yue Zhang
      Abstract: Nowadays, mankind faces increasingly energy crisis and electromagnetic radiation pollution. An energy harvester with function of protecting human health from electromagnetic radiation is a desirable solution to this problem. Here, a stretchable electromagnetic shielding hybrid nanogenerator (ES-HNG) is reported which can not only scavenge thermal and mechanical energy from living environment but also protect and monitor human health. The ES-HNG is capable of transforming mechanical and thermal energy to electricity based on triboelectric, piezoelectric, and pyroelectric effects. To be devised as a computer keyboard cover, ES-HNG takes about 200 s to charge a capacitor to 3 V by typing. The stored energy can drive the portable devices successfully. Besides, the ES-HNG eliminates electromagnetic radiation of computer completely due to its unique electromagnetic shielding property. A large range of electromagnetic wave (frequency is between 0 and 1.5 GHz) is shielded more than 99.9978% by the ES-HNG. Moreover, the ES-HNG is able to monitor human health by attaching it on human abdomen to be a self-powered sensor. This work opens up a new prospect of harvesting energy effectively as well as protecting/monitoring human health from electromagnetic radiation surroundings.An electromagnetic shielding hybrid nanogenerator (ES-HNG) is fabricated by integrating triboelectric nanogenerator and pyroelectric-piezoelectric nanogenerators. The ES-HNG is capable of harvesting thermal and mechanical energies from ambient environment, monitoring, and protecting human health from electromagnetic radiation.
      PubDate: 2017-11-13T06:17:24.27385-05:0
      DOI: 10.1002/adfm.201703801
       
  • Flexible Graphene Solution-Gated Field-Effect Transistors: Efficient
           Transducers for Micro-Electrocorticography
    • Authors: Clement Hébert; Eduard Masvidal-Codina, Alejandro Suarez-Perez, Andrea Bonaccini Calia, Gaelle Piret, Ramon Garcia-Cortadella, Xavi Illa, Elena Del Corro Garcia, Jose M. De la Cruz Sanchez, Damia Viana Casals, Elisabet Prats-Alfonso, Jessica Bousquet, Philippe Godignon, Blaise Yvert, Rosa Villa, Maria V. Sanchez-Vives, Anton Guimerà-Brunet, Jose A. Garrido
      Abstract: Brain–computer interfaces and neural prostheses based on the detection of electrocorticography (ECoG) signals are rapidly growing fields of research. Several technologies are currently competing to be the first to reach the market; however, none of them fulfill yet all the requirements of the ideal interface with neurons. Thanks to its biocompatibility, low dimensionality, mechanical flexibility, and electronic properties, graphene is one of the most promising material candidates for neural interfacing. After discussing the operation of graphene solution-gated field-effect transistors (SGFET) and characterizing their performance in saline solution, it is reported here that this technology is suitable for μ-ECoG recordings through studies of spontaneous slow-wave activity, sensory-evoked responses on the visual and auditory cortices, and synchronous activity in a rat model of epilepsy. An in-depth comparison of the signal-to-noise ratio of graphene SGFETs with that of platinum black electrodes confirms that graphene SGFET technology is approaching the performance of state-of-the art neural technologies.Flexible graphene solution-gated field-effect transistors are proposed as a new advanced technology for neural recordings thanks to the outstanding properties of single-layer graphene. In this paper, the key concepts of this technology are discussed and its perfect suitability for μ-ECoG applications is shown by demonstrating the recording of sensory-evoked potential as well as synchronous activity.
      PubDate: 2017-11-13T06:16:52.972237-05:
      DOI: 10.1002/adfm.201703976
       
  • High-Efficient Clearable Nanoparticles for Multi-Modal Imaging and
           Image-Guided Cancer Therapy
    • Authors: Qiaolin Wei; Yao Chen, Xibo Ma, Jianfeng Ji, Yue Qiao, Bo Zhou, Fei Ma, Daishun Ling, Hong Zhang, Mei Tian, Jie Tian, Min Zhou
      Abstract: Renal-clearable nanoparticles have made it possible to overcome the toxicity by nonspecific accumulation in healthy tissues/organs due to their highly efficient clearance characteristics. However, their tumor uptake is relatively low due to the short blood circulation time and rapid body elimination. Here, this problem is addressed by developing renal-clearable nanoparticles by controlled coating of sub-6 nm CuS nanodots (CuSNDs) on doxorubicin ladened mesoporous silica nanoparticles (pore size ≈6 nm) for multimodal application. High tumor uptake of the as-synthesized nanoparticles (abbreviated as MDNs) is achieved due to the longer blood circulation time. The MDNs also show excellent performance in bimodal imaging. Moreover, the MDNs demonstrated a photothermally sensitive drug release and pronounced synergetic effects of chemo-photothermal therapy, which were confirmed by two different tumor models in vivo. A novel key feature of the proposed synthesis is the use of renal-clearable CuSNDs and biodegradable mesoporous silica nanoparticles which also are renal-clearable after degradation. Therefore, the MDNs would be rapidly degraded and excreted in a reasonable period in living body and avoid long-term toxicity. Such biodegradable and clearable single-compartment theranostic agents applicable in highly integrated multimodal imaging and multiple therapeutic functions may have substantial potentials in clinical practice.Highly efficient clearable theranostic ultrasmall CuS nanodots@mesoporous silica nanoparticles with high tumor uptake are synthesized, and demonstrated to be capable for positron emission tomography/photoacoustic bimodal imaging, imaging-guided effective combined chemo-photothermal therapy, and high-efficient body clearance.
      PubDate: 2017-11-10T10:23:15.40645-05:0
      DOI: 10.1002/adfm.201704634
       
  • A Multifunctional Polymeric Periodontal Membrane with Osteogenic and
           Antibacterial Characteristics
    • Authors: Amir Nasajpour; Sahar Ansari, Chiara Rinoldi, Afsaneh Shahrokhi Rad, Tara Aghaloo, Su Ryon Shin, Yogendra Kumar Mishra, Rainer Adelung, Wojciech Swieszkowski, Nasim Annabi, Ali Khademhosseini, Alireza Moshaverinia, Ali Tamayol
      Abstract: Periodontitis is a prevalent chronic, destructive inflammatory disease affecting tooth-supporting tissues in humans. Guided tissue regeneration strategies are widely utilized for periodontal tissue regeneration generally by using a periodontal membrane. The main role of these membranes is to establish a mechanical barrier that prevents the apical migration of the gingival epithelium and hence allowing the growth of periodontal ligament and bone tissue to selectively repopulate the root surface. Currently available membranes have limited bioactivity and regeneration potential. To address such challenges, an osteoconductive, antibacterial, and flexible poly(caprolactone) (PCL) composite membrane containing zinc oxide (ZnO) nanoparticles is developed. The membranes are fabricated through electrospinning of PCL and ZnO particles. The physical properties, mechanical characteristics, and in vitro degradation of the engineered membrane are studied in detail. Also, the osteoconductivity and antibacterial properties of the developed membrane are analyzed in vitro. Moreover, the functionality of the membrane is evaluated with a rat periodontal defect model. The results confirmed that the engineered membrane exerts both osteoconductive and antibacterial properties, demonstrating its great potential for periodontal tissue engineering.An osteoconductive, antibacterial, and flexible poly(caprolactone) composite membrane containing zinc oxide (ZnO) nanoparticles is developed through electrospinning for periodontal tissue engineering. The osteoconductivity and antibacterial properties of the developed membrane are analyzed in vitro. Moreover, the functionality of the membrane is evaluated with a rat periodontal defect model.
      PubDate: 2017-11-10T02:00:02.805138-05:
      DOI: 10.1002/adfm.201703437
       
  • Multifunctional AIEgens: Ready Synthesis, Tunable Emission,
           Mechanochromism, Mitochondrial, and Bacterial Imaging
    • Authors: Meijuan Jiang; Xinggui Gu, Ryan T. K. Kwok, Ying Li, Herman H. Y. Sung, Xiaoyan Zheng, Yilin Zhang, Jacky W. Y. Lam, Ian D. Williams, Xuhui Huang, Kam Sing Wong, Ben Zhong Tang
      Abstract: Luminogens with aggregation-induced emission characteristics (AIEgens) are intriguing due to its rapid expansion in various high-tech applications. However, there is still in high demand on the development of novel AIEgens with easy preparation and functionalization, stable structures, tunable emissions, and high quantum efficiency. In this contribution, three AIEgens based on diphenyl isoquinolinium (IQ) derivatives are reported. They can be facilely synthesized and possess high structural stability, favorable visible light excitation, large Stokes shifts, high quantum yields, tunable colors, and sufficient two-photon absorption of near-infrared light. Importantly, they exhibit multifunctionalities. They exhibit mechanochromic property, making them capable to be applied for rewritable papers. They can also be applied in mitochondrial imaging with high specificity, cell permeability, brightness, biocompatibility, and photostability. They are promising for the applications in evaluation of mitochondrial membrane potential and image-guided cancer cell ablation. Last, they are able to stain bacteria in a wash-free manner. All these intriguing results suggest such readily accessible and multifunctional diphenyl IQ-based AIEgens provide a new platform for construction of advanced materials for practical applications.Based on diphenyl isoquinolinium structure, readily accessible multifunctional AIEgens are developed for mechanochromic materials, mitochondrial, and bacterial imaging probes, providing a new platform for construction of advanced materials for practical applications.
      PubDate: 2017-11-09T12:03:12.886307-05:
      DOI: 10.1002/adfm.201704589
       
  • Thermosensitive, Stretchable, and Piezoelectric Substrate for Generation
           of Myogenic Cell Sheet Fragments from Human Mesenchymal Stem Cells for
           Skeletal Muscle Regeneration
    • Authors: Jeong-Kee Yoon; Mirnmoy Misra, Seung Jung Yu, Han Young Kim, Suk Ho Bhang, Seuk Young Song, Ju-Ro Lee, Seungmi Ryu, Yeon Woong Choo, Gun-Jae Jeong, Sung Pil Kwon, Sung Gap Im, Tae Il Lee, Byung-Soo Kim
      Abstract: In a native muscle microenvironment, electrical and mechanical stimuli exist in the form of action potentials and muscle contraction. Here, a cell culture system is developed that can mimic the in vivo microenvironment and provide these stimuli to cultured cells, and it is tested whether the stimulation can promote myogenic differentiation of human umbilical cord blood mesenchymal stem cells (hUCBMSCs). A thermosensitive, stretchable, and piezoelectric substrate (TSPS) is fabricated by polydimethylsiloxane spin-coating of aligned ZnO nanorods and subsequent poly(N-isopropylacrylamide) grafting on the polydimethylsiloxane surface. Pulsatile mechanoelectrical cues are provided to hUCBMSCs cultured on the TSPS by subjecting the TSPS to cyclic stretching and bending, resulting in significant promotion of myogenic differentiation of hUCBMSCs as well as intracellular signaling related to the differentiation. After differentiation ex vivo, the cells are detached from the TSPS in the form of cell sheet fragments. Injection of the cell sheet fragments of differentiated cells into injured mouse skeletal muscle shows improved cell retention and muscle regeneration as compared to injection of either undifferentiated cells or differentiated dissociated cells. This system may serve as a tool for research on the electrical and mechanical regulation of stem cells and may be used to potentiate stem cell therapies.Thermosensitive, stretchable, and piezoelectric substrates can mimic the skeletal muscle microenvironment by providing pulsatile mechanoelectric cues to human umbilical cord blood mesenchymal stem cells (hUCBMSCs). Electrical and mechanical stimulations induce skeletal muscle differentiation of hUCBMSCs, and the differentiated cell sheet fragments are a good source of cell therapy to treat skeletal muscle diseases.
      PubDate: 2017-11-09T01:12:13.859563-05:
      DOI: 10.1002/adfm.201703853
       
  • Hydrogen Bonding Directed Colloidal Self-Assembly of Nanoparticles into 2D
           Crystals, Capsids, and Supracolloidal Assemblies
    • Authors: Nonappa; Olli Ikkala
      Abstract: Self-assembly of colloidal building blocks, like metal nanoparticles, is a rapidly progressing research area toward new functional materials. However, in-depth control of the colloidal self-assembly and especially hierarchical self-assembly is difficult due to challenges in controlling the size dispersities, shape/morphology, directionalities, and aggregation tendencies. Using either polydispersed or narrow-size dispersed nanoparticles, considerable progress has been achieved over the past few years. However, absolutely monodisperse nanoparticles could allow new options for rational designs of self-assemblies. Therein, atomically precise monolayer protected nanoclusters (d < 3 nm) have recently been synthesized with well-defined metal cores and surface ligands. Their dispersion behavior is commonly tuned by surfactant-like ligands. Beyond that, this study deals with approaches based on ligand-driven supramolecular interactions and colloidal monodispersity until atomic precision to tune the colloidal self-assembly and hierarchy from nanoscale to mesoscopic scale. Therein colloidal packing to self-assembled 2D crystals and closed virus capsid-inspired shells provide relevant research goals due to ever increasing potential of 2D materials and encapsulation. This study addresses the hydrogen bonding (H-bonding) directed self-assembly of atomically precise gold and silver nanoparticles and narrow size dispersed cobalt nanoparticles to free-standing 2D colloidal nanosheets, nanowire assemblies, capsid-like colloidal closed shells, as well as higher order structures.Unforeseen colloidal self-assemblies, hierarchies, and related functions are expected upon control of the polydispersity of nanoparticles with atomic precision and by using functional ligands incorporating supramolecular motifs, beyond surfactants. This study describes 2D colloidal crystals, composite bilayers, spherical-, ellipsoidal-, and rod-like capsids with potential applications in, e.g., colloidal encapsulation and as porous supracolloidal materials.
      PubDate: 2017-11-08T08:38:02.208267-05:
      DOI: 10.1002/adfm.201704328
       
  • Functional Defective Metal-Organic Coordinated Network of Mesostructured
           Nanoframes for Enhanced Electrocatalysis
    • Authors: Gamze Yilmaz; Chuan Fu Tan, Minghui Hong, Ghim Wei Ho
      Abstract: Although defects are traditionally perceived as undesired feature, the prevalence of tenacious low-coordinated defects can instead give rise to desirable functionalities. Here, a spontaneous etching of mesostructured crystal, cyanide-bridged cobalt-iron (CN-CoFe) organometallic hybrid into atomically crafted open framework that is populated with erosion-tolerant high surface energy defects is presented. Unprecedently, the distinct mechanistic etching pathway dictated by the mesostructured assembly, bulk defects, and strong intercoordinated cyanide-bridged hybrid mediates not only formation of excess low-coordinated defects but also more importantly stabilizes them against prevailing dissolution and migration issues. Clearly, the heteropolynuclear cyanide bonded inorganic mesostructured clusters sanction the restructuring of a new breed of stable organometallic polymorph with 3D accessible structure enclosed by electrochemical active atomic stepped edges and high index facets. The exceptional electrocatalysis performance supports the assertion that defective mesostructured polymorph offers a new material paradigm to synthetically tailor the elementary building block constituents toward functional materials.A spontaneous etching of mesostructured nanocubes readily transforms cyanide-bridged cobalt-iron (CN-CoFe) organometallic hybrids into atomically crafted nanoframes. The strong intercoordinated cyanide-bridged hybrid facilitates the formation of abundant low-coordinated defects and stabilizes them against dissolution/migration issues. The synthetically tailorable atomic bonding and crystal structure hybrid polymorphs exhibit outstanding electrochemical active and stable structure.
      PubDate: 2017-11-08T08:36:41.636389-05:
      DOI: 10.1002/adfm.201704177
       
