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  Subjects -> CHEMISTRY (Total: 846 journals)
    - ANALYTICAL CHEMISTRY (47 journals)
    - CHEMISTRY (596 journals)
    - CRYSTALLOGRAPHY (22 journals)
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    - INORGANIC CHEMISTRY (42 journals)
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CHEMISTRY (596 journals)                  1 2 3 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 4)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 27)
ACS Catalysis     Full-text available via subscription   (Followers: 21)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 14)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 22)
ACS Macro Letters     Full-text available via subscription   (Followers: 18)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 29)
ACS Nano     Full-text available via subscription   (Followers: 153)
ACS Photonics     Full-text available via subscription   (Followers: 6)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 15)
Acta Chemica Iasi     Open Access  
Acta Chimica Sinica     Full-text available via subscription   (Followers: 1)
Acta Chimica Slovaca     Open Access   (Followers: 2)
Acta Chromatographica     Full-text available via subscription   (Followers: 7)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 5)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 4)
Advanced Functional Materials     Hybrid Journal   (Followers: 40)
Advanced Science Focus     Free   (Followers: 3)
Advances in Chemical Engineering and Science     Open Access   (Followers: 31)
Advances in Chemical Science     Open Access   (Followers: 10)
Advances in Chemistry     Open Access   (Followers: 7)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 14)
Advances in Drug Research     Full-text available via subscription   (Followers: 20)
Advances in Environmental Chemistry     Open Access  
Advances in Enzyme Research     Open Access   (Followers: 3)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 13)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 13)
Advances in Nanoparticles     Open Access   (Followers: 11)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 12)
Advances in Polymer Science     Hybrid Journal   (Followers: 36)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 13)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 12)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Science and Technology     Full-text available via subscription   (Followers: 1)
African Journal of Chemical Education     Open Access   (Followers: 2)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 5)
Afrique Science : Revue Internationale des Sciences et Technologie     Open Access   (Followers: 1)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 1)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
AMB Express     Open Access  
Ambix     Hybrid Journal   (Followers: 2)
American Journal of Applied Sciences     Open Access   (Followers: 26)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 68)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 12)
American Journal of Chemistry     Open Access   (Followers: 23)
American Journal of Plant Physiology     Open Access   (Followers: 12)
American Mineralogist     Full-text available via subscription   (Followers: 7)
Anadolu University Journal of Science and Technology     Open Access  
Analyst     Full-text available via subscription   (Followers: 40)
Angewandte Chemie     Hybrid Journal   (Followers: 107)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 151)
Annales UMCS, Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 1)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 2)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 3)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 7)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 8)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 12)
Anti-Infective Agents     Hybrid Journal   (Followers: 2)
Antiviral Chemistry and Chemotherapy     Full-text available via subscription  
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 5)
Applied Spectroscopy     Full-text available via subscription   (Followers: 21)
Applied Surface Science     Hybrid Journal   (Followers: 20)
Arabian Journal of Chemistry     Full-text available via subscription   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 1)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 4)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access   (Followers: 1)
Biochemical Pharmacology     Hybrid Journal   (Followers: 8)
Biochemistry     Full-text available via subscription   (Followers: 197)
Biochemistry Insights     Open Access   (Followers: 4)
Biochemistry Research International     Open Access   (Followers: 4)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 7)
Bioinspired Materials     Open Access   (Followers: 2)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 1)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access  
Biomacromolecules     Full-text available via subscription   (Followers: 15)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 8)
Biomedical Chromatography     Hybrid Journal   (Followers: 7)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 2)
BioNanoScience     Partially Free   (Followers: 4)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 89)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 77)
Bioorganic Chemistry     Hybrid Journal   (Followers: 9)
Biopolymers     Hybrid Journal   (Followers: 16)
Biosensors     Open Access   (Followers: 1)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 2)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 3)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 23)
Bulletin of the Korean Chemical Society     Hybrid Journal  
C - Journal of Carbon Research     Open Access   (Followers: 2)
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 3)
Canadian Journal of Chemistry     Full-text available via subscription   (Followers: 6)
Canadian Mineralogist     Full-text available via subscription   (Followers: 3)
Carbohydrate Research     Hybrid Journal   (Followers: 27)
Carbon     Hybrid Journal   (Followers: 61)
Catalysis for Sustainable Energy     Open Access   (Followers: 4)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 6)
Catalysis Science and Technology     Free   (Followers: 4)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 5)
Cellulose     Hybrid Journal   (Followers: 4)
Central European Journal of Chemistry     Hybrid Journal   (Followers: 6)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
ChemBioEng Reviews     Full-text available via subscription  
ChemCatChem     Hybrid Journal   (Followers: 4)
Chemical and Engineering News     Free   (Followers: 10)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 19)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 15)
Chemical Reviews     Full-text available via subscription   (Followers: 124)
Chemical Science     Open Access   (Followers: 16)
Chemical Technology     Open Access   (Followers: 5)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 4)
Chemical Week     Full-text available via subscription   (Followers: 7)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 53)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 25)
ChemInform     Hybrid Journal   (Followers: 4)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 4)
Chemistry & Biology     Full-text available via subscription   (Followers: 29)
Chemistry & Industry     Hybrid Journal   (Followers: 2)
Chemistry - A European Journal     Hybrid Journal   (Followers: 99)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 11)
Chemistry and Materials Research     Open Access   (Followers: 13)
Chemistry Central Journal     Open Access   (Followers: 5)
Chemistry Education Research and Practice     Free   (Followers: 4)
Chemistry in Education     Open Access   (Followers: 2)
Chemistry International     Hybrid Journal   (Followers: 1)
Chemistry Letters     Full-text available via subscription   (Followers: 42)
Chemistry of Materials     Full-text available via subscription   (Followers: 135)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 8)
Chemistry World     Full-text available via subscription   (Followers: 21)
Chemistry-Didactics-Ecology-Metrology     Open Access  
ChemistryOpen     Open Access   (Followers: 1)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 2)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 6)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 3)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 10)
Chromatographia     Hybrid Journal   (Followers: 25)
Chromatography     Open Access   (Followers: 5)
Chromatography Research International     Open Access   (Followers: 5)
Clay Minerals     Full-text available via subscription   (Followers: 9)
Cogent Chemistry     Open Access  
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 8)
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 6)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 17)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 1)
Composite Interfaces     Hybrid Journal   (Followers: 3)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 1)
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: 10)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 10)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 9)
Coordination Chemistry Reviews     Full-text available via subscription  
Copernican Letters     Open Access  
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 4)
Crystal Structure Theory and Applications     Open Access   (Followers: 2)
CrystEngComm     Full-text available via subscription   (Followers: 6)
Current Catalysis     Hybrid Journal   (Followers: 1)
Current Metabolomics     Hybrid Journal   (Followers: 3)
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 7)
Current Opinion in Molecular Therapeutics     Full-text available via subscription   (Followers: 15)
Current Research in Chemistry     Open Access   (Followers: 7)
Current Trends in Biotechnology and Chemical Research     Open Access   (Followers: 3)
Dalton Transactions     Full-text available via subscription   (Followers: 17)
Detection     Open Access   (Followers: 2)
Developments in Geochemistry     Full-text available via subscription  
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: 3)
Eclética Química     Open Access   (Followers: 1)
Ecological Chemistry and Engineering S     Open Access   (Followers: 2)
Ecotoxicology and Environmental Contamination     Open Access  
Educación Química     Open Access   (Followers: 1)
Education for Chemical Engineers     Hybrid Journal   (Followers: 4)
Elements     Full-text available via subscription  
Environmental Chemistry     Hybrid Journal   (Followers: 5)
Environmental Chemistry Letters     Hybrid Journal   (Followers: 2)
Environmental Science & Technology Letters     Full-text available via subscription   (Followers: 3)

        1 2 3 | Last

Journal Cover Advanced Functional Materials
  [SJR: 4.682]   [H-I: 156]   [40 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  [1598 journals]
  • Electric Field Tunable Interlayer Relaxation Process and Interlayer
           Coupling in WSe2/Graphene Heterostructures
    • Abstract: Transition metal dichalcogenides van der Waals (vdWs) heterostructures present fascinating optical and electronic phenomena, and bear tremendous significance for electronic and optoelectronic applications. As the significant merits in vdWs heterostructures, the interlayer relaxation of excitons and interlayer coupling at the heterointerface reflect the dynamic behavior of charge transfer and the coupled electronic/structural characteristics, respectively, which may give rise to new physics induced by quantum coupling. In this work, upon tuning the photoluminescence (PL) properties of WSe2/graphene and WSe2/MoS2/graphene heterostructures by virtue of electric field, it is demonstrated that the interlayer relaxation of excitons at the heterointerface in WSe2/graphene, which is even stronger than that in MoS2/graphene and WSe2/MoS2 , plays a dominant role in PL tuning in WSe2/graphene, while the carrier population in WSe2 induced by electric field has a minor contribution. In addition, it is discovered that the interlayer coupling between monolayer WSe2 and graphene is enhanced under high electric field, which breaks the momentum conservation of first order Raman‐allowed phonons in graphene, yielding the enhanced Raman scattering of defects in graphene. The interplay between electric field and vdWs heterostructures may provide versatile approaches to tune the intrinsic electronic and optical properties of the heterostructures. It is demonstrated that the photoluminescence (PL) properties and interlayer coupling in WSe2/graphene heterostructures can be tuned by an electric field. PL intensity in monolayer WSe2/graphene is modulated 40 times. Additionally, it is discovered that the interlayer coupling between monolayer WSe2 and graphene is enhanced under high electric field, inducing the enhanced Raman scattering of defects in graphene.
      PubDate: 2016-05-02T07:57:15.769372-05:
      DOI: 10.1002/adfm.201505412
       
  • Benchtop Fluorination of Fluorescent Nanodiamonds on a Preparative Scale:
           Toward Unusually Hydrophilic Bright Particles
    • Abstract: Fluorination of diamonds modulates their optical and electromagnetic properties and creates surfaces with increased hydrophobicity. In addition, fluorination of diamonds and nanodiamonds has been recently shown to stabilize fluorescent nitrogen‐vacancy centers, which can serve as extremely sensitive single atomic defects in a vast range of sensing applications from quantum physics to high‐resolution biological imaging. Traditionally, fluorination of carbon nanomaterials has been achieved using harsh and complex experimental conditions, creating hydrophobic interfaces with difficult dispersibility in aqueous environments. Here, a mild benchtop approach to nanodiamond fluorination is described using selective Ag+‐catalyzed radical substitution of surface carboxyls for fluorine. In contrast to other approaches, this high‐yielding procedure does not etch diamond carbons and produces a highly hydrophilic interface with mixed C−F and C−OH termination. This dual functionalization of nanodiamonds suppresses detrimental hydrophobic interactions that would lead to colloidal destabilization of nanodiamonds. It is also demonstrated that even a relatively low surface density of fluorine contributes to stabilization of negatively charged nitrogen‐vacancy centers and boosts their fluorescence. The simultaneous control of the surface hydrophilicity and the fluorescence of nitrogen‐vacancy centers is an important issue enabling direct application of fluorescent nanodiamonds as nanosensors for quantum optical and magnetometry measurements operated in biological environment. Hydrophilic fluorinated nanodiamonds with stabilized fluorescence from nitrogen‐vacancy centres are presented. A high‐yielding decarboxylative fluorination performed in acqueous environment creates a unique mixed C–F/C–OH surface. In contrast to other fluorine‐based diamond terminations, it retains the colloidal stability of nanodiamonds and boosts the fluorescence of NV− centers at the same time. This nonetching one‐step approach can be easily performed on the benchtop without special safety precautions.
      PubDate: 2016-05-02T07:57:08.833954-05:
      DOI: 10.1002/adfm.201504857
       
  • Contactless and Rapid Discrimination of Improvised Explosives Realized by
           Mn2+ Doping Tailored ZnS Nanocrystals
    • Authors: Zhaofeng Wu; Chaoyu Zhou, Baiyi Zu, Yushu Li, Xincun Dou
      Abstract: In order to sensitively, selectively, and rapidly detect the constituents relevant to improvised explosive devices (IEDs), the sensing properties of ZnS nanocrystals (NCs) are regulated by tailoring the doping level of Mn2+. The responses of the sensors fabricated by ZnS NCs with different Mn‐doping levels (Mn:ZnS) toward the constituents, such as sulphur powder and black powder, generally increases first and then decreases with the increase of the concentration of doped Mn2+, and reaches the climate with an atomic ratio of 2.23% at room temperature. The sensory array based on eight sensors of Mn:ZnS NCs can realize the detection of two typical military explosives and six constituents relevant to IEDs within 7 s and can recover in 19 s. Furthermore, the fingerprinting of the constituents is achieved by pattern recognizing the inherent kinetics and thermodynamics of interaction between the sensory array and the constituents. Thus, a simple chemiresistive sensing strategy based on semiconductor NCs which can rapidly, supersensitively, and discriminatively detect the constituents relevant to IEDs is explored for the first time. A chemiresistive sensing scheme to sensitively and rapidly detect the vapors of the constituents relevant to improvised explosive devices (IEDs) at room temperature is achieved by tailoring the sensing properties of ZnS nanocrystals. The resulting differential identification capability toward explosives makes the on‐the‐spot detection of IEDs possible.
      PubDate: 2016-05-02T07:57:04.878563-05:
      DOI: 10.1002/adfm.201600592
       
  • Theranostic Oxygen Reactive Polymers for Treatment of Traumatic Brain
           Injury
    • Authors: Julia Xu; Menko Ypma, Peter A. Chiarelli, Joshua Park, Richard G. Ellenbogen, Patrick S. Stayton, Pierre D. Mourad, Donghoon Lee, Anthony J. Convertine, Forrest M. Kievit
      Abstract: Traumatic brain injury (TBI) is the leading cause of disability and death in children and adults under 45, with approximately ten million new cases per year worldwide. Significant progress has been made in understanding the complex pathophysiological response to TBI; however, reducing the damage associated with the reactive oxygen species (ROS)‐dependent secondary phase of the injury remains a substantial challenge. The development of an image‐guided, Gd‐conjugated, oxygen reactive polymer (ORP) to reduce ROS levels in damaged brain tissue is reported. ORP effectively sequesters ROS while remaining biocompatible even at elevated concentrations. ORP is retained in damaged brains of controlled cortical impact (CCI) mouse models of TBI for over 24 h when injected intravenously immediately and up to 3 h post‐CCI. The polymer reduces neurodegeneration tenfold and gliosis twofold in these mouse models. ORP shows initial promise as an effective therapy for TBI and helps provide a better understanding of nanomaterial interaction with damaged brain. Oxygen reactive polymers (ORP) can accumulate in damaged brain in mouse models of traumatic brain injury (TBI) and be visualized using magnetic resonance imaging. Accumulation and retention of ORP is accompanied by reduced neurodegeneration and gliosis, indicators of TBI severity. ORP should help further the understanding of nanomaterial interaction with TBI and hopefully leads to improved outcome for brain injury patients.
      PubDate: 2016-05-02T07:45:38.048653-05:
      DOI: 10.1002/adfm.201504416
       
  • A Versatile Self‐Organization Printing Method for Simplified Tandem
           Organic Photovoltaics
    • Authors: Seok Kim; Hongkyu Kang, Soonil Hong, Jinho Lee, Seongyu Lee, Byoungwook Park, Junghwan Kim, Kwanghee Lee
      Abstract: Despite recent dramatic enhancements in power conversion efficiencies (PCEs) resulting in values over 10%, the manufacturing of tandem organic solar cells (OSCs) via current printing technologies is subject to tremendous challenges. Existing complicated tandem structures consisting of six or more component layers have been a major obstacle that significantly increases the complexity of printing processes and substantially sacrifices the PCE for printed devices. Here, an innovative printing method is reported that simplifies the fabrication process of the tandem OSCs. By developing a new printing technique using a nanocomposites containing interfacial and photoactive materials, a simultaneously printed bilayer of consisting of interfacial and photoactive layers, achieved through vertical self‐organization, is successfully demonstrated, resulting in tandem OSCs with only four printed layers. Moreover, by rigorously controlling the molecular weight of the interfacial materials, the self‐assembly characteristics are improved and an efficient tandem OSC is yielded with a PCE of 9.1% achieved in printed layers. Efficient and simplified tandem organic solar cells are demonstrated through a new self‐assembly printing technique using a spontaneous vertical phase separation. A bilayer of interfacial and photoactive layers is simultaneously printed by improving vertical self‐organization characteristics. A high tandem efficiency of 9.1% is obtained with a four‐layer tandem structure.
      PubDate: 2016-04-30T01:30:05.707946-05:
      DOI: 10.1002/adfm.201505161
       
  • Lightweight Triboelectric Nanogenerator for Energy Harvesting and Sensing
           Tiny Mechanical Motion
    • Authors: Tao Li; Ying Xu, Magnus Willander, Fei Xing, Xia Cao, Ning Wang, Zhong Lin Wang
      Abstract: Triboelectric nanogenerators (TENGs) have shown exciting applications in mechanical energy harvesting and self‐powered sensing. Aiming at commercial applications, cost reduction and simplification of TENG structures are of great interest. In this work, a lightweight TENG based on the integration of polymer nanowires and a carbon sponge, which serves both as the substrate and an electrode, are reported. Because of the low density of the carbon sponge and the filmy nanowires, the device exhibits a total mass of less than 0.1 g for a volume of 12.5 cm3 and it produces a short‐circuit current of 6 μA, open‐circuit voltage of 75 V, and a maximum output power of 0.28 W kg−1 under light finger tapping. The device can linearly measure the acceleration at a detection limit down to 0.25 m s−2 and for a detection range from 0.25 m s−2 to 10.0 m s−2. A novel strategy to enhance the performance of triboelectric nanogenerators by combining a carbon material with nanowire films is proposed. The device has a mass less than 0.1 g and can harvest mechanical energy from light finger tapping. The determination limit of acceleration for such device was as low as 0.25 m s−2.
      PubDate: 2016-04-29T10:49:29.659809-05:
      DOI: 10.1002/adfm.201600279
       
