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  Subjects -> ENGINEERING (Total: 2312 journals)
    - CHEMICAL ENGINEERING (196 journals)
    - CIVIL ENGINEERING (192 journals)
    - ELECTRICAL ENGINEERING (104 journals)
    - ENGINEERING (1213 journals)
    - ENGINEERING MECHANICS AND MATERIALS (389 journals)
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    - MECHANICAL ENGINEERING (93 journals)

ENGINEERING (1213 journals)                  1 2 3 4 5 6 7 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 7)
3D Research     Hybrid Journal   (Followers: 19)
AAPG Bulletin     Hybrid Journal   (Followers: 7)
AASRI Procedia     Open Access   (Followers: 15)
Abstract and Applied Analysis     Open Access   (Followers: 3)
Aceh International Journal of Science and Technology     Open Access   (Followers: 2)
ACS Nano     Full-text available via subscription   (Followers: 256)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 2)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Active and Passive Electronic Components     Open Access   (Followers: 7)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 6)
Advanced Science     Open Access   (Followers: 5)
Advanced Science Focus     Free   (Followers: 3)
Advanced Science Letters     Full-text available via subscription   (Followers: 9)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 7)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 18)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 6)
Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Engineering Software     Hybrid Journal   (Followers: 27)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 11)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 22)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 27)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 10)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 30)
Advances in Operations Research     Open Access   (Followers: 12)
Advances in OptoElectronics     Open Access   (Followers: 5)
Advances in Physics Theories and Applications     Open Access   (Followers: 12)
Advances in Polymer Science     Hybrid Journal   (Followers: 41)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Remote Sensing     Open Access   (Followers: 40)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aerobiologia     Hybrid Journal   (Followers: 2)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 6)
AIChE Journal     Hybrid Journal   (Followers: 32)
Ain Shams Engineering Journal     Open Access   (Followers: 5)
Akademik Platform Mühendislik ve Fen Bilimleri Dergisi     Open Access   (Followers: 1)
Alexandria Engineering Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
American Journal of Applied Sciences     Open Access   (Followers: 28)
American Journal of Engineering and Applied Sciences     Open Access   (Followers: 11)
American Journal of Engineering Education     Open Access   (Followers: 9)
American Journal of Environmental Engineering     Open Access   (Followers: 17)
American Journal of Industrial and Business Management     Open Access   (Followers: 23)
Analele Universitatii Ovidius Constanta - Seria Chimie     Open Access  
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Regional Science     Hybrid Journal   (Followers: 8)
Annals of Science     Hybrid Journal   (Followers: 7)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 6)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 18)
Applied Clay Science     Hybrid Journal   (Followers: 5)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 4)
Applied Nanoscience     Open Access   (Followers: 8)
Applied Network Science     Open Access   (Followers: 1)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 3)
Applied Sciences     Open Access   (Followers: 2)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 5)
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Archives of Foundry Engineering     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 8)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 3)
Asia-Pacific Journal of Science and Technology     Open Access  
Asian Engineering Review     Open Access  
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 1)
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 8)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Current Engineering & Maths     Open Access  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 8)
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Full-text available via subscription   (Followers: 2)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 9)
Avances en Ciencias e Ingeniería     Open Access  
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 1)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 5)
Batteries     Open Access   (Followers: 6)
Bautechnik     Hybrid Journal   (Followers: 1)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 24)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 4)
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Motor Trade Survey     Full-text available via subscription   (Followers: 1)
BER : Retail Sector Survey     Full-text available via subscription   (Followers: 2)
BER : Retail Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Survey of Business Conditions in Manufacturing : An Executive Summary     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Retail : An Executive Summary     Full-text available via subscription   (Followers: 4)
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access   (Followers: 1)
Biofuels Engineering     Open Access   (Followers: 1)
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 10)
Biomedical Engineering     Hybrid Journal   (Followers: 15)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 14)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 5)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 18)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 34)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 9)
Biomedical Science and Engineering     Open Access   (Followers: 4)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal  
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 2)
Biotechnology Progress     Hybrid Journal   (Followers: 39)
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription   (Followers: 1)
Boundary Value Problems     Open Access   (Followers: 1)
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 14)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 14)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers, Droit, Sciences et Technologies     Open Access  
Calphad     Hybrid Journal  
Canadian Geotechnical Journal     Hybrid Journal   (Followers: 30)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 44)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 8)
Case Studies in Thermal Engineering     Open Access   (Followers: 4)
Catalysis Communications     Hybrid Journal   (Followers: 6)
Catalysis Letters     Hybrid Journal   (Followers: 2)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 8)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 7)
CEAS Space Journal     Hybrid Journal   (Followers: 2)
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 3)
Central European Journal of Engineering     Hybrid Journal   (Followers: 1)
CFD Letters     Open Access   (Followers: 6)
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 2)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Engineering     Open Access   (Followers: 2)
Chinese Science Bulletin     Open Access   (Followers: 1)
Ciencia e Ingenieria Neogranadina     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencias Holguin     Open Access   (Followers: 1)
CienciaUAT     Open Access  
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Full-text available via subscription   (Followers: 11)
CIRP Journal of Manufacturing Science and Technology     Full-text available via subscription   (Followers: 14)
City, Culture and Society     Hybrid Journal   (Followers: 24)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
Coal Science and Technology     Full-text available via subscription   (Followers: 3)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 5)
Coatings     Open Access   (Followers: 4)
Cogent Engineering     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Color Research & Application     Hybrid Journal   (Followers: 2)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 14)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 13)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Components, Packaging and Manufacturing Technology, IEEE Transactions on     Hybrid Journal   (Followers: 27)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Composite Structures     Hybrid Journal   (Followers: 272)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 200)
Composites Part B : Engineering     Hybrid Journal   (Followers: 257)
Composites Science and Technology     Hybrid Journal   (Followers: 194)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
Computational Geosciences     Hybrid Journal   (Followers: 15)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 8)
Computer Science and Engineering     Open Access   (Followers: 19)
Computers & Geosciences     Hybrid Journal   (Followers: 30)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 7)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 5)
Computers and Geotechnics     Hybrid Journal   (Followers: 11)
Computing and Visualization in Science     Hybrid Journal   (Followers: 6)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 33)
Conciencia Tecnologica     Open Access  
Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 8)
Control and Dynamic Systems     Full-text available via subscription   (Followers: 9)
Control Engineering Practice     Hybrid Journal   (Followers: 43)
Control Theory and Informatics     Open Access   (Followers: 8)
Corrosion Science     Hybrid Journal   (Followers: 25)
Corrosion Series     Full-text available via subscription   (Followers: 6)
CT&F Ciencia, Tecnologia y Futuro     Open Access   (Followers: 1)

        1 2 3 4 5 6 7 | Last

Journal Cover Advanced Science
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   ISSN (Online) 2198-3844
   Published by John Wiley and Sons Homepage  [1592 journals]
  • First-Principle-Based Phonon Transport Properties of Nanoscale Graphene
           Grain Boundaries

    • Authors: Leonardo Medrano Sandonas; Hâldun Sevinçli, Rafael Gutierrez, Gianaurelio Cuniberti
      Abstract: The integrity of phonon transport properties of large graphene (linear and curved) grain boundaries (GBs) is investigated under the influence of structural and dynamical disorder. To do this, density functional tight-binding (DFTB) method is combined with atomistic Green's function technique. The results show that curved GBs have lower thermal conductance than linear GBs. Its magnitude depends on the length of the curvature and out-of-plane structural distortions at the boundary, having stronger influence the latter one. Moreover, it is found that by increasing the defects at the boundary, the transport properties can strongly be reduced in comparison to the effect produced by heating up the boundary region. This is due to the large reduction of the phonon transmission for in-plane and out-of-plane vibrational modes after increasing the structural disorder in the GBs.Atomistic Green's function technique combined with density functional tight-binding method is used to study quantum phonon transport properties of large graphene (linear and curved) grain boundaries. The influence of defect concentration and temperature at the boundary region on the transport properties is also discussed.
      PubDate: 2018-01-11T00:06:41.284713-05:
      DOI: 10.1002/advs.201700365
       
  • Focused Ultrasound-Augmented Delivery of Biodegradable Multifunctional
           Nanoplatforms for Imaging-Guided Brain Tumor Treatment

    • Authors: Meiying Wu; Wenting Chen, Yu Chen, Haixian Zhang, Chengbo Liu, Zhiting Deng, Zonghai Sheng, Jingqin Chen, Xin Liu, Fei Yan, Hairong Zheng
      Abstract: The blood brain barrier is the main obstacle to delivering diagnostic and therapeutic agents to the diseased sites of brain. It is still of great challenge for the combined use of focused ultrasound (FUS) and theranostic nanotechnology to achieve noninvasive and localized delivery of chemotherapeutic drugs into orthotopic brain tumor. In this work, a unique theranostic nanoplatform for highly efficient photoacoustic imaging-guided chemotherapy of brain tumor both in vitro and in vivo, which is based on the utilization of hollow mesoporous organosilica nanoparticles (HMONs) to integrate ultrasmall Cu2−xSe particles on the surface and doxorubicin inside the hollow interior, is synthesized. The developed multifunctional theranostic nanosystems exhibit tumor-triggered programmed destruction due to the reducing microenvironment-responsive cleavage of disulfide bonds that are incorporated into the framework of HMONs and linked between HMONs and Cu2−xSe, resulting in tumor-specific biodegradation and on-demand drug-releasing behavior. Such tumor microenvironment-responsive biodegradable and biocompatible theranostic nanosystems in combination with FUS provide a promising delivery nanoplatform with high performance for orthotopic brain tumor imaging and therapy.A novel tumor-microenvironment-driven biodegradable HCu nanoplatform with photoacoustic imaging and on-demand drug-releasing performance, which is based on the integration of hollow mesoporous organosilica nanoparticles with ultrasmall Cu2−xSe nanoparticles, is successfully constructed. The excellent orthotopic brain tumor-inhibition effect is achieved by concurrent use of HCu nanosystems and focused ultrasound-induced blood brain barrier opening.
      PubDate: 2018-01-10T00:11:03.97089-05:0
      DOI: 10.1002/advs.201700474
       
  • Recent Advances on Functionalized Upconversion Nanoparticles for Detection
           of Small Molecules and Ions in Biosystems

    • Authors: Bin Gu; Qichun Zhang
      Abstract: Significant progress on upconversion-nanoparticle (UCNP)-based probes is witnessed in recent years. Compared with traditional fluorescent probes (e.g., organic dyes, metal complexes, or inorganic quantum dots), UCNPs have many advantages such as non-autofluorescence, high chemical stability, large light-penetration depth, long lifetime, and less damage to samples. This article focuses on recent achievements in the usage of lanthanide-doped UCNPs as efficient probes for biodetection since 2014. The mechanisms of upconversion as well as the luminescence resonance energy transfer process is introduced first, followed by a detailed summary on the recent researches of UCNP-based biodetections including the detection of inorganic ions, gas molecules, reactive oxygen species, and thiols and hydrogen sulfide.Due to the unique advantages that upconversion-nanoparticle (UCNP)-based probes have compared to traditional probes, such as non-autofluorescence, large light penetration depth, and less damage to samples, research in this field has increased rapidly over recent years. Recent progress (since 2014) on the usage of lanthanide doped UCNPs as efficient probes for biodetection of inorganic ions, gas molecules, reactive oxygen species, and thiols is presented.
      PubDate: 2018-01-09T05:07:51.782264-05:
      DOI: 10.1002/advs.201700609
       
  • Characterization of HIF-1α/Glycolysis Hyperactive Cell Population via
           Small-Molecule-Based Imaging of Mitochondrial Transporter Activity

    • Authors: Yang Wang; Xingyun Liao, Jianguo Sun, Bin Yi, Shenglin Luo, Tao Liu, Xu Tan, Dengqun Liu, Zelin Chen, Xin Wang, Chunmeng Shi
      Abstract: The characterization of cancer stem-like cells (CSCs) has profound implications for elucidating cancer biology and developing treatment strategies. Although surface markers are already used to identify CSCs, the expression of these markers is controversially linked to the phenotypes in different types of tumors and does not represent all functionally relevant of CSCs. Very recently, hyperactive HIF-1α/glycolysis metabolic pathway is recognized as a master regulator of CSCs. In this study, a near-infrared fluorescent small-molecule, IR-780, is identified for the exclusive characterization of human CSCs through the HIF-1α/glycolysis dependent mitochondrial transporter ABCB10's activity. The results identified for the first time that ABCB10 is involved in the preferential uptake of IR-780 in CSCs, which is regulated by HIF-1α via the direct interaction with the binding site of ABCB10 gene promoter region. In addition, IR-780 is demonstrated to conjugate with anticancer drug 5-fluorouracil to act as a potential drug delivery carrier for CSC-targeted therapy. Thus, the studies provide a new rational approach independent of surface markers to characterize CSCs via small-molecule-based imaging of HIF-1α/glycolysis hyperactive metabolic pathway dependent mitochondrial transporter's activity, which holds promise for the further development of CSCs targeted diagnostic and therapeutic strategies.A marker-independent strategy for the characterization of stem-like cells (CSCs) is developed by targeting hyperactive HIF-1α/glycolysis metabolic pathway via molecular imaging of mitochondrial transporter ABCB10's activity by near-infrared fluorescent small-molecule IR-780. This represents a potential drug delivery strategy for the future development of CSC-targeting diagnostic and therapeutic modalities.
      PubDate: 2018-01-09T05:06:32.942825-05:
      DOI: 10.1002/advs.201700392
       
  • Recent Advances in Sensitized Photocathodes: From Molecular Dyes to
           Semiconducting Quantum Dots