  • Photoacoustic Imaging of Embryonic Stem Cell-Derived Cardiomyocytes in
           Living Hearts with Ultrasensitive Semiconducting Polymer Nanoparticles
    • Authors: Xulei Qin; Haodong Chen, Huaxiao Yang, Haodi Wu, Xin Zhao, Huiyuan Wang, Tony Chour, Evgenios Neofytou, Dan Ding, Heike Daldrup-Link, Sarah C. Heilshorn, Kai Li, Joseph C. Wu
      Abstract: Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) have become promising tools to repair injured hearts. To achieve optimal outcomes, advanced molecular imaging methods are essential to accurately track these transplanted cells in the heart. In this study, it is demonstrated for the first time that a class of photoacoustic nanoparticles (PANPs) incorporating semiconducting polymers (SPs) as contrast agents can be used in the photoacoustic imaging (PAI) of transplanted hESC-CMs in living mouse hearts. This is achieved by virtue of two benefits of PANPs. First, strong photoacoustic (PA) signals and specific spectral features of SPs allow PAI to sensitively detect and distinguish a small number of PANP-labeled cells (2000) from background tissues. Second, the PANPs show a high efficiency for hESC-CM labeling without adverse effects on cell structure, function, and gene expression. Assisted by ultrasound imaging, the delivery and engraftment of hESC-CMs in living mouse hearts can be assessed by PANP-based PAI with high spatial resolution (≈100 µm). In summary, this study explores and validates a novel application of SPs as a PA contrast agent to track labeled cells with high sensitivity and accuracy in vivo, highlighting the advantages of integrating PAI and PANPs to advance cardiac regenerative therapies.Ultrasensitive semiconducting polymer nanoparticles (SPNs) for photoacoustic (PA) imaging of transplantation and engraftment of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) are developed. The SPNs have strong and stable PA signals as well as a specific PA spectrum, which facilitate real-time monitoring of delivery and localization of hESC-CMs in mouse hearts for cardiac regenerative therapy.
      PubDate: 2017-11-08T08:26:24.824772-05:
      DOI: 10.1002/adfm.201704939
       
  • Probing the Dynamic Nature of Self-Assembling Cyclic Peptide–Polymer
           Nanotubes in Solution and in Mammalian Cells
    • Authors: Julia Y. Rho; Johannes C. Brendel, Liam R. MacFarlane, Edward D. H. Mansfield, Raoul Peltier, Sarah Rogers, Matthias Hartlieb, Sébastien Perrier
      Abstract: Self-assembling cyclic peptide–polymer nanotubes have emerged as a fascinating supramolecular system, well suited for a diverse range of biomedical applications. Due to their well-defined diameter, tunable peptide anatomy, and ability to disassemble in situ, they have been investigated as promising materials for numerous applications including biosensors, antimicrobials, and drug delivery. Despite this continuous effort, the underlying mechanisms of assembly and disassembly are still not fully understood. In particular, the exchange of units between individual assembled nanotubes has been overlooked so far, despite its knowledge being essential for understanding their behavior in different environments. To investigate the dynamic nature of these systems, cyclic peptide–polymer nanotubes are synthesized, conjugated with complementary dyes, which undergo a Förster resonance energy transfer (FRET) in close proximity. Model conjugates enable to demonstrate not only that their self-assembly is highly dynamic and not kinetically trapped, but also that the self-assembly of the conjugates is strongly influenced by both solvent and concentration. Additionally, the versatility of the FRET system allows studying the dynamic exchange of these systems in mammalian cells in vitro using confocal microscopy, demonstrating the exchange of subunits between assembled nanotubes in the highly complex environment of a cell.Dynamically exchanging supramolecular polymers observe via FRET. Self-assembling cyclic peptide–polymer nanotubes are widely studied for their biological applications, and show dynamic behavior in a range of different environments proven by FRET; mixing takes place not only in various solvents, but also in the complex environment within a cells.
      PubDate: 2017-11-07T11:42:00.157114-05:
      DOI: 10.1002/adfm.201704569
       
  • Highly Condensed Boron Cage Cluster Anions in 2D Carrier and Its Enhanced
           Antitumor Efficiency for Boron Neutron Capture Therapy
    • Authors: Goeun Choi; Ie-Rang Jeon, Huiyan Piao, Jin-Ho Choy
      Abstract: An attempt is made to apply layered double hydroxide (LDH) as a boron delivery carrier for boron neutron capture therapy (BNCT), which needs a sufficient amount of boron in tumor cells for its successful administration. To meet this requirement, a nanohybrid (BSH-LDH), mercaptoundecahydro-closo-dodecaborate (BSH) anionic molecules in LDH, is developed as a boron delivery system. The cellular boron content upon permeation of BSH-LDH nanoparticles (42.4 µg 10B 10−6 cells) in U87 glioblastoma cell line is found to be ≈2000 times larger than the minimum boron requirement (≈0.02 µg 10B 10−6 cells) for BNCT and also orders of magnitude higher than the previous results (0.2–1.5 µg 10B 10−6 cells) by those applied with other targeting strategies, and eventually results in excellent neutron capture efficiency even under such low dose (30 µg 10B mL−1) and weak irradiation (1 × 1012 n cm−2 corresponding to 20 min) condition. According to the biodistribution studies in xenograft mice model, the tumor-to-blood ratio of BSH in the BSH-LDH-treated-group is found to be 4.4-fold higher than that in the intact BSH treated one in 2 h after drug treatment. The present BNCT combined with boron delivery system provides a promising integrative therapeutic platform for cancer treatment.Developing a novel boron neutron capture therapy-drug delivery system based on the mercaptoundecahydro-closo-dodecaborate-layered double hydroxide nanohybrid system is quite successful, which greatly enhance the boron delivery to cancer cells, and thereby resulting in effective cell destruction even after irradiation of such a low neutron flux (1 × 1012 n cm−2). This result can eventually be very helpful in the radiation administration for cancer patients.
      PubDate: 2017-11-07T11:41:34.903764-05:
      DOI: 10.1002/adfm.201704470
       
  • Construction of a Biomimetic Magnetosome and Its Application as a SiRNA
           Carrier for High-Performance Anticancer Therapy
    • Authors: Fan Zhang; Longjian Zhao, Shumin Wang, Jun Yang, Guihong Lu, Nana Luo, Xiaoyong Gao, Guanghui Ma, Hai-Yan Xie, Wei Wei
      Abstract: Precisely delivering siRNA to its target site in cancer cells is a high-demanding but challenging task. Herein, a biomimetic magnetosome is developed using magnetic nanocluster (MNC) as the core and Arg–Gly–Asp (RGD) decorated macrophage membrane as the cloak, which is achieved via a combination of MNC synthesis, azide-membrane engineering, electrical assembly, and click chemistry. Such a feature-packed magnetosome enables us to gain the success of high-performance siRNA delivery through superior stealth effect, magnetic resonance imaging, magnetic accumulation, RGD targeting, and favorable cytoplasm trafficking. As a result, target gene expression can be significantly suppressed and tumor growth is effectively inhibited, while the systemic toxicity is not notable. These results together vote the biomimetic magnetosome as a promising siRNA delivery system for anticancer therapy.A biomimetic magnetosome is developed using magnetic nanocluster as the core and Arg–Gly–Asp (RGD) decorated macrophage membrane as the cloak for siRNA delivery to cancer cells. The superior stealth effect, magnetic accumulation, RGD targeting, MR imaging, and favorable cytoplasm trafficking are demonstrated. The target gene expression is significantly suppressed, and significantly inhibited tumor growth is achieved with few side effects.
      PubDate: 2017-11-07T05:46:37.569238-05:
      DOI: 10.1002/adfm.201703326
       
  • Unusual Twisting Phonons and Breathing Modes in Tube-Terminated
           Phosphorene Nanoribbons and Their Effects on Thermal Conductivity
    • Authors: Xiangjun Liu; Junfeng Gao, Gang Zhang, Yong-Wei Zhang
      Abstract: By studying tube-terminated phosphorene nanoribbons (PNRs), it is found that unusual phonon and thermal properties can emerge from topologically new edges. The lattice dynamics calculations show that in tube-terminated PNRs, the breaking of rotation symmetry suppresses the degeneracy of phonon modes, causing the emergence of twisting mode. An anomalous change of an out-of-plane acoustic mode to breathing modes with nonzero energy at the center of Brillouin zone occurs when the phosphorene sheet is converted into a tube-terminated PNR. These unusual twisting and breathing modes provide a larger phase space for scattering phonons, thus explaining the low thermal conductivity of tube-terminated PNRs revealed by molecular dynamics calculations. Due to the change in the stress field distribution caused by the tube edge, a nearly strain-independent thermal conductivity in tube-terminated PNRs is observed, which is in contrast to the apparent enhancement of thermal conductivity in pristine and dimer-terminated PNRs under tensile strain. The work reveals intriguing phononic and thermal behaviors of tube-terminated 2D materials.Unusual phonon and thermal properties are observed for tube-terminated phosphorene nanoribbons. Converting the phosphorene sheet into a tube-edged phosphorene nanoribbon breaks the rotation symmetry. The degeneracy of phonon modes is suppressed, causing the emergence of a twisting mode and an anomalous change of the out-of-plane acoustic mode to breathing modes with nonzero energy at the center of Brillouin zone occurs.
      PubDate: 2017-11-07T05:46:03.753231-05:
      DOI: 10.1002/adfm.201702776
       
  • High Seebeck Coefficient in Mixtures of Conjugated Polymers
    • Authors: Guangzheng Zuo; Xianjie Liu, Mats Fahlman, Martijn Kemerink
      Abstract: A universal method to obtain record-high electronic Seebeck coefficients is demonstrated while preserving reasonable conductivities in doped blends of organic semiconductors through rational design of the density of states (DOSs). A polymer semiconductor with a shallow highest occupied molecular orbital (HOMO) level-poly(3-hexylthiophene) (P3HT) is mixed with materials with a deeper HOMO (PTB7, TQ1) to form binary blends of the type P3HTx:B1-x (0 ≤ x ≤ 1) that is p-type doped by F4TCNQ. For B = PTB7, a Seebeck coefficient S = 1100 µV K−1 with conductivity σ = 0.3 S m−1 at x = 0.10 is achieved, while for B = TQ1, S = 2000 µV K−1 and σ = 0.03 S m−1 at x = 0.05 is found. Kinetic Monte Carlo simulations with parameters based on experiments show good agreement with the experimental results, confirming the intended mechanism. The simulations are used to derive a design rule for parameter tuning. These results can become relevant for low-power, low-cost applications like (providing power to) autonomous sensors, in which a high Seebeck coefficient translates directly to a proportionally reduced number of legs in the thermogenerator, and hence in reduced fabrication cost and complexity.Record-high Seebeck coefficients are achieved for p-type-doped blends of common conjugated polymers. The method used is based on a rational design of the density of states, such that the characteristic hop occurs from the compound with the shallower HOMO to the compound with the deeper HOMO.
      PubDate: 2017-11-07T05:45:40.77904-05:0
      DOI: 10.1002/adfm.201703280
       
  • Investigation of the High Electron Affinity Molecular Dopant F6-TCNNQ for
           Hole-Transport Materials
    • Authors: Fengyu Zhang; Antoine Kahn
      Abstract: 2,2′-(perfluoronaphthalene-2,6-diylidene)dimalononitrile (F6-TCNNQ) is investigated as a molecular p-type dopant in two hole-transport materials, 2,2′,7,7′-tetrakis(N,N-diphenylamino)-9,9-spirobifluorene (Spiro-TAD) and tris(4-carbazoyl-9-ylphenyl)amine (TCTA). The electron affinity of F6-TCNNQ is determined to be 5.60 eV, one of the strongest organic molecular oxidizing agents used to date in organic electronics. p-Doping is found to be effective in Spiro-TAD (ionization energy = 5.46 eV) but not in TCTA (ionization energy = 5.85 eV). Optical absorption measurements demonstrate that charge transfer is the predominant doping mechanism in Spiro-TAD:F6-TCNNQ. The host–dopant interaction also leads to a significant alteration of the host film morphology. Finally, transport measurements done on Spiro-TAD:F6-TCNNQ as a function of dopant concentration and temperature, and using a highly doped contact layer to ensure negligible hole injection barrier, lead to an accurate measurement of the film conductivity and hole-hopping activation energy.2,2′-(perfluoronaphthalene-2,6-diylidene)dimalononitrile (F6-TCNNQ) is investigated as p-dopant in two hole-transport materials (HTMs). Ultrathin, heavily doped 2,2′,7,7′-tetrakis(N,N-diphenylamino)-9,9-spirobifluorene (Spiro-TAD) injection layers are implemented to ensure a negligible hole injection barrier in transport measurements, allowing accurate determination of conductivity and carrier hopping activation energy in HTMs such as Spiro-TAD.
      PubDate: 2017-11-07T05:42:19.740037-05:
      DOI: 10.1002/adfm.201703780
       
  • Spatially Configuring Wrinkle Pattern and Multiscale Surface Evolution
           with Structural Confinement
    • Authors: Ding Wang; Nontawit Cheewaruangroj, Yifan Li, Glen McHale, Yinzhu Jiang, David Wood, John Simeon Biggins, Ben Bin Xu
      Abstract: Surface elastic instabilities, such as wrinkling and creasing, can enable a convenient strategy to impart reversible patterned topography to a surface. Here the classic system of a stiff layer on a soft substrate is focused, which famously produces parallel harmonic wrinkles at modest uniaxial compression that period-double repeatedly at higher compressions and ultimately evolve into deep folds and creases. By introducing micrometer-scale planar Bravais lattice holes to spatially pattern the substrate, these instabilities are guided into a wide variety of different patterns, including wrinkling in parallel bands and star shape bands, and radically reduce the threshold compression. The experimental patterns and thresholds are enabled to understand by considering a simple plane-strain model for the patterned substrate-deformation, decorated by wrinkling on the stiff surface layer. The experiments also show localized wrinkle-crease transitions at modest compression, yielding a hierarchical surface with different generations of instability mixed together. By varying the geometrical inputs, control over the stepwise evolution of surface morphologies is demonstrated. These results demonstrate considerable control over both the patterns and threshold of the surface elastic instabilities, and have relevance to many emerging applications of morphing surfaces, including in wearable/flexible electronics, biomedical systems, and optical devices.Taking advantage of patterning lattice holes on an elastic bilayer, the formation of versatile wrinkle patterns that selectively cover the substrate and provide controllable evolution of the instability morphology is demonstrated to achieve a hierarchical surface. This provides insight into the formation and evolution of elastic instabilities on complex surfaces.
      PubDate: 2017-11-07T05:41:59.20417-05:0
      DOI: 10.1002/adfm.201704228
       
  • Liquid-Tin-Assisted Molten Salt Electrodeposition of Photoresponsive
           n-Type Silicon Films
    • Authors: Junjun Peng; Huayi Yin, Ji Zhao, Xiao Yang, Allen J. Bard, Donald R. Sadoway
      Abstract: Production of silicon film directly by electrodeposition from molten salt would have utility in the manufacturing of photovoltaic and optoelectronic devices owing to the simplicity of the process and the attendant low capital and operating costs. Here, dense and uniform polycrystalline silicon films (thickness up to 60 µm) are electrodeposited on graphite sheet substrates at 650 °C from molten KCl–KF-1 mol% K2SiF6 salt containing 0.020–0.035 wt% tin. The growth of such high-quality tin-doped silicon films is attributable to the mediation effect of tin in the molten salt electrolyte. A four-step mechanism is proposed for the generation of the films: nucleation, island formation, island aggregation, and film formation. The electrodeposited tin-doped silicon film exhibits n-type semiconductor behavior. In liquid junction photoelectrochemical measurement, this material generates a photocurrent about 38–44% that of a commercial n-type Si wafer.Dense and uniform polycrystalline silicon films (thickness up to 60 µm) were successfully electrodeposited on graphite from molten KCl-KF-1 mol% K2SiF6 containing a tiny amount of tin which promotes the growth of n-type material. In the photoelectrochemical measurement this tin-doped Si film generates a photocurrent about 38–44% that of a commercial n-type Si wafer.
      PubDate: 2017-11-07T05:41:18.69631-05:0
      DOI: 10.1002/adfm.201703551
       