  • Epitaxy of Layered Orthorhombic SnS–SnSxSe(1−x)
           Core–Shell Heterostructures with Anisotropic Photoresponse
    • Abstract: Vertical and in‐plane heterostructures based on van der Waals (vdW) crystals have drawn rapidly increasing attention owning to the extraordinary properties and significant application potential. However, current heterostructures are mainly limited to vdW crystals with a symmetrical hexagonal lattice, and the heterostructures made by asymmetric vdW crystals are rarely investigated at the moment. In this contribution, it is reported for the first time the synthesis of layered orthorhombic SnS–SnSxSe(1−x) core–shell heterostructures with well‐defined geometry via a two‐step thermal evaporation method. Structural characterization reveals that the heterostructures of SnS–SnSxSe(1−x) are in‐plane interconnected and vertically stacked, constructed by SnSxSe(1−x) shell heteroepitaxially growing on/around the pre‐synthesized SnS flake with an epitaxial relationship of (303)SnS//(033)SnSxSe(1−x), [010]SnS//[100]SnSxSe(1−x). On the basis of detailed morphology, structure and composition characterizations, a growth mechanism involving heteroepitaxial growth, atomic diffusion, as well as thermal thinning is proposed to illustrate the formation process of the heterostructures. In addition, a strong polarization‐dependent photoresponse is found on the device fabricated using the as‐prepared SnS−SnSxSe(1−x) core–shell heterostructure, enabling the potential use of the heterostructures as functional components for optoelectronic devices featured with anisotropy. Layered orthorhombic SnS–SnSxSe(1−x) core–shell heterostructures are successfully synthesized via an epitaxial growth method. Due to the structural characteristic of the components, the heterostructures are able to show a strong polarization‐dependent photoresponse, which will facilitate developing novel functional optoelectronic devices beyond conventional materials.
      PubDate: 2016-04-29T10:49:23.635556-05:
      DOI: 10.1002/adfm.201600699
       
  • Fully Transparent Nanocomposite Coating with an Amorphous Alumina Matrix
           and Exceptional Wear and Scratch Resistance
    • Abstract: This study presents a method for high temperature stabilization of amorphous alumina. The strain‐induced stabilization is obtained by dispersion of rigid globular polycarbosilane macromolecules within an alumina matrix. The alumina matrix remains amorphous even at 1200 °C. This study confirms the chemical composition of the coating with an advanced chemical depth‐profile analysis and shows its nanostructure by transmission electron microscopy. Based on this amorphous nanocomposite, a new facile and inexpensive coating for mechanical protection of glass surfaces is further developed. The nanocomposite coating is characterized by a full optical transparency and exceptional tribological characteristics. The wear resistance exceeds that of the current advanced ion‐exchanged boroaluminosilicate glass by a factor of 25–35 whereas its scratch resistance is exceeded by more than an order of magnitude. The strain‐induced high‐temperature stabilization of amorphous alumina is obtained by dispersion of rigid globular polycarbosilane macromolecules within the alumina matrix. This nanocomposite is a base for a new facile and inexpensive coating for mechanical protection of glass surfaces. The nanocomposite coating is characterized by a full optical transparency and exceptional tribological characteristics.
      PubDate: 2016-04-29T10:49:17.544239-05:
      DOI: 10.1002/adfm.201600213
       
  • Masthead: (Adv. Funct. Mater. 17/2016)
    • PubDate: 2016-04-28T05:57:56.34885-05:0
      DOI: 10.1002/adfm.201670107
       
  • The Effects of Electronic Impurities and Electron–Hole Recombination
           Dynamics on Large‐Grain Organic–Inorganic Perovskite
           Photovoltaic Efficiencies
    • Abstract: Hybrid organic‐inorganic perovskites have attracted considerable attention after promising developments in energy harvesting and other optoelectronic applications. However, further optimization will require a deeper understanding of the intrinsic photophysics of materials with relevant structural characteristics. Here, the dynamics of photoexcited charge carriers in large‐area grain organic‐inorganic perovskite thin films is investigated via confocal time‐resolved photoluminescence spectroscopy. It is found that the bimolecular recombination of free charges is the dominant decay mechanism at excitation densities relevant for photovoltaic applications. Bimolecular coefficients are found to be on the order of 10−9 cm3 s−1, comparable to typical direct‐gap semiconductors, yet significantly smaller than theoretically expected. It is also demonstrated that there is no degradation in carrier transport in these thin films due to electronic impurities. Suppressed electron–hole recombination and transport that is not limited by deep level defects provide a microscopic model for the superior performance of large‐area grain hybrid perovskites for photovoltaic applications. The local dynamics of photoexcited charge carriers in “large‐grain hybrid organic‐inorganic perovskites” is presented. Under illumination conditions relevant for photovoltaics, a suppressed recombination of free carriers is observed where electronic impurities play a negligible role in the overall kinetics. This study provides a microscopic model for low defect large‐grain hybrid perovskites where non‐Langevin recombination results in superior photovoltaic performance.
      PubDate: 2016-04-27T06:57:09.269182-05:
      DOI: 10.1002/adfm.201505324
       
  • Mussel‐Inspired Conductive Cryogel as Cardiac Tissue Patch to Repair
           Myocardial Infarction by Migration of Conductive Nanoparticles
    • Authors: Leyu Wang; Junzi Jiang, Wenxi Hua, Ali Darabi, Xiaoping Song, Chen Song, Wen Zhong, Malcolm M. Q. Xing, Xiaozhong Qiu
      Abstract: The engineered cardiac patch (ECP) is a promising strategy to repair infarct myocardium and restore the cardiac function. An ideal ECP should be able to mimic the primary attributes of native myocardium, which includes a high resilience, good cardiomyocyte adhesion, and synchronous contraction. Here, a mussel‐inspired dopamine crosslinker is used to integrate polypyrrole (Ppy) nanoparticles, gelatin‐methyacrylate, and poly(ethylene glycol) diacrylate into a cryogel form. The dopamine crosslinker and Ppy nanoparticles are coordinated to obtain optimal mechanical and superelastic properties for the ECP. The dopamine facilitates the uniform distribution of the Ppy nanoparticles, which migrate and fuse from the scaffold to the surface of the cardiomyocytes, revealing a potential mechanism for restoring infarct myocardium. The incorporated Ppy nanoparticles thus significantly enhance the functionalization of the cardiomyocytes, resulting in excellent synchronous contraction by increasing the expression of α‐actinin and CX‐43. Cardiomyocytes‐loaded ECP can improve the cardiac function in myocardial‐infarction (MI) affected rat models. The results show that the fractional shortening and ejection fraction are elevated by about 50% and that the infarct size is reduced by 42.6%. Collectively, this study highlights an effective cardiac patch based on mussel‐inspired conductive particle adhesion and a superelastic cryogel promising for the restoration of infarcted myocardium. An engineered cardiac patch (ECP) is shown for the effective in vivo repair of infarcted heart tissue. The ECP is based on a mussel‐inspired conductive cryogel incorporating a multifuntional dopamine crosslinker, gelatin, and polypyrrole nanoparticles. The hydrogel shows super‐elasticity and conductivity, which promotes the adhesion and migration of cardiomyocytes.
      PubDate: 2016-04-27T06:57:05.376369-05:
      DOI: 10.1002/adfm.201505372
       
  • Slippery Liquid‐Infused Porous Surfaces that Prevent Microbial
           Surface Fouling and Kill Non‐Adherent Pathogens in Surrounding
           Media: A Controlled Release Approach
    • Abstract: Many types of slippery liquid‐infused porous surfaces (‘SLIPS’) can resist adhesion and colonization by microorganisms. These ‘slippery’ materials thus offer approaches to prevent fouling on commercial and industrial surfaces. However, while SLIPS can prevent fouling on surfaces to which they are applied, they can currently do little to prevent the proliferation of non‐adherent organisms. Here, multi‐functional SLIPS are reported that address this issue and expand the potential utility of these materials. The approach is based on the release of antimicrobial agents from the porous matrices used to host the infused oil phases. It is demonstrated that SLIPS fabricated from nanoporous polymer multilayers can prevent colonization and biofilm formation by four common fungal and bacterial pathogens, and that the polymer and oil phases comprising these materials can be used to sustain the release of triclosan, a model antimicrobial agent, into surrounding media. This approach improves the inherent anti‐fouling properties of these materials and endows them with the ability to kill non‐adherent pathogens. This strategy has the potential to be general; the strategies and concepts reported here will enable the design of SLIPS with improved anti‐fouling properties and open the door to new applications of slippery liquid‐infused materials that host or release other active agents. Slippery liquid‐infused porous surfaces (SLIPS) that prevent colonization by microbial pathogens and also kill non‐adherent organisms in surrounding media are reported. The approach exploits the polymer and liquid phases in these materials to sustain the release of an antimicrobial agent. This approach improves the inherent anti‐fouling properties of SLIPS, is general in scope, and expands the potential utility of SLIPS in fundamental and applied contexts.
      PubDate: 2016-04-27T06:56:53.865035-05:
      DOI: 10.1002/adfm.201505522
       
  • Manipulation of Irradiative Defects at MnSe and ZnSe Dopant–Host
           Interface
    • Authors: Chunlei Wang; Jingkun Xu, Yanbin Wang, Shuhong Xu, Zhengqing Qi, Changgui Lu, Yiping Cui
      Abstract: In the past few decades, trap emission was always believed hardly manipulated to luminescent quantum dots (QDs). Actually, not all trap emissions are useless. This work shows that the interface between MnSe dopant and ZnSe host could be used for manipulating irradiative defects with a controllable manner. This study focuses on three basic challenges for manipulating interface defects, including (i) how to introduce irradiative defects at the dopant–host interface, (ii) how to control the intensity of the interface trap emission, and (iii) how to tune QD emission color via the interface trap emission. Finally, this study shows the application of dopant–host interface defects in ratiometric optical thermometry. The interface between MnSe dopant and ZnSe host can be used for manipulating irradiative defects with a controllable manner. This work focuses on the way to introduce irradiative defects at dopant–host interface, the method to control interface trap emission, and the method to tune the emission color of quantum dots by interface trap emission.
      PubDate: 2016-04-26T07:16:57.846498-05:
      DOI: 10.1002/adfm.201505172
       
  • All‐Inorganic Perovskite Nanocrystals for High‐Efficiency
           
    • Authors: Xiaoli Zhang; Bing Xu, Jinbao Zhang, Yuan Gao, Yuanjin Zheng, Kai Wang, Xiao Wei Sun
      Abstract: A dual‐phase all‐inorganic composite CsPbBr3‐CsPb2Br5 is developed and applied as the emitting layer in LEDs, which exhibited a maximum luminance of 3853 cd m–2, with current density (CE) of ≈8.98 cd A–1 and external quantum efficiency (EQE) of ≈2.21%, respectively. The parasite of secondary phase CsPb2Br5 nanoparticles on the cubic CsPbBr3 nanocrystals could enhance the current efficiency by reducing diffusion length of excitons on one side, and decrease the trap density in the band gap on the other side. In addition, the introduction of CsPb2Br5 nanoparticles could increase the ionic conductivity by reducing the barrier against the electronic and ionic transport, and improve emission lifetime by decreasing nonradiative energy transfer to the trap states via controlling the trap density. The dual‐phase all‐inorganic CsPbBr3‐CsPb2Br5 composite nanocrystals present a new route of perovskite material for advanced light emission applications. Dual‐phase CsPbBr3‐CsPb2Br5 composites for all‐inorganic perovskite light emitting diodes (LEDs) are fabricated, which exhibit significantly improved performance, representing a great increase in the CE and EQE, about 21‐ and 18‐fold improvement than that of the best reported CsPbBr3 LEDs. The dual‐phase all‐inorganic CsPbBr3‐CsPb2Br5 composite nanocrystals present a new route of perovskite material for advanced light emission applications.
      PubDate: 2016-04-26T07:16:53.425758-05:
      DOI: 10.1002/adfm.201600958
       
  • UV–Vis–Infrared Light Driven Thermocatalytic Activity of
           Octahedral Layered Birnessite Nanoflowers Enhanced by a Novel
           Photoactivation
    • Authors: Fang Liu; Min Zeng, Yuanzhi Li, Yi Yang, Mingyang Mao, Xiujian Zhao
      Abstract: Nanoflowers of octahedral layered birnessite (OL‐NF) were synthesized and characterized with a variety of techniques. Remarkably, OL‐NF exhibits a catalytic activity with a high efficiency for CO oxidation under irradiation of the full solar spectrum, visible‐infrared, or infrared light. This highly efficient catalytic activity under solar‐light irradiation originates from solar‐light‐driven thermocatalysis related to the efficient photothermal conversion and thermocatalytic activity of OL‐NF. A conceptually novel photoactivation effect is found to significantly improve the activity of the lattice oxygen of OL‐NF, thus considerably increasing the thermocatalytic activity of OL‐NF. A novel photoactivation effect is thoroughly investigated for nanoflowers of octahedral layered birnessite (OL‐NF). Their efficient catalytic activity for CO oxidation under full solar spectrum, visible‐infrared, and infrared light is shown. This originates from solar‐light‐driven thermocatalysis that is related to their efficient photothermal conversion and thermocatalytic activity.
      PubDate: 2016-04-26T07:16:31.21623-05:0
      DOI: 10.1002/adfm.201601046
       
  • Metallic Cobalt Nanoparticles Encapsulated in Nitrogen‐Enriched
           Graphene Shells: Its Bifunctional Electrocatalysis and Application in
           Zinc–Air Batteries
    • Authors: Min Zeng; Yiling Liu, Feipeng Zhao, Kaiqi Nie, Na Han, Xinxia Wang, Wenjing Huang, Xuening Song, Jun Zhong, Yanguang Li
      Abstract: There has been a continuous call for active, durable, and low‐cost electrocatalysts for a range of energy applications. Among many different nonprecious metal based candidates, transition metal nanoparticles encapsulated in graphene layers have gained increasing attention over recent years. In this study, it is demonstrated that metallic cobalt nanoparticles sheathed by multilayered nitrogen‐enriched graphene shells can be facilely prepared using cobalt‐containing Prussian blue colloids as the single precursor. These metallic cobalt cores can be readily leached out by HCl treatment, resulting in hollow graphene spheres. Products with or without acid leaching exhibit great bifunctional activities for electrocatalytic oxygen reduction and hydrogen evolution in both alkaline and acidic electrolytes. Most importantly, it is found that the removal of the metallic cores does not deteriorate but rather enhances the electrocatalytic performance. Based on this and other experimental observations, Co‐N‐C moieties are proposed as the catalytically active sites. At last, it is shown that these catalysts can be employed as the air catalyst of primary zinc–air batteries with excellent current density, power density, and operation durability. Encapsulating metallic cobalt nanoparticles by a nitrogen‐enriched graphene shell makes an excellent bifunctional electrocatalyst and zinc–air battery cathode material.
      PubDate: 2016-04-26T07:15:58.036325-05:
      DOI: 10.1002/adfm.201600636
       
  • Fully Solution‐Processed Small Molecule Semitransparent Solar Cells:
           Optimization of Transparent Cathode Architecture and Four Absorbing Layers
           
    • Abstract: Semitransparent solar cells (SSCs) can open photovoltaic applications in many commercial areas, such as power‐generating windows and building integrated photovoltaics. This study successfully demonstrates solution‐processed small molecule SSCs with a conventional configuration for the presently tested material systems, namely BDTT‐S‐TR:PC70BM, N(Ph‐2T‐DCN‐Et)3:PC70BM, SMPV1:PC70BM, and UU07:PC60BM. The top transparent cathode coated through solution processes employs a highly transparent silver nanowire as electrode together with a combination interface bilayer of zinc oxide nanoparticles (ZnO) and a perylene diimide derivative (PDINO). This ZnO/PDINO bilayer not only serves as an effective cathode buffer layer but also acts as a protective film on top of the active layer. With this integrated contribution, this study achieves a power conversion efficiency (PCE) of 3.62% for fully solution‐processed SSCs based on BDTT‐S‐TR system. Furthermore, the other three systems with various colors exhibited the PCEs close to 3% as expected from simulations, demonstrate the practicality and versatility of this printed semitransparent device architecture for small mole­cule systems. This work amplifies the potential of small molecule solar cells for window integration. Small molecule semitransparent solar cells are successfully demonstrated with conventional structure using a zinc oxide nanoparticles and a perylene diimide with N‐oxide as electron extraction bilayer and silver nanowire as the top transparent electrode.
      PubDate: 2016-04-26T07:15:28.970484-05:
      DOI: 10.1002/adfm.201505411
       
  • Explosive Raspberries: Controlled Magnetically Triggered Bursting of
           Microcapsules
    • Abstract: On‐demand and spatially controlled release of active components is crucial in several applications ranging from medicine to food and agriculture. Although many encapsulation approaches have been developed to address specific application‐related boundary conditions, microcapsule systems that enable quick and site‐specific release are still highly demanded. Here, a new design for a magnetically triggered release system consisting of an inductively heatable core covered by temperature‐sensitive bursting microcapsules is proposed. Release of the microcapsule content is achieved within a few seconds by a locally induced thermal shock without overheating the surrounding matrix. The bursting microcapsules are produced from monodisperse double emulsion templates made by microfluidics. The microcapsule shell structure is heterogeneous, consisting of a polymer particle network wetted by a liquid blowing agent and sealed by a polymeric skin. Steel particles (1 mm) are selected as an exemplary heat source because of their fast temperature increase through magnetic induced heating. Proof‐of‐concept microbursting experiments are performed to demonstrate the efficacy of the proposed raspberry design in achieving controlled local release using a magnetic trigger. In this study, it is shown that the system can be applied for the on‐demand setting of cementitious materials by externally triggering the release of a cement accelerator without undesired excessive heating of the matrix. A magnetically triggered release system consisting of a metal core covered by temperature‐sensitive bursting microcapsules is proposed for site‐specific on‐demand release of active compounds. In this raspberry architecture, fast release is achieved by a locally induced thermal shock without overheating the surrounding matrix. Proof‐of‐concept bursting experiments successfully demonstrate the efficacy of the proposed raspberry design.
      PubDate: 2016-04-25T15:04:01.236198-05:
      DOI: 10.1002/adfm.201504656
       