    • Authors: Hao-Lin Wu; Xu-Bing Li, Chen-Ho Tung, Li-Zhu Wu
      Abstract: The increasing demand for sustainable and environmentally benign energy has stimulated intense research to establish highly efficient photo-electrochemical (PEC) cells for direct solar-to-fuel conversion via water splitting. Light absorption, as the initial step of the catalytic process, is regarded as the foundation of establishing highly efficient PEC systems. To make full use of visible light, sensitization on photoelectrodes using either molecular dyes or semiconducting quantum dots provides a promising method. In this field, however, there remain many fundamental issues to be solved, which need in-depth study. Here, fundamental knowledge of PEC systems is introduced to enable readers a better understanding of this field. Then, the development history and current state in both molecular dye- and quantum dot-sensitized photocathodes for PEC water splitting are discussed. A systematical comparison between the two systems has been made. Special emphasis is placed on the research of quantum dot-sensitized photocathodes, which have shown superiority in both efficiency and durability towards PEC water splitting at the present stage. Finally, the opportunities and challenges in the future for sensitized PEC water-splitting systems are proposed.Recent advances in photo-electrochemical hydrogen evolution via molecular dyes or quantum dots sensitized photocathodes are reviewed. The fundamental catalytic principles of water splitting using sensitized photocathodes are discussed. Also, further efforts to improve the performance, both efficiency and stability, of such systems are proposed.
      PubDate: 2018-01-08T02:44:04.784283-05:
      DOI: 10.1002/advs.201700684
       
  • Polysaccharide-Based Controlled Release Systems for Therapeutics Delivery
           and Tissue Engineering: From Bench to Bedside

    • Authors: Tianxin Miao; Junqing Wang, Yun Zeng, Gang Liu, Xiaoyuan Chen
      Abstract: Polysaccharides or polymeric carbohydrate molecules are long chains of monosaccharides that are linked by glycosidic bonds. The naturally based structural materials are widely applied in biomedical applications. This article covers four different types of polysaccharides (i.e., alginate, chitosan, hyaluronic acid, and dextran) and emphasizes their chemical modification, preparation approaches, preclinical studies, and clinical translations. Different cargo fabrication techniques are also presented in the third section. Recent progresses in preclinical applications are then discussed, including tissue engineering and treatment of diseases in both therapeutic and monitoring aspects. Finally, clinical translational studies with ongoing clinical trials are summarized and reviewed. The promise of new development in nanotechnology and polysaccharide chemistry helps clinical translation of polysaccharide-based drug delivery systems.Unique physiochemical and biological properties of polysaccharides hold great promise in controlled release for therapeutics delivery and tissue engineering. A comprehensive overview of four common types of polysaccharides is provided and their controlled release systems are discussed in terms of chemical modification, preparation approaches, preclinical studies, and clinical translations.
      PubDate: 2018-01-08T02:42:53.658947-05:
      DOI: 10.1002/advs.201700513
       
  • Tin Selenide (SnSe): Growth, Properties, and Applications

    • Authors: Weiran Shi; Minxuan Gao, Jinping Wei, Jianfeng Gao, Chenwei Fan, Eric Ashalley, Handong Li, Zhiming Wang
      Abstract: The indirect bandgap semiconductor tin selenide (SnSe) has been a research hotspot in the thermoelectric fields since a ZT (figure of merit) value of 2.6 at 923 K in SnSe single crystals along the b-axis is reported. SnSe has also been extensively studied in the photovoltaic (PV) application for its extraordinary advantages including excellent optoelectronic properties, absence of toxicity, cheap raw materials, and relative abundance. Moreover, the thermoelectric and optoelectronic properties of SnSe can be regulated by the structural transformation and appropriate doping. Here, the studies in SnSe research, from its evolution to till now, are reviewed. The growth, characterization, and recent developments in SnSe research are discussed. The most popular growth techniques that have been used to prepare SnSe materials are discussed in detail with their recent progress. Important phenomena in the growth of SnSe as well as the problems remaining for future study are discussed. The applications of SnSe in the PV fields, Li-ion batteries, and other emerging fields are also discussed.The special crystal structure of tin selenide (both cubic and orthorhombic) and its outstanding thermoelectric and optoelectronic properties attributed to the structure are discussed. Applications and synthesis methods of SnSe materials are concretely summarized to present a comprehensive picture of SnSe.
      PubDate: 2018-01-08T02:41:33.204219-05:
      DOI: 10.1002/advs.201700602
       
  • TiO2 Phase Junction Electron Transport Layer Boosts Efficiency of Planar
           Perovskite Solar Cells

    • Authors: Yayun Zhu; Kaimo Deng, Haoxuan Sun, Bangkai Gu, Hao Lu, Fengren Cao, Jie Xiong, Liang Li
      Abstract: In the planar perovskite solar cells (PSCs), the electron transport layer (ETL) plays a critical role in electron extraction and transport. Widely utilized TiO2 ETLs suffer from the low conductivity and high surface defect density. To address these problems, for the first time, two types of ETLs based on TiO2 phase junction are designed and fabricated distributed in the opposite space, namely anatase/rutile and rutile/anatase. The champion efficiency of PSCs based on phase junction ETL is over 15%, which is much higher than that of cells with single anatase (9.8%) and rutile (11.8%) TiO2 as ETL. The phase junction based PSCs also demonstrated obviously reduced hysteresis. The enhanced performance is discussed and mainly ascribed to the excellent capability of carrier extraction, defect passivation, and reduced recombination at the ETL/perovskite interface. This work opens a new phase junction ETL strategy toward interfacial energy band manipulation for improved PSC performance.Perovskite solar cells using TiO2 anatase and rutile phase junctions as the electron transport layers demonstrate improved efficiency and reduced hysteresis compared with the single phase counterparts, resulting from the excellent capability of carrier extraction, defect passivation, and reduced recombination at the phase junction/perovskite interface.
      PubDate: 2018-01-06T00:07:54.763449-05:
      DOI: 10.1002/advs.201700614
       
  • Compositionally Graded Absorber for Efficient and Stable
           Near-Infrared-Transparent Perovskite Solar Cells

    • Authors: Fan Fu; Stefano Pisoni, Thomas P. Weiss, Thomas Feurer, Aneliia Wäckerlin, Peter Fuchs, Shiro Nishiwaki, Lukas Zortea, Ayodhya N. Tiwari, Stephan Buecheler
      Abstract: Compositional grading has been widely exploited in highly efficient Cu(In,Ga)Se2, CdTe, GaAs, quantum dot solar cells, and this strategy has the potential to improve the performance of emerging perovskite solar cells. However, realizing and maintaining compositionally graded perovskite absorber from solution processing is challenging. Moreover, the operational stability of graded perovskite solar cells under long-term heat/light soaking has not been demonstrated. In this study, a facile partial ion-exchange approach is reported to achieve compositionally graded perovskite absorber layers. Incorporating compositional grading improves charge collection and suppresses interface recombination, enabling to fabricate near-infrared-transparent perovskite solar cells with power conversion efficiency of 16.8% in substrate configuration, and demonstrate 22.7% tandem efficiency with 3.3% absolute gain when mechanically stacked on a Cu(In,Ga)Se2 bottom cell. Non-encapsulated graded perovskite device retains over 93% of its initial efficiency after 1000 h operation at maximum power point at 60 °C under equivalent 1 sun illumination. The results open an avenue in exploring partial ion-exchange to design graded perovskite solar cells with improved efficiency and stability.A compositionally graded perovskite absorber is designed by partial ion-exchange reaction to improve charge collection and suppress interfacial recombination, which leads to improved efficiency and operational stability in near-infrared-transparent planar perovskite solar cells. The non-encapsulated graded perovskite device retains over 93% of its initial efficiency after 1000 h operation at maximum power point at 60 °C under equivalent 1 sun illumination.
      PubDate: 2018-01-05T00:07:52.916796-05:
      DOI: 10.1002/advs.201700675
       
  • Triboelectrification-Enabled Self-Powered Data Storage

    • Authors: Shuang Yang Kuang; Guang Zhu, Zhong Lin Wang
      Abstract: Data storage by any means usually requires an electric driving power for writing or reading. A novel approach for self-powered, triboelectrification-enabled data storage (TEDS) is presented. Data are incorporated into a set of metal-based surface patterns. As a probe slides across the patterned surface, triboelectrification between the scanning probe and the patterns produces alternatively varying voltage signal in quasi-square wave. The trough and crest of the quasi-square wave signal are coded as binary bits of “0” and “1,” respectively, while the time span of the trough and the crest is associated with the number of bits. The storage of letters and sentences is demonstrated through either square-shaped or disc-shaped surface patterns. Based on experimental data and numerical calculation, the theoretically predicted maximum data storage density could reach as high as 38.2 Gbit in−2. Demonstration of real-time data retrieval is realized with the assistance of software interface. For the TEDS reported in this work, the measured voltage signal is self-generated as a result of triboelectrification without the reliance on an external power source. This feature brings about not only low power consumption but also a much more simplified structure. Therefore, this work paves a new path to a unique approach of high-density data storage that may have widespread applications.A novel approach of self-powered data storage is reported. Data are incorporated into a set of metal-based surface patterns. As a probe slides across the patterned surface, triboelectrification between the scanning probe and the patterns produces alternatively varying voltage signal in a quasi-square wave. This approach has the potential to achieve high data storage density according to theoretical calculation. The data reading process is successfully demonstrated with the assistance of software.
      PubDate: 2018-01-05T00:06:48.179251-05:
      DOI: 10.1002/advs.201700658
       
  • Periodically Self-Pulsating Microcapsule as Programmed Microseparator via
           ATP-Regulated Energy Dissipation

    • Authors: Xiang Hao; Liang Chen, Wei Sang, Qiang Yan
      Abstract: Living systems can experience time-dependent dynamic self-assembly for periodic, adaptive behavior via energy dissipation pathway. Creating in vitro mimics is a daunting mission. Here a “living” giant vesicle system that can perform a periodic pulsating motion using adenosine-5'-triphosphate (ATP)-fuelled dissipative self-assembly is described. This dynamic system is built on transient supramolecular interactions between the polymer and cellular energy currency ATP. The vesicles capturing ATPs will deviate away from equilibrium, leading to an energy ascent that drives a continuous vesicular expansion, until a competitive ATP hydrolysis predominates to break the ATP–polymer interactions and deplete the energy stored in the vesicles, leading to an opposing vesicular contraction. The input of ATP energy can sustain that these vesicles run periodically along this reciprocating expansile–contractile process, resembling a “pulsating” behavior. ATP level can orchestrate the rhythm, amplitude, and lifetime of this biomimetic pulsation. By pre-programming the ATP stimulation protocol, this kind of adaptive microcapsules can function as high-performance microseparators to perform size-selective sieving of different nanoparticles through ATP-mediated transmembrane traffic. This man-made system offers a primitive model of time-dependent dynamic self-assembly and may offer new ways to build life-like materials with biomimetic functions.A periodically self-pulsating microcapsule is designed using adenosine-5'-triphosphate (ATP)-mediated dissipative self-assembly and is fabricated to serve as high-efficient microseparator. Presetting programmable ATP stimulation, the microcapsules can rhythmically self-regulate the size of their membrane nanopores for sieving a different-sized nanoparticle mixture in a programmed manner.
      PubDate: 2018-01-04T05:35:50.121542-05:
      DOI: 10.1002/advs.201700591
       
  • Spin Solid versus Magnetic Charge Ordered State in Artificial Honeycomb
           Lattice of Connected Elements

    • Authors: Artur Glavic; Brock Summers, Ashutosh Dahal, Joseph Kline, Walter Van Herck, Alexander Sukhov, Arthur Ernst, Deepak K. Singh
      Abstract: The nature of magnetic correlation at low temperature in two-dimensional artificial magnetic honeycomb lattice is a strongly debated issue. While theoretical researches suggest that the system will develop a novel zero entropy spin solid state as T 0 K, a confirmation to this effect in artificial honeycomb lattice of connected elements is lacking. This study reports on the investigation of magnetic correlation in newly designed artificial permalloy honeycomb lattice of ultrasmall elements, with a typical length of ≈12 nm, using neutron scattering measurements and temperature-dependent micromagnetic simulations. Numerical modeling of the polarized neutron reflectometry data elucidates the temperature-dependent evolution of spin correlation in this system. As temperature reduces to ≈7 K, the system tends to develop novel spin solid state, manifested by the alternating distribution of magnetic vortex loops of opposite chiralities. Experimental results are complemented by temperature-dependent micromagnetic simulations that confirm the dominance of spin solid state over local magnetic charge ordered state in the artificial honeycomb lattice with connected elements. These results enable a direct investigation of novel spin solid correlation in the connected honeycomb geometry of 2D artificial structure.The ground state magnetic configuration in artificial permalloy honeycomb lattice of ultrasmall connecting element is investigated using neutron reflectometry, grazing incidence neutron scattering (GISANS) measurements, and temperature-dependent micromagnetic simulations. The investigations demonstrate the development of spin solid state, consisting of the vortex loops of opposite chiralities at low temperature in the connected honeycomb lattice.
      PubDate: 2018-01-04T05:26:37.083852-05:
      DOI: 10.1002/advs.201700856
       
  • A Micropatterned Multielectrode Shell for 3D Spatiotemporal Recording from
           Live Cells