  • Photoswitchable Nanomaterials Based on Hierarchically Organized Siloxane
           Oligomers
    • Authors: R. Helen Zha; Ghislaine Vantomme, José Augusto Berrocal, Ronald Gosens, Bas de Waal, Stefan Meskers, E. W. Meijer
      Abstract: Materials with highly ordered molecular arrangements have the capacity to display unique properties derived from their nanoscale structure. Here, the synthesis and characterization of azobenzene (AZO)-functionalized siloxane oligomers of discrete length that form photoswitchable supramolecular materials are described. Specifically, synergy between phase segregation and azobenzene crystallization leads to the self-assembly of an exfoliated 2D crystal that becomes isotropic upon photoisomerization with UV light. Consequently, the material undergoes a rapid athermal solid-to-liquid transition which can be reversed using blue light due to the unexpectedly fast 2D crystallization that is facilitated by phase segregation. In contrast, enabling telechelic supramolecular polymerization through hydrogen bonding inhibits azobenzene crystallization, and nanostructured pastes with well-ordered morphologies are obtained based on phase segregation alone, thus demonstrating block copolymer-like behavior. Therefore, by tailoring the balance of self-assembly forces in the azobenzene-functionalized siloxane oligomers, fast and reversible phase-changing materials can be engineered with various mechanical properties for applications in photolithography or switchable adhesion to lubricant properties.Azobenzene-functionalized siloxane oligomers self-assemble into supramolecular materials with well-ordered nanostructure and highly organized molecular arrangement. Photoisomerization with UV and visible wavelengths alter molecular organization, resulting in materials with rapid and reversible athermal phase transitions. Furthermore, by varying the synergy between phase segregation and azobenzene crystallization, material properties can be tailored for applications in photoswitchable adhesion and photolithography.
      PubDate: 2017-11-07T05:40:59.972427-05:
      DOI: 10.1002/adfm.201703952
       
  • Reversible Switching of Spiropyran Molecules in Direct Contact With a
           Bi(111) Single Crystal Surface
    • Authors: Fabian Nickel; Matthias Bernien, Kai Kraffert, Dennis Krüger, Lucas M. Arruda, Lalminthang Kipgen, Wolfgang Kuch
      Abstract: Photochromic molecular switches immobilized by direct contact with surfaces typically show only weak response to optical excitation, which often is not reversible. In contrast, here, it is shown that a complete and reversible ring-opening and ring-closing reaction of submonolayers of spironaphthopyran on the Bi(111) surface is possible. The ring opening to the merocyanine isomer is initiated by ultraviolet light. Switching occurs in a two-step process, in which after optical excitation, an energy barrier needs to be overcome to convert to the merocyanine form. This leads to a strong temperature dependence of the conversion efficiency. Switching of the merocyanine isomer back to the closed form is achieved by a temperature increase. Thus, the process can be repeated in a fully reversible manner, in contrast to previously studied nitrospiropyran molecules on surfaces. This is attributed to the destabilization of the merocyanine isomer by the electron-donating nature of the naphtho group and the reduced van der Waals interaction of the Bi(111) surface. The result shows that molecules designed for switching in solutions need to be modified to function in direct contact with a surface.Reversible on-surface switching of spiropyran (SP) is achieved using a weakly interacting substrate and choosing a SP derivative such that the modification of the energetics in the adsorbed state is taken into account. The ring-opening reaction is induced by UV light. By an increase of temperature, the open merocyanine isomer is converted back to the closed SP form.
      PubDate: 2017-11-06T04:42:03.702869-05:
      DOI: 10.1002/adfm.201702280
       
  • Photoelectrochemically Active and Environmentally Stable CsPbBr3/TiO2
           Core/Shell Nanocrystals
    • Authors: Zhi-Jun Li; Elan Hofman, Jian Li, Andrew Hunter Davis, Chen-Ho Tung, Li-Zhu Wu, Weiwei Zheng
      Abstract: Inherent poor stability of perovskite nanocrystals (NCs) is the main impediment preventing broad applications of the materials. Here, TiO2 shell coated CsPbBr3 core/shell NCs are synthesized through the encapsulation of colloidal CsPbBr3 NCs with titanium precursor, followed by calcination at 300 °C. The nearly monodispersed CsPbBr3/TiO2 core/shell NCs show excellent water stability for at least three months with the size, structure, morphology, and optical properties remaining identical, which represent the most water-stable inorganic shell passivated perovskite NCs reported to date. In addition, TiO2 shell coating can effectively suppress anion exchange and photodegradation, therefore dramatically improving the chemical stability and photostability of the core CsPbBr3 NCs. More importantly, photoluminescence and (photo)electrochemical characterizations exhibit increased charge separation efficiency due to the electrical conductivity of the TiO2 shell, hence leading to an improved photoelectric activity in water. This study opens new possibilities for optoelectronic and photocatalytic applications of perovskites-based NCs in aqueous phase.TiO2 shell coated CsPbBr3 core/shell nanocrystals are successfully constructed, resulting in excellent water, photo and thermal stability. TiO2 shell coating effectively increases charge separation efficiency, hence leading to an improved photoelectric activity in water.
      PubDate: 2017-11-06T04:41:22.870782-05:
      DOI: 10.1002/adfm.201704288
       
  • A Multiparameter pH-Sensitive Nanodevice Based on Plasmonic Nanopores
    • Authors: Hailing Liu; Qiucen Jiang, Jie Pang, Zeyu Jiang, Jiao Cao, Lina Ji, Xinghua Xia, Kang Wang
      Abstract: With controllable mass transfer and special optical properties, plasmonic nanopores may be applied as a nanodevice and possibly create a new generation of single molecule detection technique based on plasmon-enhanced spectra. In the present study, gold nanoparticles self-assemble into a gold porous sphere (GPS) on the tip of a glass nanopipette with the help of i-motif DNA thiolated by both ends as linker molecules. The gaps among neighboring gold nanoparticles are considered as plasmonic nanopores. The size of the formed nanopores can be tuned by the folded–unfolded conformational change of i-motif DNA upon pH adjustment from 4.5 to 7.0. Based on its tunable structural property, the GPS shows reversible changes in ionic current, potential, and surface-enhanced Raman scattering signal. The GPS is further used to probe regional pH in single cells. The successful application of GPS in multiparameter pH probing and single cell analysis suggests that the new physical properties of the self-assembled plasmonic nanopores can be used for fabricating multiple types of nanodevices and nanosensors.Plasmonic nanopores are developed by assembling gold nanoparticles into a gold porous sphere (GPS) on the tip of a glass nanopipette using i-motif DNA as linker molecules. The GPS with clear ionic current rectification, potential response, and strong surface-enhanced Raman scattering properties is used as a multiparameter pH-sensitive nanodevice and successfully applied in probing the regional pH in single cells.
      PubDate: 2017-11-06T04:40:50.584867-05:
      DOI: 10.1002/adfm.201703847
       
  • Photosensitizers for Two-Photon Excited Photodynamic Therapy
    • Authors: Zhiyuan Sun; Li-Peng Zhang, Feipeng Wu, Yuxia Zhao
      Abstract: Photodynamic therapy (PDT) is a noninvasive protocol for the treatment of various cancers and nonmalignant diseases. Light, oxygen, and photosensitizer (PS) are the essential three elements in a typical PDT process. Currently, there are two major barriers limiting the further development of PDT. One issue is limited tissue penetration, and the other is the lack of high-performance PSs. Therefore, the newly emerging two-photon excited PDT (2PE-PDT) has attracted considerable attention in recent years due to its advantages such as a higher spatial resolution and a greater penetration depth. In this review, focus is on (i) the principle of 2PE-PDT, (ii) the progression of PSs for 2PE-PDT, and (iii) the potential indications and future directions in this field.Two-photon excited photodynamic therapy (2PE-PDT) has attracted considerable attention in recent years due to its advantages such as a greater tissue penetration depth and a higher spatial selectivity, which can promote the development of PDT in clinic. This review introduces the principle of 2PE-PDT, the progression of photosensitizers, and potential indications and future directions for this newly emerging branch of PDT.
      PubDate: 2017-11-03T08:04:12.19054-05:0
      DOI: 10.1002/adfm.201704079
       
  • Integrated Quasiplane Heteronanostructures of MoSe2/Bi2Se3 Hexagonal
           Nanosheets: Synergetic Electrocatalytic Water Splitting and Enhanced
           Supercapacitor Performance
    • Authors: Jing Yang; Chunde Wang, Huanxin Ju, Yuan Sun, Shiqi Xing, Junfa Zhu, Qing Yang
      Abstract: MoSe2 as a typical transition metal dichalcogenide holds great potential for energy storage and catalysis but its performance is largely limited by its poor conductivity. Bi2Se3 nanosheets, a kind of topological insulators, possess gapless edges on boundary and show metallic character on surface. According to the principle of complementary, a novel integrated quasiplane structure of MoSe2/Bi2Se3 hybrids is designed with artistic heteronanostructures via a hot injection in colloidal system. Interestingly, the heteronanostructures are typically constituted by single-layer Bi2Se3 hexagonal nanoplates evenly enclosed by small ultrathin hierarchical MoSe2 nanosheets on the whole surfaces. X-ray photoelectron spectroscopy investigations suggest obvious electron transfer from Bi2Se3 to MoSe2, which can help to enhance the conductivity of the hybrid electrode. Especially, schematic energy band diagrams derived from ultraviolet photoelectron spectroscopy studies indicate that Bi2Se3 has higher EF and smaller Φ than MoSe2, further confirming the electronic modulation between Bi2Se3 and MoSe2, where Bi2Se3 serves as an excellent substrate to provide electrons and acts as channels for high-rate transition. The MoSe2/Bi2Se3 hybrids demonstrating a low onset potential, small Tafel slope, high current density, and long-term stability suggest excellent hydrogen evolution reaction activity, whereas a high specific capacitance, satisfactory rate capability, and rapid ions diffusion indicate enhanced supercapacitor performance.Integrated quasiplane heteronanostructures of MoSe2/Bi2Se3 hexagonal nanosheets are fabricated via a hot injection process for the first time. Investigations suggest there is obvious electron transfer from Bi2Se3 to MoSe2, which can help enhance the conductivity of the hybrid electrode. Owing to synergistic structural features, the MoSe2/Bi2Se3 hybrids exhibit significantly enhanced electrocatalytic water splitting activity and supercapacitive performance.
      PubDate: 2017-11-02T03:02:48.877646-05:
      DOI: 10.1002/adfm.201703864
       
  • PtCoFe Nanowire Cathodes Boost Short-Circuit Currents of Ru(II)-Based
           Dye-Sensitized Solar Cells to a Power Conversion Efficiency of 12.29%
    • Authors: Chin-Cheng (Paul) Chiang; Chang-Yu Hung, Shang-Wei Chou, Jing-Jong Shyue, Kum-Yi Cheng, Pei-Jen Chang, Ya-Yun Yang, Ching-Yen Lin, Ting-Kuang Chang, Yun Chi, Hung-Lung Chou, Pi-Tai Chou
      Abstract: PtCoFe nanowires with different alloying compositions are chemically prepared and acted as counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) with Ru(II)-based dyes. Due to their superior I3− reduction activity, PtCoFe nanowires with rich (111) facets enhance the performance of DSSCs. Hence, N719 DSSCs with PtCoFe nanowires, respectively, produce better power conversion efficiency (PCE) of 8.10% for Pt33Co24Fe43 nanowire, 8.33% for Pt74Co12Fe14 nanowire, and 9.26% for Pt49Co23Fe28 nanowire in comparison to the PCE of Pt CE (7.32%). Further, the PRT-22 DSSC with Pt49Co23Fe28 nanowire exhibits a maximum PCE of 12.29% with a certificated value of 12.0%, which surpass the previous PCE record of the DSSCs with Ru(II)-based dyes. The photovoltaic and electrochemical results reveal the composition-dependent activity along with a volcano-shaped trend in the I−/I3− redox reaction. Theoretical work on the adsorption energies of I2, the desorption energies of I−, and the corresponding absolute energy demonstrates that the I3− reduction activity followed in the order of Pt49Co23Fe28(111) plane> Pt74Co12Fe14(111) plane> Pt33Co24Fe43(111) plane, proving Pt49Co23Fe28 nanowire to be a superior cathode material for DSSCs.PtCoFe nanowires with rich (111) planes are chemically prepared and act as the counter electrodes of dye-sensitized solar cells (DSSCs). Evidently, Pt49Co23Fe28 nanowires demonstrate the superior catalytic properties with respect to the I−/I3− redox reactions. Thus, PRT-22 DSSC based on Pt49Co23Fe28 nanowire produces an impressive power conversion efficiency of 12.29%.
      PubDate: 2017-11-02T03:01:33.373176-05:
      DOI: 10.1002/adfm.201703282
       
  • Schottky-Barrier-Controllable Graphene Electrode to Boost Rectification in
           Organic Vertical P–N Junction Photodiodes
    • Authors: Jong Su Kim; Young Jin Choi, Hwi Je Woo, Jeehye Yang, Young Jae Song, Moon Sung Kang, Jeong Ho Cho
      Abstract: Monolayer graphene is used as an electrode to develop novel electronic device architectures that exploit the unique, atomically thin structure of the material with a low density of states at its charge neutrality point. For example, a single semiconductor layer stacked onto graphene can provide a semiconductor–electrode junction with a tunable injection barrier, which is the basis for a primitive transistor architecture known as the Schottky barrier field-effect transistor. This work demonstrates the next level of complexity in a vertical graphene–semiconductor architecture. Specifically, an organic vertical p-n junction (p-type pentacene/n-type N,N′-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8)) on top of a graphene electrode constituting a novel gate-tunable photodiode device structure is fabricated. The model device confirms that controlling the Schottky barrier height at the pentacene–graphene junction can (i) suppress the dark current density and (ii) enhance the photocurrent of the device, both of which are critical to improve the performance of a photodiode.Organic vertical p–n junction stacked on top of a graphene electrode is demonstrated for gate-tunable photodiodes. The model device confirms that controlling the Schottky barrier height at the pentacene–graphene junction can (i) suppress the dark current density and (ii) enhance the photocurrent of the device.
      PubDate: 2017-11-02T02:57:53.010029-05:
      DOI: 10.1002/adfm.201704475
       
  • Bioinspired Continuous and Spontaneous Antigravity Oil Collection and
           Transportation
    • Authors: Yaxin Zhang; Moyuan Cao, Yun Peng, Xu Jin, Dongliang Tian, Kesong Liu, Lei Jiang
      Abstract: Liquids with low surface tension, such as petroleum, serve as the source of power for development of modern industry. Spontaneous and directional transportation of oily liquids in aqueous environment has drawn wide attentions owing to its scientific significance and practical prospect in marine petroleum exploitation and oil spill cleanup. Persistent effort has been made to the directional transportation of oil droplets under specific assistance. However, the spontaneous oriented movement of oil, especially the air/water two-phase oil delivery is still identified as a big challenge. Here, a bioinspired superoleophobic pump has been fabricated through the assembly of a superoleophobic mesh and an oil column. Depending on the directional releases of surface energy, oil droplets can be continuously collected and pumped to centimeters high without additional driving forces. The antigravity oil delivery system can realize continuous oil flow under water, even the air/water two-phase oil transportation. This work demonstrates a new mode of liquid transportation without external energy and should open a new way to design novel fluid delivery systems to realize diverse liquid transport.Spontaneous and directional transportation of oily liquids in aqueous environment has drawn wide attentions owing to its scientific significance and practical application. A superoleophobic pump has been fabricated to achieve oil collection and transportation without external energy. This work may serve as an inspiration in the field of microfluidics, oil transportation, oil–water separation, etc.
      PubDate: 2017-11-02T02:57:26.147742-05:
      DOI: 10.1002/adfm.201704220
       