  • Flexible Transparent Reduced Graphene Oxide Sensor Coupled with Organic
           Dye Molecules for Rapid Dual‐Mode Ammonia Gas Detection
    • Abstract: Flexible chemical sensors utilizing chemically sensitive nanomaterials are of great interest for wearable sensing applications. However, obtaining high performance flexible chemical sensors with high sensitivity, fast response, transparency, stability, and workability at ambient conditions is still challenging. Herein, a newly designed flexible and transparent chemical sensor of reduced graphene oxide (R‐GO) coupled with organic dye molecules (bromophenol blue) is introduced. This device has promising properties such as high mechanical flexibility (>5000 bending cycles with a bending radius of 0.95 cm) and optical transparency (>60% in the visible region). Furthermore, stacking the water‐trapping dye layer on R‐GO enables a higher response as well as workability in a large relative humidity range (up to 80%), and dual‐mode detection capabilities of colorimetric and electrical sensing for NH3 gas (5–40 ppm). These advantageous attributes of the flexible and transparent R‐GO sensor coupled with organic dye molecules provide great potential for real‐time monitoring of toxic gas/vapor in future practical chemical sensing at room conditions in wearable electronics. A flexible, transparent, dual‐mode chemical sensing device based on reduced graphene oxide and an organic dye is developed for wearable sensing applications. Demonstrative measurements upon exposure to NH3 reveal a novel combination of two complimentary sensing modes of conductometry and colorimetry for practical wearable chemical sensors at ambient conditions. These devices are low‐cost and require minimal power usage.
      PubDate: 2016-04-25T15:03:47.128108-05:
      DOI: 10.1002/adfm.201505477
       
  • Size‐Induced Switching of Nanowire Growth Direction: a New Approach
           Toward Kinked Nanostructures
    • Authors: Youde Shen; Oleg I. Lebedev, Stuart Turner, Gustaaf Van Tendeloo, Xiaohui Song, Xuechao Yu, Qijie Wang, Hongyu Chen, Shadi A. Dayeh, Tom Wu
      Abstract: Exploring self‐assembled nanostructures with controllable architectures has been a central theme in nanoscience and nanotechnology because of the tantalizing perspective of directly integrating such bottom‐up nanostructures into functional devices. Here, the growth of kinked single‐crystal In2O3 nanostructures consisting of a nanocone base and a nanowire tip with an epitaxial and defect‐free transition is demonstrated for the first time. By tailoring the growth conditions, a reliable switching of the growth direction from [111] to [110] or [112] is observed when the Au catalyst nanoparticles at the apexes of the nanocones shrink below ≈100 nm. The natural formation of kinked nanoarchitectures at constant growth pressures is related to the size‐dependent free energy that changes for different orientations of the nanowires. The results suggest that the mechanism of forming such kinked nanocone–nanowire nanostructures in well‐controlled growth environment may be universal for a wide range of functional materials. Kinked nanocone–nanowire In2O3 nanostructures are fabricated via precisely controlling the nanowire growth directions. The reliable switching of growth direction from [111] to [110] and [112] at a critical nanowire radius of 100 nm is explained by the size‐dependent free energy of growing nanowires with different orientations, which represents a vital step toward constructing nanoarchitectures with tailored structural complexities.
      PubDate: 2016-04-25T15:03:41.0124-05:00
      DOI: 10.1002/adfm.201600142
       
  • Strategies for Volumetric Recovery of Large Scale Damage in Polymers
    • Authors: Brett P. Krull; Ryan C. R. Gergely, Windy A. Santa Cruz, Yelizaveta I. Fedonina, Jason F. Patrick, Scott R. White, Nancy R. Sottos
      Abstract: The maximum volume that can be restored after catastrophic damage in a newly developed regenerative polymer system is explored for various mixing, surface wetting, specimen configuration, and microvascular delivery conditions. A two‐stage healing agent is implemented to overcome limitations imposed by surface tension and gravity on liquid retention within a damage volume. The healing agent is formulated as a two‐part system in which the two reagent solutions are delivered to a through‐thickness, cylindrical defect geometry by parallel microvascular channels in thin epoxy sheets. Mixing occurs as the solutions enter the damage region, inducing gelation to initiate an accretive deposition process that enables large damage volume regeneration. The progression of the damage recovery process is tracked using optical and fluorescent imaging, and the mixing efficiency is analyzed. Complete recovery of gaps spanning 11.2 mm in diameter (98 mm2) is achieved under optimal conditions. The maximum volume recovery achievable by two‐stage healing chemistry is investigated for various mixing, surface wetting, specimen configuration, and microvascular delivery conditions. Gelation enables the healing agents to overcome the influence of gravity and surface tension to regenerate cylindrical damage volumes. Complete material recovery is achieved for damage regions ranging up to 11.2 mm in diameter, an increase of 197% over non‐gelling control fluids.
      PubDate: 2016-04-25T15:03:34.035407-05:
      DOI: 10.1002/adfm.201600486
       
  • Delocalized Electron Accumulation at Nanorod Tips: Origin of Efficient H2
           Generation
    • Abstract: Photocatalytic hydrogen (H2) evolution requires efficient electron transfer to catalytically active sites in competition with charge recombination. Thus, controlling charge‐carrier dynamics in the photocatalytic H2 evolution process is essential for optimized photocatalyst nanostructures. Here, the efficient delocalization of electrons is demonstrated in a heterostructure consisting of optimized MoS2 tips and CdS nanorods (M‐t‐CdS Nrs) synthesized by amine‐assisted oriented attachment. The heterostructure achieves photocatalytic H2 activity of 8.44 mmol h−1 g−1 with excellent long‐term durability (>23 h) without additional passivation under simulated solar light (AM 1.5, 100 mW cm−2). This activity is nearly two orders of magnitude higher than that of pure CdS Nrs. The impressive photocatalytic H2 activity of M‐t‐CdS Nrs reflects favorable charge‐carrier dynamics, as determined by steady‐state PL and time‐correlated single photon counting correlation analysis at low temperature. The MoS2 cocatalysts precisely located at the end of the CdS Nrs exhibit ultrafast charge transfer and slow charge recombination via spatially localized deeper energy states, resulting in a highly efficient H2 evolution reaction in lactic acid containing an electrolyte. MoS2 tipped CdS nanorods synthesized by amine‐assisted oriented attachment exhibit ultrafast charge transfer and slow charge recombination via spatially localized deeper energy states, resulting in photocatalytic H2 activity of 8.44 mmol h−1 g−1 with excellent long‐term durability (>23 h) without additional passivation under simulated solar light.
      PubDate: 2016-04-25T15:03:10.561275-05:
      DOI: 10.1002/adfm.201600285
       
  • A Novel Photocathode Material for Sunlight‐Driven Overall Water
           Splitting: Solid Solution of ZnSe and Cu(In,Ga)Se2
    • Authors: Hiroyuki Kaneko; Tsutomu Minegishi, Mamiko Nakabayashi, Naoya Shibata, Yongbo Kuang, Taro Yamada, Kazunari Domen
      Abstract: Thin films of a solid solution of ZnSe and CuIn0.7Ga0.3Se2 ((ZnSe) x (CIGS) 1–x ) are prepared by co‐evaporation. Structural characterization reveals that the ZnSe and CIGS form a solid solution with no phase separation. (ZnSe)0.85(CIGS)0.15‐based photocathodes modified with Pt, Mo, Ti, and CdS exhibit a photocurrent of 7.1 mA cm−2 at 0 VRHE, and a relatively high onset potential of 0.89 VRHE under simulated sunlight. A two‐electrode cell containing a (ZnSe)0.85(CIGS)0.15 photocathode and a BiVO4‐based photoanode has an initial solar‐to‐hydrogen conversion efficiency of 0.91%, which is one of the highest values reported for a photoanode–photocathode combination. Thus, (ZnSe)0.85(CIGS)0.15 is a promising photocathode material for efficient photoelectrochemical water splitting. (ZnSe)0.85(CIGS)0.15‐based photocathodes for hydrogen evolution from water show a notably high onset potential of 0.89 VRHE under simulated sunlight. A photoelectrochemical cell composed of a (ZnSe)0.85(CIGS)0.15‐based photocathode and a BiVO4‐based photoanode drives overall water splitting utilizing simulated sunlight without an external bias voltage, exhibiting a solar‐to‐hydrogen conversion efficiency of 0.91%.
      PubDate: 2016-04-25T15:03:00.434836-05:
      DOI: 10.1002/adfm.201600615
       
  • Designing Multicolored Photonic Micropatterns through the Regioselective
           Thermal Compression of Inverse Opals
    • Abstract: Colloidal assemblies develop pronounced structural colors due to the selective diffraction of light. Micropatterns with multiple structural colors are appealing for the use in a variety of photonic applications. Here, a lithographic approach is reported, which provides a high level of control over the size, shape, and color of a micropattern using the anisotropic shrinkage of inverse opals made of a negative photoresist heated to high temperatures. Shrinkage occurs uniformly across the thickness of the film, leading to a blueshift in the structural color while maintaining a high reflectivity across the full visible spectrum. The rate of shrinkage is determined by the annealing temperature and the photoresist crosslinking density. The rate can, therefore, be spatially modulated by applying UV radiation through a photomask to create multicolor micropatterns from single‐colored inverse opals. The lateral dimensions of the micropattern features can be as small as the thickness of the inverse opal. Multicolored photonic micropatterns with high reflectivity and resolution are simply created by anisotropic shrinkage of inverse opals made of a negative photoresist. The rate of shrinkage is determined by annealing temperature and UV dose, which enables the spatial modulation of structural color through a photolithography. This spatially addressable and rate‐controllable anisotropic compression will benefit a wide range of photonic applications.
      PubDate: 2016-04-25T15:02:56.174378-05:
      DOI: 10.1002/adfm.201601095
       
  • Combinatorial Study of Temperature‐Dependent Nanostructure and
           Electrical Conduction of Polymer Semiconductors: Even Bimodal Orientation
           Can Enhance 3D Charge Transport
    • Authors: Sangsik Park; Moo Hyung Lee, Kwang Seok Ahn, Hyun Ho Choi, Jihye Shin, Jie Xu, Jianguo Mei, Kilwon Cho, Zhenan Bao, Dong Ryeol Lee, Moon Sung Kang, Do Hwan Kim
      Abstract: Temperature‐dependent (80–350 K) charge transport in polymer semiconductor thin films is studied in parallel with in situ X‐ray structural characterization at equivalent temperatures. The study is conducted on a pair of isoindigo‐based polymers containing the same π‐conjugated backbone with different side chains: one with siloxane‐terminated side chains (PII2T‐Si) and the other with branched alkyl‐terminated side chains (PII2T‐Ref). The different chemical moiety in the side chain results in a completely different film morphology. PII2T‐Si films show domains of both edge‐on and face‐on orientations (bimodal orientation) while PII2T‐Ref films show domains of edge‐on orientation (unimodal orientation). Electrical transport properties of this pair of polymers are also distinctive, especially at high temperatures (>230 K). Smaller activation energy (E A) and larger pre‐exponential factor (μ 0) in the mobility‐temperature Arrhenius relation are obtained for PII2T‐Si films when compared to those for PII2T‐Ref films. The results indicate that the more effective transport pathway is formed for PII2T‐Si films than for the other, despite the bimodally oriented film structure. The closer π–π packing distance, the longer coherence length of the molecular ordering, and the smaller disorder of the transport energy states for PII2T‐Si films altogether support the conduction to occur more effectively through a system with both edge‐on and face on orientations of the conjugated molecules. Reminding the 3D nature of conduction in polymer semiconductor, our results suggest that the engineering rules for advanced polymer semiconductors should not simply focus on obtaining films with conjugated backbone in edge‐on orientation only. Instead, the engineering should also encounter the contribution of the inevitable off‐directional transport process to attain effective transport from polymer thin films. 3D charge conduction behavior of sister isoindigo‐based polymer semiconductor thin films is described complementarily with X‐ray structural analyses at varying temperatures. Because the overall charge transport occurs three dimensionally, rather than through a simple 2D manner, films formed with mixtures of edge‐on and face‐on orientations can also be beneficial, as long as good π‐stacking is attained in molecular scale.
      PubDate: 2016-04-25T15:02:47.391527-05:
      DOI: 10.1002/adfm.201601164
       
  • Simple Salt‐Coordinated n‐Type Nanocarbon Materials Stable in
           Air
    • Authors: Yoshiyuki Nonoguchi; Motohiro Nakano, Tomoko Murayama, Harutoshi Hagino, Shota Hama, Koji Miyazaki, Ryosuke Matsubara, Masakazu Nakamura, Tsuyoshi Kawai
      Abstract: After more than three decades of molecular and carbon‐based electronics, the creation of air‐ and thermally stable n‐type materials remains a challenge in the development of future p/n junction devices such as solar cells and thermoelectric modules. Here a series of ordinary salts are reported such as sodium chloride (NaCl), sodium hydroxide (NaOH), and potassium hydroxide (KOH) with crown ethers as new doping reagents for converting single‐walled carbon nanotubes to stable n‐type materials. Thermoelectric analyses reveal that these new n‐type single‐walled carbon nanotubes display remarkable air stability even at 100 °C for more than 1 month. Their thermoelectric properties with a dimensionless figure‐of‐merit (ZT) of 0.1 make these new n‐type single‐walled carbon nanotubes a most promising candidate for future n‐type carbon‐based thermoelectric materials. Highly stable n‐type nanocarbon materials are prepared using the complexes of ordinary salts and crown ethers. Negatively charged π‐conjugated structures in n‐type materials are stabilized by the coordination of soft acids on the basis of classical hard and soft acids and bases (HSAB) theory. The exceptional thermal stability of n‐type single‐walled carbon nanotubes at 150 °C in air is demonstrated.
      PubDate: 2016-04-25T01:06:03.553532-05:
      DOI: 10.1002/adfm.201600179
       
  • Chitosan–Alginate Microcapsules Provide Gastric Protection and
           Intestinal Release of ICAM‐1‐Targeting Nanocarriers, Enabling
           GI Targeting In Vivo
    • Abstract: When administered intravenously, active targeting of drug nanocarriers (NCs) improves biodistribution and endocytosis. Targeting may also improve NC oral delivery to treat gastrointestinal (GI) pathologies or for systemic absorption. However, GI instability of targeting moieties compromises this strategy. This study explores whether encapsulation of antibody‐coated NCs in microcapsules would protect against gastric degradation, providing NC release and targeting in intestinal conditions. Nanoparticles coated with antibodies against intercellular adhesion molecule‐1 (anti‐ICAM) or nonspecific immunoglobulin G (IgG) are encapsulated in chitosan (shell) ‐ alginate (core) microcapsules. Encapsulation efficiency is >95% and NC relase from microcapsules in storage is
      PubDate: 2016-04-23T03:40:50.255524-05:
      DOI: 10.1002/adfm.201600084
       
  • Flexible Sodium‐Ion Pseudocapacitors Based on 3D Na2Ti3O7 Nanosheet
           Arrays/Carbon Textiles Anodes
    • Authors: Shengyang Dong; Laifa Shen, Hongsen Li, Gang Pang, Hui Dou, Xiaogang Zhang
      Abstract: Flexible energy storage devices are critical components for emerging flexible and wearable electronics. Improving the electrochemical performance of flexible energy storage devices depends largely on development of novel electrode architectures and new systems. Here, a new class of flexible energy storage device called flexible sodium‐ion pseudocapacitors is developed based on 3D‐flexible Na2Ti3O7 nanosheet arrays/carbon textiles (NTO/CT) as anode and flexible reduced graphene oxide film (GFs) as cathode without metal current collectors or conducting additives. The NTO/CT anode with advanced electrode architectures is fabricated by directly growing Na2Ti3O7 nanosheet arrays on carbon textiles with robust adhesion through a simple hydrothermal process. The flexible GF//NTO/CT configuration achieves a high energy density of 55 Wh kg−1 and high power density of 3000 W kg−1. Taking the fully packaged flexible sodium‐ion pseudocapacitors into consideration, the maximum practical volumetric energy density and power density reach up to 1.3 mWh cm−3 and 70 mW cm−3, respectively. In addition, the flexible GF//NTO/CT device demonstrates a stable electrochemical performances with almost 100% capacitance retention under harsh mechanical deformation. A new class of flexible energy storage device called flexible sodium‐ion pseudocapacitor is developed by using 3D flexible Na2Ti3O7 nanosheet arrays/carbon textile as anode and reduced graphene oxide films as cathode. Due to its structural features and hybrid energy storage mechanisms, the flexible sodium‐ion pseudocapacitor demonstrates high mechanical flexibility, high energy density, high power density, and long capacity retention.
      PubDate: 2016-04-23T03:40:45.633321-05:
      DOI: 10.1002/adfm.201600264
       
  • Preparation of MnCo2O4@Ni(OH)2 Core–Shell Flowers for Asymmetric
           Supercapacitor Materials with Ultrahigh Specific Capacitance
    • Authors: Yan Zhao; Linfeng Hu, Shuyan Zhao, Limin Wu
      Abstract: Supercapacitors have attracted much interest in the past decades owing to their important applications, but most of them are focused on solitary or simple metal oxides. Here, a novel supercapacitor electrode composed of multicomponent MnCo2O4@Ni(OH)2 belt‐based core–shell nanoflowers is reported by a facile and cost‐effective method. This hybrid electrode exhibits a significantly enhanced specific capacitance. An asymmetric supercapacitor based on this unique hybrid nanoflowers as anode and an activated carbon film as cathode demonstrates high energy density, high power density, and long cycling lifespan. Manganese cobalt spinel and nickel hydroxide hybrid belt‐based core–shell nanoflowers are successfully fabricated by a facile and cost‐effective strategy. The hybrid electrode exhibits an ultrahigh specific capacitance (2154 F g−1 at 5 A g−1). An asymmetric supercapacitor device based on this hybrid nanoflowers demonstrates high energy density, high power density, and long cycling lifespan.
      PubDate: 2016-04-23T03:40:39.795036-05:
      DOI: 10.1002/adfm.201600494
       