    • Authors: Jordi Cools; Qianru Jin, Eugene Yoon, Diego Alba Burbano, Zhenxiang Luo, Dieter Cuypers, Geert Callewaert, Dries Braeken, David H. Gracias
      Abstract: Microelectrode arrays (MEAs) have proved to be useful tools for characterizing electrically active cells such as cardiomyocytes and neurons. While there exist a number of integrated electronic chips for recording from small populations or even single cells, they rely primarily on the interface between the cells and 2D flat electrodes. Here, an approach that utilizes residual stress-based self-folding to create individually addressable multielectrode interfaces that wrap around the cell in 3D and function as an electrical shell-like recording device is described. These devices are optically transparent, allowing for simultaneous fluorescence imaging. Cell viability is maintained during and after electrode wrapping around the cel and chemicals can diffuse into and out of the self-folding devices. It is further shown that 3D spatiotemporal recordings are possible and that the action potentials recorded from cultured neonatal rat ventricular cardiomyocytes display significantly higher signal-to-noise ratios in comparison with signals recorded with planar extracellular electrodes. It is anticipated that this device can provide the foundation for the development of new-generation MEAs where dynamic electrode–cell interfacing and recording substitutes the traditional method using static electrodes.A novel multielectrode shell chip with individually addressable, self-folding electrodes is presented. Using residual stress-based self-folding, the multielectrode shells wrap around primary heart cells and function as an electrical shell-like recording device. The chip allows parallel readout of all cardinal points of electrogenic cells with higher signal-to-noise ratios, bridging the gap from 2D planar recordings to more complex 3D interfacing.
      PubDate: 2018-01-04T05:26:14.140907-05:
      DOI: 10.1002/advs.201700731
       
  • Hierarchically Nanostructured Transition Metal Oxides for Lithium-Ion
           Batteries

    • Authors: Mingbo Zheng; Hao Tang, Lulu Li, Qin Hu, Li Zhang, Huaiguo Xue, Huan Pang
      Abstract: Lithium-ion batteries (LIBs) have been widely used in the field of portable electric devices because of their high energy density and long cycling life. To further improve the performance of LIBs, it is of great importance to develop new electrode materials. Various transition metal oxides (TMOs) have been extensively investigated as electrode materials for LIBs. According to the reaction mechanism, there are mainly two kinds of TMOs, one is based on conversion reaction and the other is based on intercalation/deintercalation reaction. Recently, hierarchically nanostructured TMOs have become a hot research area in the field of LIBs. Hierarchical architecture can provide numerous accessible electroactive sites for redox reactions, shorten the diffusion distance of Li-ion during the reaction, and accommodate volume expansion during cycling. With rapid research progress in this field, a timely account of this advanced technology is highly necessary. Here, the research progress on the synthesis methods, morphological characteristics, and electrochemical performances of hierarchically nanostructured TMOs for LIBs is summarized and discussed. Some relevant prospects are also proposed.Hierarchical nanostructures have been extensively investigated in the field of lithium-ion batteries because they can provide numerous accessible electroactive sites, shorten the ion diffusion pathway, and accommodate volume expansion. Research progress on hierarchically nanostructured transition metal oxides as electrode materials for lithium-ion batteries is summarized and evaluated.
      PubDate: 2018-01-03T07:54:25.121148-05:
      DOI: 10.1002/advs.201700592
       
  • Superlubricity of Graphite Induced by Multiple Transferred Graphene
           Nanoflakes

    • Authors: Jinjin Li; Tianyang Gao, Jianbin Luo
      Abstract: 2D or 3D layered materials, such as graphene, graphite, and molybdenum disulfide, usually exhibit superlubricity properties when sliding occurs between the incommensurate interface lattices. This study reports the superlubricity between graphite and silica under ambient conditions, induced by the formation of multiple transferred graphene nanoflakes on the asperities of silica surfaces after the initial frictional sliding. The friction coefficient can be reduced to as low as 0.0003 with excellent robustness and is independent of the surface roughness, sliding velocities, and rotation angles. The superlubricity mechanism can be attributed to the extremely weak interaction and easy sliding between the transferred graphene nanoflakes and graphite in their incommensurate contact. This finding has important implications for developing approaches to achieve superlubricity of layered materials at the nanoscale by tribointeractions.Superlubricity between graphite and silica is achieved under ambient conditions, induced by the formation of multiple transferred graphene nanoflakes (GNFs) on the silica surfaces. The friction coefficient can reduce to 0.0003 at a maximal local contact pressure of 700 MPa, which is attributed to the extremely weak interaction and easy sliding between the transferred GNFs and graphite in incommensurate contact.
      PubDate: 2018-01-03T07:52:20.639829-05:
      DOI: 10.1002/advs.201700616
       
  • Self-Assembled Biomolecular 1D Nanostructures for Aqueous Sodium-Ion
           Battery

    • Authors: Huiwu Long; Wen Zeng, Hua Wang, Mengmeng Qian, Yanhong Liang, Zhongchang Wang
      Abstract: Aqueous sodium-ion battery of low cost, inherent safety, and environmental benignity holds substantial promise for new-generation energy storage applications. However, the narrow potential window of water and the enlarged ionic radius because of hydration restrict the selection of electrode materials used in the aqueous electrolyte. Here, inspired by the efficient redox reaction of biomolecules during cellular energy metabolism, a proof of concept is proposed that the redox-active biomolecule alizarin can act as a novel electrode material for the aqueous sodium-ion battery. It is demonstrated that the specific capacity of the self-assembled alizarin nanowires can reach as high as 233.1 mA h g−1, surpassing the majority of anodes ever utilized in the aqueous sodium-ion batteries. Paired with biocompatible and biodegradable polypyrrole, this full battery system shows excellent sodium storage ability and flexibility, indicating its potential applications in wearable electronics and biointegrated devices. It is also shown that the electrochemical properties of electrodes can be tailored by manipulating naturally occurring 9,10-anthroquinones with various substituent groups, which broadens application prospect of biomolecules in aqueous sodium-ion batteries.The successful fabrication of a novel aqueous sodium-ion battery system based on the biomolecule alizarin is reported. It and it is demonstrated that the self-assembled alizarin nanowires surpass in specific capacity the majority of anodes utilized so far. Paired with a polypyrrole cathode, it is shown that such a full battery system holds substantial promise in the applications in wearable electronics and biointegrated devices.
      PubDate: 2018-01-03T07:48:42.582988-05:
      DOI: 10.1002/advs.201700634
       
  • Ultraconformable Temporary Tattoo Electrodes for Electrophysiology

    • Authors: Laura M. Ferrari; Sudha Sudha, Sergio Tarantino, Roberto Esposti, Francesco Bolzoni, Paolo Cavallari, Christian Cipriani, Virgilio Mattoli, Francesco Greco
      Abstract: Electrically interfacing the skin for monitoring personal health condition is the basis of skin-contact electrophysiology. In the clinical practice the use of stiff and bulky pregelled or dry electrodes, in contrast to the soft body tissues, imposes severe restrictions to user comfort and mobility while limiting clinical applications. Here, in this work dry, unperceivable temporary tattoo electrodes are presented. Customized single or multielectrode arrays are readily fabricated by inkjet printing of conducting polymer onto commercial decal transfer paper, which allows for easy transfer on the user's skin. Conformal adhesion to the skin is provided thanks to their ultralow thickness (
      PubDate: 2018-01-03T07:48:14.794846-05:
      DOI: 10.1002/advs.201700771
       
  • Chemotherapeutic Drug Based Metal–Organic Particles for
           Microvesicle-Mediated Deep Penetration and Programmable pH/NIR/Hypoxia
           Activated Cancer Photochemotherapy

    • Authors: Da Zhang; Ming Wu, Zhixiong Cai, Naishun Liao, Kun Ke, Hongzhi Liu, Ming Li, Gang Liu, Huanghao Yang, Xiaolong Liu, Jingfeng Liu
      Abstract: A novel metal–organic particle (MOP) based nanodrug formed by mild self-assembly of chemotherapeutic drugs, including banoxantrone and doxorubicin, through Cu(II)-mediated coordination effects, is reported. In this nanodrug, Cu(II) acts as a bridge to join AQ4N and DOX, and then, self-assembly of [-AQ4N-Cu(II)-(DOX)2-Cu(II)-]n complexes forms nanosized MOPs (referred to as ADMOPs) through multiple interactions including host–metal–guest coordination, hydrophobic interactions, π-stacking, and van der Waals force. The ADMOPs reported here have several important features over conventional drugs, including tumor microenvironment pH-sensitive drug release that can be tracked by “turning on” the fluorescence of AQ4N or DOX through proton competition with Cu(II) to break the coordination bonds and much deeper penetration into solid tumors via microvesicle-mediated intercellular transfer. Most strikingly, the ADMOPs can serve as stimuli-responsive nanocarriers to efficiently load the photosensitizer phthalocyanine due to their inherent highly porous characteristics. Thus, the ADMOPs significantly enhance the chemotherapeutic efficacy by “on-demand” photodynamic therapy, which further induces a hypoxic environment that enhances the reduction of AQ4N to systematically increase the therapeutic efficiency. Taken together, the designed ADMOPs composed of chemotherapeutic drugs may serve as a potential programmable controlled synergistic agent for cancer therapy.Novel metal organic particles (MOPs) are obtained by self-assembly of chemotherapeutic drugs. The reported MOP structure has extremely high drug payload, pH responsive ability, and deep penetration ability. The porous characteristics of MOPs allow them to act as stimuli-responsive nanocarriers to load photosensitizer, which significantly enhance reduction of AQ4N under photodynamic therapy induced hypoxia to achieve synergistic photochemotherapy.
      PubDate: 2018-01-03T07:47:38.846639-05:
      DOI: 10.1002/advs.201700648
       
  • Metal–Organic Framework-Derived ZnO/ZnS Heteronanostructures for
           Efficient Visible-Light-Driven Photocatalytic Hydrogen Production

    • Authors: Xiuxia Zhao; Jianrui Feng, Jingwei Liu, Jia Lu, Wei Shi, Guangming Yang, Guichang Wang, Pingyun Feng, Peng Cheng
      Abstract: Developing highly active, recyclable, and inexpensive photocatalysts for hydrogen evolution reaction (HER) under visible light is significant for the direct conversion of solar energy into chemical fuels for various green energy applications. For such applications, it is very challenging but vitally important for a photocatalyst to simultaneously enhance the visible-light absorption and suppress photogenerated electron–hole recombination, while also to maintain high stability and recyclability. Herein, a metal–organic framework (MOF)-templated strategy has been developed to prepare heterostructured nanocatalysts with superior photocatalytic HER activity. Very uniquely, the synthesized photocatalytic materials can be recycled easily after use to restore the initial photocatalytic activity. It is shown that by controlling the calcination temperature and time with MOF-5 as a host and guest thioacetamide as a sulfur source, the chemical compositions of the formed heterojunctions of ZnO/ZnS can be tuned to further enhance the visible-light absorption and photocatalytic activity. The nanoscale heterojunction ZnO/ZnS structural feature serves to reduce the average free path of charge carriers and improve the charge separation efficiency, thus leading to significantly enhanced HER activity under visible-light irradiation (λ> 420 nm) with high stability and recyclability without any cocatalyst.A metal–organic framework-templated strategy is developed to prepare heterostructured nanocatalysts for the first time with superior photocatalytic hydrogen evolution reaction activity, high stability, and recyclability under visible-light irradiation. The chemical compositions of the formed heterojunctions of ZnO/ZnS can be tuned by controlling the calcination time to further enhance the photocatalytic activity.
      PubDate: 2018-01-03T05:19:32.117876-05:
      DOI: 10.1002/advs.201700590
       
  • Polymer Functionalization of Isolated Mitochondria for Cellular
           Transplantation and Metabolic Phenotype Alteration

    • Authors: Suhong Wu; Aijun Zhang, Shumin Li, Somik Chatterjee, Ruogu Qi, Victor Segura-Ibarra, Mauro Ferrari, Anisha Gupte, Elvin Blanco, Dale J. Hamilton
      Abstract: Aberrant mitochondrial energy transfer underlies prevalent chronic health conditions, including cancer, cardiovascular, and neurodegenerative diseases. Mitochondrial transplantation represents an innovative strategy aimed at restoring favorable metabolic phenotypes in cells with dysfunctional energy metabolism. While promising, significant barriers to in vivo translation of this approach abound, including limited cellular uptake and recognition of mitochondria as foreign. The objective is to functionalize isolated mitochondria with a biocompatible polymer to enhance cellular transplantation and eventual in vivo applications. Herein, it is demonstrated that grafting of a polymer conjugate composed of dextran with triphenylphosphonium onto isolated mitochondria protects the organelles and facilitates cellular internalization compared with uncoated mitochondria. Importantly, mitochondrial transplantation into cancer and cardiovascular cells has profound effects on respiration, mediating a shift toward improved oxidative phosphorylation, and reduced glycolysis. These findings represent the first demonstration of polymer functionalization of isolated mitochondria, highlighting a viable strategy for enabling clinical applications of mitochondrial transplantation.Metabolic impairment is a hallmark of various diseases. Herein, it is aimed to polymerically functionalize the surface of isolated mitochondria to facilitate transplantation into metabolically compromised cells. These results demonstrate that coating mitochondria enhanced their preservation ex vivo, increased their internalization within cancer and cardiac cells, and induced a superior shift in the metabolic phenotype of these cells compared with uncoated mitochondria.
      PubDate: 2018-01-03T05:19:08.042562-05:
      DOI: 10.1002/advs.201700530
       
  • Smart Construction of Integrated CNTs/Li4Ti5O12 Core/Shell Arrays with
           Superior High-Rate Performance for Application in Lithium-Ion Batteries