  • Glass-Like Through-Plane Thermal Conductivity Induced by Oxygen Vacancies
           in Nanoscale Epitaxial La0.5Sr0.5CoO3−δ
    • Authors: Xuewang Wu; Jeff Walter, Tianli Feng, Jie Zhu, Hong Zheng, John F. Mitchell, Neven Biškup, Maria Varela, Xiulin Ruan, Chris Leighton, Xiaojia Wang
      Abstract: Ultrafast time-domain thermoreflectance (TDTR) is utilized to extract the through-plane thermal conductivity (ΛLSCO) of epitaxial La0.5Sr0.5CoO3−δ (LSCO) of varying thickness (
      PubDate: 2017-11-02T02:56:35.89316-05:0
      DOI: 10.1002/adfm.201704233
       
  • Efficiency Enhancement of Single-Walled Carbon Nanotube-Silicon
           Heterojunction Solar Cells Using Microwave-Exfoliated Few-Layer Black
           Phosphorus
    • Authors: Munkhjargal Bat-Erdene; Munkhbayar Batmunkh, Sherif Abdulkader Tawfik, Marco Fronzi, Michael J. Ford, Cameron J. Shearer, LePing Yu, Mahnaz Dadkhah, Jason R. Gascooke, Christopher T. Gibson, Joseph G. Shapter
      Abstract: Carbon nanotube-silicon (CNT-Si)-based heterojunction solar cells (HJSCs) are a promising photovoltaic (PV) system. Herein, few-layer black phosphorus (FL-BP) sheets are produced in N-methyl-2-pyrrolidone (NMP) using microwave-assisted liquid-phase exfoliation and introduced into the CNTs-Si-based HJSCs for the first time. The NMP-based FL-BP sheets remain stable after mixing with aqueous CNT dispersion for device fabrication. Due to their unique 2D structure and p-type dominated conduction, the FL-BP/NMP incorporated CNT-Si devices show an impressive improvement in the power conversion efficiency from 7.52% (control CNT-Si cell) to 9.37%. Our density-functional theory calculation reveals that lowest unoccupied molecular orbital (LUMO) of FL-BP is higher in energy than that of single-walled CNT. Therefore, we observed a reduction in the orbitals localized on FL-BP upon highest occupied molecular orbital to LUMO transition, which corresponds to an improved charge transport. This study opens a new avenue in utilizing 2D phosphorene nanosheets for next-generation PVs.Few-layer black phosphorus sheets are prepared using a microwave-assisted liquid-phase exfoliation method and introduced into high efficiency single-walled carbon nanotube-silicon heterojunction solar cells.
      PubDate: 2017-11-02T02:56:06.701733-05:
      DOI: 10.1002/adfm.201704488
       
  • Correlated In Situ Low-Frequency Noise and Impedance Spectroscopy Reveal
           Recombination Dynamics in Organic Solar Cells Using Fullerene and
           Non-Fullerene Acceptors
    • Authors: Kyle A. Luck; Vinod K. Sangwan, Patrick E. Hartnett, Heather N. Arnold, Michael R. Wasielewski, Tobin J. Marks, Mark C. Hersam
      Abstract: Non-fullerene acceptors based on perylenediimides (PDIs) have garnered significant interest as an alternative to fullerene acceptors in organic photovoltaics (OPVs), but their charge transport phenomena are not well understood, especially in bulk heterojunctions (BHJs). Here, charge transport and current fluctuations are investigated by performing correlated low-frequency noise and impedance spectroscopy measurements on two BHJ OPV systems, one employing a fullerene acceptor and the other employing a dimeric PDI acceptor. In the dark, these measurements reveal that PDI-based OPVs have a greater degree of recombination in comparison to fullerene-based OPVs. Furthermore, for the first time in organic solar cells, 1/f noise data are fit to the Kleinpenning model to reveal underlying current fluctuations in different transport regimes. Under illumination, 1/f noise increases by approximately four orders of magnitude for the fullerene-based OPVs and three orders of magnitude for the PDI-based OPVs. An inverse correlation is also observed between noise spectral density and power conversion efficiency. Overall, these results show that low-frequency noise spectroscopy is an effective in situ diagnostic tool to assess charge transport in emerging photovoltaic materials, thereby providing quantitative guidance for the design of next-generation solar cell materials and technologies.Low-frequency electronic noise is measured in polymer solar cells with fullerene and non-fullerene acceptors. Charge carrier lifetimes deduced from impedance spectroscopy enable the noise data to be fit to the Kleinpenning model. The results establish that low-frequency noise elucidates charge recombination processes that limit power conversion efficiency. This correlated analytical tool provides quantitative guidance to the optimization of emerging photovoltaic materials.
      PubDate: 2017-11-02T02:12:23.889264-05:
      DOI: 10.1002/adfm.201703805
       
  • Mixed-Dimensional 1D ZnO–2D WSe2 van der Waals Heterojunction Device
           for Photosensor
    • Authors: Young Tack Lee; Pyo Jin Jeon, Jae Hyun Han, Jongtae Ahn, Hyo Sun Lee, June Yeong Lim, Won Kook Choi, Jin Dong Song, Min-Chul Park, Seongil Im, Do Kyung Hwang
      Abstract: 2D layered van der Waals (vdW) atomic crystals are an emerging class of new materials that are receiving increasing attention owing to their unique properties. In particular, the dangling-bond-free surface of 2D materials enables integration of differently dimensioned materials into mixed-dimensional vdW heterostructures. Such mixed-dimensional heterostructures herald new opportunities for conducting fundamental nanoscience studies and developing nanoscale electronic/optoelectronic applications. This study presents a 1D ZnO nanowire (n-type)–2D WSe2 nanosheet (p-type) vdW heterojunction diode for photodetection and imaging process. After amorphous fluoropolymer passivation, the ZnO–WSe2 diode shows superior performance with a much-enhanced rectification (ON/OFF) ratio of over 106 and an ideality factor of 3.4–3.6 due to the carbon–fluorine (CF) dipole effect. This heterojunction device exhibits spectral photoresponses from ultraviolet (400 nm) to near infrared (950 nm). Furthermore, a prototype visible imager is demonstrated using the ZnO–WSe2 heterojunction diode as an imaging pixel. To the best of our knowledge, this is the first demonstration of an optoelectronic device based on a 1D–2D hybrid vdW heterojunction. This approach using a 1D ZnO–2D WSe2 heterojunction paves the way for the further development of electronic/optoelectronic applications using mixed-dimensional vdW heterostructures.A novel mixed-dimensional 1D ZnO–2D WSe2 van der Waals heterojunction device for photodetection and imaging processes is demonstrated. The ZnO–WSe2 heterojunction diode exhibits a spectral photodetection range from ultraviolet to near infrared. A prototype visible imager is demonstrated using the ZnO–WSe2 heterojunction diode as an imaging pixel.
      PubDate: 2017-11-02T02:11:05.366941-05:
      DOI: 10.1002/adfm.201703822
       
  • Flexible Modulation of Electronic Band Structures of Wide Band Gap GaN
           Semiconductors Using Bioinspired, Nonbiological Helical Peptides
    • Authors: Sven Mehlhose; Nataliya Frenkel, Hirotaka Uji, Sara Hölzel, Gesche Müntze, Daniel Stock, Silvio Neugebauer, Armin Dadgar, Wasim Abuillan, Martin Eickhoff, Shunsaku Kimura, Motomu Tanaka
      Abstract: Modulation of the electronic band profiles of wide band gap GaN semiconductors is achieved by the macromolecular dipole potentials exerted from ordered monolayers of synthetic, nonbiological aldehyde terminated helical peptides deposited on wet chemically oxidized GaN surfaces functionalized with aminosilanes. The selective coupling of either N- or C-terminal to the amino-terminated surface enables one to control the direction of the dipole moment, while the number of amino acids determines its magnitude. After confirming the formation of highly ordered peptide monolayers, the impact of macromolecular dipole potentials is quantified by electrochemical impedance spectroscopy. Moreover, the chronoamperometry measurements of ferrocene-terminated peptides suggest that the transfer of electrons injected from ferrocene follows inelastic hopping, while the current responses of peptides with no ferrocene moieties are purely capacitive. Finally, the same functionalization steps are transferred to GaN/AlGaN/GaN high electron mobility transistor structures. Stable and quantitative modulation of the current–voltage characteristics of the 2D electron gas by the deposition of bioinspired peptides is a promising strategy for the macromolecular dipole engineering of GaN semiconductors.Grafting of bioinspired but nonbiological peptides realizes the flexible modulation of the electronic band structures of GaN. The regulation of carrier mobility in 2D electron gases based on GaN/AlGaN/GaN heterostructures opens a large potential toward the macromolecular dipole engineering of GaN semiconductors without doping or deposition of inorganic materials.
      PubDate: 2017-11-02T02:10:50.930454-05:
      DOI: 10.1002/adfm.201704034
       
  • 3D Multiscale Superhydrophilic Sponges with Delicately Designed Pore Size
           for Ultrafast Oil/Water Separation
    • Authors: Weiyang Lv; Qingqing Mei, Jianliang Xiao, Miao Du, Qiang Zheng
      Abstract: Developing novel filtering materials with both high permeation flux and rejection rate presents an enticing prospect for oil/water separation. In this paper, robust porous poly(melamine formaldehyde) (PMF) sponges with superwettability and controlled pore sizes through introducing layered double hydroxides (LDH) and SiO2 electrospun nanofibers are reported. The LDH nanoscrolls endow the sponge with inherent superhydrophilicity and the SiO2 nanofibers act as pore size regulators by overlapping the PMF mainframe. This approach allows the intrinsic large pores in the pristine sponge to decrease quickly from 109.50 to 23.35 µm, while maintaining porosity above 97.8%. The resulting modified sponges with varied pore sizes can effectively separate a wide range of oil/water mixtures, including the surfactant-stabilized emulsions, solely by gravity, with ultrahigh permeation flux (maximum of 3 × 105 L m−2 h−1 bar−1) and satisfactory oil rejection (above 99.46%). Moreover, separation of emulsions stabilized by different surfactants, such as anionic, nonionic, and cationic surfactants has been investigated for further practical evaluation. It is expected that such a pore size tuning technology can provide a low cost and easily scaled-up method to construct a series of filtering materials for high-efficient separation of target oil/water mixtures.A series of multiscale sponges with controlled pore sizes have been successfully developed via the adsorption of SiO2 electrospun nanofibers and following hydrothermal treatment. With their combined superhydrophilicity, high porosity, and delicately designed pore size compatible with oil/water mixtures, the obtained sponges can effectively separate a wide range of oily wastewater with ultrahigh permeation flux and satisfactory oil rejection.
      PubDate: 2017-11-02T02:09:30.841221-05:
      DOI: 10.1002/adfm.201704293
       
  • Stretchable Electrode Based on Laterally Combed Carbon Nanotubes for
           Wearable Energy Harvesting and Storage Devices
    • Authors: Seungki Hong; Jongsu Lee, Kyungsik Do, Minbaek Lee, Ji Hoon Kim, Sangkyu Lee, Dae-Hyeong Kim
      Abstract: Carbon nanotubes (CNTs) are a promising material for use as a flexible electrode in wearable energy devices due to their electrical conductivity, soft mechanical properties, electrochemical activity, and large surface area. However, their electrical resistance is higher than that of metals, and deformations such as stretching can lead to deterioration of electrical performances. To address these issues, here a novel stretchable electrode based on laterally combed CNT networks is presented. The increased percolation between combed CNTs provides a high electrical conductivity even under mechanical deformations. Additional nickel electroplating and serpentine electrode designs increase conductivity and deformability further. The resulting stretchable electrode exhibits an excellent sheet resistance, which is comparable to conventional metal film electrodes. The resistance change is minimal even when stretched by ≈100%. Such high conductivity and deformability in addition to intrinsic electrochemically active property of CNTs enable high performance stretchable energy harvesting (wireless charging coil and triboelectric generator) and storage (lithium ion battery and supercapacitor) devices. Monolithic integration of these devices forms a wearable energy supply system, successfully demonstrating its potential as a novel soft power supply module for wearable electronics.Stretchable electrodes using a laterally combed carbon nanotube (CNT) network are fabricated by restructuring of vertically aligned CNTs through a lateral-combing process. Subsequent Ni-electroplating further enhances the conductivity of the laterally combed CNT network. This novel nanostructure is used as electrically and electrochemically high performance electrodes in wearable energy harvesting (wireless charger and triboelectric generator) and storage (lithium ion battery and supercapacitor) devices.
      PubDate: 2017-11-02T02:07:17.748185-05:
      DOI: 10.1002/adfm.201704353
       
  • Virus-Templated Self-Mineralization of Ligand-Free Colloidal Palladium
           Nanostructures for High Surface Activity and Stability
    • Authors: Insu Kim; Kyungnam Kang, Mi Hwa Oh, Moon Young Yang, Inkyu Park, Yoon Sung Nam
      Abstract: In solution-based synthesis of colloidal nanostructures, additions of ligands, stabilizers, and redox reagents are generally required to obtain desirable structures, though ligands and stabilizers on the surface of nanostructures can substantially affect the surface-related activity. Accordingly, an extensive rinsing process is usually required to remove residual reagents and stabilizers. This study reports a spontaneous self-biomineralization of palladium (Pd) ions on a filamentous virus to form ligand-free Pd nanowires under ambient conditions. No reducing reagents or additional surface stabilizers are used; the genetically modified virus alone supports the polycrystalline Pd nanowires within the nanostructure, maintaining the clean surface even without a rinsing process. The advantage of the ligand-free Pd nanowires is found in the Suzuki-coupling reaction, in which the nanowire catalytic activity is maintained after repeated reactions, while conventional Pd colloids undergo surface contamination by the stabilizer and lose their catalytic activity during repeated uses. The ligand-free surface, high electronic connectivity, and structural stability of the Pd nanowires also allow high sensitivity and selectivity in hydrogen gas sensing analysis. This work emphasizes the importance of the ligand-free surface of biotemplated nanostructures in maintaining functionalities without surface contamination.Virus-directed biomineralization realizes the formation of the entangled polycrystalline Pd nanowires (PdNWs) without reducing reagents under ambient conditions. The virus-templated PdNWs exhibit high catalytic activity for the repeated Suzuki-coupling reaction and high sensitivity and selectivity for hydrogen gas sensing owing to the porous, well-interconnected, and stabilizer-free clean surface of PdNWs.
      PubDate: 2017-11-02T02:06:56.898376-05:
      DOI: 10.1002/adfm.201703262
       