  • Bipolar Electrochemical Synthesis of WS2 Nanoparticles and Their
           Application in Magneto‐Immunosandwich Assay
    • Abstract: WS2 nanoparticles are prepared using bipolar electrochemistry. Obtained material exhibits high activity for hydrogen evolution reaction (HER) and it is used as a label in standard magneto‐immunosandwich assay for protein detection through HER. This new system shows high analytical performance in terms of a wide range, selectivity, sensitivity, and reproducibility. WS2 nanoparticles are prepared using bipolar electrochemistry. The potential applications of these materials as a label for protein detection are demonstrated utilizing hydrogen evolution reaction with electrochemical impedance spectroscopy as a transduction method. This new system shows high analytical performance in terms of a wide range, selectivity, sensitivity, and reproducibility.
      PubDate: 2016-04-23T03:40:30.279383-05:
      DOI: 10.1002/adfm.201600961
       
  • Mussel‐Inspired Approach to Constructing Robust Multilayered
           Alginate Films for Antibacterial Applications
    • Abstract: The exceptional mechanical properties of the byssus—the fibrous holdfast of mussels that provides underwater adhesion—have potential applications in medicine and technology. The catechol–Fe3+–catechol interaction underlies the unique properties of mussel byssus and has emerged as a tool for developing functional hybrid materials such as pH‐responsive, self‐healing gels. Herein, the construction of functional alginate (Alg) film on a solid substrate inspired by mussel byssus is reported. The approach consists of spin‐coating‐assisted deposition of Alg catechols onto a solid substrate and their subsequent crosslinking via catechol–Fe3+–catechol interactions. This yields robust and multilayered Alg films that are resistant to protein adsorption and suppress bacterial adhesion. This method can be used to create antibacterial films for coating implanted medical devices. A novel method for generating a multilayered alginate film is developed by mimicking the formation of cuticle layers around the byssus of mussels. The approach consists of spin‐coating‐assisted deposition of alginate catechols onto a solid substrate and their subsequent crosslinking via catechol–Fe3+–catechol interactions, which yields a robust alginate film that inhibits bacterial adhesion.
      PubDate: 2016-04-23T03:40:26.579876-05:
      DOI: 10.1002/adfm.201600613
       
  • Charge‐Carrier Density Independent Mobility in Amorphous
           Fluorene‐Triarylamine Copolymers
    • Authors: Alasdair J. Campbell; Ruth Rawcliffe, Alexander Guite, Jorge Costa Dantas Faria, Abhimanyu Mukherjee, Martyn A. McLachlan, Maxim Shkunov, Donal D. C. Bradley
      Abstract: A charge‐carrier density dependent mobility has been predicted for amorphous, glassy energetically disordered semiconducting polymers, which would have considerable impact on their performance in devices. However, previous observations of a density dependent mobility are complicated by the polycrystalline materials studied. Here charge transport in field‐effect transistors and diodes of two amorphous, glassy fluorene‐triarylamine copolymers is investigated, and the results explored in terms of a charge‐carrier density dependent mobility model. The nondispersive nature of the time‐of‐flight (TOF) transients and analysis of dark injection transient results and transistor transfer characteristics indicate a charge‐carrier density independent mobility in both the low‐density diode and the high‐density transistor regimes. The mobility values for optimized transistors are in good agreement with the TOF values at the same field, and both have the same temperature dependency. The measured transistor mobility falls two to three orders of magnitude below that predicted from the charge‐carrier density dependent model, and does not follow the expected power‐law relationship. The experimental results for these two amorphous polymers are therefore consistent with a charge‐carrier density independent mobility, and this is discussed in terms of polaron‐dominated hopping and interchain correlated disorder. Charge transport in diodes and transistors of two amorphous glassy fluorene‐triarylamine copolymers is found to be consistent with a charge‐carrier density independent mobility. This is in contradiction to many theoretical models, which predict a charge‐carrier density dependent mobility for such energetically disordered organic semiconductors. This could indicate that interchain correlations can smooth out the energy landscape in amorphous conjugated polymers.
      PubDate: 2016-04-21T03:50:29.901768-05:
      DOI: 10.1002/adfm.201504722
       
  • Stretchable‐Fiber‐Confined Wetting Conductive Liquids as
           Wearable Human Health Monitors
    • Authors: Liyun Guan; Azadeh Nilghaz, Bin Su, Lei Jiang, Wenlong Cheng, Wei Shen
      Abstract: Wetting behaviors on stretchable supports are very common in our daily lives, however, received limited attention even they show promising potentials in flexible electronics and other fields. In this study, stretchable wetting behaviors of conductive liquids deposited onto two horizontal rubber fibers are investigated. A firm liquid/solid interaction during the stretching process can contribute to a stable liquid bridge between the fibers even under extremely stretching, showing their proof‐to‐principle ability to monitor human movement toward early diagnosis of Parkinson's disease or sports injury prevention. Stretchable wetting behaviors of conductive liquids deposited onto two horizontal rubber fibers are investigated. Optimized parameters contribute to a stable liquid bridge between the fibers even under externally stretching, showing the potentials to monitor human movement toward early diagnosis of Parkinson's disease or sports protection.
      PubDate: 2016-04-18T11:49:30.419275-05:
      DOI: 10.1002/adfm.201600443
       
  • Photoluminescence Enhancement in Formamidinium Lead Iodide Thin Films
    • Abstract: Formamidinium lead iodide (FAPbI3) has a broader absorption spectrum and better thermal stability than the most famous methylammonium lead iodide, thus exhibiting great potential for photovoltaic applications. In this report, the light‐induced photoluminescence (PL) evolution in FAPbI3 thin films is investigated. The PL intensity evolution is found to be strongly dependent on the atmosphere surrounding the samples. When the film is exposed to air, its photoluminescence intensity is enhanced more than 140 times after continuous ultraviolet laser illumination for 2 h, and the average lifetime is prolonged from 17 to 389 ns. The enhanced photoluminescence implies that the trap density is significantly reduced. The comparative study of the photoluminescence properties in air, nitrogen, and oxygen/helium environment suggests that moisture is important for the PL enhancement. This is explained in terms of moisture‐assisted light‐healing effect in FAPbI3 thin films. With this study, a new method is demonstrated to increase and control the quality of hybrid perovskite thin films. Laser healing perovskites: Photophysical properties of FAPbI3 thin films under continuous UV illumination are investigated. Giant light‐induced enhancement of the photoluminescence intensity is observed when the sample is exposed to air. It is demonstrated that moisture plays a critical role in the light‐induced photoluminescence enhancement effect. Laser healing in air can become a way to improve the quality of perovskite thin films.
      PubDate: 2016-04-18T11:49:26.954284-05:
      DOI: 10.1002/adfm.201600715
       
  • Large‐Area Bilayer ReS2 Film/Multilayer ReS2 Flakes Synthesized by
           Chemical Vapor Deposition for High Performance Photodetectors
    • Authors: Muhammad Hafeez; Lin Gan, Huiqiao Li, Ying Ma, Tianyou Zhai
      Abstract: Rhenium disulfide (ReS2) is attracting more and more attention for its thickness‐depended direct band gap. As a new appearing 2D transition metal dichalcogenide, the studies on synthesis method via chemical vapor deposition (CVD) is still rare. Here a systematically study on the CVD growth of continuous bilayer ReS2 film and single crystalline hexagonal ReS2 flake, as well as their corresponding optoelectronic properties is reported. Moreover, the growth mechanism has been proposed, accompanied with simulation study. High‐performance photodetector based on ReS2 flake shows a high responsivity of 604 A·W−1, high external quantum efficiency of 1.50 × 105 %, and fast response time of 2 ms. ReS2 film‐based photodetector exhibits weaker performance than the flake one; however, it still demonstrates a much faster response time (≈103 ms) than other reported CVD‐grown ReS2‐based photodetector (≈104–105 ms). Such good properties of ReS2 render it a promising future in 2D optoelectronics. Hexagonal single‐crystal ReS2 flakes and large‐area continuous polycrystalline bilayer ReS2 film are achieved via CVD method, and their possible growth mechanism is studied. Potential utilization of ReS2 in high performance photodetector is explored. A single‐crystal ReS2‐based photodetector is found to be of excellent photoresponsivity (604 A W−1), high external quantum efficiency (1.50 × 105%), and fast response time (2 ms), obviously superior to many other similar transition‐metal‐dichalcogenide‐based photodetectors.
      PubDate: 2016-04-18T11:49:22.537542-05:
      DOI: 10.1002/adfm.201601019
       
  • Thiolation and Cell‐Penetrating Peptide Surface Functionalization of
           Porous Silicon Nanoparticles for Oral Delivery of Insulin
    • Abstract: During the last decades, advanced oral delivery systems to enhance the intestinal absorption of widely applicable proteins and peptides, particularly insulin, have been developed. Here, chitosan‐conjugated undecylenic acid‐modified thermally hydrocarbonized porous silicon nanoparticles (CSUn NPs) are used, which promote the mucoadhesion and cellular interactions, thus boosting the intestinal permeability of insulin. Then, to further potentiate the mucoadhesion and permeability enhancement of chitosan‐modified NPs, the surface of the NPs is further modified with either l‐cysteine (CYS‐CSUn NPs) or a cell‐penetrating peptide (CPP‐CSUn NPs). CYS‐CSUn and CPP‐CSUn NPs show 17‐ and 12‐fold increase in the apparent permeability of insulin across cellular intestinal cells, respectively, with significant enhancement in the cellular interactions. The insulin uptake mechanism pathways in intestinal cells from the developed NPs are also unraveled, which demonstrates major involvement of active transport process and electrostatic interactions, along with adsorptive and clathrin‐mediated endocytic pathways. Moreover, after oral administration in diabetic rats, CYS‐CSUn NPs show 1.86‐ and 2.03‐fold increase in the relative bioavailability of insulin, as compared to empty NPs and oral insulin solution, respectively. In conclusion, this study presents l‐cysteine modified CSUn NPs as a promising strategy with the ability to overcome the multiple barriers for oral delivery of insulin. l‐cysteine‐ and cell‐penetrating‐peptide‐modified, chitosan‐conjugated porous silicon nanoparticles (NPs) are developed for oral delivery of insulin. The NPs site‐specifically deliver insulin in the intestine where it associate with the mucus layers and come in close proximity to the intestinal epithelia where enhances its permeation across the intestine wall.
      PubDate: 2016-04-18T02:27:11.638554-05:
      DOI: 10.1002/adfm.201505252
       
  • Flexible Polymer Transducers for Dynamic Recognizing Physiological Signals
    • Abstract: Ferroelectric polymers are of interest as most promising electroactive materials. Flexible transducers from ferroelectric polymer thin film with underneath semiconducting polymer active layer for high sensitive and versatile detection of physiological signals are described. When attached directly on the wrist, the flexible transducers can distinguish the transient pulse waves non‐invasively and in situ, due to their fast response (milliseconds) and high sensitivity (down to several Pascal) to instantaneous change of blood pressure. High‐resolution picture of one pulse wave is available to provide two most common parameters for arterial stiffness diagnosis. The transducers are also suitable for dynamic recognizing physiological signals under both physical exercise and medicine treatment, demonstrating their enormous potential for warning the risk of cardiovascular disease, and evaluating the efficacy of heart medicines. The transducers are easy to carry around with an operating voltage of 1 V and the power consumption less than 1 μW. Thus, they are valuable for applications like electronic skin and mobile health monitoring. Portable devices for diagnosis of cardiovascular system: A simple yet efficient and low‐cost method can fabricate a wearable transducer for non‐invasive and dynamic diagnosis of cardiovascular system by using smart dielectric polymer poly(vinylidene fluoride‐trifluoroethylene‐chlorofluoroethylene). The transducer has low power consumption and is facile to integrate into portable devices for remote detecting warning signals of heart attacks and assessing efficiency of heart drugs.
      PubDate: 2016-04-18T02:27:05.114774-05:
      DOI: 10.1002/adfm.201600008
       
  • The Application of Stimuli‐Responsive VEGF‐ and
           ATP‐Aptamer‐Based Microcapsules for the Controlled Release of
           an Anticancer Drug, and the Selective Targeted Cytotoxicity toward Cancer
           Cells
    • Abstract: The synthesis of microcapsules consisting of DNA shells crosslinked by anti‐VEGF (vascular epithelial growth factor) or anti‐ATP (adenosine triphosphate) aptamers and loaded with tetramethylrhodamine‐modified dextran, TMR‐D, and Texas Red‐modified dextran, TR‐D, respectively, as fluorescence labels acting as models for drug loads, is described. The aptamer‐functionalized microcapsules act as stimuli‐responsive carriers for the triggered release of the fluorescent labels in the presence of the overexpressed cancer cell biomarkers VEGF or ATP. The VEGF‐ and ATP‐responsive microcapsules are, also, loaded with the anticancer drug doxorubicin (DOX), in the form of DOX‐functionalized dextran, DOX‐D. The release of DOX‐D from the respective microcapsules proceeds in the presence of VEGF or ATP as triggers. Preliminary cell experiments reveal that the ATP‐responsive DOX‐D‐loaded microcapsules undergo effective endocytosis into MDA‐MB‐231 cancer cells. The ATP‐responsive DOX‐D‐loaded microcapsules incorporated into the MDA‐MB‐231 cancer cells reveal impressive cytotoxicity as compared to normal epithelial MCF‐10A breast cells (50% vs 0% cell death after 24 h, respectively). The cytotoxicity of the ATP‐responsive DOX‐D‐loaded microcapsules toward the cancer cells is attributed to the effective unlocking of the microcapsules by overexpressed ATP, and to the subsequent release of DOX from the dextran backbone under acidic conditions present in cancer cells (pH = 6.2). Adenosine triphosphate (ATP)‐ or vascular epithelial growth factor (VEGF)‐responsive DNA‐based microcapsules loaded with fluorescent labels or the doxorubicin‐modified dextran are unlocked in the presence of ATP or VEGF cancer biomarkers, resulting in the release of the loads. Selective cytotoxicity toward cancer cells is observed upon the intracellular ATP‐triggered release of doxorubicin.
      PubDate: 2016-04-18T02:26:59.222429-05:
      DOI: 10.1002/adfm.201600069
       
  • Fully Solution‐Processed Conductive Films Based on Colloidal Copper
           Selenide Nanosheets for Flexible Electronics
    • Authors: Sergey Vikulov; Francesco Di Stasio, Luca Ceseracciu, Pearl L. Saldanha, Alice Scarpellini, Zhiya Dang, Roman Krahne, Liberato Manna, Vladimir Lesnyak
      Abstract: A novel colloidal synthesis of copper selenide nanosheets (NSs) with lateral dimensions of up to 3 μm is developed. This material is used for the fabrication of flexible conductive films prepared via simple drop‐casting of the NS dispersions without any additional treatment. The electrical performance of these coatings is benchmarked against copper selenide spherical nanocrystals (SNCs) in order to demonstrate the advantage of 2D morphology of the NSs for flexible electronics. In this contest, Cu2−xSe SNC films exhibit higher conductivity but lower reproducibility due to the formation of cracks leading to discontinuous films. Furthermore, the electrical properties of the films deposited on different flexible substrates following their bending, stretching and folding are studied. A comparison of Cu2−xSe SNC and CuSe NS films reveals an increased stability of the CuSe NS films under mechanical stress applied to the samples and their improved long‐term stability in air. Two types of colloidal copper selenide nanomaterials (spherical particles and sheets) are used for fabrication of flexible conductive films. The morphology of the nanosheet films with overlapping contacts between the individual sheets results in almost complete recovery of their conductivity after bending and stretching. Similar treatment of Cu2−xSe spherical nanoparticle‐based samples leads to irreversible loss of their conductivity.
      PubDate: 2016-04-18T02:26:51.228065-05:
      DOI: 10.1002/adfm.201600124
       
  • Toward High Performance Photoelectrochemical Water Oxidation: Combined
           Effects of Ultrafine Cobalt Iron Oxide Nanoparticle
    • Abstract: Photocleavage of H2O into clean and storable H2 fuel by photoelectrochemical (PEC) cell is a vital part of the sustainable hydrogen economy. However, thus far one of the limitations confronted by PEC cell to preferable performance is the insufficient behavior of photoanode for water oxidation half‐reaction. One of the strategies to elevate the photoanode performance is integrating with an oxygen evolution catalyst (OEC) to remove the bottleneck of the water oxidation kinetics. Herein, an ultrafine cobalt iron oxide (CIO) nanocrystalline is reported as a novel OEC for photoelectrochemical water splitting. The CIO evenly distributing on the surface of hematite nanorod arrays not only greatly facilitates the surface hole injection, but also promotes the charge separation along with passivating the surface states. Such combined effects of CIO finally lead to an impressive 1.71 fold enhancement on the photocurrent density at 1.23 VRHE and ≈170 mV negative shift of onset potential, even overwhelms the commonly utilized Co‐Pi. Along with its excellent long‐term stability, the CIO possesses a great potential application in PEC water splitting devices. One design for multiple effects: ultrafine CoFe2O4 (CIO) nanoparticles are synthesized as an efficient water oxidation co‐catalyst for α‐Fe2O3 photoelectrode to achieve comprehensive promotions on photoelectrochemical water splitting performances.
      PubDate: 2016-04-18T02:26:46.047-05:00
      DOI: 10.1002/adfm.201600232
       