    • Authors: Zhujun Yao; Xinhui Xia, Cheng-ao Zhou, Yu Zhong, Yadong Wang, Shengjue Deng, Weiqi Wang, Xiuli Wang, Jiangping Tu
      Abstract: Exploring advanced high-rate anodes is of great importance for the development of next-generation high-power lithium-ion batteries (LIBs). Here, novel carbon nanotubes (CNTs)/Li4Ti5O12 (LTO) core/shell arrays on carbon cloth (CC) as integrated high-quality anode are constructed via a facile combined chemical vapor deposition–atomic layer deposition (ALD) method. ALD-synthesized LTO is strongly anchored on the CNTs' skeleton forming core/shell structures with diameters of 70–80 nm the combined advantages including highly conductive network, large surface area, and strong adhesion are obtained in the CC-LTO@CNTs core/shell arrays. The electrochemical performance of the CC-CNTs/LTO electrode is completely studied as the anode of LIBs and it shows noticeable high-rate capability (a capacity of 169 mA h g−1 at 1 C and 112 mA h g−1 at 20 C), as well as a stable cycle life with a capacity retention of 86% after 5000 cycles at 10 C, which is much better than the CC-LTO counterpart. Meanwhile, excellent cycling stability is also demonstrated for the full cell with LiFePO4 cathode and CC-CNTs/LTO anode (87% capacity retention after 1500 cycles at 10 C). These positive features suggest their promising application in high-power energy storage areas.Novel carbon nanotubes (CNTs)/Li4Ti5O12 (LTO) core/shell arrays on carbon cloth (CC) as an integrated high-quality anode are constructed using a facile combined chemical vapor deposition–atom layer deposition method. The CC-CNT/LTO arrays possess enhanced electrochemical kinetics, leading to excellent high-rate capability and long cycle life for both half coin cells and full batteries of Li4Ti5O12//LiFePO4.
      PubDate: 2018-01-03T05:18:30.972937-05:
      DOI: 10.1002/advs.201700786
       
  • Molybdenum Carbide Nanoparticles Coated into the Graphene Wrapping N-Doped
           Porous Carbon Microspheres for Highly Efficient Electrocatalytic Hydrogen
           Evolution Both in Acidic and Alkaline Media

    • Authors: Huifang Wei; Qiaoya Xi, Xi'an Chen, Daying Guo, Feng Ding, Zhi Yang, Shun Wang, Juan Li, Shaoming Huang
      Abstract: Molybdenum carbide (Mo2C) is recognized as an alternative electrocatalyst to noble metal for the hydrogen evolution reaction (HER). Herein, a facile, low cost, and scalable method is provided for the fabrication of Mo2C-based eletrocatalyst (Mo2C/G-NCS) by a spray-drying, and followed by annealing. As-prepared Mo2C/G-NCS electrocatalyst displays that ultrafine Mo2C nanopartilces are uniformly embedded into graphene wrapping N-doped porous carbon microspheres derived from chitosan. Such designed structure offer several favorable features for hydrogen evolution application: 1) the ultrasmall size of Mo2C affords a large exposed active sites; 2) graphene-wrapping ensures great electrical conductivity; 3) porous structure increases the electrolyte–electrode contact points and lowers the charge transfer resistance; 4) N-dopant interacts with H+ better than C atoms and favorably modifies the electronic structures of adjacent Mo and C atoms. As a result, the Mo2C/G-NCS demonstrates superior HER activity with a very low overpotential of 70 or 66 mV to achieve current density of 10 mA cm−2, small Tafel slope of 39 or 37 mV dec−1, respectively, in acidic and alkaline media, and high stability, indicating that it is a great potential candidate as HER electrocatalyst.A simple, low cost, and scalable strategy for the fabrication of Mo2C-based eletrocatalyst through spray-drying and followed by annealing is demonstrated. As-prepared Mo2C/G-NCS catalyst exhibits excellent hydrogen evolution reaction performance both in acidic and alkaline media, which is attributed to synergistic effect from such an unique structure with graphene wrapping, ultrasmall Mo2C nanocrystallite, nitrogen-dopant, and the well-defined porous microspheres.
      PubDate: 2018-01-03T05:17:26.256243-05:
      DOI: 10.1002/advs.201700733
       
  • Modularized Extracellular Vesicles: The Dawn of Prospective Personalized
           and Precision Medicine

    • Authors: Shi-Cong Tao; Shang-Chun Guo, Chang-Qing Zhang
      Abstract: Extracellular vesicles (EVs) are ubiquitous nanosized membrane vesicles consisting of a lipid bilayer enclosing proteins and nucleic acids, which are active in intercellular communications. EVs are increasingly seen as a vital component of many biological functions that were once considered to require the direct participation of stem cells. Consequently, transplantation of EVs is gradually becoming considered an alternative to stem cell transplantation due to their significant advantages, including their relatively low probability of neoplastic transformation and abnormal differentiation. However, as research has progressed, it is realized that EVs derived from native-source cells may have various shortcomings, which can be corrected by modification and optimization. To date, attempts are made to modify or improve almost all the components of EVs, including the lipid bilayer, proteins, and nucleic acids, launching a new era of modularized EV therapy through the “modular design” of EV components. One high-yield technique, generating EV mimetic nanovesicles, will help to make industrial production of modularized EVs a reality. These modularized EVs have highly customized “modular design” components related to biological function and targeted delivery and are proposed as a promising approach to achieve personalized and precision medicine.Extracellular vesicles (EVs) are ubiquitous nanosized membrane vesicles involved in intercellular communications, and attempts are made to modify almost all the components of EVs, including the lipid bilayer, proteins, and nucleic acids, launching a new era of modularized EV therapy, which is a promising approach to achieving personalized and precision medicine, by “modular design” of EV components.
      PubDate: 2018-01-02T09:07:10.406721-05:
      DOI: 10.1002/advs.201700449
       
  • Multifunctional Sandwich-Structured Electrolyte for High-Performance
           Lithium–Sulfur Batteries

    • Authors: Hongtao Qu; Jianjun Zhang, Aobing Du, Bingbing Chen, Jingchao Chai, Nan Xue, Longlong Wang, Lixin Qiao, Chen Wang, Xiao Zang, Jinfeng Yang, Xiaogang Wang, Guanglei Cui
      Abstract: Due to its high theoretical energy density (2600 Wh kg−1), low cost, and environmental benignity, the lithium–sulfur (Li-S) battery is attracting strong interest among the various electrochemical energy storage systems. However, its practical application is seriously hampered by the so-called shuttle effect of the highly soluble polysulfides. Herein, a novel design of multifunctional sandwich-structured polymer electrolyte (polymer/cellulose nonwoven/nanocarbon) for high-performance Li-S batteries is demonstrated. It is verified that Li-S battery with this sandwich-structured polymer electrolyte delivers excellent cycling stability (only 0.039% capacity decay cycle−1 on average exceeding 1500 cycles at 0.5 C) and rate capability (with a reversible capacity of 594 mA h g−1 at 4 C). These electrochemical performances are attributed to the synergistic effect of each layer in this unique sandwich-structured polymer electrolyte including steady lithium stripping/plating, strong polysulfide absorption ability, and increased redox reaction sites. More importantly, even with high sulfur loading of 4.9 mg cm−2, Li-S battery with this sandwich-structured polymer electrolyte can deliver high initial areal capacity of 5.1 mA h cm−2. This demonstrated strategy here may open up a new era of designing hierarchical structured polymer electrolytes for high-performance Li-S batteries.A novel design of multifunctional sandwich-structured polymer electrolyte is demonstrated for high performance lithium-sulfur batteries. The assembled lithium-sulfur battery delivers superior cycling stability and rate capability. The performance is attributed to the synergistic effect of each layer in the polymer electrolyte. This strategy may open up a new era of designing hierarchical structured polymer electrolytes for high-performance lithium-sulfur batteries.
      PubDate: 2018-01-02T09:06:46.611883-05:
      DOI: 10.1002/advs.201700503
       
  • Engineering a Tumor Microenvironment-Mimetic Niche for Tissue Regeneration
           with Xenogeneic Cancer Cells

    • Authors: Zhenzhen Wang; Chunming Wang, Ayipaxia Abudukeremu, Xiaying Rui, Shang Liu, Xiaoyi Zhang, Min Zhang, Junfeng Zhang, Lei Dong
      Abstract: The insufficient number of cells suitable for transplantation is a long-standing problem to cell-based therapies aimed at tissue regeneration. Xenogeneic cancer cells (XCC) may be an alternative source of therapeutic cells, but their transplantation risks both immune rejection and unwanted spreading. In this study, a strategy to facilitate XCC transplantation is reported and their spreading in vivo is confined by constructing an engineering matrix that mimics the characteristics of tumor microenvironment. The data show that this matrix, a tumor homogenate-containing hydrogel (THAG), successfully creates an immunosuppressive enclave after transplantation into immunocompetent mice. XCC of different species and tissue origins seeded into THAG survive well, integrated with the host and developed the intrinsic morphology of the native tissue, without being eliminated or spreading out of the enclave. Most strikingly, immortalized human hepatocyte cells and rat β-cells loaded into THAG exert the physiological functions of the human liver and rat pancreas islets, respectively, in the mouse body. This study demonstrates a novel and feasible approach to harness the unique features of tumor development for tissue transplantation and regenerative medicine.An engineered tumor microenvironment mimetic niche formed by active soluble factors in tumor extract (tumor homogenate), basic fibroblast growth factor, and injectable hydrogel facilitates the xenogeneic cancer cells to develop into a functional tissue in immunocompetent mice and confines their unwanted spreading in vivo.
      PubDate: 2018-01-02T03:07:54.196671-05:
      DOI: 10.1002/advs.201700666
       
  • Toroidal Localized Spoof Plasmons on Compact Metadisks

    • Authors: Pengfei Qin; Yihao Yang, Muhyiddeen Yahya Musa, Bin Zheng, Zuojia Wang, Ran Hao, Wenyan Yin, Hongsheng Chen, Erping Li
      Abstract: Localized spoof surface plasmons (LSSPs) have recently emerged as a new research frontier due to their unique properties and increasing applications. Despite the importance, most of the current researches only focus on electric/magnetic LSSPs. Very recent research has revealed that toroidal LSSPs, LSSPs modes with multipole toroidal moments, can be achieved at a point defect in a 2D groove metal array. However, this metamaterial shows the limitations of large volume and poor compatibility to photonic integrated circuits. To overcome the above challenges, here it is proposed and experimentally demonstrated compact planar metadisks based on split ring resonators to support the toroidal LSSPs at microwave frequencies. Additionally, it is experimentally demonstrated that the toroidal LSSPs resonance is very sensitive to the structure changes and the background medium. These might facilitate its utilization in the design and application of plasmonic deformation sensors and the refractive index sensors.The localized spoof surface plasmons with toroidal dipolar moments in compact metadisks are proposed and experimentally demonstrated at microwave frequencies. The present metadisks with elegance and compactness are beneficial to compatibility with the photonic integrated circuits. Additionally, the proposed resonators are very sensitive to the structure changes and surroundings, and may find applications in the deformation sensors and the refractive index sensors.
      PubDate: 2017-12-31T00:07:10.786463-05:
      DOI: 10.1002/advs.201700487
       
  • Multiplex Photoluminescent Silicon Nanoprobe for Diagnostic Bioimaging and
           Intracellular Analysis

    • Authors: Meysam Keshavarz; Bo Tan, Krishnan Venkatakrishnan
      Abstract: Herein, a label-free multiplex photoluminescent silicon nanoprobe (PLSN-probe) is introduced as a potential substitute for quantum dots (QDs) in bioimaging. An inherently non-photoluminescent silicon substrate is altered to create the PLSN-probe, to overcome the major drawbacks of presently available QDs. Additionally, crystallinity alterations of the multiplane crystalline PLSN-probes lead to broad absorption and multiplex fluorescence emissions, which are attributed to the simultaneous existence of multiple crystal planes. The PLSN-probe not only demonstrates unique optical properties that can be exploited for bioimaging but also exhibits cell-selective uptake that allows the differentiation and diagnosis of HeLa and fibroblast cells. Moreover, multiplex emissions of the PLSN-probe illuminate different organelles such as the nucleus, nucleolemma, and cytoskeleton, depending on size-based preferential uptake by the cell organs. This in vitro study reveals that cancerous HeLa cells have a higher propensity for taking up the PLSN-probe compared to fibroblast cells, allowing the diagnosis of cancerous HeLa cells. Additionally, the fluorescence intensity per unit area of the cell is found to be a reliable means for distinguishing between dead and healthy cells. It is anticipated that the multifunctionality of the PLSN-probes will lead to better insight into the use of such probes for bioimaging and diagnosis applications.A label-free multiplex photoluminescent silicon nanoprobe (PLSN-probe) is introduced as a potential substitute for quantum dots in bioimaging. Broad absorption and multiplex fluorescence emissions are achieved by crystallinity alterations of the PLSN-probes, which are attributed to the simultaneous existence of multiple crystal planes, exploited for bioimaging of different organelles as well as differentiation and diagnosis of cancerous HeLa cells.
      PubDate: 2017-12-31T00:06:53.261344-05:
      DOI: 10.1002/advs.201700548
       
  • A Vesicular Stomatitis Virus-Inspired DNA Nanocomplex for Ovarian Cancer
           Therapy