  • Enhancing Therapeutic Efficacy of Combined Cancer Phototherapy by
           Ultrasound-Mediated In Situ Conversion of Near-Infrared Cyanine/Porphyrin
           Microbubbles into Nanoparticles
    • Authors: Yunxue Xu; Xiaolong Liang, Pravin Bhattarai, Yang Sun, Yiming Zhou, Shumin Wang, Wen Chen, Huiyu Ge, Jinrui Wang, Ligang Cui, Zhifei Dai
      Abstract: Nanoparticles (NPs)-based diagnosis and phototherapy are emerging as the cutting-edge technologies for detection and treatment of cancer but their applications are still limited since insufficient and heterogeneous NPs accumulation in cancer often causes recurrence. To overcome these limitations, multifunctional microbubbles (MBs) were constructed with 1, 1-dioctadecyl-3, 3, 3, 3-tetramethylindotricarbocyanine iodide (DiR) and porphyrin grafted lipid (PGL). Both DiR and PGL self-assembled as microbubbles, the as-designed PGL-DiR MBs possess remarkably high drug loading contents (5.8% PGL and 10.38% DiR) and stable co-delivery drug combinations. In vivo experiments showed PGL-DiR MBs could serve as an excellent ultrasound contrast agent to enhance ultrasound imaging greatly for identifying the location and size of the tumors. Upon exposure to ultrasound, in situ conversion of PGL-DiR MBs into nanoparticles resulted in a remarkable increase in fluorescence intensity (~5 folds) in tumor compared with PGL-DiR NPs, validating the enhanced tumor accumulation and cellular uptake of therapeutic agents. PGL-DiR MBs showed complete tumor ablation without recurrence in vivo, while PGL-DiR NPs showed only 72.6% tumor growth inhibition at the same dose. We believe that PGL-DiR MBs will soon reach their full potential as an important class of phototherapeutic formulations and will contribute to remarkable advances in cancer treatments.The multifunctional PGL-DiR MBs, fabricated with 1, 1-dioctadecyl-3, 3, 3, 3-tetramethylindotricarbocyanine iodide (DiR) and porphyrin grafted lipid (PGL), possess remarkably high drug loading contents and could serve as an excellent ultrasound contrast agent. Upon exposure to ultrasound, in situ conversion of PGL-DiR MBs into nanoparticles, compared with PGL-DiR NPs, resulted in enhanced tumor accumulation and cellular uptake of therapeutic agents.
      PubDate: 2017-11-02T02:06:17.480348-05:
      DOI: 10.1002/adfm.201704096
       
  • Bilayer Nanomesh Structures for Transparent Recording and Stimulating
           Microelectrodes
    • Authors: Yi Qiang; Kyung Jin Seo, Xuanyi Zhao, Pietro Artoni, Negar H. Golshan, Stanislav Culaclii, Po-Min Wang, Wentai Liu, Katherine S. Ziemer, Michela Fagiolini, Hui Fang
      Abstract: Nanomeshed forms of metal have emerged as a promising biocompatible electrode material for future soft bioelectronics. However, metal/electrolyte interfaces are intrinsically capacitive, severely limiting their electrochemical performance, especially for scaled electrodes, which are essential for high-resolution brain mapping. Here, an innovative bilayer nanomesh approach is demonstrated to address this limitation while preserving the nanomesh advantage. Electroplating low-impedance coatings on a gold nanomesh template achieves an impedance < 30 kΩ at 1 kHz and a charge injection limit of 1 mC cm−2 for 80 × 80 µm2 microelectrodes, a 4.3× and 12.8× improvement over uncoated electrodes, respectively, while maintaining a transparency of ≈70% at 550 nm. Systematic characterization of transmittance, impedance, charge injection limits, cyclic charge injection, and light-induced artifacts reveal an encouraging performance of the bilayer nanomesh microelectrodes. The bilayer nanomesh approach presented here is expected to enable next-generation large-scale transparent bioelectronics with broad utility in biology.Transparent metal-based bilayer nanomesh microelectrodes serve as promising neural interfaces for simultaneous electrophysiology with optical imaging and optogenetics, enabling both high temporal and spatial resolution of neural recording and stimulation. By electrodepositing low-impedance coatings on gold nanomesh microelectrodes, a significant decrease of impedance and a boost of charge injection limit are achieved, while preserving high transmittance.
      PubDate: 2017-11-02T02:05:41.786792-05:
      DOI: 10.1002/adfm.201704117
       
  • Thermogelling, ABC Triblock Copolymer Platform for Resorbable Hydrogels
           with Tunable, Degradation-Mediated Drug Release
    • Authors: Mukesh K. Gupta; John R. Martin, Bryan R. Dollinger, Madison E. Hattaway, Craig L. Duvall
      Abstract: Clinical application of injectable, thermoresponsive hydrogels is hindered by lack of degradability and controlled drug release. To overcome these challenges, a family of thermoresponsive, ABC triblock polymer-based hydrogels has been engineered to degrade and release drug cargo through either oxidative or hydrolytic/enzymatic mechanisms dictated by the “A” block composition. Three ABC triblock copolymers are synthesized with varying “A” blocks, including oxidation-sensitive poly(propylene sulfide), slow hydrolytically/enzymatically degradable poly(ε-caprolactone), and fast hydrolytically/enzymatically degradable poly(d,l-lactide-co-glycolide), forming the respective formulations PPS135-b-PDMA152-b-PNIPAAM225 (PDN), PCL85-b-PDMA150-b-PNIPAAM150 (CDN), and PLGA60-b-PDMA148-b-PNIPAAM152 (LGDN). For all three polymers, hydrophilic poly(N,N-dimethylacrylamide) and thermally responsive poly(N-isopropylacrylamide) comprise the “B” and “C” blocks, respectively. These copolymers form micelles in aqueous solutions at ambient temperature that can be preloaded with small molecule drugs. These solutions quickly transition into hydrogels upon heating to 37 °C, forming a supra-assembly of physically crosslinked, drug-loaded micelles. PDN hydrogels are selectively degraded under oxidative conditions while CDN and LGDN hydrogels are inert to oxidation but show differential rates of hydrolytic/enzymatic decomposition. All three hydrogels are cytocompatible in vitro and in vivo, and drug-loaded hydrogels demonstrate differential release kinetics in vivo corresponding with their specific degradation mechanism. These collective data highlight the potential cell and drug delivery use of this tunable class of ABC triblock polymer thermogels.Two-stage assembly, ABC triblock polymer-based, thermally responsive hydrogel formulations are engineered to degrade through either ROS or hydrolytic mechanisms based on composition of hydrophobic “A” block. In vitro and in vivo drug release kinetics from these hydrogels correlate to their respective degradation mechanism/susceptibility and enable tailoring of release profiles for drug delivery and tissue regenerative applications.
      PubDate: 2017-10-27T02:18:26.106302-05:
      DOI: 10.1002/adfm.201704107
       
  • A Multicolor Chameleon DNA-templated Silver Nanocluster and Its
           Application for Ratiometric Fluorescence Target Detection with Exponential
           Signal Response
    • Authors: Weijun Zhou; Jinbo Zhu, Daoqing Fan, Ye Teng, Xiaoqing Zhu, Shaojun Dong
      Abstract: For the first time, a novel type of chameleon DNA-templated silver nanocluster (AgNC) is found whose fluorescence color can be switched among yellow, orange, and red by the regulation of complementary DNA, nonfluorescent assistant AgNC as well as Mg2+. AgNC templated by A20-C55 (A20-C55-NC) possesses strong yellow fluorescence (Y signal) in phosphate buffer solution. When approaching to the nonfluorescent assistant AgNC through template hybridization, Y signal decreases while a new red emission (R signal) rises, leading to a dramatic color change of AgNC solution from yellow to red. On the other hand, hybridization of A20-C55-NC with complementary DNA (T20) largely enhances the Y signal while A20-C55-NC shows R and Y signal with equal intensity simultaneously in the presence of Mg2+. Therefore, the chameleon AgNC achieves controllable multicolor fluorescence variation. Based on above mechanism, a series of ratiometric analysis platforms are constructed for DNA target detection. Surprisingly, the ratiometric probes demonstrate an exponential growth of signal response with nanomolar sensitivity whether in double-stranded or hairpin-shaped structure. Accordingly, this universal ratiometric analysis platform possesses low background, large signal variation in a narrow concentration range, which presents obvious advantages over most of previous DNA detection strategies that are based on DNA-templated AgNC.Herein, a novel type of chameleon DNA-templated AgNC whose fluorescence color can be switched among yellow, orange and red by the regulation of complementary DNA, nonfluorescent assistant AgNC as well as Mg2+ is found. Therefore, ratiometric analysis platforms that possess low background and large signal variation in a narrow concentration range have been constructed for DNA target detection.
      PubDate: 2017-10-27T02:17:45.079602-05:
      DOI: 10.1002/adfm.201704092
       
  • Traceable Nanoparticles with Spatiotemporally Controlled Release Ability
           for Synergistic Glioblastoma Multiforme Treatment
    • Authors: Zhiguo Lu; Yan Li, Yuanjie Shi, Yanhui Li, Zuobing Xiao, Xin Zhang
      Abstract: Doxorubicin (DOX), one of the most widely used clinical antineoplastics, has ineffective therapeutic efficacy on glioblastoma multiforme (GBM) with extremely short survival time due to many obstacles such as blood–brain barrier (BBB), tumor angiogenesis, and glioblastoma stem cells (GSCs). To overcome, biocompatible nanoparticles named CARD-B6 loading three clinical drugs are developed. Unlike other nanomedicines, CARD-B6, with the ability of spatiotemporally controlled release, maximize the effectiveness of DOX. (1) After CARD-B6 cross the BBB via B6, combretastatin A4 that is first released via protonation of poly (β-amino ester) specifically destroys angiogenesis to facilitate the interaction between GBM and CARD-B6. (2) Internalized into glioblastoma cells later, DOX is released via the breakage of amido bond to induce apoptosis, which is facilitated by the simultaneously released all-trans retinoic acid (ATRA). (3) After endocytosis into GSCs, the rapidly released ATRA induces the GSCs differentiation and downregulates the survival pathways, which enhances the sensitivity of GSCs to the subsequently released DOX. This synergistic antitumor effect significantly extends survival time of GBM mouse model. CARD-B6 are traced by superparamagnetic iron oxide nanocubes with high r2 relaxivity for magnetic resonance imaging. Therefore, the traceable CARD-B6 with spatiotemporally controlled release ability are emerging as a powerful platform for GBM treatment.CARD-B6 with spatiotemporally controlled release ability are successfully fabricated. CARD-B6 deliver CA4, ATRA, and Doxorubicin (DOX) to their corresponding active sites sequentially after across blood–brain barrier. The nanoparticles overcome the barriers of DOX for glioblastoma multiforme (GBM) therapy and significantly enhance the therapeutic efficacy of DOX with extended survival time, holding great potential for GBM therapy.
      PubDate: 2017-10-27T02:17:21.304789-05:
      DOI: 10.1002/adfm.201703967
       
  • High Mobility WS2 Transistors Realized by Multilayer Graphene Electrodes
           and Application to High Responsivity Flexible Photodetectors
    • Authors: Adha Sukma Aji; Pablo Solís-Fernández, Hyun Goo Ji, Kenjiro Fukuda, Hiroki Ago
      Abstract: The electrical contact is one of the main issues preventing semiconducting 2D materials to fulfill their potential in electronic and optoelectronic devices. To overcome this problem, a new approach is developed here that uses chemical vapor deposition grown multilayer graphene (MLG) sheets as flexible electrodes for WS2 field-effect transistors. The gate-tunable Fermi level, van der Waals interaction with the WS2, and the high electrical conductivity of MLG significantly improve the overall performance of the devices. The carrier mobility of single-layer WS2 increases about a tenfold (50 cm2 V−1 s−1 at room temperature) by replacing conventional Ti/Au metal electrodes (5 cm2 V−1 s−1) with the MLG electrodes. Further, by replacing the conventional SiO2 substrate with a thin (1 µm) parylene-C flexible film as insulator, flexible WS2 photodetectors that are able to sustain multiple bending stress tests without significant performance degradation are realized. The flexible photodetectors exhibited extraordinarily high gate-tunable photoresponsivities, reaching values of 4500 A W−1, and with very short (
      PubDate: 2017-10-27T02:15:53.758989-05:
      DOI: 10.1002/adfm.201703448
       
  • Effective Prevention of Charge Trapping in Graphitic Carbon Nitride with
           Nanosized Red Phosphorus Modification for Superior Photo(electro)catalysis
           
    • Authors: Lin Jing; Ruixue Zhu, David Lee Phillips, Jimmy C. Yu
      Abstract: The high occurrence of trapped unreactive charges due to chemical defects seriously affects the performance of g-C3N4 in photocatalytic applications. This problem can be overcome by introducing ultrasmall red phosphorus (red P) crystals on g-C3N4 sheets. The elemental red P atoms reduce the number of defects in the g-C3N4 structure by forming new chemical bonds for much more effective charge separation. The product shows significantly enhanced photocatalytic activity toward hydrogen production. To the best of our knowledge, the hydrogen evolution rate obtained on this hybrid should be the highest among all P-containing g-C3N4 photocatalysts reported so far. The trapping and detrapping processes in this red P/g-C3N4 system are thoroughly revealed by using time-resolved transient absorption spectroscopy.Chemical bonding of elemental red phosphorus (red P) remediates the chemical defects in g-C3N4 structure. This would effectively suppress the charges trapping and prolong the lifetime of active charges in g-C3N4 during the photocatalytic applications. This optimized red P/g-C3N4 composite holds the highest record toward photocatalytic hydrogen production in the reported P-containing g-C3N4 systems to date.
      PubDate: 2017-10-25T10:07:55.258374-05:
      DOI: 10.1002/adfm.201703484
       
  • Novel Ω-Shaped Core–Shell Photodetector with High Ultraviolet
           Selectivity and Enhanced Responsivity
    • Authors: Mingxiang Hu; Feng Teng, Hongyu Chen, Mingming Jiang, Yuzhu Gu, Hongliang Lu, Linfeng Hu, Xiaosheng Fang
      Abstract: The design of nanostructure plays an important role in performance enhancement of low-dimensional optoelectronic devices. Herein, a novel photodetector (PD) based on electrospun SnO2 nanofibers with Ω-shaped ZnO shell (SnO2@ZnO) is fabricated. With 87.4% transmittance at 550 nm, SnO2@ZnO PD exhibits a high photo-to-dark current ratio up to 104 at around 280 nm. Owing to the additional Ω-shaped ZnO shell, SnO2@ZnO PD possesses a responsivity of nearly 100 A W−1 under 5 V bias and the illumination of 250 nm light, which is 30-time enhancement of pristine SnO2 PD. The enhancement is mainly attributed to type-II energy band structure. Furthermore, by changing the direction of incident light, SnO2@ZnO PD has a high UV selectivity with an UV–vis rejection ratio (R250 nm/R400 nm) as much as 2.0 × 103 at 5 V bias under back illumination, which is fourfold higher than that under face illumination. The UV selectivity improvement may be attributed to light confinement in the Ω-shaped structure. With both theoretical simulations and experimental comparisons, it is demonstrated that the unique compact Ω-shaped nanostructure does contribute to photon trapping and gaining process, especially in back-illumination configuration. The approach can be easily extended to other materials, preparing novel building blocks for optoelectronic devices.Combining electrospinning and atomic layer deposition, a novel photodetector based on SnO2 nanofibers @ Ω-shaped ZnO (semi core–shell) is fabricated, resulting in a 30-time enhanced responsivity. The direction of illumination will influence ultraviolet selectivity and back illumination gives a fourfold higher one. The enhancement may be attributed to type-II energy band diagram and light confinement of the unique configuration.
      PubDate: 2017-10-25T02:16:08.857186-05:
      DOI: 10.1002/adfm.201704477
       