  • Enhancing Charge Separation in Metallic Photocatalysts: A Case Study of
           the Conducting Molybdenum Dioxide
    • Authors: Zhuofeng Hu; Gang Liu, Xingqiu Chen, Zhurui Shen, Jimmy C. Yu
      Abstract: A new visible‐light responsive metallic photocatalyst, nanostructured MoO2, has been discovered. The metallic nature of MoO2 is confirmed by valance X‐ray photoelectron spectroscopy spectrum and theoretical calculations. However, MoO2 itself shows only moderate activity due to the serious charge recombination, a general disadvantage of metallic photocatalysts. The findings suggest that its effective charge diffusion length Lp is smaller than 1.0 nm while the separation efficiency ηsep is less than 10%. Therefore, only the periphery of the metallic MoO2 can effectively contribute to photocatalysis. This limitation is overcome by integrating MoO2 in a hydrothermal carbonation carbon (HTCC) matrix (mainly contains semiconductive polyfuran). This simple chemical modification brings two advantages: (i) an internal electric field is formed at the interface between MoO2 and HTCC due to their appropriate band alignment; (ii) the nanostructured MoO2 and the HTCC matrix are intertwined with each other intimately. Their small size and large contact area promote charge transfer, especially under the internal electric field. Therefore, the separation rate of photoexcited charge carrier in MoO2 is greatly enhanced. The activity increases by 2.4, 16.8, and 4.0 times in photocatalytic oxygen evolution, dyes degradation, and photoelectrochemicl cell, respectively. The new approach is helpful for further development of metallic photocatalysts. An effective solution to the problem of serious charge recombination in metallic photocatalysts is described. The concept is demonstrated by encapsulating individual metallic MoO2 particles in a hydrothermal carbonation carbon (HTCC) matrix. When integrating with HTCC, MoO2 exhibits enhanced charge separation efficiency and photocatalytic activity because of an internal electric field and appropriate band alignment.
      PubDate: 2016-04-18T02:26:41.660473-05:
      DOI: 10.1002/adfm.201600239
       
  • Reality Check for Nanomaterial‐Mediated Therapy with 3D Biomimetic
           Culture Systems
    • Abstract: The recent progresses in tissue engineering and nanomaterial‐based therapeutics/theranostics have led to the ever increasing utilization of 3D in vitro experimental models as the bona fide culture systems to evaluate the therapeutic/theranostic effects of nanomedicine. Compared to the use of conventional 2D culture platforms, 3D biomimetic cultures offer unmatched advantages as relevant physiological and pathological elements can be incorporated to allow better characterization of the engineered bio‐nanomaterials in the targeted tissue‐specific microenvironment. In this Feature Article, the current state‐of‐the‐art 3D in vitro models that have been developed for the evaluation of biosafety and efficacy of nano‐ therapeutics/theranostics targeting the colon, blood–brain barrier (BBB), lungs, skin tumor models to bridge the nanomedicine bench to pre‐clinical ravine are reviewed. Furthermore, the critical physicochemical parameters of the bio‐nanomaterials that govern its transport and biodistribution in a complex 3D microenvironment will be highlighted. The major challenges and future prospects of evaluating nanomedicine in the third dimension will also be discussed. In vitro 3D cell culture systems have emerged as important tools to evaluate the efficacy and toxicity of nano‐scale drug delivery vehicles. The use of 3D colon, blood brain barriers, lungs, skin, and tumor in vitro surrogates is here reviewed, to reveal salient insights that underpin the rational design of advanced nanomedicine.
      PubDate: 2016-04-18T02:26:35.593313-05:
      DOI: 10.1002/adfm.201600476
       
  • Efficient Charge Injection in Organic Field‐Effect Transistors
           Enabled by Low‐Temperature Atomic Layer Deposition of Ultrathin VOx
           Interlayer
    • Authors: Yuanhong Gao; Youdong Shao, Lijia Yan, Hao Li, Yantao Su, Hong Meng, Xinwei Wang
      Abstract: Charge injection at metal/organic interface is a critical issue for organic electronic devices in general as poor charge injection would cause high contact resistance and severely limit the performance of organic devices. In this work, a new approach is presented to enhance the charge injection by using atomic layer deposition (ALD) to prepare an ultrathin vanadium oxide (VOx) layer as an efficient hole injection interlayer for organic field‐effect transistors (OFETs). Since organic materials are generally delicate, a gentle low‐temperature ALD process is necessary for compatibility. Therefore, a new low‐temperature ALD process is developed for VOx at 50 °C using a highly volatile vanadium precursor of tetrakis(dimethylamino)vanadium and non‐oxidizing water as the oxygen source. The process is able to prepare highly smooth, uniform, and conformal VOx thin films with precise control of film thickness. With this ALD process, it is further demonstrated that the ALD VOx interlayer is able to remarkably reduce the interface contact resistance, and, therefore, significantly enhance the device performance of OFETs. Multiple combinations of the metal/VOx/organic interface (i.e., Cu/VOx/pentacene, Au/VOx/pentacene, and Au/VOx/BOPAnt) are examined, and the results uniformly show the effectiveness of reducing the contact resistance in all cases, which, therefore, highlights the broad promise of this ALD approach for organic devices applications in general. A low‐temperature atomic layer deposition process for vanadium oxide (VOx), using tetrakis(dimethylamino)vanadium and water vapor, is developed to prepare high‐quality ultrathin charge injection layer directly on organic semiconducting materials. The prepared VOx is able to remarkably reduce the contact resistance at metal/organic interface, and, therefore, greatly enhance the performance of organic field‐effect transistors.
      PubDate: 2016-04-18T02:26:28.692047-05:
      DOI: 10.1002/adfm.201600482
       
  • Intercalation‐Induced Tunable Stimuli‐Responsive
           Color‐Change Properties of Crystalline Organic Layered Compound
    • Authors: Mamoru Okaniwa; Yuya Oaki, Hiroaki Imai
      Abstract: Layered structures accommodate guest molecules and ions in the interlayer space through intercalation. Organic layered compounds, such as layered polymers, have both intercalation and dynamic properties. Here intercalation‐induced tunable temperature‐ and mechanical‐stress‐responsive color‐change properties of crystalline layered polydiacetylene (PDA) as an organic layered compound are reported. In general, organic materials with stimuli responsivity are developed by molecular design and synthesis. In the present work, intercalation of guest metal cations in the layered PDA directs tuning of the stimuli‐responsive color‐change properties, such as color, responsivity, and reversibility. Whereas PDA without intercalation of metal ions distinctly changes the color from blue to red at the threshold temperature, the PDA with intercalation of the divalent metal ions (PDA‐M2+) shows a variety of color‐change properties. The present study indicates that intercalation has versatile potentials for functionalization of organic layered compounds. Dynamic properties of functional organic materials are tuned by not molecular design and synthesis but intercalation of guests in the layered crystal structure. Intercalation of metal ions in the interlayer space of layered crystalline polydiacetylene induces tunable stimuli‐responsive color‐change properties, such as color, responsivity, and reversibility.
      PubDate: 2016-04-18T02:26:24.087621-05:
      DOI: 10.1002/adfm.201600560
       
  • Improving Performance and Stability of Flexible
           Planar‐Heterojunction Perovskite Solar Cells Using Polymeric
           Hole‐Transport Material
    • Abstract: For realizing flexible perovskite solar cells (PSCs), it is important to develop low‐temperature processable interlayer materials with excellent charge transporting properties. Herein, a novel polymeric hole‐transport material based on 1,4‐bis(4‐sulfonatobutoxy)benzene and thiophene moieties (PhNa‐1T) and its application as a hole‐transport layer (HTL) material of high‐performance inverted‐type flexible PSCs are introduced. Compared with the conventionally used poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), the incorporation of PhNa‐1T into HTL of the PSC device is demonstrated to be more effective for improving charge extraction from the perovskite absorber to the HTL and suppressing charge recombination in the bulk perovskite and HTL/perovskite interface. As a result, the flexible PSC using PhNa‐1T achieves high photovoltaic performances with an impressive power conversion efficiency of 14.7%. This is, to the best of our knowledge, among the highest performances reported to date for inverted‐type flexible PSCs. Moreover, the PhNa‐1T‐based flexible PSC shows much improved stability under an ambient condition than PEDOT:PSS‐based PSC. It is believed that PhNa‐1T is a promising candidate as an HTL material for high‐performance flexible PSCs. By incorporating low‐temperature solution‐processable 1,4‐bis(4‐sulfonatobutoxy)benzene and thiophene moieties polymer as a hole‐transport layer, highly efficient, environmental stable, and mechanically flexible planar‐heterojunction perovskite solar cell has been successfully achieved with an excellent power conversion efficiency of 14.7%.
      PubDate: 2016-04-18T02:26:19.265886-05:
      DOI: 10.1002/adfm.201600746
       
  • Self‐Assembled Dense Colloidal Cu2Te Nanodisk Networks in P3HT Thin
           Films with Enhanced Photocurrent
    • Authors: Milena P. Arciniegas; Francesco Di Stasio, Hongbo Li, Davide Altamura, Luca De Trizio, Mirko Prato, Alice Scarpellini, Iwan Moreels, Roman Krahne, Liberato Manna
      Abstract: The integration of colloidal nanocrystals with polymers adds optoelectronic functionalities to flexible and mechanically robust organic films. In particular, self‐assembled structures of nanocrystals in polymers can act as functional components enhancing, for instance, transport or optical properties of the hybrid material. This study presents Cu2Te hexagonal nanodisks that assemble into ribbons with a face‐to‐face configuration in poly(3‐hexylthiophene‐2,5‐diyl) through a controlled solvent evaporation process. The ribbons form weaving patterns that create 3D networks fully embedded in the thin polymer film at high nanodisk concentration. The photoresponse of these composite films measured in a layered vertical geometry demonstrates increased photocurrent with increasing nanocrystal loading. This study attributes this behavior to the presence of networks of Cu2Te nanodisks that form a bulk heterojunction with the semiconducting polymer, which improves exciton dissociation and the overall photoelectric response. A remarkable self‐organization of hexagonal Cu2Te nanodisks into worm‐like structures is formed in P3HT thin films by a controlled solvent evaporation process, creating a 3D network fully embedded in the polymer. Such internal nanoarchitecture, extended over several microns in the polymer, significantly improves the performance of the polymer film by acting as an active material and enhancing the photocurrent response.
      PubDate: 2016-04-18T02:26:15.158549-05:
      DOI: 10.1002/adfm.201600751
       
  • Highly Emissive, Water‐Repellent, Soft Materials: Hydrophobic
           Wrapping and Fluorescent Plasticizing of Conjugated Polyelectrolyte via
           Electrostatic Self‐Assembly
    • Abstract: Sulfonated poly(diphenylacetylene) (SPDPA) is used as an anionic conjugated polyelectrolyte to examine stoichiometric electrostatic self‐assembly with homologous cationic surfactants (octadecyl)X(methyl)Y ammonium bromides (OXMYABs) having different numbers of long hydrophobic tails. The SPDPA–OXMYAB complexes formed show significantly increased water contact angle and enhanced fluorescence (FL) emissions compared with the pristine SPDPA. The complexes exist in a gum state at room temperature owing to the plasticizer effect of the hydrophobic tails, hence they are very soft and highly stretchable. The hydrophobicity, softness, and FL quantum efficiency of the SPDPA–OXMYAB complexes increase as the number of hydrophobic tails increases. SPDPA adsorbs uniformly onto filter papers to produce fluorescent papers. The SPDPA‐adsorbed papers have many unique applications, including FL image writing, fingerprinting, stamping, and inkjet printing using the surfactant solutions as an ink to reveal high‐resolution FL images. In particular, multideposit inkjet‐printing using SPDPA and OXMYAB solutions as inks produces water‐resistant, embedded figures in paper currency. Conjugated polyelectrolyte–surfactant complexes are constructed via stoichiometric electrostatic self‐assembly, which reveals remarkably enhanced fluorescence emission, water‐resistance, and softness relative to the pristine polymer owing to the plasticizer effect of the hydrophobic tails of surfactant. This chemistry allows for various imaging and printing on paper, especially for embedding figure in paper money.
      PubDate: 2016-04-18T02:26:06.295788-05:
      DOI: 10.1002/adfm.201600889
       
  • Design of Multistimuli Responsive Hydrogels Using Integrated Modeling and
           Genetically Engineered Silk–Elastin‐Like Proteins
    • Authors: Wenwen Huang; Anna Tarakanova, Nina Dinjaski, Qin Wang, Xiaoxia Xia, Ying Chen, Joyce Y. Wong, Markus J. Buehler, David L. Kaplan
      Abstract: Elastomeric, robust, and biocompatible hydrogels are rare, while the need for these types of biomaterials in biomedical‐related uses remains high. Here, a new family of genetically engineered silk–elastin‐like proteins (SELPs) with encoded enzymatic crosslinking sites is developed for a new generation of stimuli‐responsive yet robust hydrogels. Input into the designs is guided by simulation and realized via genetic engineering strategies. The avoidance of gamma irradiation or chemical crosslinking during gel fabrication, in lieu of an enzymatic process, expands the versatility of these new gels for the incorporation of labile proteins and cells. In the present study, the new SELP hydrogels offer sequence‐dependent, reversible stimuli‐responsive features. Their stiffness covers almost the full range of the elasticity of soft tissues. Further, physical modification of the silk domains provides a secondary control point to fine‐tune mechanical stiffness while preserving stimuli‐responsive features, with implications for a variety of biomedical material and device needs. A new family of robust, tunable stimuli‐responsive hydrogels using rationally designed genetically engineered silk–elastin copolymers is reported. These dynamic hydrogels exhibit significant reversible changes in size, optical transparency, mechanical properties, and micromorphology upon exposure to designed target stimuli, dependent on the silk‐to‐elastin ratio or the guest amino acid residue designed in the elastin domain.
      PubDate: 2016-04-15T02:00:31.161418-05:
      DOI: 10.1002/adfm.201600236
       
  • Label‐Free Microfluidic Manipulation of Particles and Cells in
           Magnetic Liquids
    • Authors: Wujun Zhao; Rui Cheng, Joshua R. Miller, Leidong Mao
      Abstract: Manipulating particles and cells in magnetic liquids through “negative magnetophoresis” is a new research field. It has resulted in label‐free and low‐cost manipulation techniques in microfluidic systems and many exciting applications. It is the goal of this review to introduce the fundamental principles of negative magnetophoresis and its recent applications in microfluidic manipulation of particles and cells. The theoretical background of three commonly used specificities of manipulation in magnetic liquids is first discussed, including the size, density and magnetic property of particles and cells. This is followed by a review and comparison of the media used in negative magnetophoresis, which include paramagnetic salt solutions and ferrofluids. Afterwards, the existing microfluidic applications of negative magnetophoresis are reviewed, including separation, focusing, trapping and concentration of particles and cells, determination of cell density, measurement of particles' magnetic susceptibility, and others. The need for developing biocompatible magnetic liquids for live cell manipulation and analysis and its recent progress are also examined. Finally, the review is concluded with a brief outlook for this exciting research field. Manipulating particles and cells in magnetic liquids is a new and exciting research field. It offers label‐free and low‐cost techniques for microfluidic manipulation. Fundamental principles and recent applications of particle manipulation using magnetic liquids are reviewed.
      PubDate: 2016-04-14T06:17:04.22307-05:0
      DOI: 10.1002/adfm.201504178
       
  • Self‐Healable Polymer Nanocomposites Capable of Simultaneously
           Recovering Multiple Functionalities
    • Authors: Lixin Xing; Qi Li, Guangzu Zhang, Xiaoshan Zhang, Feihua Liu, Li Liu, Yudong Huang, Qing Wang
      Abstract: The continuous evolution toward electronics with high power densities and integrated circuits with smaller feature sizes and faster speeds places high demands on a set of material properties, namely, the electrical, thermal, and mechanical properties of polymer dielectrics. Herein, a supramolecular approach is described to self‐healable polymer nanocomposites that are mechanically robust and capable of restoring simultaneously structural, electrical, dielectric, and thermal transport properties after multiple fractures. With the incorporation of surface‐functionalized boron nitride nanosheets, the polymer nanocomposites exhibit many desirable features as dielectric materials such as higher breakdown strength, larger electrical resistivity, improved thermal conductivity, greater mechanical strength, and much stabilized dielectric properties when compared to the pristine polymer. It is found that the recovery condition has remained the same during sequential cycles of cutting and healing, therefore suggesting no aging of the polymer nanocomposites with mechanical breakdown. Moreover, moisture has a minimal effect on the healing and dielectric properties of the polymer nanocomposites, which is in stark contrast to what is typically observed in the hydrogen‐bonded supramolecular structures. Supramolecular polymer nanocomposites can be healed efficiently and repeatedly to fully recover multiple functionalities in addition to structural integrity. The introduction of surface‐modified boron nitride nanosheets leads to the nanocomposites exhibiting superior mechanical strength, improved electrical resistivity, higher breakdown strength, enhanced thermal conductivity, and stabilized dielectric properties compared to the pristine polymer.
      PubDate: 2016-04-14T06:16:30.818485-05:
      DOI: 10.1002/adfm.201505305
       
  • Reusable and Long‐Lasting Active Microcleaners for Heterogeneous
           Water Remediation
    • Abstract: Self‐powered micromachines are promising tools for future environmental remediation technology. Waste‐water treatment and water reuse is an essential part of environmental sustainability. Herein, we present reusable Fe/Pt multi‐functional active microcleaners that are capable of degrading organic pollutants (malachite green and 4‐nitrophenol) by generated hydroxyl radicals via a Fenton‐like reaction. Various different properties of microcleaners, such as the effect of their size, short‐term storage, long‐term storage, reusability, continuous swimming capability, surface composition, and mechanical properties, are studied. It is found that these microcleaners can continuously swim for more than 24 hours and can be stored more than 5 weeks during multiple cleaning cycles. The produced microcleaners can also be reused, which reduces the cost of the process. During the reuse cycles the outer iron surface of the Fe/Pt microcleaners generates the in‐situ, heterogeneous Fenton catalyst and releases a low concentration of iron into the treated water, while the mechanical properties also appear to be improved due to both its surface composition and structural changes. The microcleaners are characterized by scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), nanoindentation, and finite‐element modeling (FEM). Reusable Fe/Pt multi‐functional active microcleaners are capable of degrading organic pollutants (malachite green and 4‐nitrophenol) by generated hydroxyl radicals via an in situ heterogeneous Fenton‐like reaction. The microcleaners can continuously swim for more than 24 hours and can be stored for more than 5 weeks and subjected to multiple cleaning cycles for reuse, which reduces the cost of the process.
      PubDate: 2016-04-14T06:16:03.399346-05:
      DOI: 10.1002/adfm.201600381
       