    • Authors: Wei Zhao; Yuping Yang, Lingling Song, Tianyi Kang, Ting Du, Yujiao Wu, Meimei Xiong, Li Luo, Jianlin Long, Ke Men, Lan Zhang, Xiaoxin Chen, Meijuan Huang, Maling Gou
      Abstract: Gene therapy provides a novel method for cancer therapy. This study shows a DNA nanocomplex that is inspired from vesicular stomatitis virus (VSV) for ovarian cancer therapy. This DNA nanocomplex consists of a cationized monomethoxy poly (ethylene glycol)-poly (d,l-lactide) (MPEG-PLA) nanoparticle and a plasmid encoding the matrix protein of vesicular stomatitis virus (VSVMP) that plays a critical role in the VSV-induced apoptosis of cancer cells. The cationized MPEG-PLA nanoparticle that is self-assembled by MPEG-PLA copolymer and N-[1-(2,3-dioleoyloxy) propyl]-N,N,N-trimethylammonium chloride (DOTAP) has low cytotoxicity and high transfection efficiency (>80%). Intraperitoneal administration of the pVSVMP nanocomplex remarkably inhibits the intraperitoneal metastasis of ovarian cancer and does not cause significant systemic toxicity. The apoptosis induction and anti-angiogenesis are involved in the anticancer mechanism. This work demonstrates a VSV-inspired DNA nanocomplex that has potential application for the treatment of intraperitoneal metastasis of ovarian cancer.The vesicular stomatitis virus-inspired DNA nanocomplex consists of a cationized monomethoxy poly (ethylene glycol)-poly (d,l-lactide) nanoparticle and a matrix protein of vesicular stomatitis virus plasmid. This DNA nanocomplex can act like vesicular stomatitis virus to efficiently inhibit ovarian cancer through apoptosis induction in vitro and in vivo, showing potential clinical application for treating the intraperitoneal metastasis of ovarian cancer.
      PubDate: 2017-12-29T00:07:12.613981-05:
      DOI: 10.1002/advs.201700263
       
  • Carbon Nanofiber versus Graphene-Based Stretchable Capacitive Touch
           Sensors for Artificial Electronic Skin

    • Authors: Pietro Cataldi; Simeone Dussoni, Luca Ceseracciu, Marco Maggiali, Lorenzo Natale, Giorgio Metta, Athanassia Athanassiou, Ilker S. Bayer
      Abstract: Stretchable capacitive devices are instrumental for new-generation multifunctional haptic technologies particularly suited for soft robotics and electronic skin applications. A majority of elongating soft electronics still rely on silicone for building devices or sensors by multiple-step replication. In this study, fabrication of a reliable elongating parallel-plate capacitive touch sensor, using nitrile rubber gloves as templates, is demonstrated. Spray coating both sides of a rubber piece cut out of a glove with a conductive polymer suspension carrying dispersed carbon nanofibers (CnFs) or graphene nanoplatelets (GnPs) is sufficient for making electrodes with low sheet resistance values (≈10 Ω sq−1). The electrodes based on CnFs maintain their conductivity up to 100% elongation whereas the GnPs-based ones form cracks before 60% elongation. However, both electrodes are reliable under elongation levels associated with human joints motility (≈20%). Strikingly, structural damages due to repeated elongation/recovery cycles could be healed through annealing. Haptic sensing characteristics of a stretchable capacitive device by wrapping it around the fingertip of a robotic hand (ICub) are demonstrated. Tactile forces as low as 0.03 N and as high as 5 N can be easily sensed by the device under elongation or over curvilinear surfaces.Enabling cost-effective technologies for human–robot interactions is crucial for humanoid robotics. Clean room and polydimethylsiloxane-free fabrication and characterization of durable and stretchable touch sensors based on carbon nanofibers or graphene nanoplatelets by spraying on synthetic rubber gloves are presented. Carbon nanofiber sensors demonstrate superior sensing ability under elongation.
      PubDate: 2017-12-27T03:28:36.422295-05:
      DOI: 10.1002/advs.201700587
       
  • Design and Construction of Hybrid Microcapsules with Higher-Order
           Structure and Multiple Functions

    • Authors: Guangyu Wu; Lei Wang, Pei Zhou, Ping Wen, Chao Ma, Xin Huang, Yudong Huang
      Abstract: The construction of inorganic-protein hybrid microcapsules by using bovine serum albumin, metal ion clusters, and poly (N-isopropylacrylamide) nanoconjugates as building blocks is presented. These microcapsules have robust membranes, which can keep their spherical morphology. They support interfacial catalytic activity by the ion clusters on their surface, and can be used as a platform to immobilize enzyme on the interface of oil/water to increase the diversity and efficiency of catalysis. These microcapsules also act as a container to make materials away from bacteria when existing silver clusters on the membrane. The obtained results highlight the construction of these microcompartments. These novel microcompartments can provide some new opportunities in bottom-up synthetic biology, bioinspired microstorage/ microreactor, and drug/gene delivery in the future.Hybrid microcapsules are successfully fabricated from protein (bovine serum albumin), inorganic metal clusters (gold or silver nanoclusters), and polymer (poly (N-isopropylacrylamides) as building blocks. The constructed hybrid microcapsules show additional virtues compared with those of the without metal ion hybrid capsules, including photoluminescence, self-rehydration, enhanced antibacterial effect, and enhanced interfacial catalysis.
      PubDate: 2017-12-27T03:22:38.625321-05:
      DOI: 10.1002/advs.201700460
       
  • In Situ Synthesis of Vertical Standing Nanosized NiO Encapsulated in
           Graphene as Electrodes for High-Performance Supercapacitors

    • Authors: Jinghuang Lin; Henan Jia, Haoyan Liang, Shulin Chen, Yifei Cai, Junlei Qi, Chaoqun Qu, Jian Cao, Weidong Fei, Jicai Feng
      Abstract: NiO is a promising electrode material for supercapacitors. Herein, the novel vertically standing nanosized NiO encapsulated in graphene layers (G@NiO) are rationally designed and synthesized as nanosheet arrays. This unique vertical standing structure of G@NiO nanosheet arrays can enlarge the accessible surface area with electrolytes, and has the benefits of short ion diffusion path and good charge transport. Further, an interconnected graphene conductive network acts as binder to encapsulate the nanosized NiO particles as core–shell structure, which can promote the charge transport and maintain the structural stability. Consequently, the optimized G@NiO hybrid electrodes exhibit a remarkably enhanced specific capacity up to 1073 C g−1 and excellent cycling stability. This study provides a facial strategy to design and construct high-performance metal oxides for energy storage.The novel vertical-standing nanosized NiO encapsulated in graphene (G@NiO) is rationally designed and synthesized while maintaining the nanosheet morphology. This study feasibly offers insight into the in situ forming graphene on nanosized transition metal oxides (TMOs) particles directly as electrodes for maximizing their electrochemical performances, which may help to accelerate development of TMOs as electrode for high-performance supercapacitors.
      PubDate: 2017-12-27T03:21:59.145922-05:
      DOI: 10.1002/advs.201700687
       
  • Formation and Diffusion of Metal Impurities in Perovskite Solar Cell
           Material CH3NH3PbI3: Implications on Solar Cell Degradation and Choice of
           Electrode

    • Authors: Wenmei Ming; Dongwen Yang, Tianshu Li, Lijun Zhang, Mao-Hua Du
      Abstract: Solar cells based on methylammonium lead triiodide (MAPbI3) have shown remarkable progress in recent years and have demonstrated efficiencies greater than 20%. However, the long-term stability of MAPbI3-based solar cells has yet to be achieved. Besides the well-known chemical and thermal instabilities, significant native ion migration in lead halide perovskites leads to current–voltage hysteresis and photoinduced phase segregation. Recently, it is further revealed that, despite having excellent chemical stability, the Au electrode can cause serious solar cell degradation due to Au diffusion into MAPbI3. In addition to Au, many other metals have been used as electrodes in MAPbI3 solar cells. However, how the external metal impurities introduced by electrodes affect the long-term stability of MAPbI3 solar cells has rarely been studied. A comprehensive study of formation energetics and diffusion dynamics of a number of noble and transition metal impurities (Au, Ag, Cu, Cr, Mo, W, Co, Ni, Pd) in MAPbI3 based on first-principles calculations is reported herein. The results uncover important general trends of impurity formation and diffusion in MAPbI3 and provide useful guidance for identifying the optimal metal electrodes that do not introduce electrically active impurity defects in MAPbI3 while having low resistivities and suitable work functions for carrier extraction.Solar cell degradation has been the number one hurdle to the commercialization of the perovskite solar cells. The origin has been predominantly attributed to chemical and thermal instability of light-absorbing perovskite layers. A critically important, but largely hidden and underdiscussed, problem related to the solar cell degradation caused by metal electrode contamination is herein addressed.
      PubDate: 2017-12-27T03:21:29.3162-05:00
      DOI: 10.1002/advs.201700662
       
  • High Discharge Energy Density at Low Electric Field Using an Aligned
           Titanium Dioxide/Lead Zirconate Titanate Nanowire Array

    • Authors: Dou Zhang; Weiwei Liu, Ru Guo, Kechao Zhou, Hang Luo
      Abstract: Polymer-based capacitors with high energy density have attracted significant attention in recent years due to their wide range of potential applications in electronic devices. However, the obtained high energy density is predominantly dependent on high applied electric field, e.g., 400–600 kV mm−1, which may bring more challenges relating to the failure probability. Here, a simple two-step method for synthesizing titanium dioxide/lead zirconate titanate nanowire arrays is exploited and a demonstration of their ability to achieve high discharge energy density capacitors for low operating voltage applications is provided. A high discharge energy density of 6.9 J cm−3 is achieved at low electric fields, i.e., 143 kV mm−1, which is attributed to the high relative permittivity of 218.9 at 1 kHz and high polarization of 23.35 µC cm−2 at this electric field. The discharge energy density obtained in this work is the highest known for a ceramic/polymer nanocomposite at such a low electric field. The novel nanowire arrays used in this work are applicable to a wide range of fields, such as energy harvesting, energy storage, and photocatalysis.Titanium dioxide/lead zirconate titanate nanowire arrays are prepared for the first time, and a demonstration of their ability to achieve high discharge energy density of 6.9 J cm−3 in poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) nanocomposites at 143 kV mm−1 is provided. This is the highest value compared with the current “state-of-the-art” dielectric nanocomposites at the same level of electric field.
      PubDate: 2017-12-27T03:20:49.450652-05:
      DOI: 10.1002/advs.201700512
       
  • Guidance and Self-Sorting of Active Swimmers: 3D Periodic Arrays Increase
           Persistence Length of Human Sperm Selecting for the Fittest

    • Authors: Thiruppathiraja Chinnasamy; James L. Kingsley, Fatih Inci, Paul J. Turek, Mitchell P. Rosen, Barry Behr, Erkan Tüzel, Utkan Demirci
      Abstract: Male infertility is a reproductive disease, and existing clinical solutions for this condition often involve long and cumbersome sperm sorting methods, including preprocessing and centrifugation-based steps. These methods also fall short when sorting for sperm free of reactive oxygen species, DNA damage, and epigenetic aberrations. Although several microfluidic platforms exist, they suffer from structural complexities, i.e., pumps or chemoattractants, setting insurmountable barriers to clinical adoption. Inspired by the natural filter-like capabilities of the female reproductive tract for sperm selection, a model-driven design, featuring pillar arrays that efficiently and noninvasively isolate highly motile and morphologically normal sperm, with lower epigenetic global methylation, from raw semen, is presented. The Simple Periodic ARray for Trapping And isolatioN (SPARTAN) created here modulates the directional persistence of sperm, increasing the spatial separation between progressive and nonprogressive motile sperm populations within an unprecedentedly short 10 min assay time. With over 99% motility of sorted sperm, a 5-fold improvement in morphology, 3-fold increase in nuclear maturity, and 2–4-fold enhancement in DNA integrity, SPARTAN offers to standardize sperm selection while eliminating operator-to-operator variations, centrifugation, and flow. SPARTAN can also be applied in other areas, including conservation ecology, breeding of farm animals, and design of flagellar microrobots for diagnostics.A model-driven design featuring pillar arrays that efficiently and noninvasively isolate highly motile and morphologically normal sperm, with lower epigenetic global methylation, is presented.
      PubDate: 2017-12-27T00:10:05.466645-05:
      DOI: 10.1002/advs.201700531
       
  • Vertical Hydrodynamic Focusing and Continuous Acoustofluidic Separation of
           Particles via Upward Migration

    • Authors: Husnain Ahmed; Ghulam Destgeer, Jinsoo Park, Jin Ho Jung, Hyung Jin Sung
      Abstract: A particle suspended in a fluid within a microfluidic channel experiences a direct acoustic radiation force (ARF) when traveling surface acoustic waves (TSAWs) couple with the fluid at the Rayleigh angle, thus producing two components of the ARF. Most SAW-based microfluidic devices rely on the horizontal component of the ARF to migrate prefocused particles laterally across a microchannel width. Although the magnitude of the vertical component of the ARF is more than twice the magnitude of the horizontal component, it is long ignored due to polydimethylsiloxane (PDMS) microchannel fabrication limitations and difficulties in particle focusing along the vertical direction. In the present work, a single-layered PDMS microfluidic chip is devised for hydrodynamically focusing particles in the vertical plane while explicitly taking advantage of the horizontal ARF component to slow down the selected particles and the stronger vertical ARF component to push the particles in the upward direction to realize continuous particle separation. The proposed particle separation device offers high-throughput operation with purity>97% and recovery rate>99%. It is simple in its fabrication and versatile due to the single-layered microchannel design, combined with vertical hydrodynamic focusing and the use of both the horizontal and vertical components of the ARF.An acoustofluidic microparticle separation device to sort variable diameter particles inside a microfluidic channel is demonstrated. A single-layered polydimethylsiloxane microfluidic chip is devised for hydrodynamically focusing particles in the vertical plane, while taking advantage of the principal component of the acoustic radiation force to push the particles in the upward direction to realize continuous high-throughput particle separation.
      PubDate: 2017-12-22T00:07:48.365724-05:
      DOI: 10.1002/advs.201700285
       