  • Bulk Doping of Millimeter-Thick Conjugated Polymer Foams for Plastic
           Thermoelectrics
    • Authors: Renee Kroon; Jason D. Ryan, David Kiefer, Liyang Yu, Jonna Hynynen, Eva Olsson, Christian Müller
      Abstract: Foaming of plastics allows for extensive tuning of mechanical and physicochemical properties. Utilizing the foam architecture for plastic semiconductors can be used to improve ingression of external molecular species that govern the operation of organic electronic devices. In case of plastic thermoelectrics, utilizing solid semiconductors with realistic (millimeter (mm)-thick) dimensions does not permit sequential doping—while sequential doping offers the higher thermoelectric performance compared to other methods—because this doping methodology is diffusion limited. In this work, a fabrication process for poly(3-hexylthiophene) (P3HT) foams is presented, based on a combination of salt leaching and thermally induced phase separation. The obtained micro- and nanoporous architecture permits rapid and uniform doping of mm-thick foams with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, while thick solid P3HT structures suffer from protracted doping times and a dopant-depleted central region. Importantly, the thermoelectric performance of a P3HT foam is largely retained when normalized with regard to the quantity of used material.P3HT foams are fabricated through a combination of thermally induced phase separation and salt leaching. The foam architecture shows vastly improved dopant uptake compared to solid P3HT, enabling the superior sequential doping sequence for millimeter-thick semiconductor structures. The thermoelectric performance of P3HT foams is largely retained per material quantity, implying that foams are attractive for plastic thermoelectrics.
      PubDate: 2017-10-24T06:20:22.012129-05:
      DOI: 10.1002/adfm.201704183
       
  • Inverting the Swelling Trends in Modular Self-Oscillating Gels Crosslinked
           by Redox-Active Metal Bipyridine Complexes
    • Authors: Michael Aizenberg; Kosuke Okeyoshi, Joanna Aizenberg
      Abstract: The developing field of active, stimuli-responsive materials is in need for new dynamic architectures that may offer unprecedented chemomechanical switching mechanisms. Toward this goal, syntheses of polymerizable bipyridine ligands, bis(4-vinylbenzyl)[2,2′-bipyridine]-4,4′-dicarboxylate and N4,N4′-bis(4-vinylphenyl)-2,2′-bipyridine-4,4′-dicarboxamide, and a number of redox-active Ruthenium(II) and Iron(II) complexes with them are reported. Detailed characterizations by NMR, Fourier transform infrared spectroscopy, high-resolution mass-spectrometry, X-ray, and cyclic voltammetry show that the topology of these molecules allows them to serve as both comonomers and crosslinkers in polymerization reactions. Electronic properties of the ligands are tunable by choosing carboxylate- or carboxamido-linkages between the core and the vinylaryl moieties, leading to a library of Ru and Fe complexes with the M(III)/M(II) standard redox potentials suitable for catalyzing self-oscillating Belousov–Zhabotinskii (BZ) reaction. New poly(N-isopropylacrylamide)-based redox-responsive functional gels containing hydrophilic comonomers, which have been prepared using representative Ru bpy complexes as both a crosslinker and redox-active catalyst, exhibit a unique feature: their swelling/contraction mode switches its dependence on the oxidation state of the Ru center, upon changing the ratio of comonomers in the hybrid gel network. The BZ self-oscillations of such crosslinked hydrogels have been observed and quantified for both supported film and free-standing gel samples, demonstrating their potential as chemomechanically active modules for new functional materials.New series of polymerizable redox-active Ru and Fe complex crosslinkers with functionalized bipyridine ligands expand the toolbox for fabricating functional self-oscillating materials with new swelling/contraction response modes. The presented examples of Ru complex-crosslinked hydrogels promise higher modularity in the field of Belousov–Zhabotinskii-active metallopolymers, enriching the field of chemomechanically active functional materials and their applications in responsive and self-regulated systems.
      PubDate: 2017-10-24T06:19:53.50138-05:0
      DOI: 10.1002/adfm.201704205
       
  • Enzyme-Driven Hasselback-Like DNA-Based Inorganic Superstructures
    • Authors: Jae Sung Lee; Hyejin Kim, Changshin Jo, Jaepil Jeong, Jeonghyun Ko, Sangwoo Han, Min Sun Lee, Ho-Young Lee, Jeong Woo Han, Jinwoo Lee, Jong Bum Lee
      Abstract: DNA structures have gained much attention due to its ease of self-assembly and precise controllability. Although DNA technology has been successfully applied to generate a variety of DNA structures, there are only few attempts to apply DNA technology to generate inorganic materials due to lack of controllability of interactions between DNA and inorganic materials. In addition, the synthesis of a predictable structure of hybrid materials still remains a significant challenge. To address the challenge, here a novel strategy for the synthesis of DNA-based inorganic superstructures using DNA polymerase is reported. In particular, strategic feeding of metal ions for generating DNA-inorganic hybrid superstructures during DNA polymerization is established. This approach can produce a variety of structures with varying metal ions and can easily add functionality to the product. The structural features are also easily studied by first-principles calculations. With these advantages, DNA-Mn particles show the potential as a cell tracking agent, a contrast agent for MRI, and an electrode material for supercapacitors. The enzyme-driven synthesis in this study will provide a novel route for the generation of a range of organic–inorganic hybrid superstructures for biomedical and energy applications.A novel strategy for enzymatic synthesis of DNA-based inorganic micro/nanostructures is developed with a highly precise control of morphologies, components, and functionalities by employing the continuous pyrophosphate feeding system via DNA polymerase.
      PubDate: 2017-10-24T06:18:52.789672-05:
      DOI: 10.1002/adfm.201704213
       
  • Hierarchically Controlled Inside-Out Doping of Mg Nanocomposites for
           Moderate Temperature Hydrogen Storage
    • Authors: Eun Seon Cho; Anne M. Ruminski, Yi-Sheng Liu, Patrick T. Shea, ShinYoung Kang, Edmond W. Zaia, Jae Yeol Park, Yi-De Chuang, Jong Min Yuk, Xiaowang Zhou, Tae Wook Heo, Jinghua Guo, Brandon C. Wood, Jeffrey J. Urban
      Abstract: Demand for pragmatic alternatives to carbon-intensive fossil fuels is growing more strident. Hydrogen represents an ideal zero-carbon clean energy carrier with high energy density. For hydrogen fuel to compete with alternatives, safe and high capacity storage materials that are readily cycled are imperative. Here, development of such a material, comprised of nickel-doped Mg nanocrystals encapsulated by molecular-sieving reduced graphene oxide (rGO) layers, is reported. While most work on advanced hydrogen storage composites to date endeavor to explore either nanosizing or addition of carbon materials as secondary additives individually, methods to enable both are pioneered: “dual-channel” doping combines the benefits of two different modalities of enhancement. Specifically, both external (rGO strain) and internal (Ni doping) mechanisms are used to efficiently promote both hydriding and dehydriding processes of Mg nanocrystals, simultaneously achieving high hydrogen storage capacity (6.5 wt% in the total composite) and excellent kinetics while maintaining robustness. Furthermore, hydrogen uptake is remarkably accomplished at room temperature and also under 1 bar—as observed during in situ measurements—which is a substantial advance for a reversible metal hydride material. The realization of three complementary functional components in one material breaks new ground in metal hydrides and makes solid-state materials viable candidates for hydrogen-fueled applications.A new and innovative dual-doping strategy is employed to magnesium nanocrystal system that demonstrates a reversible hydrogen storage at moderate temperature range with an unprecedented storage performance. This result makes a remarkable advance towards safe and efficient solid-state hydrogen storage, and it can be adapted to both mobile and stationary fuel cell system to power a wide range of applications.
      PubDate: 2017-10-24T06:17:03.890439-05:
      DOI: 10.1002/adfm.201704316
       
  • Dual-Fiber Approach toward Flexible Multifunctional Hybrid Materials
    • Authors: Bernd Wicklein; Achim M. Diem, Andrea Knöller, Manoella S. Cavalcante, Lennart Bergström, Joachim Bill, Zaklina Burghard
      Abstract: Multifunctional paper-like materials containing metal oxide nanofibers are important for flexible electronics and other redox-based applications, but are often prone to mechanical failure. This work presents the coassembly of V2O5 nanofibers (VNFs) in a dual-fiber approach together with cellulose nanofibers to produce tough (0.26 MJ m−3), but strong (250 MPa) flexible hybrid materials. Indeed, nanotensile tests reveal a significant increase in toughness (200%) and strength (85%) of the hybrid films as compared to pristine VNF films. The microstructure of the films shows a transition from an anisotropic texture for the single-component films to an isotropic, entangled network in case of the hybrid films, which facilitates effective fracture resistance mechanisms. The flexible hybrid films display high electrical conductivity (0.2 S cm−1) and elastic properties originating from V2O5 nanofibers with excellent toughness and transparency endowed by the cellulose nanofibers. The self-supported hybrid films show reversible electrochromic behavior without the need for common substrates such as conducting indium tin oxide glass. It is conceivable that these self-supported films can be exploited in the future in smart, flexible optoelectronic devices.A dual-fiber synthesis approach to produce strong and flexible hybrid films by coassembly of cellulose and V2O5 nanofibers is presented. The self-supported films display reversible electrochromic behavior without the need for substrates such as indium tin oxide glass, opening up great opportunities for the design of smart, flexible optoelectronic devices.
      PubDate: 2017-10-24T06:15:51.5509-05:00
      DOI: 10.1002/adfm.201704274
       
  • Novel Reversible Humidity-Responsive Light Transmission Hybrid Thin-Film
           Material Based on a Dispersive Porous Structure with Embedded Hygroscopic
           and Deliquescent Substances
    • Authors: Erick Castellón; Marcos Zayat, David Levy
      Abstract: The article describes a new concept of an optical hybrid thin-film material that exhibits reversible humidity-driven light transmittance (scattering) properties. The film consists of a dispersive porous structure, with embedded hygroscopic and deliquescent compounds, that is able to scavenge water molecules from humid air to fill up the pores and become transparent to the incident light. Upon exposure to dry air, water is released from the structure and the material recovers its original light scattering properties. The developed thin films can change their transparency when exposed to air with different relative humidity (RH), adjusting the light throughput. This material can, therefore, be used to design new optical switching systems, having the advantage that they do not require liquid crystal, transparent conductive glass substrates, or complex layer-by-layer architectures for operation. In this work, a thin film was prepared by the sol–gel technique using calcium chloride as deliquescent substance embedded in a hybrid silica–titania matrix. At dry air, the thin films show a highly dispersive state, with a light transmittance T = 0.06, while at 51% RH the film exhibits a transparent state with a transmittance T =0.67 (measured at 633 nm).A thin-film material with humidity-driven light transmission properties is developed by embedding a porous matrix with a hygroscopic and deliquescent substance. When the material is in contact with dry air, it shows an opaque state that switches to transparent state by increasing the air humidity. This working principle is based on the filling/draining of the film porosity by the hydration/drying of the embedded hygroscopic substance in humid/dry environments.
      PubDate: 2017-10-24T00:56:36.486743-05:
      DOI: 10.1002/adfm.201704717
       
  • Hierarchically Porous Carbon Photonic Structures
    • Authors: Luz Karime Gil-Herrera; Jose Angel Pariente, Francisco Gallego-Gómez, Felipe Gándara, Beatriz H. Juárez, Álvaro Blanco, Cefe López
      Abstract: Hierarchically porous carbon holds promise for many applications involving not only electrical, catalytic, power storage and related functionalities but, despite absorption in the visible and near-infrared, also optical and sensing uses are envisaged. In this paper, the self-assembly of heterogeneous core–shell and hollow carbon spheres based on polystyrene cores, their optical properties and their response to humidity are described. The remarkable high quality of the crystals permits to exploit their singular optical properties among which a very high sensitivity to adsorption of guest materials stands out. In this regard, an original characterization of the system response is performed by means of the photonic bandgap variation with the relative gas pressure. Controlled pyrolysis enables to create and tune the features of the porosity brought about by degassing and the restructuring of the carbon lattice. Functionality associated with diverse pore populations reveals sensitivity to diverse ranges of humidity owing to selective adsorption of water in different size pores.Hydrothermal synthesis polystyrene-seeded carbon spheres are assembled by colloidal methods to form large-area opals. Their optical properties can be tuned through the seed/shell size. Furthermore, a posterior pyrolysis treatment allows controlling the carbon porosity and their ability to adsorb water. This adsorption has an impact on color that enables the structures to act as humidity sensors.
      PubDate: 2017-10-23T06:38:54.800897-05:
      DOI: 10.1002/adfm.201703885
       
  • Graphene Oxide-Based Lamella Network for Enhanced Sound Absorption
    • Authors: Md Julker Nine; Md Ayub, Anthony C. Zander, Diana N. H. Tran, Benjamin S. Cazzolato, Dusan Losic
      Abstract: Noise is an environmental pollutant with recognized impacts on the psychological and physiological health of humans. Many porous materials are often limited by low sound absorption over a broad frequency range, delicacy, excessive weight and thickness, poor moisture insulation, high temperature instability, and lack of readiness for high volume commercialization. Herein, an efficient and robust lamella-structure is reported as an acoustic absorber based on self-assembled interconnected graphene oxide (GO) sheets supported by a grill-shaped melamine skeleton. The fabricated lamella structure exhibits ≈60.3% enhancement over a broad absorption band between 128 and 4000 Hz (≈100% at lower frequencies) compared to the melamine foam. The enhanced acoustic absorption is identified to be structure dependent regardless of the density. The sound dissipation in the open-celled structure is due to the viscous and thermal losses, whereas it is predominantly tortuosity in wave propagation and enhanced surface area for the GO-based lamella. In addition to the enhanced acoustic absorption and mechanical robustness, the lamella provides superior structural functionality over many conventional sound absorbers including, moisture/mist insulation and fire retardancy. The fabrication of this new sound absorber is inexpensive, scalable and can be adapted for extensive applications in commercial, residential, and industrial building structures.A robust and light density lamella structure is developed based on self-assembly of graphene-oxide. The incorporation of this unique structure in an open cell network showed ~60.3% enhancement in acoustic absorption between 128 Hz and 4000 Hz. The moisture insulation and fire-retardancy further reinforce their functionality for using in adverse environments including high humidity, under water and fire risks conditions.
      PubDate: 2017-10-23T06:38:29.199541-05:
      DOI: 10.1002/adfm.201703820
       
  • Fatigue-Resistant Bioinspired Graphene-Based Nanocomposites
    • Authors: Sijie Wan; Qunfeng Cheng
      Abstract: Graphene is an attractive building block for constructing functional materials of flexible electronic devices, due to its extraordinary mechanical and electrical properties. Up to now, large amounts of high-performance graphene-based nanocomposites are fabricated. However, the fatigue behavior of graphene-based nanocomposites, a key parameter for flexible electronic devices, is rarely investigated. According to the fatigue mechanisms of thermosetting polymer composites, the fatigue resistance of graphene-based nanocomposites can be significantly improved by effectively restricting the crack growth. Natural nacre demonstrates unique multisuppression of crack propagation, which is attributed to its sophisticated interfacial architecture over multiple length scales, resulting in remarkable fracture toughness. The crack suppression mechanisms corresponding to different interfacial design strategies within bioinspired graphene-based nanocomposites (BGBNs) are summarized in this feature article. The static mechanical properties, electrical conductivity, and fatigue resistance of these BGBNs are compared and discussed. The synergistic effect from various interfacial interactions and building blocks is highlighted to serve as the guidance for constructing novel fatigue-resistant BGBNs. The promising applications of fatigue-resistant BGBNs in flexible electronic devices are reviewed, and several challenges and corresponding solutions are proposed. The perspective of fatigue-resistant BGBNs for fundamental research and commercial application is depicted.Natural nacre provides an inspiration for constructing fatigue-resistant graphene-based nanocomposites by means of interfacial interactions crosslinking and building blocks toughening, which can impede the crack growth through crack deflection, crack bridging, and plastic deformation.
      PubDate: 2017-10-11T06:48:15.577302-05:
      DOI: 10.1002/adfm.201703459
       