  • Bifunctional Porous NiFe/NiCo2O4/Ni Foam Electrodes with Triple Hierarchy
           and Double Synergies for Efficient Whole Cell Water Splitting
    • Authors: Changlong Xiao; Yibing Li, Xunyu Lu, Chuan Zhao
      Abstract: A 3D hierarchical porous catalyst architecture based on earth abundant metals Ni, Fe, and Co has been fabricated through a facile hydrothermal and electrodeposition method for efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). The electrode is comprised of three levels of porous structures including the bottom supermacroporous Ni foam (≈500 μm) substrate, the intermediate layer of vertically aligned macroporous NiCo2O4 nanoflakes (≈500 nm), and the topmost NiFe(oxy)hydroxide mesoporous nanosheets (≈5 nm). This hierarchical architecture is binder‐free and beneficial for exposing catalytic active sites, enhancing mass transport and accelerating dissipation of gases generated during water electrolysis. Serving as an anode catalyst, the designed hierarchical electrode displays excellent OER catalytic activity with an overpotential of 340 mV to achieve a high current density of 1200 mA cm−2. Serving as a cathode catalyst, the catalyst exhibits excellent performance toward HER with a moderate overpotential of 105 mV to deliver a current density of 10 mA cm−2. Serving as both anode and cathode catalysts in a two‐electrode water electrolysis system, the designed electrode only requires a potential of 1.67 V to deliver a current density of 10 mA cm−2 and exhibits excellent durability in prolonged bulk alkaline water electrolysis. A freestanding, bifunctional NiFe nanosheet/NiCo2O4 nanoflake/Ni foam electrode is reported for water splitting. The electrode exhibits extraordinary catalytic activity toward both oxygen evolution and hydrogen evolution reactions in alkaline media, comparable to the state‐of‐the‐art catalysts including noble metal based catalysts. The unique multiple hierarchical porous architecture offers significantly enlarged reactive surface area and abundant synergistic effects for water splitting.
      PubDate: 2016-04-13T05:45:13.324305-05:
      DOI: 10.1002/adfm.201505302
       
  • Tunable Optical Mode Ferromagnetic Resonance in FeCoB/Ru/FeCoB Synthetic
           Antiferromagnetic Trilayers under Uniaxial Magnetic Anisotropy
    • Abstract: Ferromagnetic resonance (FMR) is one of the most important characteristics of soft magnetic materials, which practically sets the maximum operation speed of these materials. There are two FMR modes in exchange coupled ferromagnet/nonmagnet/ferromagnet sandwich films. The acoustic mode has relatively lower frequency and is widely used in radio‐frequency/microwave devices, while the optical mode is largely neglected due to its tiny permeability even though it supports much higher frequency. Here, a realistic method is reported to enhance the permeability in the optical mode to an applicable level. FeCoB/Ru/FeCoB trilayers are carefully engineered with both uniaxial magnetic anisotropy and antiferromagnetic interlayer exchange coupling. This special magnetic structure exhibits a high optical mode frequency up to 11.28 GHz and a maximum permeability of 200 at resonance. An abnormally low inverse switch field (
      PubDate: 2016-04-13T05:45:04.073827-05:
      DOI: 10.1002/adfm.201600122
       
  • Carrier Type Control of WSe2 Field‐Effect Transistors by Thickness
           Modulation and MoO3 Layer Doping
    • Authors: Changjian Zhou; Yuda Zhao, Salahuddin Raju, Yi Wang, Ziyuan Lin, Mansun Chan, Yang Chai
      Abstract: Control of the carrier type in 2D materials is critical for realizing complementary logic computation. Carrier type control in WSe2 field‐effect transistors (FETs) is presented via thickness engineering and solid‐state oxide doping, which are compatible with state‐of‐the‐art integrated circuit (IC) processing. It is found that the carrier type of WSe2 FETs evolves with its thickness, namely, p‐type (15 nm). This layer‐dependent carrier type can be understood as a result of drastic change of the band edge of WSe2 as a function of the thickness and their band offsets to the metal contacts. The strong carrier type tuning by solid‐state oxide doping is also demonstrated, in which ambipolar characteristics of WSe2 FETs are converted into pure p‐type, and the field‐effect hole mobility is enhanced by two orders of magnitude. The studies not only provide IC‐compatible processing method to control the carrier type in 2D semiconductor, but also enable to build functional devices, such as, a tunable diode formed with an asymmetrical‐thick WSe2 flake for fast photodetectors. In the thickness‐dependent transport behavior of WSe2 transistors, it is revealed that all p‐type, ambipolar, and n‐type characteristics are obtained by merely varying the thickness of WSe2 flakes. The layer‐dependent band structure is a determining factor in achieving this strong thickness‐dependent transport behavior in WSe2 field‐effect transistors. The unique band structure of WSe2 also enables efficient p‐type doping in WSe2 by solid‐state oxide.
      PubDate: 2016-04-13T05:44:59.585868-05:
      DOI: 10.1002/adfm.201600292
       
  • Platelet‐in‐Box Colloidal Quantum Wells: CdSe/CdS@CdS
           Core/Crown@Shell Heteronanoplatelets
    • Authors: Yusuf Kelestemur; Burak Guzelturk, Onur Erdem, Murat Olutas, Kivanc Gungor, Hilmi Volkan Demir
      Abstract: Here, the CdSe/CdS@CdS core/crown@shell heterostructured nanoplatelets (NPLs) resembling a platelet‐in‐box structure are developed and successfully synthesized. It is found that the core/crown@shell NPLs exhibit consistently substantially improved photoluminescence quantum yield compared to the core@shell NPLs regardless of their CdSe‐core size, CdS‐crown size, and CdS‐shell thickness. This enhancement in quantum yield is attributed to the passivation of trap sites resulting from the critical peripheral growth with laterally extending CdS‐crown layer before the vertical shell growth. This is also verified with the disappearance of the fast nonradiative decay component in the core/crown NPLs from the time‐resolved fluorescence spectroscopy. When compared to the core@shell NPLs, the core/crown@shell NPLs exhibit relatively symmetric emission behavior, accompanied with suppressed lifetime broadening at cryogenic temperatures, further suggesting the suppression of trap sites. Moreover, constructing both the CdS‐crown and CdS‐shell regions, significantly enhanced absorption cross‐section is achieved. This, together with the suppressed Auger recombination, enables the achievement of the lowest threshold amplified spontaneous emission (≈20 μJ cm−2) from the core/crown@shell NPLs among all different architectures of NPLs. These findings indicate that carefully heterostructured NPLs will play a critical role in building high‐performance colloidal optoelectronic devices, which may even possibly challenge their traditional epitaxially grown thin‐film based counterparts. CdSe/CdS@CdS core/crown@shell nanoplatelets (NPLs) have been synthesized with a novel 3D architecture resembling a platelet‐in‐box structure. With the coformation of the CdS‐crown and CdS‐shell regions, core/crown@shell nanoplatelets exhibit increased photoluminescence quantum yield (PL‐QY), enhanced absorption cross‐section, and eliminated trap sites which enable favorable excitonic properties for the achievement of low‐threshold gain.
      PubDate: 2016-04-13T05:44:52.718905-05:
      DOI: 10.1002/adfm.201600588
       
  • Enhanced Nanodrug Delivery to Solid Tumors Based on a Tumor
           Vasculature‐Targeted Strategy
    • Authors: Chenghua Song; Yejun Zhang, Chunyan Li, Guangcun Chen, Xiaofeng Kang, Qiangbin Wang
      Abstract: Tumor angiogenesis is a hallmark of tumor growth and metastasis, and inhibition of tumor angiogenesis is an effective strategy for tumor therapy. The high expression levels of specific biomarkers such as integrin receptors (e.g., αvβ3) in the endothelium of tumor vessels make angiogenesis an ideal target for drug delivery and thus tumor therapy. Herein, a new nanodrug (T&D@RGD‐Ag2S) is presented, which can effectively inhibit tumor growth by integrating the specific recognition peptide cyclo(Arg‐Gly‐Asp‐d‐Phe‐Cys) (cRGD) for tumor vascular targeting, the broad‐spectrum endothelial inhibitor O‐(chloroacetyl‐carbamoyl) fumagillol (TNP‐470), and chemotherapeutic drug doxorubicin (DOX) for synergetic tumor therapy. The results show that the T&D@RGD‐Ag2S nanodrug rapidly and specifically binds to the tumor vasculature after intravenous injection. Tumor vascular density is greatly reduced following effective angiogenesis inhibition by TNP‐470. Meanwhile, increased delivery of DOX deep into the tumor induces extensive tumor apoptosis, resulting in remarkable tumor growth inhibition in a human U87‐MG malignant glioma xenograft model. In addition, the therapeutic effects of T&D@RGD‐Ag2S on inhibiting tumor growth and decreasing vessel density are monitored in situ using near‐infrared II (NIR‐II) fluorescence imaging of Ag2S quantum dots. This tumor vasculature‐targeted strategy can be extended as a general method for treating a broad range of tumors and holds promise for future clinical applications. A novel nanodrug (T&D@RGD‐Ag2S) for tumor vasculature‐targeted therapy is presented, which can effectively inhibit tumor growth by integrating the specific tumor vascular targeting peptide cyclo(Arg‐Gly‐Asp‐d‐Phe‐Cys) (cRGD), the broad‐spectrum endothelial inhibitor O‐(chloroacetyl‐carbamoyl) fumagillol (TNP‐470) and chemotherapeutic drug doxorubicin for synergetic tumor therapy, as well as an in situ fluorescence imaging agent of Ag2S quantum dots.
      PubDate: 2016-04-13T05:42:56.17902-05:0
      DOI: 10.1002/adfm.201600417
       
  • High‐Performance Inverted Planar Heterojunction Perovskite Solar
           Cells Based on Lead Acetate Precursor with Efficiency Exceeding 18%
    • Authors: Lichen Zhao; Deying Luo, Jiang Wu, Qin Hu, Wei Zhang, Ke Chen, Tanghao Liu, Yi Liu, Yifei Zhang, Feng Liu, Thomas P. Russell, Henry J. Snaith, Rui Zhu, Qihuang Gong
      Abstract: Organic–inorganic lead halide perovskites are emerging materials for the next‐generation photovoltaics. Lead halides are the most commonly used lead precursors for perovskite active layers. Recently, lead acetate (Pb(Ac)2) has shown its superiority as the potential replacement for traditional lead halides. Here, we demonstrate a strategy to improve the efficiency for the perovskite solar cell based on lead acetate precursor. We utilized methylammonium bromide as an additive in the Pb(Ac)2 and methylammonium iodide precursor solution, resulting in uniform, compact and pinhole‐free perovskite films. We observed enhanced charge carrier extraction between the perovskite layer and charge collection layers and delivered a champion power conversion efficiency of 18.3% with a stabilized output efficiency of 17.6% at the maximum power point. The optimized devices also exhibited negligible current density–voltage (J–V) hysteresis under the scanning conditions. High‐performance inverted perovskite solar cells based on lead acetate precursor are demonstrated with power conversion efficiency exceeding 18% and stabilized output efficiency of 17.6%. Methylammonium bromide was utilized as additive into the lead acetate precursor solutions, leading to the perovskite films with improved performance.
      PubDate: 2016-04-13T05:42:48.946015-05:
      DOI: 10.1002/adfm.201601175
       
  • Molecular Storage of Mg Ions with Vanadium Oxide Nanoclusters
    • Authors: Yingwen Cheng; Yuyan Shao, Vadivukarasi Raju, Xiulei Ji, B. Layla Mehdi, Kee Sung Han, Mark H. Engelhard, Guosheng Li, Nigel D. Browning, Karl T. Mueller, Jun Liu
      Abstract: Mg batteries have potential advantages in terms of safety, cost, and reliability over existing battery technologies, but their practical implementations are hindered by the lack of amenable high‐voltage cathode materials. The development of cathode materials is complicated by limited understandings of the unique divalent Mg2+ ion electrochemistry and the interaction/transportation of Mg2+ ions with host materials. Here, it is shown that highly dispersed vanadium oxide (V2O5) nanoclusters supported on porous carbon frameworks are able to react with Mg2+ ions reversibly in electrolytes that are compatible with Mg metal, and exhibit high capacities and good reaction kinetics. They are able to deliver initial capacities exceeding 300 mAh g−1 at 40 mA g−1 in the voltage window of 0.5 to 2.8 V. The combined electron microscope, spectroscopy, and electrochemistry characterizations suggest a surface‐controlled pseudocapacitive electrochemical reaction, and may be best described as a molecular energy storage mechanism. This work can provide a new approach of using the molecular mechanism for pseudocapacitive storage of Mg2+ for Mg batteries cathode materials. A new molecular storage approach with supported V2O5 nanoclusters is described for developing Mg batteries cathode materials. The highly dispersed V2O5 nanoclusters are able to react with Mg2+ ions reversibly in Mg battery electrolytes, and delivered initial capacities exceed 300 mAh g−1. The electrochemical reaction has surface limited pseudocapacitive characteristics with outstanding kinetics.
      PubDate: 2016-04-13T02:56:18.430089-05:
      DOI: 10.1002/adfm.201505501
       
  • Bifunctional Nickel Phosphide Nanocatalysts Supported on Carbon Fiber
           Paper for Highly Efficient and Stable Overall Water Splitting
    • Authors: Xiaoguang Wang; Wei Li, Dehua Xiong, Dmitri Y. Petrovykh, Lifeng Liu
      Abstract: Self‐supported electrodes comprising carbon fiber paper (CP) integrated with bifunctional nickel phosphide (Ni‐P) electrocatalysts are fabricated by electrodeposition of Ni on functionalized CP, followed by a convenient one‐step phosphorization treatment in phosphorus vapor at 500 °C. The as‐fabricated CP@Ni‐P electrode exhibits excellent electrocatalytic performance toward hydrogen evolution in both acidic and alkaline solutions, with only small overpotentials of 162 and 250 mV, respectively, attaining a cathodic current density of 100 mA cm−2. Furthermore, the CP@Ni‐P electrode also exhibits superior catalytic performance toward oxygen evolution reaction (OER). An exceptionally high OER current of 50.4 mA cm−2 is achieved at an overpotential of 0.3 V in 1.0 m KOH. The electrode can sustain 10 mA cm−2 for 180 h with only negligible degradation, showing outstanding durability. Detailed microstructural and compositional studies reveal that upon OER in alkaline solution the surface Ni‐P is transformed to NiO covered with a thin Ni(OH)x layer, forming a Ni‐P/NiO/Ni(OH)x heterojunction, which presumably enhances the electrocatalytic performance for OER. Given the well‐defined bifunctionality, a full alkaline electrolyzer is constructed using two identical CP@Ni‐P electrodes as cathode and anode, respectively, which can realize overall water splitting with efficiency as high as 91.0% at 10 mA cm−2 for 100 h. Overall water splitting is realized at a high efficiency (91.0% at 10 mA cm−2) with excellent stability and durability by an alkaline electrolyzer made from self‐supported carbon fiber paper electrodes integrated with bifunctional nickel phosphide catalysts. The self‐supported electrode exhibits superior electrocatalytic performance toward both hydrogen evolution and oxygen evolution reactions in alkaline medium.
      PubDate: 2016-04-13T02:56:10.758215-05:
      DOI: 10.1002/adfm.201505509
       
  • Metal Based Nonvolatile Field‐Effect Transistors
    • Authors: Chong Bi; Meng Xu, Hamid Almasi, Macus Rosales, Weigang Wang
      Abstract: The reduction of metals from their oxides through solid electrochemical reactions usually requires a high temperature above 800 °C and a specially designed electrochemical structure. It is demonstrated that, in a simple field‐effect transistor (FET) structure, the redox reaction between Co metal and CoOx is reversible under a small electric field and can be achieved at a moderate temperature below 200 °C. The FETs functioning through the reversible redox reaction show nonvolatile behavior and a high on/off ratio of about 105. Moreover, the FETs show a threshold resistance switching behavior at high resistance states, but with opposite switching directions compared to normal metal/oxide/metal structures. The electric field induced metal–oxide transition may also be used for other energy storage applications. The reversible metal–oxide transition induced by an electric field is demonstrated at a moderate temperature below 200 °C. The field‐effect transistors based on the metal–oxide transition are compatible with complementary metal oxide semiconductor technology and show nonvolatile behavior and a high on/off ratio of about 105.
      PubDate: 2016-04-13T02:56:04.690034-05:
      DOI: 10.1002/adfm.201600048
       
  • Lithium‐Ion Batteries: Discovering a Dual‐Buffer Effect for
           Lithium Storage: Durable Nanostructured Ordered Mesoporous Co–Sn
           Intermetallic Electrodes (Adv. Funct. Mater. 17/2016)
    • Pages: 2773 - 2773
      Abstract: Novel insights into the nanostructural changes of ordered mesoporous intermetallic CoSn electrode materials during the lithiation–delithiation process are demonstrated by H. Kim, W.‐S. Yoon, J. M. Kim, and co‐workers on page 2800, using in operando small angle X‐ray scattering. A dual‐buffer effect allows for a durable nanostructured electrode upon prolonged cycling and thus leads to stable electrochemical behavior for Li storage.
      PubDate: 2016-04-28T05:57:53.109937-05:
      DOI: 10.1002/adfm.201670104
       
  • Amorphous Semiconductors: Ionic Liquid Activation of Amorphous
           Metal‐Oxide Semiconductors for Flexible Transparent Electronic
           Devices (Adv. Funct. Mater. 17/2016)
    • Authors: Pushpa Raj Pudasaini; Joo Hyon Noh, Anthony T. Wong, Olga S. Ovchinnikova, Amanda V. Haglund, Sheng Dai, Thomas Zac Ward, David Mandrus, Philip D. Rack
      Pages: 2774 - 2774
      Abstract: Athermal field induced activation of amorphous indium gallium zinc oxide is demonstrated for flexible transparent thin film transistor applications, by P. D. Rack and co‐workers on page 2820. The activation process is controlled by field‐induced oxygen migration across the ionic liquid–semiconductor interface, which shows potential as a promising alternative to traditional post‐deposition thermal annealing and opens the door to wide‐scale implementation into flexible electronic applications.
      PubDate: 2016-04-28T05:57:56.454561-05:
      DOI: 10.1002/adfm.201670105
       
  • Contents: (Adv. Funct. Mater. 17/2016)
    • Pages: 2775 - 2782
      PubDate: 2016-04-28T05:57:56.544695-05:
      DOI: 10.1002/adfm.201670106
       