  • Alkali Metal Doping for Improved CH3NH3PbI3 Perovskite Solar Cells

    • Authors: Wangen Zhao; Zhun Yao, Fengyang Yu, Dong Yang, Shengzhong (Frank) Liu
      Abstract: Organic–inorganic hybrid halide perovskites are proven to be a promising semiconductor material as the absorber layer of solar cells. However, the perovskite films always suffer from nonuniform coverage or high trap state density due to the polycrystalline characteristics, which degrade the photoelectric properties of thin films. Herein, the alkali metal ions which are stable against oxidation and reduction are used in the perovskite precursor solution to induce the process of crystallization and nucleation, then affect the properties of the perovskite film. It is found that the addition of the alkali metal ions clearly improves the quality of perovskite film: enlarges the grain sizes, reduces the defect state density, passivates the grain boundaries, increases the built-in potential (Vbi), resulting to the enhancement in the power conversion efficiency of perovskite thin film solar cell.The alkali metal ions Na+ and K+ which are stable against oxidation and reduction are used in the perovskite precursor solution to improve the quality of perovskite film. It is found that the addition of alkali metal ions reduces the defect states and prolonges the carrier lifetime of perovskite film, resulting to the higher performance of the photovoltaic device.
      PubDate: 2017-12-21T00:07:49.734715-05:
      DOI: 10.1002/advs.201700131
       
  • Contents: (Adv. Sci. 12/2017)

    • PubDate: 2017-12-20T08:36:42.492405-05:
      DOI: 10.1002/advs.201770060
       
  • Masthead: (Adv. Sci. 12/2017)

    • PubDate: 2017-12-20T08:36:41.766679-05:
      DOI: 10.1002/advs.201770061
       
  • Artificial Muscles: Electroionic Antagonistic Muscles Based on
           Nitrogen-Doped Carbons Derived from Poly(Triazine-Triptycene) (Adv. Sci.
           12/2017)

    • Authors: Sandipan Roy; Jaehwan Kim, Moumita Kotal, Kwang Jin Kim, Il-Kwon Oh
      Abstract: Il-Kwon Oh and co-workers develop high-performance electroionic antagonistic muscles based on nitrogen-doped carbons derived from a poly(triazine-triptycene) organic framework. As reported in article number 1700410, the antagonistic muscles exhibit extremely reliable and large bending actuation performance for long periods under ultralow input voltages due to the outstanding electro-chemomechanical properties of nitrogen-doped carbons. A Dionaea muscipula inspired flower device is successfully demonstrated under the controlled electric signals.
      PubDate: 2017-12-20T08:36:39.227581-05:
      DOI: 10.1002/advs.201770062
       
  • Biocompatibility of Nanoparticles: Hematological Effects of Gold Nanorods
           on Erythrocytes: Hemolysis and Hemoglobin Conformational and Functional
           Changes (Adv. Sci. 12/2017)

    • Authors: Xingchen Zhao; Dawei Lu, Qian S. Liu, Yiling Li, Rui Feng, Fang Hao, Guangbo Qu, Qunfang Zhou, Guibin Jiang
      Abstract: In article 1700296, Qunfang Zhou and co-workers report the hemocompatibility of gold nanorods (GNRs). In contrast to negatively charged GNRs, positively charged GNRs (C-GNRs) induce instant hemolysis. After cellular encapsulation, the GNRs are found to bind with hemoglobin and to induce conformational and functional changes in the protein. This demonstrates that surface modification holds great promise as an approach to improve the biocompatibility of GNRs for clinical use.
      PubDate: 2017-12-20T08:36:38.509969-05:
      DOI: 10.1002/advs.201770058
       
  • Hybrid Nanoparticles: Corrosion-Protected Hybrid Nanoparticles (Adv. Sci.
           12/2017)

    • Authors: Hyeon-Ho Jeong; Mariana Alarcón-Correa, Andrew G. Mark, Kwanghyo Son, Tung-Chun Lee, Peer Fischer
      Abstract: A method that permits the complete encapsulation of nanoparticles and nanostructures is reported by Peer Fischer and co-workers in article number 1700234. It is demonstrated that, unlike unprotected nanoparticles that quickly corrode, nanomaterials that are chemically unstable and prone to corrosion can be encapsulated with a nanometer-thick shell and stabilized for days in corrosive environments. Image by Alejandro Posada Boada (MPI-IS).
      PubDate: 2017-12-20T08:36:36.171932-05:
      DOI: 10.1002/advs.201770059
       
  • Enhanced Photodynamic Cancer Treatment by Mitochondria-Targeting and
           Brominated Near-Infrared Fluorophores

    • Authors: Ilkoo Noh; DaeYong Lee, Heegon Kim, Chan-Uk Jeong, Yunsoo Lee, Jung-Oh Ahn, Hoon Hyun, Ji-Ho Park, Yeu-Chun Kim
      Abstract: A noninvasive and selective therapy, photodynamic therapy (PDT) is widely researched in clinical fields; however, the lower efficiency of PDT can induce unexpected side effects. Mitochondria are extensively researched as target sites to maximize PDT effects because they play crucial roles in metabolism and can be used as cancer markers due to their high transmembrane potential. Here, a mitochondria targeting photodynamic therapeutic agent (MitDt) is developed. This photosensitizer is synthesized from heptamethine cyanine dyes, which are conjugated or modified as follows. The heptamethine meso-position is conjugated with a triphenylphosphonium derivative for mitochondrial targeting, the N-alkyl side chain is modified for regulation of charge balance and solubility, and the indolenine groups are brominated to enhance reactive oxygen species generation (ROS) after laser irradiation. The synthesized MitDt increases the cancer uptake efficiency due to the lipo-cationic properties of the triphenylphosphonium, and the PDT effects of MitDt are amplified after laser irradiation because mitochondria are susceptible to ROS, the response to which triggers an apoptotic anticancer effect. Consequently, these hypotheses are demonstrated by in vitro and in vivo studies, and the results indicate strong potential for use of MitDts as efficient single-molecule-based PDT agents for cancer treatment.Mitochondria targeting photodynamic therapeutic agents (MitDt) including triphenylphosphonium, which can be guided to mitochondrial membranes, are devised. Among them, the brominated indolenine structure can boost reactive oxygen species production after near-infrared (NIR) laser irradiation, which elicits outstanding cellular apoptotic death in vitro and in vivo. Therefore, MitDt suggests a promising therapeutic probe for cancer therapy.
      PubDate: 2017-12-19T08:42:02.846778-05:
      DOI: 10.1002/advs.201700481
       
  • Redox-Active Separators for Lithium-Ion Batteries

    • Authors: Zhaohui Wang; Ruijun Pan, Changqing Ruan, Kristina Edström, Maria Strømme, Leif Nyholm
      Abstract: A bilayered cellulose-based separator design is presented that can enhance the electrochemical performance of lithium-ion batteries (LIBs) via the inclusion of a porous redox-active layer. The proposed flexible redox-active separator consists of a mesoporous, insulating nanocellulose fiber layer that provides the necessary insulation between the electrodes and a porous, conductive, and redox-active polypyrrole-nanocellulose layer. The latter layer provides mechanical support to the nanocellulose layer and adds extra capacity to the LIBs. The redox-active separator is mechanically flexible, and no internal short circuits are observed during the operation of the LIBs, even when the redox-active layer is in direct contact with both electrodes in a symmetric lithium–lithium cell. By replacing a conventional polyethylene separator with a redox-active separator, the capacity of the proof-of-concept LIB battery containing a LiFePO4 cathode and a Li metal anode can be increased from 0.16 to 0.276 mA h due to the capacity contribution from the redox-active separator. As the presented redox-active separator concept can be used to increase the capacities of electrochemical energy storage systems, this approach may pave the way for new types of functional separators.The performance of lithium-ion batteries can be enhanced by replacing the separator with a flexible redox-active separator comprising a cellulose layer and an electrically conducting and redox-active layer.
      PubDate: 2017-12-19T08:27:20.536178-05:
      DOI: 10.1002/advs.201700663
       
  • Hollow TiO2@Co9S8 Core–Branch Arrays as Bifunctional Electrocatalysts
           for Efficient Oxygen/Hydrogen Production

    • Authors: Shengjue Deng; Yu Zhong, Yinxiang Zeng, Yadong Wang, Xiuli Wang, Xihong Lu, Xinhui Xia, Jiangping Tu
      Abstract: Designing ever more efficient and cost-effective bifunctional electrocatalysts for oxygen/hydrogen evolution reactions (OER/HER) is greatly vital and challenging. Here, a new type of binder-free hollow TiO2@Co9S8 core–branch arrays is developed as highly active OER and HER electrocatalysts for stable overall water splitting. Hollow core–branch arrays of TiO2@Co9S8 are readily realized by the rational combination of crosslinked Co9S8 nanoflakes on TiO2 core via a facile and powerful sulfurization strategy. Arising from larger active surface area, richer/shorter transfer channels for ions/electrons, and reinforced structural stability, the as-obtained TiO2@Co9S8 core–branch arrays show noticeable exceptional electrocatalytic performance, with low overpotentials of 240 and 139 mV at 10 mA cm−2 as well as low Tafel slopes of 55 and 65 mV Dec−1 for OER and HER in alkaline medium, respectively. Impressively, the electrolysis cell based on the TiO2@Co9S8 arrays as both cathode and anode exhibits a remarkably low water splitting voltage of 1.56 V at 10 mA cm−2 and long-term durability with no decay after 10 d. The versatile fabrication protocol and smart branch-core design provide a new way to construct other advanced metal sulfides for energy conversion and storage.A new type of binder-free hollow TiO2@Co9S8 core–branch arrays are developed as highly active oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) electrocatalysts using a facile and powerful sulfurization strategy. The as-obtained TiO2@Co9S8 electrode shows exceptional electrocatalytic performance, superior to most other metal sulfides/oxides.
      PubDate: 2017-12-19T08:26:07.791222-05:
      DOI: 10.1002/advs.201700772
       
  • Quantitative Assessments of Mechanical Responses upon Radial
           Extracorporeal Shock Wave Therapy

    • Authors: Yajun Liu; Xiaodong Chen, Anyi Guo, Sijin Liu, Guoqing Hu
      Abstract: Although radial extracorporeal shock wave therapy (rESWT) has been widely used to treat orthopedic disorders with promising clinical results, rESWT largely relies on clinicians' personal experiences and arbitrary judgments, without knowing relationships between administration doses and effective doses at target sites. In fact, practitioners lack a general and reliable way to assess propagation and distribution of pressure waves inside biological tissues quantitatively. This study develops a methodology to combine experimental measurements and computational simulations to obtain pressure fields from rESWT through calibrating and validating computational models with experimental measurements. Wave pressures at the bottom of a petri dish and inside biological tissues are measured, respectively, by attaching and implanting flexible membrane sensors. Detailed wave dynamics are simulated through explicit finite element analyses. The data decipher that waves from rESWT radiate directionally and can be modeled as acoustic waves generated from a vibrating circular piston. Models are thus established to correlate pressure amplitudes at the bottom of petri dishes and in the axial direction of biological tissues. Additionally, a pilot simulation upon rESWT for human lumbar reveals a detailed and realistic pressure field mapping. This study will open a new avenue of personalized treatment planning and mechanism research for rESWT.A combined experimental and numerical methodology is developed to quantify pressure waves inside biotissues generated from a radial extracorporeal shock wave therapy (rESWT) device. Results reveal that pressure waves radiate directionally and can be modeled as those generated from a vibrating circular piston. Models are thus established to correlate wave pressures. This methodology could advance personalized treatment planning for rESWT.
      PubDate: 2017-12-19T08:22:16.095161-05:
      DOI: 10.1002/advs.201700797
       
  • Impact of Plasma Electron Flux on Plasma Damage-Free Sputtering of
           Ultrathin Tin-Doped Indium Oxide Contact Layer on p-GaN for InGaN/GaN
           Light-Emitting Diodes

    • Authors: Kwang Jeong Son; Tae Kyoung Kim, Yu-Jung Cha, Seung Kyu Oh, Shin-Jae You, Jae-Hyun Ryou, Joon Seop Kwak
      Abstract: The origin of plasma-induced damage on a p-type wide-bandgap layer during the sputtering of tin-doped indium oxide (ITO) contact layers by using radiofrequency-superimposed direct current (DC) sputtering and its effects on the forward voltage and light output power (LOP) of light-emitting diodes (LEDs) with sputtered ITO transparent conductive electrodes (TCE) is systematically studied. Changing the DC power voltage from negative to positive bias reduces the forward voltages and enhances the LOP of the LEDs. The positive DC power drastically decreases the electron flux in the plasma obtained by plasma diagnostics using a cutoff probe and a Langmuir probe, suggesting that the repulsion of plasma electrons from the p-GaN surface can reduce plasma-induced damage to the p-GaN. Furthermore, electron-beam irradiation on p-GaN prior to ITO deposition significantly increases the forward voltages, showing that the plasma electrons play an important role in plasma-induced damage to the p-GaN. The plasma electrons can increase the effective barrier height at the ITO/deep-level defect (DLD) band of p-GaN by compensating DLDs, resulting in the deterioration of the forward voltage and LOP. Finally, the plasma damage-free sputtered-ITO TCE enhances the LOP of the LEDs by 20% with a low forward voltage of 2.9 V at 20 mA compared to LEDs with conventional e-beam-evaporated ITO TCE.The plasma electrons, and not the ions, play a key role in causing plasma-induced damage to the p-GaN during the sputtering of tin-doped indium oxide. The repulsion of plasma electrons from the p-GaN surface using radiofrequency (RF) superimposed direct current (DC) (RF+DC) sputtering with positive DC power greatly enhances the light output power of the light-emitting diodes by 20% with a low forward voltage of 2.9 V at 20 mA.
      PubDate: 2017-12-19T08:21:29.213056-05:
      DOI: 10.1002/advs.201700637
       