  • CoS Quantum Dot Nanoclusters for High-Energy Potassium-Ion Batteries
    • Authors: Hong Gao; Tengfei Zhou, Yang Zheng, Qing Zhang, Yuqing Liu, Jun Chen, Huakun Liu, Zaiping Guo
      Abstract: Potassium-ion batteries (PIBs) are a promising alternative to lithium-ion batteries because potassium is an abundant natural resource. To date, PIBs are in the early stages of exploration and only a few anode materials have been investigated. This study reports a cobalt sulfide and graphene (CoS@G) composite as anode electrode for PIBs for the first time. The composite features interconnect quantum dots of CoS nanoclusters uniformly anchored on graphene nanosheets. The coexistence of CoS quantum dot nanoclusters and graphene nanosheets endows the composite with large surface area, highly conductive network, robust structural stability, and excellent electrochemical energy storage performance. An unprecedented capacity of 310.8 mA h g−1 at 500 mA g−1 is obtained after 100 cycles, with a rate capability better than an equivalent sodium-ion batteries (SIBs). This work provides the evidence that PIBs can be a promising alternative to SIBs, especially at high charge–discharge rates. The development of the CoS@G anode material also provides the basis of expanding the library of suitable anode materials for PIBs.A CoS quantum dot nanoclusters graphene composite (CoS@G) is applied as anode in potassium-ion batteries (PIBs). The coexistence of CoS quantum dots nanoclusters and graphene nanosheets endows the composite with a large surface area, a highly conductive network, and robust structural stability. In PIBs, the electrode delivers an unprecedented capacity of 310.8 mA h g−1 at 500 m A g−1 after 100 cycles.
      PubDate: 2017-10-09T07:27:25.433926-05:
      DOI: 10.1002/adfm.201702634
       
  • Low-Power Nonvolatile Charge Storage Memory Based on MoS2 and an Ultrathin
           Polymer Tunneling Dielectric
    • Authors: Myung Hun Woo; Byung Chul Jang, Junhwan Choi, Khang June Lee, Gwang Hyuk Shin, Hyejeong Seong, Sung Gap Im, Sung-Yool Choi
      Abstract: Low-power, nonvolatile memory is an essential electronic component to store and process the unprecedented data flood arising from the oncoming Internet of Things era. Molybdenum disulfide (MoS2) is a 2D material that is increasingly regarded as a promising semiconductor material in electronic device applications because of its unique physical characteristics. However, dielectric formation of an ultrathin low-k tunneling on the dangling bond-free surface of MoS2 is a challenging task. Here, MoS2-based low-power nonvolatile charge storage memory devices are reported with a poly(1,3,5-trimethyl-1,3,5-trivinyl cyclotrisiloxane) (pV3D3) tunneling dielectric layer formed via a solvent-free initiated chemical vapor deposition (iCVD) process. The surface-growing polymerization and low-temperature nature of the iCVD process enable the conformal growing of low-k (≈2.2) pV3D3 insulating films on MoS2. The fabricated memory devices exhibit a tunable memory window with high on/off ratio (≈106), excellent retention times of 105 s with an extrapolated time of possibly years, and an excellent cycling endurance of more than 103 cycles, which are much higher than those reported previously for MoS2-based memory devices. By leveraging the inherent flexibility of both MoS2 and polymer dielectric films, this research presents an important milestone in the development of low-power flexible nonvolatile memory devices.Molybdenum disulfide (MoS2)-based low-power nonvolatile charge storage memory is developed using an ultrathin poly(1,3,5-trimethyl-1,3,5-trivinyl cyclotrisiloxane) tunneling dielectric layer with low-k (≈2.2) that is uniformly deposited on dangling bond-free surface of MoS2 via solvent-free initiated chemical vapor deposition process. The fabricated devices exhibit reliable memory operation with low-power consumption, presenting a new solution for developing a low-power, flexible, nonvolatile memory device.
      PubDate: 2017-10-06T08:59:06.297685-05:
      DOI: 10.1002/adfm.201703545
       
  • Protein Biophosphors: Biodegradable, Multifunctional, Protein-Based
           Hydrogel for White Emission, Sensing, and pH Detection
    • Authors: Kyle Benson; Ananta Ghimire, Ajith Pattammattel, Challa V. Kumar
      Abstract: A highly efficient, multifunctional, bioderived white-emitting hydrogel (biophosphor) consisting of crosslinked bovine serum albumin and three fluorescent dyes, Coumarin 460, fluorescein, and 5(6)-carboxy-x-rhodamine, is reported here. White emission is obtained upon excitation of the biophosphor at 365 nm with appropriate mole ratios of the above dyes. The CIE 1931 chromaticity coordinates of white emission with 365 nm excitation are (0.36, 0.37), and the correlated color temperature is 5300 K. Multifunctional nature of the biophosphor is also demonstrated. A UV-light-emitting-diode (361 nm) coated with this biophosphor, for example, indicates white emission (CIE 0.28, 0.31) with a half-life of 106 (±5) h. The white emission is also highly sensitive to pH over a broad range (pH 1–11). Incorporation of glucose oxidase and peroxidase in the biophosphor allows for the detection of glucose over a physiologically relevant range of 1.8–288 mg dL−1. This is a unique, advanced biophosphor with LED and sensing applications, and it is the first example of a multifunctional, proteinaceous white emitter.This work reports a multifunctional, bioderived white-emitting hydrogel (biophosphor) produced from crosslinked bovine serum albumin embedded with blue-, green-, and red-emitting dyes. White emission is obtained when excited at 365 nm, and the chromaticity coordinates are (0.36, 0.37). The resulting biophosphor is suitable for light emitting diode coating, pH sensing (1–11), and glucose detection (1.8 to 288 mg dL−1).
      PubDate: 2017-10-06T08:56:48.97466-05:0
      DOI: 10.1002/adfm.201702955
       
  • Laser-Induced In-Fiber Fluid Dynamical Instabilities for Precise and
           Scalable Fabrication of Spherical Particles
    • Authors: Jing Zhang; Kaiwei Li, Ting Zhang, Pio John S. Buenconsejo, Ming Chen, Zhe Wang, Mengying Zhang, Zhixun Wang, Lei Wei
      Abstract: Scalable fabrication of spherical particles at both the micro- and nanoscales is of significant importance for applications spanning optical devices, electronics, targeted drug delivery, biodevices, sensors, and cosmetics. However, current top-down and bottom-up fabrication methods are unable to provide the full spectrum of uniformly sized, well-ordered, and high-quality spheres due to their inherent restrictions. Here, a generic, scalable, and precisely controllable fabrication method is demonstrated for generating spherical particles in a full range of diameters from microscale to nanoscale. This method begins with a macroscopic composite multimaterial solid-state preform drawn into a fiber that defines precisely the initial conditions for the process. It is then followed by CO2 laser heating to enable the transformation from a continuous fiber core into a series of homogeneous spheres via Plateau–Rayleigh capillary instability inside the fiber. This physical breakup method applies to a wide range of functional materials with different melting temperatures from 400 to 2400 K and 10 orders of difference in fiber core/cladding viscosity ratio. Furthermore, an ordered array of silicon-based whispering-gallery mode resonators with the Q factor as high as 7.1 × 105 is achieved, owing to the process induced ultrasmooth surface and highly crystalline nature.A scalable and precisely controllable in-fiber fabrication method is demonstrated by using Plateau–Rayleigh capillary instability to produce uniformly sized, high-quality, and globally ordered spherical particles from microscale to nanoscale. This fabrication tool works for a variety of materials in a wide range of processing temperature from 400 to 2400 K and 10 orders of difference in fiber core/cladding viscosity ratio.
      PubDate: 2017-10-05T05:17:40.423186-05:
      DOI: 10.1002/adfm.201703245
       
  • Eco-Friendly SnTe Thermoelectric Materials: Progress and Future Challenges
    • Authors: Raza Moshwan; Lei Yang, Jin Zou, Zhi-Gang Chen
      Abstract: As a key type of emerging thermoelectric material, tin telluride (SnTe) has received extensive attention because of its low toxicity and eco-friendly nature. The recent trend shows that band engineering and nanostructuring can enhance thermoelectric performance of SnTe as intermediate temperature (400–800 K) thermoelectrics, which provides an alternative for toxic PbTe with the same operational temperature. This review highlights the key strategies to enhance the thermoelectric performance of SnTe materials through band engineering, carrier concentration optimization, synergistic engineering, and structure design. A fundamental analysis elucidates the underpinnings for the property improvement. This comprehensive review will boost the relevant research with a view to work on further performance enhancement of SnTe materials.SnTe qualifies as an eco-friendly alternative to medium-temperature thermoelectric PbTe by showing robust potential as high-performance thermoelectrics via effective strategies through band engineering, carrier concentration optimization, synergistic engineering, and structure design.
      PubDate: 2017-09-28T11:32:53.027024-05:
      DOI: 10.1002/adfm.201703278
       
  • Effect of Alkyl Chain Branching Point on 3D Crystallinity in High N-Type
           Mobility Indolonaphthyridine Polymers
    • Authors: Kealan J. Fallon; Annikki Santala, Nilushi Wijeyasinghe, Eric F. Manley, Niall Goodeal, Anastasia Leventis, David M. E. Freeman, Mohammed Al-Hashimi, Lin X. Chen, Tobin J. Marks, Thomas D. Anthopoulos, Hugo Bronstein
      Abstract: Herein, this study investigates the impact of branching-point-extended alkyl chains on the charge transport properties of three ultrahigh n-type mobility conjugated polymers. Using grazing incidence wide-angle X-ray scattering, analysis of the crystallinity of the series shows that while π–π interactions are increased for all three polymers as expected, the impact of the side-chain engineering on polymer backbone crystallinity is unique to each polymer and correlates to the observed changes in charge transport. With the three polymers exhibiting n-type mobilities between 0.63 and 1.04 cm2 V−1 s−1, these results ratify that the indolonaphthyridine building block has an unprecedented intrinsic ability to furnish high-performance n-type organic semiconductors.The effect of alkyl side-chain branching position on charge transport in organic semiconductors exhibiting high crystallinity is discussed herein. This study confirms that the indolonapthryidine building block has an intrinsic ability to facilitate ultrahigh n-type mobility in organic field-effect transistors, of which examples remain lacking, with recorded μe = 0.63–1.04 cm2 V−1 s−1.
      PubDate: 2017-09-28T11:29:33.485672-05:
      DOI: 10.1002/adfm.201704069
       
  • Organometal Trihalide Perovskites with Intriguing Ferroelectric and
           Piezoelectric Properties
    • Authors: Ran Ding; Xiaoli Zhang, Xiao Wei Sun
      Abstract: Organometal trihalide perovskites (OTPs) as a new subclass of perovskite materials have recently aroused increasing interest due to their numerous advantages of facile low-temperature processing, tunable bandgaps, diverse compositions, and superior charge transfer dynamics, which have been widely used in various applications. In particular, solar cells composed of these perovskites have made unprecedented progress in just a few years with maximum power conversion efficiency, evolving from 3.8 to 21.6%. In spite of such impressive achievement, a fundamental understanding of intrinsic optoelectronic and physiochemical properties is a key challenge impeding the development of the OTPs. This review article aims to provide a concise overview of the current status of OTPs research, highlighting the unique properties of OTPs, especially ferroelectric and piezoelectric properties, which are vital to photovoltaic and piezoelectric applications but still not adequately explained. Various material synthesis strategies of OTPs are surveyed, exhibiting that the OTPs architecture can serve as a promising and robust platform for opening new horizons in ferroelectric and piezoelectric researches. Several applications, including piezoelectric generators, solar cells, light-emitting diodes, lasers, photodetectors, and water-splitting cells, demonstrate the latent potentialities of OTPs.Recent progress on organometal trihalide perovskites in terms of intrinsic properties, with a focus on ferroelectricity and piezoelectricity, synthesis strategies of thin films and bulk/nanocrystals, and various applications, is reviewed. The importance of an in-depth understanding on the underlying ferroelectricity and piezoelectricity is discussed, and a thorough investigation is the main factor necessary for facilitating the functionalization of these materials.
      PubDate: 2017-09-27T10:05:55.888017-05:
      DOI: 10.1002/adfm.201702207
       
  • Fabrication of Chitosan-18β-Glycyrrhetinic Acid Modified Titanium
           Implants with Nanorod Arrays for Suppression of Osteosarcoma Growth and
           Improvement of Osteoblasts Activity
    • Authors: Meng Zhang; Haoyan Cheng, Zheni Gong, Jiting Zhang, Xi Liu, Bingbing Wang, Lina Ban, Yan Zeng, Zhihong Zhu
      Abstract: Surgery has been combined with chemotherapy to treat osteosarcoma. However, the recovery rate of osteosarcoma patients is still low. To prevent post-operative recurrence of the osteosarcoma, developing an alternative biomaterial is essential. 18β-Glycyrrhetinic acid (GA) has shown potential anticancer activity in various malignancies. Here it is proposed that GA can induce osteosarcoma cell apoptosis, and a polydopamine-mediated titanium oxide nanorod (TiO2NR) surface is functionalized by covalently grafting the chitosan-18β-glycyrrhetinic acid conjugate (CS–GA). In vitro and in vivo biological tests indicate that the CS–GA modified surface shows significant antiproliferation and apoptosis in osteosarcoma cells (MG63). Additionally, this modified surface with nanoarray structure stimulation and chitosan supplementation significantly promotes osteoblast (MC3T3-E1) adhesion and proliferation in vitro. This dual-functional, Ti-based implant with balanced antitumor and biocompatibility properties represents an effective strategy for the surgical treatment of osteosarcoma.A bifunctional TiO2 nanorod implant with balanced antitumor and biocompatibility properties is successfully fabricated by modification with a chitosan-18β-glycyrrhetinic acid conjugate (CS–GA), and using polydopamine as an assisting layer. Biological assays indicate that the CS–GA-modified Ti-based implant can effectively inhibit osteosarcoma MG63 cells growth and promote MC3T3-E1 cell adhesion and proliferation.
      PubDate: 2017-09-27T10:00:13.380537-05:
      DOI: 10.1002/adfm.201703932
       
  • Direct Laser Writing of Low-Density Interdigitated Foams for Plasma Drive
           Shaping
    • Authors: James S. Oakdale; Raymond F. Smith, Jean-Baptiste Forien, William L. Smith, Suzanne J. Ali, Leonardus B. Bayu Aji, Trevor M. Willey, Jianchao Ye, Anthony W. van Buuren, Matthew A. Worthington, Shon T. Prisbrey, Hye-Sook Park, Peter A. Amendt, Theodore F. Baumann, Juergen Biener
      Abstract: Monolithic porous bulk materials have many promising applications ranging from energy storage and catalysis to high energy density physics. High resolution additive manufacturing techniques, such as direct laser writing via two photon polymerization (DLW-TPP), now enable the fabrication of highly porous microlattices with deterministic morphology control. In this work, DLW-TPP is used to print millimeter-sized foam reservoirs (down to 0.06 g cm−3) with tailored density-gradient profiles, where density is varied by over an order of magnitude (for instance from 0.6 to 0.06 g cm−3) along a length of
      PubDate: 2017-09-27T01:24:24.634702-05:
      DOI: 10.1002/adfm.201702425
       