  • Electroluminochromic Materials and Devices
    • Authors: Jingwei Sun; Yani Chen, Ziqi Liang
      Pages: 2783 - 2799
      Abstract: Modulation of luminescent color or intensity by varying external stimuli, such as temperature, light, ion concentration, etc., has received increasing attention recently because of numerous applications such as sensors, bioanalysis, optical imaging and memories. For instance, electrically induced luminescent switching — electroluminochromism (ELC) — is one of the most powerful and promising approaches to implement controllable emission due to its facile and precise operation. Recent years have witnessed significant advances in ELC research in the context of materials development and device optimizations. This feature article reviews the fundamentals and recent progress in this emerging field, focusing on working mechanisms, materials, devices and performance improvements. Perspectives for future ELCs are also outlined. Electroluminochromic (ELC) materials and devices are reviewed with respect to working mechanisms, materials, devices and performance improvements. Perspectives for current challenges and future opportunities of ELCs, in particular improvement of long‐term stability and device performance for large−area mass−production are also outlined.
      PubDate: 2016-03-15T02:41:52.631883-05:
      DOI: 10.1002/adfm.201505013
       
  • Discovering a Dual‐Buffer Effect for Lithium Storage: Durable
           Nanostructured Ordered Mesoporous Co–Sn Intermetallic Electrodes
    • Pages: 2800 - 2808
      Abstract: Lithiation–delithiation reactions in Li‐ion batteries do exhibit a huge electrochemically driven volume change of the anode material between the lithium‐free and lithiated‐host states, which results in a gradually fading capacity. Minimizing this volume change of the electrode during cycling is essential to achieve stable electrochemical behavior and thus for innovating design of electrode materials for Li storage. Here, ordered mesoporous CoSn intermetallic anode materials with various Co/Sn atomic ratios are developed. A dual‐buffer effect is discovered that accommodates the volume changes in the electrode material by not only repeatedly generating void nanospaces but also by incorporating electrochemically inactive elements. Novel insights into the nanostructural changes of electrode materials during the lithiation–delithiation process are obtained by in operando small angle X‐ray scattering. The degrees of volume change and nanoscopic order are found to be highly dependent on the Co contents in the mesoporous CoSn intermetallic anode materials, being possible to achieve a durable nanostructured electrode upon prolonged cycling. Ordered mesoporous intermetallic CoxSny electrode materials with various Co/Sn ratios are successfully constructed. In operando small angle X‐ray scattering relveals the nanostructural changes of electrode materials during the lithiation–delithiation process. A dual‐buffer effect accomodating the volume changes in the mesoporous intermetallic electrodes is discovered.
      PubDate: 2016-03-04T08:58:51.719881-05:
      DOI: 10.1002/adfm.201600121
       
  • Injectable Stem Cell‐Laden Photocrosslinkable Microspheres
           Fabricated Using Microfluidics for Rapid Generation of Osteogenic Tissue
           Constructs
    • Authors: Xin Zhao; Shen Liu, Lara Yildirimer, Hong Zhao, Ruihua Ding, Huanan Wang, Wenguo Cui, David Weitz
      Pages: 2809 - 2819
      Abstract: Direct injection is a minimally invasive method of stem cell transplantation for numerous injuries and diseases. However, despite its promising potential, its clinical translation is difficult due to the low cell retention and engraftment after injection. With high versatility, high‐resolution control and injectability, microfabrication of stem‐cell laden biomedical hydrogels holds great potential as minimally invasive technology. Herein, a strategy of microfluidics‐assisted technology entrapping bone marrow‐derived mesenchymal stem cells (BMSCs) and growth factors in photocrosslinkable gelatin (GelMA) microspheres to ultimately generate injectable osteogenic tissue constructs is presented. Additionally, it is demonstrated that the GelMA microspheres can sustain stem cell viability, support cell spreading inside the microspheres and migration from the interior to the surface as well as enhance cell proliferation. This finding shows that encapsulated cells have the potential to directly and actively participate in the regeneration process. Furthermore, it is found that BMSCs encapsulated in GelMA microspheres show enhanced osteogenesis in vitro and in vivo, associated with a significant increase in mineralization. In short, the proposed strategy can be utilized to facilitate bone regeneration with minimum invasiveness, and can potentially be applied along with other matrices for extended applications. A microfluidics‐assisted stra­tegy for entrapping bone marrow‐derived mesenchymal stem cells (BMSCs) and growth factors in photocrosslinkable gelatin microspheres which can sustain BMSC viability, support cell spreading inside the microspheres and migration to the microsphere surface, and enhance osteogenesis both in vitro and in vivo, is presented. The proposed approach can be utilized to facilitate bone regeneration with minimum invasiveness.
      PubDate: 2016-02-16T11:23:48.59987-05:0
      DOI: 10.1002/adfm.201504943
       
  • Ionic Liquid Activation of Amorphous Metal‐Oxide Semiconductors for
           Flexible Transparent Electronic Devices
    • Authors: Pushpa Raj Pudasaini; Joo Hyon Noh, Anthony T. Wong, Olga S. Ovchinnikova, Amanda V. Haglund, Sheng Dai, Thomas Zac Ward, David Mandrus, Philip D. Rack
      Pages: 2820 - 2825
      Abstract: Amorphous metal‐oxide semiconductors offer the high carrier mobilities and excellent large‐area uniformity required for high performance, transparent, flexible electronic devices; however, a critical bottleneck to their widespread implementation is the need to activate these materials at high temperatures which are not compatible with flexible polymer substrates. The highly controllable activation of amorphous indium gallium zinc oxide semiconductor channels using ionic liquid gating at room temperature is reported. Activation is controlled by electric field‐induced oxygen migration across the ionic liquid‐semiconductor interface. In addition to activation of unannealed devices, it is shown that threshold voltages of a transistor can be linearly tuned between the enhancement and depletion modes. Finally, the first ever example of transparent flexible thin film metal oxide transistor on a polyamide substrate created using this simple technique is demonstrated. This study demonstrates the potential of field‐induced activation as a promising alternative to traditional postdeposition thermal annealing which opens the door to wide scale implementation into flexible electronic applications. Field induced activation of amorphous indium gallium zinc oxide is demonstrated for flexible transparent thin film transistor applications. The activation process is controlled by field induced oxygen migration across the ionic liquid‐semiconductor interface. Field‐induced activation shows potential as a promising alternative to traditional postdeposition thermal annealing which opens the door to wide scale implementation into flexible electronic applications.
      PubDate: 2016-02-09T06:06:42.630627-05:
      DOI: 10.1002/adfm.201505274
       
  • Mitochondria‐Targeted Small‐Molecule Fluorophores for Dual
           Modal Cancer Phototherapy
    • Authors: Shenglin Luo; Xu Tan, Shengtao Fang, Yu Wang, Tao Liu, Xin Wang, Yi Yuan, Huiqin Sun, Qingrong Qi, Chunmeng Shi
      Pages: 2826 - 2835
      Abstract: Mitochondria are recognized as the ideal target for cancer treatment because they play a central role in oxidative metabolism and apoptosis. In this work, a mitochondria‐targeted near‐infrared (NIR) photosensitizer (PS) for synchronous cancer photodynamic therapy (PDT) and photothermal therapy (PTT) is synthesized. This multifunctional small‐molecule PS is developed from a variety of synthesized heptamethine cyanine dyes, which are modified with various N‐alkyl side chains on the lipophilic cationic heptamethine core. It is demonstrated to preferentially accumulate in cancer cells by organic‐anion transporting polypeptide mediated active transport and retain in mitochondria by its lipophilic cationic property. As mitochondria are susceptible to hyperthermia and excessive reactive oxygen species, this new PS integrating PTT and PDT treatment exhibits highly efficient phototherapy in multiple cancer cells and animal xenograft models. Furthermore, this targeted PS with NIR imaging property also enables tumors and their margins clearly visualized, providing the potential for precisely imaging‐guided phototherapy and treatment monitoring. This is the first report that a small‐molecule PS integrates both cancer PTT and PDT treatment by targeting mitochondria, significantly increasing the photosensitization. This work may also present a practicable strategy to develop small‐molecule‐based cancer theranostic agents for simultaneous cancer targeting, imaging, and therapy. A heptamethine cyanine dye preferentially accumulates in cancer cells by organic‐anion‐transporting‐polypeptide‐mediated active transport and penetrates into mitochondria by its lipophilic cationic property. This multifunctional small‐molecule photosensitizer (PS) is developed for synchronous cancer photodynamic therapy (PDT) and photothermal therapy (PTT) by targeting cancer‐cell mitochondria.
      PubDate: 2016-03-22T03:15:46.333751-05:
      DOI: 10.1002/adfm.201600159
       
  • A Roadmap for Controlled and Efficient n‐Type Doping of
           Self‐Assisted GaAs Nanowires Grown by Molecular Beam Epitaxy
    • Pages: 2836 - 2845
      Abstract: N‐type doping of GaAs nanowires has proven to be difficult because the amphoteric character of silicon impurities is enhanced by the nanowire growth mechanism and growth conditions. The controllable growth of n‐type GaAs nanowires with carrier density as high as 1020 electron cm−3 by self‐assisted molecular beam epitaxy using Te donors is demonstrated here. Carrier density and electron mobility of highly doped nanowires are extracted through a combination of transport measurement and Kelvin probe force microscopy analysis in single‐wire field‐effect devices. Low‐temperature photoluminescence is used to characterize the Te‐doped nanowires over several orders of magnitude of the impurity concentration. The combined use of those techniques allows the precise definition of the growth conditions required for effective Te incorporation. The control of doping in semiconductor nanowires is a crucial issue in the design of reliable nanowire‐based devices. The complementary use of transport measurements, Kelvin probe force microscopy, and photoluminescence demonstrates efficiency and reliability of Te as donor impurity in GaAs nanowires grown by self‐assisted molecular beam epitaxy.
      PubDate: 2016-03-17T12:53:17.643441-05:
      DOI: 10.1002/adfm.201504853
       
  • Photovoltaic and Amplified Spontaneous Emission Studies of
           High‐Quality Formamidinium Lead Bromide Perovskite Films
    • Pages: 2846 - 2854
      Abstract: This study demonstrates the formation of extremely smooth and uniform formamidinium lead bromide (CH(NH2)2PbBr3 = FAPbBr3) films using an optimum mixture of dimethyl sulfoxide and N,N‐dimethylformamide solvents. Surface morphology and phase purity of the FAPbBr3 films are thoroughly examined by field emission scanning electron microscopy and powder X‐ray diffraction, respectively. To unravel the photophysical properties of these films, systematic investigation based on time‐integrated and time‐dependent photoluminescence studies are carried out which, respectively, bring out relatively lower nonradiative recombination rates and long lasting photogenerated charge carriers in FAPbBr3 perovskite films. The devices based on FTO/TiO2/FAPbBr3/spiro‐OMeTAD/Au show highly reproducible open‐circuit voltage (Voc) of 1.42 V, a record for FAPbBr3‐based perovskite solar cells. Voc as a function of illumination intensity indicates that the contacts are very selective and higher Voc values are expected to be achieved when the quality of the FAPbBr3 film is further improved. Overall, the devices based on these films reveal appreciable power conversion efficiency of 7% under standard illumination conditions with negligible hysteresis. Finally, the amplified spontaneous emission (ASE) behavior explored in a cavity‐free configuration for FAPbBr3 perovskite films shows a sharp ASE threshold at a fluence of 190 μJ cm−2 with high quantum efficiency further confirming the high quality of the films. The fabrication of smooth and uniform formamidinium lead bromide perovskite films exhibiting strong emission and long charge carrier lifetime paves the way for high open‐circuit voltage and amplified spontaneous emission with a low threshold carrier density.
      PubDate: 2016-02-22T07:22:43.213121-05:
      DOI: 10.1002/adfm.201504977
       
  • Well‐Defined Protein‐Based Supramolecular Nanoparticles with
           Excellent MRI Abilities for Multifunctional Delivery Systems
    • Pages: 2855 - 2865
      Abstract: Protein‐based nanoparticles are widely used for effective biomedical applications. The objective of this work is to design series of magnetic resonance imaging (MRI)‐visible cationic supramolecular nanoparticles (PGEA@BSA‐Ad/Gd3+) based on bovine serum albumin (BSA) and β‐cyclodextrin‐cored star ethanolamine‐functionalized poly(glycidyl methacrylate) (CD‐PGEA) in the presence of Gd3+ ions for multifunctional delivery systems. CD‐PGEA is prepared via atom transfer radical polymerization and ring‐opening reaction. It is found that in the absence of Gd3+ ions, CD‐PGEA does not well interact with adamantine‐modified BSA (BSA‐Ad). The well‐defined PGEA@BSA‐Ad/Gd3+ supramolecular nanoparticles could be produced through the synergistic actions of the host–guest and electrostatic self‐assemblies by mixing aqueous solutions of CD‐PGEA, BSA‐Ad, and Gd3+. In comparison with CD‐PGEA assembly units, such kinds of uniform PGEA@BSA‐Ad/Gd3+ supramolecular nanoparticles exhibit better pDNA condensation ability, lower cytotoxicity, higher gene transfection, and easier cellular uptake. In addition, PGEA@BSA‐Ad/Gd3+ also produces outstanding MRI abilities, much better than Magnevist (Gd‐diethylenetriaminepentacetate acid). The present design of protein–polymer supramolecular nanoparticles with MRI contrast agents would provide a new way for multifunctional gene/drug delivery systems. A series of well‐defined protein‐based cationic supramolecular nanoparticles, with excellent magnetic resonance imaging ability, low cytotoxicity, and high gene transfection efficiency, are readily designed via the synergistic actions of host–guest and electrostatic self‐assemblies for multifunctional delivery systems.
      PubDate: 2016-02-18T12:46:26.833863-05:
      DOI: 10.1002/adfm.201504980
       
  • Upconverting Nanoparticle Relays for Resonance Energy Transfer Networks
    • Authors: Craig D. LaBoda; Chris L. Dwyer
      Pages: 2866 - 2874
      Abstract: Networks of fluorophores arranged at the nanoscale can perform basic computation using resonance energy transfer (RET) to transport and manipulate information in the form of excitons. As excitons travel through RET circuits, they are red‐shifted due to vibrational energy loss at each transfer event. This loss prohibits RET circuits from being cascaded to form larger, more computationally complex systems. To address this issue, a nanoassembly capable of converting three or more low energy excitons into a single high energy exciton is designed and fabricated. Deemed the RET relay, this device uses upconverting nanoparticles to achieve anti‐Stokes energy transfer from near‐infrared excited fluorophores to visibly excited fluorophores. In this work, the relay is explored by first breaking it into its halves. Each fluorophore's ability to donate energy to or from the nanoparticle is characterized by a series of photoluminescence experiments. The adsorption of these fluorophores to the particle is modeled as a Langmuir process, revealing the fractional occupancy of each dye that optimizes energy transfer. A fully functional relay is then demonstrated by exciting the near‐infrared dye and extracting the visible dye's fluorescence. Lastly, the performance of the entire construct is optimized over a small sampling of assembly reaction coordinates. A nanoassembly that converts low energy excitons into high energy excitons is designed and fabricated by adsorbing organic fluorophores to upconverting nanoparticles. Assembly is modeled as a Langmuir process and the optimal fractional occupancy of each fluorophore is extracted. This is the first device to use upconverting nanoparticles as both donors and acceptors in a multistep resonance energy transfer cascade.
      PubDate: 2016-03-15T13:50:59.924684-05:
      DOI: 10.1002/adfm.201505029
       
  • Photonic Hydrogels from Chiral Nematic Mesoporous Chitosan Nanofibril
           Assemblies
    • Pages: 2875 - 2881
      Abstract: Iridescence in animals and plants often arises from structural coloration, which involves hierarchical organization of minerals and biopolymers over length scales of the visible spectrum, leading to diffraction of light. In this work, discarded crustacean shells that are not known for their structural colors are used to produce photonic nanostructures of large, freestanding chiral nematic mesoporous chitosan membranes with tunable iridescent color. Bioinspired by colorful nanostructures in nature, photonic hydrogels with Bouligand‐type organization are fabricated from the twisted mesoporous membranes, where the chitosan nanofibrils are a novel precursor for surface acetylation and are also a biotemplate for polymerizing methyl methacrylate. The colors of the hydrogels can be tailored by swelling as they show large volume changes in response to changes in solvent environment. Photonic hydrogels: Crustacean exoskeletons as discarded biomass sources are used to develop functional photonic nano­materials with a twist. The bioinspired photonic hydrogels have tunable iridescence that is imprinted by the natural Bouligand‐type organization of chitin nanfibrils.
      PubDate: 2016-03-15T02:41:42.69373-05:0
      DOI: 10.1002/adfm.201505032
       
  • Domain Selectivity in BiFeO3 Thin Films by Modified Substrate Termination
    • Authors: Alim Solmaz; Mark Huijben, Gertjan Koster, Ricardo Egoavil, Nicolas Gauquelin, Gustaaf Van Tendeloo, Jo Verbeeck, Beatriz Noheda, Guus Rijnders
      Pages: 2882 - 2889
      Abstract: Ferroelectric domain formation is an essential feature in ferroelectric thin films. These domains and domain walls can be manipulated depending on the growth conditions. In rhombohedral BiFeO3 thin films, the ordering of the domains and the presence of specific types of domain walls play a crucial role in attaining unique ferroelectric and magnetic properties. In this study, controlled ordering of domains in BiFeO3 film is presented, as well as a controlled selectivity between two types of domain walls is presented, i.e., 71° and 109°, by modifying the substrate termination. The experiments on two different substrates, namely SrTiO3 and TbScO3, strongly indicate that the domain selectivity is determined by the growth kinetics of the initial BiFeO3 layers. Growth of the BiFeO3 thin films is shown to depend on the atomic termination of the SrTiO3 and TbScO3 substrates. Interface engineering with a single SrO layer on substrate surfaces enables the control of domain ordering and selectivity between 71° and 109° domain walls. Underlying mechanism is claimed to be growth dynamic during the initial phase of growth.
      PubDate: 2016-03-21T03:26:46.382116-05:
      DOI: 10.1002/adfm.201505065
       