  • Electrochemically Synthesized Nanoporous Molybdenum Carbide as a Durable
           Electrocatalyst for Hydrogen Evolution Reaction

    • Authors: Jin Soo Kang; Jin Kim, Myeong Jae Lee, Yoon Jun Son, Dong Young Chung, Subin Park, Juwon Jeong, Ji Mun Yoo, Heejong Shin, Heeman Choe, Hyun S. Park, Yung-Eun Sung
      Abstract: Demands for sustainable production of hydrogen are rapidly increasing because of environmental considerations for fossil fuel consumption and development of fuel cell technologies. Thus, the development of high-performance and economical catalysts has been extensively investigated. In this study, a nanoporous Mo carbide electrode is prepared using a top-down electrochemical process and it is applied as an electrocatalyst for the hydrogen evolution reaction (HER). Anodic oxidation of Mo foil followed by heat treatment in a carbon monoxide (CO) atmosphere forms a nanostructured Mo carbide with excellent interconnections, and these structural characteristics lead to high activity and durability when applied to the HER. Additionally, characteristic behavior of Mo is observed; metallic Mo nanosheets form during electrochemical anodization by exfoliation along the (110) planes. These nanosheets are viable for chemical modification, indicating their feasibility in various applications. Moreover, the role of carbon shells is investigated on the surface of the electrocatalysts, whereby it is suggested that carbon shells serve as a mechanical barrier against the oxidative degradation of catalysts that accompanies unavoidable volume expansion.Electrochemically synthesized molybdenum carbide is applied as an electrocatalyst for hydrogen evolution reaction. Due to the interconnected nanostructure and thin carbon shells formed on the surface, the catalyst shows extremely high durability. In addition, characteristic behavior of Mo in electrochemical corrosion and the role of carbon shells on the surface of the catalysts are investigated.
      PubDate: 2017-12-19T07:26:02.167462-05:
      DOI: 10.1002/advs.201700601
       
  • Intrinsically High Thermoelectric Performance in AgInSe2 n-Type
           Diamond-Like Compounds

    • Authors: Pengfei Qiu; Yuting Qin, Qihao Zhang, Ruoxi Li, Jiong Yang, Qingfeng Song, Yunshan Tang, Shengqiang Bai, Xun Shi, Lidong Chen
      Abstract: Diamond-like compounds are a promising class of thermoelectric materials, very suitable for real applications. However, almost all high-performance diamond-like thermoelectric materials are p-type semiconductors. The lack of high-performance n-type diamond-like thermoelectric materials greatly restricts the fabrication of diamond-like material-based modules and their real applications. In this work, it is revealed that n-type AgInSe2 diamond-like compound has intrinsically high thermoelectric performance with a figure of merit (zT) of 1.1 at 900 K, comparable to the best p-type diamond-like thermoelectric materials reported before. Such high zT is mainly due to the ultralow lattice thermal conductivity, which is fundamentally limited by the low-frequency Ag-Se “cluster vibrations,” as confirmed by ab initio lattice dynamic calculations. Doping Cd at Ag sites significantly improves the thermoelectric performance in the low and medium temperature ranges. By using such high-performance n-type AgInSe2-based compounds, the diamond-like thermoelectric module has been fabricated for the first time. An output power of 0.06 W under a temperature difference of 520 K between the two ends of the module is obtained. This work opens a new window for the applications using the diamond-like thermoelectric materials.The data reveal that the n-type AgInSe2 diamond-like compound has intrinsically high thermoelectric performance with a maximal zT of 1.1 at 900 K. By using such high-performance n-type AgInSe2-based compounds, the diamond-like thermoelectric module is fabricated for the first time, with an output power of 0.06 W under a temperature difference of 520 K.
      PubDate: 2017-12-18T04:52:25.077314-05:
      DOI: 10.1002/advs.201700727
       
  • Valence State Manipulation of Cerium Oxide Nanoparticles on a Titanium
           Surface for Modulating Cell Fate and Bone Formation

    • Authors: Jinhua Li; Jin Wen, Bin Li, Wan Li, Wei Qiao, Jie Shen, Weihong Jin, Xinquan Jiang, Kelvin W. K. Yeung, Paul K. Chu
      Abstract: Understanding cell–biomaterial interactions is critical for the control of cell fate for tissue engineering and regenerative medicine. Here, cerium oxide nanoparticles (CeONPs) are applied at different Ce4+/Ce3+ ratios (i.e., 0.46, 1.23, and 3.23) to titanium substrate surfaces by magnetron sputtering and vacuum annealing. Evaluation of the cytotoxicity of the modified surface to cultured rat bone marrow mesenchymal stem cells (BMSCs) reveals that the cytocompatibility and cell proliferation are proportional to the increases in Ce4+/Ce3+ ratio on titanium surface. The bone formation capability induced by these surface modified titanium alloys is evaluated by implanting various CeONP samples into the intramedullary cavity of rat femur for 8 weeks. New bone formation adjacent to the implant shows a close relationship to the surface Ce4+/Ce3+ ratio; higher Ce4+/Ce3+ ratio achieves better osseointegration. The mechanism of this in vivo outcome is explored by culturing rat BMSCs and RAW264.7 murine macrophages on CeONP samples for different durations. The improvement in osteogenic differentiation capability of BMSCs is directly proportional to the increased Ce4+/Ce3+ ratio on the titanium surface. Increases in the Ce4+/Ce3+ ratio also elevate the polarization of the M2 phenotype of RAW264.7 murine macrophages, particularly with respect to the healing-associated M2 percentage and anti-inflammatory cytokine secretion. The manipulation of valence states of CeONPs appears to provide an effective modulation of the osteogenic capability of stem cells and the M2 polarization of macrophages, resulting in favorable outcomes of new bone formation and osseointegration.Cerium oxide nanoparticles (CeONPs) with different surface Ce4+/Ce3+ molar ratios are immobilized on a titanium surface by magnetron sputtering. The promoted osteogenic differentiation of stem cells and M2 phenotype polarization of macrophages is observed for higher surface Ce4+/Ce3+ ratios. This can elicit beneficial outcomes of new bone formation and osseointegration, demonstrating the promise of CeONPs for bone regenerative medicine.
      PubDate: 2017-12-18T04:32:49.36182-05:0
      DOI: 10.1002/advs.201700678
       
  • Enabling Photon Upconversion and Precise Control of Donor–Acceptor
           Interaction through Interfacial Energy Transfer

    • Authors: Bo Zhou; Long Yan, Lili Tao, Nan Song, Ming Wu, Ting Wang, Qinyuan Zhang
      Abstract: Upconverting materials have achieved great progress in recent years, however, it remains challenging for the mechanistic research on new upconversion strategy of lanthanides. Here, a novel and efficient strategy to realize photon upconversion from more lanthanides and fine control of lanthanide donor–acceptor interactions through using the interfacial energy transfer (IET) is reported. Unlike conventional energy-transfer upconversion and recently reported energy-migration upconversion, the IET approach is capable of enabling upconversions from Er3+, Tm3+, Ho3+, Tb3+, Eu3+, Dy3+ to Sm3+ in NaYF4- and NaYbF4-based core–shell nanostructures simultaneously. Applying the IET in a Nd–Yb coupled sensitizing system can also enable the 808/980 nm dual-wavelength excited upconversion from a single particle. More importantly, the construction of IET concept allows for a fine control and manipulation of lanthanide donor–acceptor interactions and dynamics at the nanometer-length scale by establishing a physical model upon an interlayer-mediated nanostructure. These findings open a door for the fundamental understanding of the luminescence dynamics involving lanthanides at nanoscale, which would further help conceive new scientific concepts and control photon upconversion at a single lanthanide ion level.The interfacial energy transfer is shown to be a general and efficient strategy for upconversion of lanthanides, widely ranging from Er3+, Tm3+, Ho3+, Tb3+, Eu3+, Dy3+, to Sm3+, and the use of this strategy also contributes to establishing a physical platform for the precise control of lanthanide donor–acceptor interactions on the nanometer-length scale.
      PubDate: 2017-12-18T04:31:22.658507-05:
      DOI: 10.1002/advs.201700667
       
  • The Dawn of Lead-Free Perovskite Solar Cell: Highly Stable Double
           Perovskite Cs2AgBiBr6 Film

    • Authors: Cuncun Wu; Qiaohui Zhang, Yang Liu, Wei Luo, Xuan Guo, Ziru Huang, Hungkit Ting, Weihai Sun, Xinrui Zhong, Shiyuan Wei, Shufeng Wang, Zhijian Chen, Lixin Xiao
      Abstract: Recently, lead-free double perovskites have emerged as a promising environmentally friendly photovoltaic material for their intrinsic thermodynamic stability, appropriate bandgaps, small carrier effective masses, and low exciton binding energies. However, currently no solar cell based on these double perovskites has been reported, due to the challenge in film processing. Herein, a first lead-free double perovskite planar heterojunction solar cell with a high quality Cs2AgBiBr6 film, fabricated by low-pressure assisted solution processing under ambient conditions, is reported. The device presents a best power conversion efficiency of 1.44%. The preliminary efficiency and the high stability under ambient condition without encapsulation, together with the high film quality with simple processing, demonstrate promise for lead-free perovskite solar cells.A high-quality double perovskite Cs2AgBiBr6 film is successfully demonstrated using a low-pressure assisted solution method. A planar heterojunction solar cell based on this Cs2AgBiBr6 film shows high stability with an optimal power conversion efficiency of 1.44%. The preliminary results are promising for the development lead-free perovskite solar cells.
      PubDate: 2017-12-18T04:29:19.647827-05:
      DOI: 10.1002/advs.201700759
       
  • Imaging Inelastic Fracture Processes in Biomimetic Nanocomposites and
           Nacre by Laser Speckle for Better Toughness

    • Authors: Tuukka Verho; Pasi Karppinen, André H. Gröschel, Olli Ikkala
      Abstract: Mollusk nacre is a prototypical biological inorganic–organic composite that combines high toughness, stiffness, and strength by its brick-and-mortar microstructure, which has inspired several synthetic mimics. Its remarkable fracture toughness relies on inelastic deformations at the process zone at the crack tip that dissolve stress concentrations and stop cracks. The micrometer-scale structure allows resolving the size and shape of the process zone to understand the fracture processes. However, for better scalability, nacre-mimetic nanocomposites with aligned inorganic or graphene nanosheets are extensively pursued, to avoid the packing problems of mesoscale sheets like in nacre or slow in situ biomineralization. This calls for novel methods to explore the process zone of biomimetic nanocomposites. Here the fracture of nacre and nacre-inspired clay/polymer nanocomposite is explored using laser speckle imaging that reveals the process zone even in absence of changes in optical scattering. To demonstrate the diagnostic value, compared to nacre, the nacre-inspired nanocomposite develops a process zone more abruptly with macroscopic crack deflection shown by a flattened process zone. In situ scanning electron microscopy suggests similar toughening mechanisms in nanocomposite and nacre. These new insights guide the design of nacre-inspired nanocomposites toward better mechanical properties to reach the level of synergy of their biological model.Laser speckle imaging and in situ scanning electron microscopy (SEM) reveal fracture process zone evolution and crack deflection in nacre and nacre-inspired nanocomposite. The new speckle imaging method allows real-time imaging of crack formation during mechanical testing, while in situ SEM shows microscopic toughening mechanisms in thick nacre-mimetic clay/polymer nanocomposite specimens, including crack deflection, bridging, and microcracking, helping efforts to improve toughness.
      PubDate: 2017-12-18T04:19:01.272025-05:
      DOI: 10.1002/advs.201700635
       
  • Development of Nanostructured Water Treatment Membranes Based on
           Thermotropic Liquid Crystals: Molecular Design of Sub-Nanoporous Materials
           

    • Authors: Takeshi Sakamoto; Takafumi Ogawa, Hiroki Nada, Koji Nakatsuji, Masato Mitani, Bartolome Soberats, Ken Kawata, Masafumi Yoshio, Hiroki Tomioka, Takao Sasaki, Masahiro Kimura, Masahiro Henmi, Takashi Kato
      Abstract: Supply of safe fresh water is currently one of the most important global issues. Membranes technologies are essential to treat water efficiently with low costs and energy consumption. Here, the development of self-organized nanostructured water treatment membranes based on ionic liquid crystals composed of ammonium, imidazolium, and pyridinium moieties is reported. Membranes with preserved 1D or 3D self-organized sub-nanopores are obtained by photopolymerization of ionic columnar or bicontinuous cubic liquid crystals. These membranes show salt rejection ability, ion selectivity, and excellent water permeability. The relationships between the structures and the transport properties of water molecules and ionic solutes in the sub-nanopores in the membranes are examined by molecular dynamics simulations. The results suggest that the volume of vacant space in the nanochannel greatly affects the water and ion permeability.Filtration membranes with 1D or 3D ordered ionic sub-nanopores prepared from thermotropic liquid crystals show unique salt rejection properties and applicable water permeability. Molecular dynamics simulation show the effects of the ionic sub-nanopores on transport of water molecules and ionic solutes in the pores. Membranes with liquid-crystalline ordered structures have great potential for highly selective separation.
      PubDate: 2017-12-18T03:53:02.589423-05:
      DOI: 10.1002/advs.201700405
       