  • Multicolor Printing Using Electric-Field-Responsive and Photocurable
           Photonic Crystals
    • Authors: Ke Chen; Qianqian Fu, Siyun Ye, Jianping Ge
      Abstract: Efficient and large scale printing of photonic crystal patterns with multicolor, multigrayscale, and fine resolution is highly desired due to its application in smart prints, sensors, and photonic devices. Here, an electric-field-assisted multicolor printing is reported based on electrically responsive and photocurable colloidal photonic crystal, which is prepared by supersaturation-induced self-assembly of SiO2 particles in the mixture of propylene carbonate (PC) and trimethylolpropane ethoxylate triacrylate (ETPTA). This colloidal crystal suspension, named as E-ink, has tunable structural color, controllable grayscale, and instantly fixable characteristics at the same time because the SiO2/ETPTA-PC photonic crystal has metastable and reversible assembly as well as polymerizable features. Lithographical printing with photomask and maskless pixel printing techniques are developed respectively to efficiently prepare multicolor and high-resolution photonic patterns using a single-component E-ink.Electric-field-responsive and photocurable liquid photonic crystals composed of SiO2 particles, propylene carbonate, and trimethylolpropane ethoxylate triacrylate are used as E-ink to prepare multicolor and high-resolution photonic crystal patterns by lithographic and pixel printing methods, respectively.
      PubDate: 2017-09-27T01:23:45.513892-05:
      DOI: 10.1002/adfm.201702825
       
  • Morphology-Control Strategy of the Superhydrophobic Poly(Methyl
           Methacrylate) Surface for Efficient Bubble Adhesion and Wastewater
           Remediation
    • Authors: Chunhui Zhang; Moyuan Cao, Hongyu Ma, Cunlong Yu, Kan Li, Cunming Yu, Lei Jiang
      Abstract: As one common form of gas existing in aqueous environment, gas bubbles have attracted considerable worldwide attention, owing to their promising applications in industrial production and daily life, such as pressure sensors, the recovery of valuable minerals from ores, aeration process, and water treatment. Usually, the behaviors of gas bubbles in aqueous environment are mainly dominated by buoyancy force. It drives the gas bubbles out of aqueous medium rapidly, which is unfavorable in various processes, especially in wastewater treatment. In this paper, various types of superhydrophobic poly(methyl methacrylate) (PMMA) sheets are facilely fabricated, such as five-pointed star, triangle, circular, and ellipse. Compared with other shapes of superhydrophobic PMMA sheets, the prepared superhydrophobic PMMA circular sheet is capable of efficiently adhering gas bubbles and subsequently elongating their retention time in an aqueous environment. Furthermore, superhydrophobic PMMA circular sheet arrays are prepared, which can greatly improve the degradation efficiency of methyl blue by ozone (O3). The investigations indicate that the present approach will find wild applications in bubble-related fields and provide people with inspirations to develop efficient methods to manipulate gas bubbles in aqueous environment.Utilizing laser cutting and superhydrophobic surface coating, superhydrophobic poly(methyl methacrylate) (PMMA) circular sheets (SPCS) are facilely fabricated. The prepared SPCS can elongate the retention time and enlarge the contact area of bubbles in water. Furthermore, integrating the superhydrophobic PMMA circular sheet arrays with O3 improves the degradation efficiency of dye pollutants by O3.
      PubDate: 2017-09-27T01:22:17.458822-05:
      DOI: 10.1002/adfm.201702020
       
  • Decorating Perovskite Quantum Dots in TiO2 Nanotubes Array for Broadband
           Response Photodetector
    • Authors: Zhi Zheng; Fuwei Zhuge, Yaguang Wang, Jianbing Zhang, Lin Gan, Xing Zhou, Huiqiao Li, Tianyou Zhai
      Abstract: Broadband photodetectors based on TiO2 nanotubes (NTs) array have significant prospects in many fields such as environmental monitoring. Herein, a simple spin-coating process is successfully adopted to incorporate MAPbI3 quantum dots (QDs) onto the surface of TiO2 NTs to form a heterostructure, extending the response range of TiO2 NT from ultraviolet to visible. Compared with pure TiO2 NTs, the heterostructure demonstrates an improvement of responsivity in visible range by three orders of magnitude, and maintains its response performance in the UV range simultaneously. The TiO2 NTs based heterostructure photodetectors demonstrate a relative fast and stable response in the 300–800 nm range and even have a reponsivity of 0.2 A W−1 at 700 nm. The photoelectric performance of the hybrid photodetector based on TiO2 NTs maintains well when exposed to moist air for 72 h or heated from room temperature to 100 °C. Moreover, such a TiO2 NTs/MAPbI3 QDs heterostructure device demonstrates excellent flexibility and high transparency (85%) in the 400–800 nm range, their photodetecting performance is well retained after 200 cycles of repeated bending at 90°. The present strategy that combines facile electrospinning and solution-processed QDs may open a new avenue for wide range response and flexible devices construction.TiO2 NTs array and MAPbI3 QDs heterostructures are ideal candidates for broadband photodetectors. The spectral response range of TiO2 NTs is expanded to visible from UV when MAPbI3 QDs are incorporated. Moreover, this heterostructure photodetector exhibits a superior performance compared with TiO2 NWs array based device, demonstrating a thermal and excellent photoelectric bending stability and high transparency in the visible range.
      PubDate: 2017-09-27T01:17:14.702408-05:
      DOI: 10.1002/adfm.201703115
       
  • In-Plane Micro-Supercapacitors for an Integrated Device on One Piece of
           Paper
    • Authors: Ruisheng Guo; Jiangtao Chen, Bingjun Yang, Lingyang Liu, Lijun Su, Baoshou Shen, Xingbin Yan
      Abstract: Portable and wearable sensors have attracted considerable attention in the healthcare field because they can be worn or implanted into a human body to monitor environmental information. However, sensors cannot work independently and require power. Flexible in-plane micro-supercapacitor (MSC) is a suitable power device that can be integrated with sensors on a single chip. Meanwhile, paper is an ideal flexible substrate because it is cheap and disposable and has a porous and rough surface that enhances interface adhesion with electronic devices. In this study, a new strategy to integrate MSCs, which have excellent electrochemical and mechanical performances, with sensors on a single piece of paper is proposed. The integration is achieved by printing Ni circuit on paper without using a precoating underlay. Ink diffusion is also addressed to some degree. Meanwhile, a UV sensor is integrated on a single paper, and the as-integrated device shows good sensing and self-powering capabilities. MSCs can also be integrated with a gas sensor on one-piece paper and can be charged by connecting it to a solar cell. Thus, it is potentially feasible that a flexible paper can be used for integrating MSCs with solar cell and various sensors to generate, store, and use energy.An integrated device that is composed of in-plane micro-supercapacitors (MSCs) and sensor on one piece of paper is fabricated based on screen-printed Ni circuit for flexible and wearable electronics. The fabricated MSC shows excellent static and dynamic bending performances. The as-integrated devices present good sensing responsibility and self-powering capability.
      PubDate: 2017-09-14T07:25:56.378169-05:
      DOI: 10.1002/adfm.201702394
       
  • 3D-Printed All-Fiber Li-Ion Battery toward Wearable Energy Storage
    • Authors: Yibo Wang; Chaoji Chen, Hua Xie, Tingting Gao, Yonggang Yao, Glenn Pastel, Xiaogang Han, Yiju Li, Jiupeng Zhao, Kun (Kelvin) Fu, Liangbing Hu
      Abstract: Conventional bulky and rigid power systems are incapable of meeting flexibility and breathability requirements for wearable applications. Despite the tremendous efforts dedicated to developing various 1D energy storage devices with sufficient flexibility, challenges remain pertaining to fabrication scalability, cost, and efficiency. Here, a scalable, low-cost, and high-efficiency 3D printing technology is applied to fabricate a flexible all-fiber lithium-ion battery (LIB). Highly viscous polymer inks containing carbon nanotubes and either lithium iron phosphate (LFP) or lithium titanium oxide (LTO) are used to print LFP fiber cathodes and LTO fiber anodes, respectively. Both fiber electrodes demonstrate good flexibility and high electrochemical performance in half-cell configurations. All-fiber LIB can be successfully assembled by twisting the as-printed LFP and LTO fibers together with gel polymer as the quasi-solid electrolyte. The all-fiber device exhibits a high specific capacity of ≈110 mAh g−1 at a current density of 50 mA g−1 and maintains a good flexibility of the fiber electrodes, which can be potentially integrated into textile fabrics for future wearable electronic applications.Printable all-fiber quasi-solid-state lithium-ion batteries are developed through an efficient, scalable, and cost-effective 3D printing approach. The all-fiber device demonstrates high mechanical flexibility, mechanical strength, and excellent electrochemical performance, holding great promise for flexible and wearable electronic applications.
      PubDate: 2017-09-14T07:22:44.80012-05:0
      DOI: 10.1002/adfm.201703140
       
  • Improvement and Regeneration of Perovskite Solar Cells via Methylamine Gas
           Post-Treatment
    • Authors: Li Hong; Yue Hu, Anyi Mei, Yusong Sheng, Pei Jiang, Chengbo Tian, Yaoguang Rong, Hongwei Han
      Abstract: The control of film morphology is crucial in achieving high-performance perovskite solar cells (PSCs). Herein, the crystals of the perovskite films are reconstructed by post-treating the MAPbI3 devices with methylamine gas, yielding a homogeneous nucleation and crystallization of the perovskite in the triple mesoscopic inorganic layers structured PSCs. As a result, a uniform, compact, and crystalline perovskite layer is obtained after the methylamine gas post-treatment, yielding high power conversion efficiency (PCE) of 15.26%, 128.8% higher than that of the device before processing. More importantly, this post-treatment process allows the regeneration of the photodegraded PSCs via the crystal reconstruction and the PCE can recover to 91% of the initial value after two cycles of the photodegradation-recovery process. This simple method allows for the regeneration of perovskite solar cells on site without reconstruction or replacing any components, thus prolonging the service life of the perovskite solar cells and distinguishing from any other photovoltaic devices in practice.The crystals of the perovskite films are reconstructed by post-treating the MAPbI3 devices with methylamine gas, yielding high power conversion efficiency (PCE) of 15.26%, which is 128.8% higher than that of the device before processing. More importantly, the photodegraded perovskite solar cells are regenerated via crystal reconstruction, and the PCE recovers to 91% of the initial value after two cycles of the photodegradation-recovery process.
      PubDate: 2017-09-14T07:21:30.389181-05:
      DOI: 10.1002/adfm.201703060
       
  • One-Pot Synthesis of Antimony-Embedded Silicon Oxycarbide Materials for
           High-Performance Sodium-Ion Batteries
    • Authors: Yongho Lee; Kwan Young Lee, Wonchang Choi
      Abstract: Sodium-ion batteries have recently attracted intensive attention due to their natural abundance and low cost. Antimony is a desirable candidate for an anode material for sodium-ion batteries due to its high theoretical capacity (660 mA h g−1). However, the utilization of alloy-based anodes is still limited by their inherent huge volume changes and sluggish kinetics. The Sb-embedded silicon oxycarbide (SiOC) composites are simply synthesized via a one-pot pyrolysis process at 900 °C without any additives or surfactants, taking advantage of the superior self-dispersion properties of antimony acetate powders in silicone oil. The structural and morphological characterizations confirm that Sb nanoparticles are homogeneously embedded into the amorphous SiOC matrix. The composite materials exhibit an initial desodiation capacity of around 510 mA h g−1 and maintained an excellent capacity retention above 97% after 250 cycles. The rate capability test reveals that the composites deliver capacity greater than 453 mA h g−1, even at the high current density of 20 C rate, owing to the free-carbon domain of SiOC material. The electrochemical and postmortem analyses confirm that the SiOC matrix with a uniform distribution of Sb nanoparticles provides the mechanical strength without degradation in conductive characteristics, suppressing the agglomeration of Sb particles during the electrochemical reaction.Sb-embedded SiOC composites are synthesized by direct one-pot pyrolysis without any additional surfactants or chemicals. The crystalline Sb nanoparticles are homogeneously embedded into the amorphous SiOC. The mechanical strength of SiOC enhances its long-term performance. The free-carbon domain in SiOC provides the superior rate capability of the composite electrode.
      PubDate: 2017-09-13T01:03:13.666257-05:
      DOI: 10.1002/adfm.201702607
       
  • An O2 Self-Supplementing and Reactive-Oxygen-Species-Circulating Amplified
           Nanoplatform via H2O/H2O2 Splitting for Tumor Imaging and Photodynamic
           Therapy
    • Authors: Chi Zhang; Wei-Hai Chen, Li-Han Liu, Wen-Xiu Qiu, Wu-Yang Yu, Xian-Zheng Zhang
      Abstract: Conventional photodynamic therapy (PDT) has limited applications in clinical cancer therapy due to the insufficient O2 supply, inefficient reactive oxygen species (ROS) generation, and low penetration depth of light. In this work, a multifunctional nanoplatform, upconversion nanoparticles (UCNPs)@TiO2@MnO2 core/shell/sheet nanocomposites (UTMs), is designed and constructed to overcome these drawbacks by generating O2 in situ, amplifying the content of singlet oxygen (1O2) and hydroxyl radical (•OH) via water-splitting, and utilizing 980 nm near-infrared (NIR) light to increase penetration depth. Once UTMs are accumulated at tumor site, intracellular H2O2 is catalyzed by MnO2 nanosheets to generate O2 for improving oxygen-dependent PDT. Simultaneously, with the decomposition of MnO2 nanosheets and 980 nm NIR irradiation, UCNPs can efficiently convert NIR to ultraviolet light to activate TiO2 and generate toxic ROS for deep tumor therapy. In addition, UCNPs and decomposed Mn2+ can be used for further upconversion luminescence and magnetic resonance imaging in tumor site. Both in vitro and in vivo experiments demonstrate that this nanoplatform can significantly improve PDT efficiency with tumor imaging capability, which will find great potential in the fight against tumor.Enhanced and amplified photodynamic therapy: A multifunctional nanoplatform, UCNPs@TiO2@MnO2 core/shell/sheet nanocomposites, is designed to overcome the drawbacks of photodynamic therapy by generating O2 in situ, amplifying the content of singlet oxygen (1O2) and hydroxyl radical (•OH) via water-splitting, and utilizing 980 nm near-infrared light to increase penetration depth, which significantly improves PDT efficiency as well as reduces the side effects.
      PubDate: 2017-09-13T01:02:36.486717-05:
      DOI: 10.1002/adfm.201700626
       
  • Fluorescent Protein Nanovessels: A New Platform to Generate Bio–Abiotic
           Hybrid Materials for Bioimaging
    • Authors: Xiaoliang Wang; Jianxu Zhang, Youjun Wang, Yang Liu, Zhenhua Li, Zhigang Xie, Zhijun Chen
      Abstract: In this report, a new platform to generate fluorescent protein nanovessels is described. Based on systemic analyses and reconstitution experiments, a combination of protein scaffold and organic dye is identified. Briefly, certain proteins such as bovine serum albumin (BSA) can rapidly form cube-like scaffold upon heating. This protein scaffolds intrinsically interact with nonfluorescent dyes such as bromophenol blue (BPB), forming BSA-BPB nanocubes (BBNCs). Moreover, it turns out that the commercially available dye BPB contains aggregation-induced emission (AIE) properties, allowing the BBNCs emissive upon irradiation. The fluorescent protein nanovessels are highly biocompatible and can be readily internalized by different type of cells. The fluorescent signal of the materials is well-penetrable from mouse tissues and can be detected at near-infrared region, making it a useful tool for various biological imaging studies. This platform for making fluorescent protein nanovessels is green, rapid, and cost-effective and can be extended to other protein scaffolds and possibly other dye/AIE molecules.A new platform to generate fluorescent protein nanovessels for bioimaging is described. Certain proteins can rapidly form nanoscaffolds upon denaturation. These scaffolds intrinsically nature interact with certain nonfluorescent dyes, forming fluorescent protein nanovessels. The platform is green, rapid, and cost-effective and may be extended to diversified proteins and possibly various dye/AIE molecules.
      PubDate: 2017-09-13T01:01:33.677341-05:
      DOI: 10.1002/adfm.201702051
       
 
 
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