  • Noncontact Temperature Probing: Highly Efficient Nonradiative Energy
           Transfer from Colloidal Semiconductor Quantum Dots to Wells for Sensitive
           Noncontact Temperature Probing (Adv. Funct. Mater. 17/2016)
    • Authors: Murat Olutas; Burak Guzelturk, Yusuf Kelestemur, Kivanc Gungor, Hilmi Volkan Demir
      Pages: 2890 - 2890
      Abstract: On page 2891, H. V. Demir and co‐workers show that nonradiative energy transfer (NRET) in hybrid thin films of solution‐processed colloidal quantum dots and quantum wells is a function of the donor‐to‐acceptor molar concentration ratio and temperature, and achieve remarkably high NRET efficiencies (up to 94%). Highly linear response of NRET efficiency with changing temperature also makes this new hybrid system appealing for noncontact sensitive temperature probing.
      PubDate: 2016-04-28T05:57:50.480652-05:
      DOI: 10.1002/adfm.201670108
       
  • Highly Efficient Nonradiative Energy Transfer from Colloidal Semiconductor
           Quantum Dots to Wells for Sensitive Noncontact Temperature Probing
    • Authors: Murat Olutas; Burak Guzelturk, Yusuf Kelestemur, Kivanc Gungor, Hilmi Volkan Demir
      Pages: 2891 - 2899
      Abstract: This study develops and shows highly efficient exciton‐transferring hybrid semiconductor nanocrystal films of mixed dimensionality comprising quasi 0D and 2D colloids. Through a systematic study of time‐resolved and steady‐state photoluminescence spectroscopy as a function of the donor‐to‐acceptor molar concentration ratio and temperature, a high‐efficiency nonradiative energy transfer (NRET) process from CdZnS/ZnS core/shell quantum dots (QDs) directed to atomically flat CdSe nanoplatelets (NPLs) in their solid‐state thin films is uncovered. The exciton funneling in this system reaches transfer efficiency levels as high as 90% at room temperature. In addition, this study finds that with decreasing temperature exciton transfer efficiency is increased to a remarkable maximum level of ≈94%. The enhancement in the dipole–dipole coupling strength with decreasing temperature is well accounted by increasing photoluminescence quantum yield of the donor and growing spectral overlap between the donor and the acceptor. Furthermore, NRET efficiency exhibits a highly linear monotonic response with changing temperature. This makes the proposed QD–NPL composites appealing for noncontact sensitive temperature probing based on NRET efficiencies as a new metric. These findings indicate that combining colloidal nanocrystals of different dimensionality enables efficient means of temperature probing at an unprecedented sensitivity level at nanoscale through almost complete exciton transfer. Nonradiative energy transfer (NRET) in hybrid thin films of solution‐processed colloidal quantum dots and quantum wells is presented as a function of the donor‐to‐acceptor molar concentration ratio and temperature with remarkably high NRET efficiencies (up to 94%). Highly linear response of NRET efficiency with changing temperature also makes this new hybrid system appealing for noncontact sensitive temperature probing.
      PubDate: 2016-03-17T12:53:13.175125-05:
      DOI: 10.1002/adfm.201505108
       
  • Poisson Ratio and Piezoresistive Sensing: A New Route to
           High‐Performance 3D Flexible and Stretchable Sensors of Multimodal
           Sensing Capability
    • Pages: 2900 - 2908
      Abstract: The performance of flexible and stretchable sensors relies on the optimization of both the flexible substrate and the sensing element, and their synergistic interactions. Herein, a novel strategy is reported for cost‐effective and scalable manufacturing of a new class of porous materials as 3D flexible and stretchable piezoresistive sensors, by assembling carbon nanotubes onto porous substrates of tunable Poisson ratios. It is shown that the piezoresistive sensitivity of the sensors increases as the substrate's Poisson's ratio decreases. Substrates with negative Poisson ratios (auxetic foams) exhibit significantly higher piezoresistive sensitivity, resulting from the coherent mode of deformation of the auxetic foam and enhanced changes of tunneling resistance of the carbon nanotube networks. Compared with conventional foam sensors, the auxetic foam sensor (AFS) with a Poisson's ratio of –0.5 demonstrates a 300% improvement in piezoresistive sensitivity and the gauge factor increases as much as 500%. The AFS has high sensing capability, is extremely robust, and capable of multimodal sensing, such as large deformation sensing, pressure sensing, shear/torsion sensing, and underwater sensing. AFS shows great potential for a broad range of wearable and portable devices applications, which are described by reporting on a series of demonstrations. The performance of flexible and stretchable sensors relies on the optimization of both the flexible substrate and the sensing element, along with their synergistic interactions. Herein, a novel strategy for cost‐effective and scalable manufacturing of a new class of porous materials as 3D flexible and stretchable piezoresistive sensors, by assembling carbon nanotubes onto porous substrates of tunable Poisson ratios.
      PubDate: 2016-02-19T10:34:27.339317-05:
      DOI: 10.1002/adfm.201505070
       
  • Guided Formation of 3D Helical Mesostructures by Mechanical Buckling:
           Analytical Modeling and Experimental Validation
    • Pages: 2909 - 2918
      Abstract: 3D helical mesostructures are attractive for applications in a broad range of microsystem technologies due to their mechanical and electromagnetic properties as stretchable interconnects, radio frequency antennas, and others. Controlled compressive buckling of 2D serpentine‐shaped ribbons provides a strategy to formation of such structures in wide ranging classes of materials (from soft polymers to brittle inorganic semiconductors) and length scales (from nanometer to centimeter), with an ability for automated, parallel assembly over large areas. The underlying relations between the helical configurations and fabrication parameters require a relevant theory as the basis of design for practical applications. Here, an analytic model of compressive buckling in serpentine microstructures is presented based on the minimization of total strain energy that results from various forms of spatially dependent deformations. Experiments at micro‐ and millimeter scales, together with finite element analyses, have been exploited to examine the validity of developed model. The theoretical analyses shed light on general scaling laws in terms of three groups of fabrication parameters (related to loading, material, and 2D geometry), including a negligible effect of material parameters and a square root dependence of primary displacements on the compressive strain. Furthermore, analytic solutions were obtained for the key physical quantities (e.g., displacement, curvature and maximum strain). A demonstrative example illustrates how to leverage the analytic solutions in choosing the various design parameters, such that brittle fracture or plastic yield can be avoided in the assembly process. Analytic models, finite element analyses, and experiments are presented to capture all quantitative aspects of buckling‐guided formation of 3D helical mesostructures. The resulting scaling laws include negligible roles of cross‐sectional and material parameters on the 3D configurations, enabling predictions of physical quantities with analytic solutions. These findings can serve as design references for assembly of structures optimized for device applications.
      PubDate: 2016-02-24T03:38:32.49495-05:0
      DOI: 10.1002/adfm.201505132
       
  • Sustained‐Release Synthetic Biomarkers for Monitoring Thrombosis and
           Inflammation Using Point‐of‐Care Compatible Readouts
    • Authors: Jaideep S. Dudani; Colin G. Buss, Reid T. K. Akana, Gabriel A. Kwong, Sangeeta N. Bhatia
      Pages: 2919 - 2928
      Abstract: Postoperative infection and thromboembolism represent significant sources of morbidity and mortality but cannot be easily tracked after hospital discharge. Therefore, a molecular test that could be performed at home would significantly impact disease management. The laboratory has previously developed intravenously delivered “synthetic biomarkers” that respond to dysregulated proteases to produce a urinary signal. These assays, however, have been limited to chronic diseases or acute diseases initiated at the time of diagnostic administration. Here, a subcutaneously administered sustained‐release system, using small poly(ethylene glycol) scaffolds (
      PubDate: 2016-03-22T03:15:35.546988-05:
      DOI: 10.1002/adfm.201505142
       
  • Direct Imprinting of Porous Silicon via Metal‐Assisted Chemical
           Etching
    • Pages: 2929 - 2939
      Abstract: Conventional lithographical techniques used for bulk semiconductors produce dramatically poor results when used for micro and mesoporous materials such as porous silicon (PS). In this work, for the first time, a high‐throughput, single‐step, direct imprinting process for PS not involving plastic deformation or high‐temperature processing is reported. Based on the underlying mechanism of metal‐assisted chemical etching (MACE), this process uses a pre‐patterned polymer stamp coated with a noble metal catalyst to etch PS immersed in an HF‐oxidizer mixture. The process not only overcomes the difficulties in patterning PS but it does so with a stamp that may be reused multiple times depending on its chemical and mechanical degradation. The process is shown to be capable of centimeter‐scale parallel 3D patterning with sub‐20 nm resolution. It is found that PS facilitates mass transport of reactants and products, and the overall etch rate is limited by local depletion of reactants. The versatility of this direct imprinting technique is demonstrated by its ability to produce curvilinear and planar 3D features (e.g., paraboloids, parabolic cylinders, sinusoidal waves, and straight sidewall channels). Miniaturized optical elements such as diffraction gratings and microconcentrators are built and characterized highlighting potential use of PS in silicon photonics. A high‐throughput, single‐step, highly parallelizable, direct imprinting process for porous silicon that does not involve plastic deformation or high‐temperature processing is presented. Exploiting the underlying mechanism of metal‐assisted chemical etching, this process not only overcomes the difficulties in patterning porous silicon, but it does so with a reusable stamp producing 3D patterns with sub‐20 nm resolution.
      PubDate: 2016-02-22T07:25:23.2533-05:00
      DOI: 10.1002/adfm.201505153
       
  • Current Enhancement in Organic Films through Gap Compression by Cold and
           Hot Isostatic Pressing
    • Authors: Yu Esaki; Toshinori Matsushima, Chihaya Adachi
      Pages: 2940 - 2949
      Abstract: The spatial gaps in organic films are compressed using cold and hot isostatic pressing (CIP and HIP, respectively) with the aim of enhancing their electrical characteristics. The microscopic gaps formed in amorphous organic films by inefficient molecular packing are difficult to compress using CIP and HIP; however, the macroscopic gaps formed between grains and other grains or substrates in polycrystalline organic films can be compressed using CIP and HIP. The gap compression by CIP and HIP in polycrystalline films enhances their electrical characteristics. Conversely, the electrical characteristics of amorphous films remain unchanged after CIP and HIP. HIP gives almost the same results as CIP in terms of gap compression and current enhancement, probably because the expected activation of molecular motion at high temperature is suppressed under high applied pressure. CIP markedly improves the performance of organic light‐emitting diodes, organic solar cells, and organic field‐effect transistors containing polycrystalline films. These findings are important for understanding the carrier injection and transport mechanisms of organic films containing gaps as well as enhancing the performance of future organic devices, especially those with polycrystalline films. Cold and hot isostatic pressing (CIP and HIP, respectively) compress spatial gaps and enhance the electrical characteristics of polycrystalline organic films. Conversely, the electrical characteristics of amorphous organic films remain unchanged after CIP and HIP because there is no gap compression. CIP markedly improves the performance of organic light‐emitting diodes, organic solar cells, and organic field‐effect transistors containing polycrystalline films.
      PubDate: 2016-03-15T02:41:30.091949-05:
      DOI: 10.1002/adfm.201505190
       
  • Effects of a Molecular Monolayer Modification of NiO Nanocrystal Layer
           Surfaces on Perovskite Crystallization and Interface Contact toward Faster
           Hole Extraction and Higher Photovoltaic Performance
    • Pages: 2950 - 2958
      Abstract: NiO is a promising hole transporting material for perovskite solar cells due to its high hole mobility, good stability, easy processibility, and suitable Fermi level for hole extraction. However, the efficiency of NiO‐based cells is still limited by the slow hole extraction due to the poor perovskite/NiO interface and the inadequate quality of the two solution‐processed material phases. Here, large influences of a monolayer surface modification of NiO nanocrystal layers with ethanolamine molecules are demonstrated on the enhancement of hole extraction/transport and thus the photovoltaic performance. The underlying causes have been revealed by a series of studies, pointing to a favorable dipole layer formed by the molecular adsorption along with the enhanced perovskite crystallization and the improved interface contact. Comparatively, the solar cells based on a diethanolamine‐modified NiO layer have achieved a rather high fill factor, indeed one of the highest among NiO‐based perovskite solar cells, and high short‐circuit photocurrent density (Jsc), resulting in a power conversion efficiency of ≈16%, most importantly, without hysteresis. Diethanolamine (DEA) modification of the thin NiO film surface in perovskite solar cells enhances the interfacial hole extraction rate and thus the photovoltaic performance. Perovskite film quality and the contact at the perovskite/NiO interface are greatly improved through the chemical coordination of Ni and Pb with the –NH– and –OH groups of DEA, respectively.
      PubDate: 2016-03-02T07:54:48.761855-05:
      DOI: 10.1002/adfm.201505215
       
  • Core–Shelled Low‐Oxidation State Oxides@Reduced Graphene
           Oxides Cubes via Pressurized Reduction for Highly Stable Lithium Ion
           Storage
    • Authors: Kan Zhang; Ping Li, Ming Ma, Jong Hyeok Park
      Pages: 2959 - 2965
      Abstract: Metal oxides have been regarded as promising next‐generation anode materials for rechargeable lithium ion batteries; however, their poor stability, which is caused by large volume changes during repeated lithiation/delithiation, remains a challenge. Here, conformally encapsulated low‐oxidation state oxide cubes with reduced graphene oxide (RGO) obtained via a new pressurized reduction consisting of external mechanical compression and internal thermokinetic reduction from highly porous metal oxides/RGO aerogel (RGOA) are reported. Using single crystalline (SC) cobalt oxides and iron oxide cubes as model systems, the SC‐Co3O4 or Fe2O3 cube/RGOA are pressurized into compacted xerogel along with a uniform thermokinetic reduction, which result in topotactic transformation to core‐shelled CoO/RGO or Fe3O4@RGO cubes. The SC‐CoO and SC‐Fe3O4 cubes isolated perfectly in the RGO shells have dramatically improved their cycling stabilities for lithium ion storage to hundreds of times. The lithium‐ion storage stability of the core/shelled low‐oxidation state oxide/RGO cubes can be prolonged by at least 400 times.
      PubDate: 2016-02-29T03:55:08.910515-05:
      DOI: 10.1002/adfm.201504979
       
  • Design, Synthesis, and Versatile Processing of
           Indolo[3,2‐b]indole‐Based π‐Conjugated Molecules
           for High‐Performance Organic Field‐Effect Transistors
    • Authors: Illhun Cho; Sang Kyu Park, Boseok Kang, Jong Won Chung, Jin Hong Kim, Kilwon Cho, Soo Young Park
      Pages: 2966 - 2973
      Abstract: A series of indolo[3,2‐b]indole (IDID) derivatives comprising the core unit of N,N‐dihexyl‐IDID with different aromatic and aliphatic substituents at 2‐ and 7‐position are designed and synthesized to construct high‐performance organic semiconductors by different processing routes. Structure‐property relationship of the derivatives is comprehensively studied in terms of their photophysical, electrochemical, structural, and electrical characteristics. IDID derivatives are either evaporated in vacuum or dissolved in common organic solvents to ensure applicalbility in different processing routes toward outstanding p‐type semiconductor films. Among others, the excellently soluble compound 4H4TIDID (with 2‐ and 7‐substituents of 5‐hexyl‐2,2′‐bithiophene moiety, solubility >20 wt% in chloroform), shows the highest field‐effect hole mobility of 0.97 cm2 V−1 s−1 in a device constructed by vacuum‐deposition and 0.18 cm2 V−1 s−1 in device cosntructed by spin‐coating, respectively. The 2D grazing incidence X‐ray diffraction of 4H4TIDID films in both devices identically show the 2D molecular orientation favorable for the high transistor mobility. A series of indolo[3,2‐b]indole (IDID) derivatives are prepared to develop high‐performance organic semiconductors. Among others, films of compound 4H4TIDID possess a 2D ordered surface‐parallel orientation and respective devices exhibit hole mobilites of 0.97 cm2 V−1 s−1 if formed by vacuum‐deposition, and 0.18 cm2 V−1 s−1 if spin‐coated. The long‐axis parallel aliphatic units enhance solubility as well as charge transport property.
      PubDate: 2016-03-23T06:11:17.139608-05:
      DOI: 10.1002/adfm.201505023
       
  • Cancer Phototherapy: Mitochondria‐Targeted Small‐Molecule
           Fluorophores for Dual Modal Cancer Phototherapy (Adv. Funct. Mater.
           17/2016)
    • Authors: Shenglin Luo; Xu Tan, Shengtao Fang, Yu Wang, Tao Liu, Xin Wang, Yi Yuan, Huiqin Sun, Qingrong Qi, Chunmeng Shi
      Pages: 2975 - 2975
      Abstract: Mitochondria play a central role in energy production and cell survival. On page 2826, Q. Qi, C. Shi, and co‐workers develop a multifunctional, mitochondria‐targeting, near‐infrared small‐molecule dye for synchronous cancer photodynamic and photothermal therapy. Its structure‐inherent cancer targeting and imaging capabilities also enable tumors and their margins to be visualized, providing potential for imaging‐guided cancer treatment.
      PubDate: 2016-04-28T05:57:56.744396-05:
      DOI: 10.1002/adfm.201670109
       
  • Microfluidics‐Assisted Osteogenesis: Injectable Stem
           Cell‐Laden Photocrosslinkable Microspheres Fabricated Using
           Microfluidics for Rapid Generation of Osteogenic Tissue Constructs (Adv.
           Funct. Mater. 17/2016)
    • Authors: Xin Zhao; Shen Liu, Lara Yildirimer, Hong Zhao, Ruihua Ding, Huanan Wang, Wenguo Cui, David Weitz
      Pages: 2976 - 2976
      Abstract: A bone regeneration strategy with minimum invasiveness is developed on page 2809 by W. Cui, D. Weitz, and co‐workers, using microfluidics‐fabricated photocrosslinkable gelatin microspheres encapsulating bone marrow‐derived mesenchymal stem cells and growth factors. The cell‐laden microspheres are found to enhance and accelerate osteogenesis in vitro and in vivo, associated with a significant increase in mineralization.
      PubDate: 2016-04-28T05:57:59.023346-05:
      DOI: 10.1002/adfm.201670110
       
 
 
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