  • Climate-Dependent Heat-Triggered Opening Mechanism of Banksia Seed Pods

    • Authors: Jessica C. Huss; Vanessa Schoeppler, David J. Merritt, Christine Best, Eric Maire, Jérôme Adrien, Oliver Spaeker, Nils Janssen, Johannes Gladisch, Notburga Gierlinger, Ben P. Miller, Peter Fratzl, Michaela Eder
      Abstract: Heat-triggered fruit opening and delayed release of mature seeds are widespread among plants in fire-prone ecosystems. Here, the material characteristics of the seed-containing follicles of Banksia attenuata (Proteaceae), which open in response to heat frequently caused by fire, are investigated. Material analysis reveals that long-term dimensional stability and opening temperatures of follicles collected across an environmental gradient increase as habitats become drier, hotter, and more fire prone. A gradual increase in the biaxial curvature of the hygroscopic valves provides the follicles in the driest region with the highest flexural rigidity. The irreversible deformation of the valves for opening is enabled via a temperature-dependent reduction of the elastic modulus of the innermost tissue layer, which then allows releasing the stresses previously generated by shrinkage of the fiber bundles in the adjacent layer during follicle drying. These findings illustrate the level of sophistication by which this species optimizes its fruit opening mechanism over a large distribution range with varying environmental conditions, and may not only have great relevance for developing biomimetic actuators, but also for elucidating the species' capacity to cope with climatic changes.Seed pods of Banksia attenuata open through cycles of humidity following an initial heat stimulus. The heat-triggered, initial opening process is regulated by an interplay of geometry, temperature, and mechanics. Gradual changes in curvature result in distinct opening temperatures along a pronounced climatic gradient in Western Australia with varying fire risk.
      PubDate: 2017-12-13T05:28:32.709566-05:
      DOI: 10.1002/advs.201700572
       
  • A One-Structure-Based Multieffects Coupled Nanogenerator for
           Simultaneously Scavenging Thermal, Solar, and Mechanical Energies

    • Authors: Yun Ji; Kewei Zhang, Ya Yang
      Abstract: Rapid advances in various energy harvesters impose the challenge on integrating them into one device structure with synergetic effects for full use of the available energies from the environment. Here, a multieffect coupled nanogenerator based on ferroelectric barium titanate is reported. It promotes the ability to simultaneously scavenging thermal, solar, and mechanical energies. By integration of a pyroelectric nanogenerator, a photovoltaic cell, and a triboelectric–piezoelectric nanogenerator in one structure with only two electrodes, multieffects interact with each other to alter the electric output, and a complementary power source with peak current of ≈1.5 µA, peak voltage of ≈7 V, and platform voltage of ≈6 V is successfully achieved. Compared with traditional hybridized nanogenerators with stacked architectures, the one-structure-based multieffects coupled nanogenerator is smaller, simpler, and less costly, showing prospective in practical applications and represents a new trend of all-in-one multiple energy scavenging.A tribo-piezo-pyro-photoelectric-effect coupled nanogenerator based on multifunctional barium titanate is designed. The component of the pyroelectric nanogenerator can scavenge thermal energy from temperature changes, the component of the photovoltaic cell can scavenge solar energy from light illumination, and the component of the triboelectric–piezoelectric nanogenerator can scavenge mechanical energy from strain-induced deformation of barium titanate, as well as triboelectrification.
      PubDate: 2017-12-08T02:07:11.962662-05:
      DOI: 10.1002/advs.201700622
       
  • Rationally Designed Hierarchically Structured Tungsten Nitride and
           Nitrogen-Rich Graphene-Like Carbon Nanocomposite as Efficient Hydrogen
           Evolution Electrocatalyst

    • Authors: Yanping Zhu; Gao Chen, Yijun Zhong, Wei Zhou, Zongping Shao
      Abstract: Practical application of hydrogen production from water splitting relies strongly on the development of low-cost and high-performance electrocatalysts for hydrogen evolution reaction (HER). The previous researches mainly focused on transition metal nitrides as HER catalysts due to their electrical conductivity and corrosion stability under acidic electrolyte, while tungsten nitrides have reported poorer activity for HER. Here the activity of tungsten nitride is optimized through rational design of a tungsten nitride–carbon composite. More specifically, tungsten nitride (WNx) coupled with nitrogen-rich porous graphene-like carbon is prepared through a low-cost ion-exchange/molten-salt strategy. Benefiting from the nanostructured WNx, the highly porous structure and rich nitrogen dopant (9.5 at%) of the carbon phase with high percentage of pyridinic-N (54.3%), and more importantly, their synergistic effect, the composite catalyst displays remarkably high catalytic activity while maintaining good stability. This work highlights a powerful way to design more efficient metal–carbon composites catalysts for HER.Tungsten nitride coupled with nitrogen-rich porous graphene-like carbon is prepared through a low-cost ion-exchange/molten-salt strategy. Benefiting from the nanostructured WNx, the highly porous structure and rich nitrogen dopant (9.5 at%) of the carbon phase with high percentage of pyridinic-N (54.3%), and more importantly, their synergistic effect, the composite catalyst displays remarkably high catalytic activity while maintaining good stability.
      PubDate: 2017-12-08T02:02:13.881464-05:
      DOI: 10.1002/advs.201700603
       
  • Computational Intelligence-Assisted Understanding of Nature-Inspired
           Superhydrophobic Behavior

    • Authors: Xia Zhang; Bei Ding, Ran Cheng, Sebastian C. Dixon, Yao Lu
      Abstract: In recent years, state-of-the-art computational modeling of physical and chemical systems has shown itself to be an invaluable resource in the prediction of the properties and behavior of functional materials. However, construction of a useful computational model for novel systems in both academic and industrial contexts often requires a great depth of physicochemical theory and/or a wealth of empirical data, and a shortage in the availability of either frustrates the modeling process. In this work, computational intelligence is instead used, including artificial neural networks and evolutionary computation, to enhance our understanding of nature-inspired superhydrophobic behavior. The relationships between experimental parameters (water droplet volume, weight percentage of nanoparticles used in the synthesis of the polymer composite, and distance separating the superhydrophobic surface and the pendant water droplet in adhesive force measurements) and multiple objectives (water droplet contact angle, sliding angle, and adhesive force) are built and weighted. The obtained optimal parameters are consistent with the experimental observations. This new approach to materials modeling has great potential to be applied more generally to aid design, fabrication, and optimization for myriad functional materials.Computational intelligence techniques are used to understand nature-inspired superhydrophobic behavior, this method does not require large sets of experimental data or any in-depth physicochemical theoretical background in order to predict and optimize experiments, and the new approach to materials modeling has great potential to be applied more generally to aid design, fabrication, and optimization for myriad functional materials.
      PubDate: 2017-12-08T02:00:51.014191-05:
      DOI: 10.1002/advs.201700520
       
  • Recent Progress on MOF-Derived Heteroatom-Doped Carbon-Based
           Electrocatalysts for Oxygen Reduction Reaction

    • Authors: Qian Ren; Hui Wang, Xue-Feng Lu, Ye-Xiang Tong, Gao-Ren Li
      Abstract: The oxygen reduction reaction (ORR) is the core reaction of numerous sustainable energy-conversion technologies such as fuel cells and metal–air batteries. It is crucial to develop a cost-effective, highly active, and durable electrocatalysts for ORR to overcome the sluggish kinetics of four electrons pathway. In recent years, the carbon-based electrocatalysts derived from metal–organic frameworks (MOFs) have attracted tremendous attention and have been shown to exhibit superior catalytic activity and excellent intrinsic properties such as large surface area, large pore volume, uniform pore distribution, and tunable chemical structure. Here in this review, the development of MOF-derived heteroatom-doped carbon-based electrocatalysts, including non-metal (such as N, S, B, and P) and metal (such as Fe and Co) doped carbon materials, is summarized. It furthermore, it is demonstrated that the enhancement of ORR performance is associated with favorably well-designed porous structure, large surface area, and high-tensity active sites. Finally, the future perspectives of carbon-based electrocatalysts for ORR are provided with an emphasis on the development of a clear mechanism of MOF-derived non-metal-doped electrocatalysts and certain metal-doped electrocatalysts.Molecular organic framework-derived heteroatom-doped carbon-based electrocatalysts, including nonmetal (such as N, S, B, and P) and metal (such as Fe and Co) doped carbon materials, have attracted tremendous attention and some of them exhibit superior electrocatalytic performance for oxygen reduction reaction. Significant progress has been achieved and more innovations for carbon-based electrocatalysts will be realized in the future.
      PubDate: 2017-12-05T06:06:55.78564-05:0
      DOI: 10.1002/advs.201700515
       
  • Increasing Photovoltaic Performance of an Organic Cationic Chromophore by
           Anion Exchange

    • Authors: Donatas Gesevičius; Antonia Neels, Sandra Jenatsch, Erwin Hack, Lucas Viani, Stavros Athanasopoulos, Frank Nüesch, Jakob Heier
      Abstract: A symmetrical cyanine dye chromophore is modified with different counteranions to study the effect on crystal packing, polarizability, thermal stability, optical properties, light absorbing layer morphology, and organic photovoltaic (OPV) device parameters. Four sulfonate-based anions and the bulky bistriflylimide anion are introduced to the 2-[5-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)-1,3-pentadien-1-yl]-1,3,3-trimethyl-3H-indolium chromophore using an Amberlyst A26 (OH− form) anion exchanger. Anionic charge distribution clearly correlates with device performance, whereby an average efficiency of 2% was reached in a standard bilayer organic solar. Evidence is given that the negative charge of the anion distributed over a large number of atoms is significantly more important than the size of the organic moieties of the sulfonate charge carrying group. This provides a clear strategy for future design of more efficient cyanine dyes for OPV applications.A facile route for introducing various organic sulfonates and the bistriflylimide to a cationic cyanine chromophore using an Amberlyst A26 (OH− form) anion exchanger is demonstrated. The impact of these anions on crystal packing, thin-film morphology, optical properties, and organic photovoltaic device performance is investigated. It can be concluded that the negative charge distribution of the anion is a critical factor in cyanine salt design.
      PubDate: 2017-12-05T06:05:48.110685-05:
      DOI: 10.1002/advs.201700496
       
  • Radiation-Sensitive Dendrimer-Based Drug Delivery System

    • Authors: Szu-Yuan Wu; Hsiao-Ying Chou, Chiou-Hwa Yuh, Shewaye Lakew Mekuria, Yu-Chih Kao, Hsieh-Chih Tsai
      Abstract: Combination of chemotherapy and radiotherapy is used to enhance local drug delivery while reducing off-target tissue effects. Anticancer drug doxorubicin (DOX) is loaded into l-cysteine modified G4.5 dendrimer (GC/DOX) and released at different pH values in the presence and absence of γ-radiation. Presence of γ-radiation significantly improves DOX release from the GC/DOX under acidic pH conditions, suggesting that GC dendrimer is a radiation-sensitive drug delivery system. GC/DOX is further evaluated by determining cytotoxicity in uterine cervical carcinoma HeLa cells. GC/DOX shows high affinity for cancer cells and effective drug release following an external stimulus (radiation exposure), whereas an in vivo zebrafish study confirms that l-cysteine acts as a radiosensitizer. GC/DOX treatment combined with radiotherapy synergistically and successfully inhibits cancer cell growth.Radiation sensitive dendrimeric nanoparticles are constructed from carboxyl-terminate polyamidoamine dendrimers generation 4.5 conjugated with cysteine (GC). Doxorubicin (DOX)-loaded GC nanoparticle can be taken up by HeLa cells and drug can be released from GC nanoparticles in the presence of radiation and an acidic environment. The DOX-loaded GC nanoparticles exhibit promising radiation therapeutic results in a zebrafish cancer model.
      PubDate: 2017-12-05T06:02:05.351332-05:
      DOI: 10.1002/advs.201700339
       
  • Asymmetric Hybrid Polymer–Lipid Giant Vesicles as Cell Membrane
           Mimics

    • Authors: Ariane Peyret; Emmanuel Ibarboure, Jean-François Le Meins, Sebastien Lecommandoux
      Abstract: Lipid membrane asymmetry plays an important role in cell function and activity, being for instance a relevant signal of its integrity. The development of artificial asymmetric membranes thus represents a key challenge. In this context, an emulsion-centrifugation method is developed to prepare giant vesicles with an asymmetric membrane composed of an inner monolayer of poly(butadiene)-b-poly(ethylene oxide) (PBut-b-PEO) and outer monolayer of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). The formation of a complete membrane asymmetry is demonstrated and its stability with time is followed by measuring lipid transverse diffusion. From fluorescence spectroscopy measurements, the lipid half-life is estimated to be 7.5 h. Using fluorescence recovery after photobleaching technique, the diffusion coefficient of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(lissamine rhodamine B sulfonyl) (DOPE-rhod, inserted into the POPC leaflet) is determined to be about D = 1.8 ± 0.50 μm2 s−1 at 25 °C and D = 2.3 ± 0.7 μm2 s−1 at 37 °C, between the characteristic values of pure POPC and pure polymer giant vesicles and in good agreement with the diffusion of lipids in a variety of biological membranes. These results demonstrate the ability to prepare a cell-like model system that displays an asymmetric membrane with transverse and translational diffusion properties similar to that of biological cells.Cell-sized biomimetic vesicles with an asymmetric lipid/polymer membrane are generated from an emulsion/centrifugation method. Lipid transverse and lateral diffusion kinetics as studied via fluorescence quenching assays and confocal microscopy reveals consistent similarity to cells.
      PubDate: 2017-12-05T06:01:12.53418-05:0
      DOI: 10.1002/advs.201700453
       
  • In Vivo Photoacoustic Imaging of Brain Injury and Rehabilitation by
           High-Efficient Near-Infrared Dye Labeled Mesenchymal Stem Cells with
           Enhanced Brain Barrier Permeability

    • Authors: Weitao Li; Ronghe Chen, Jing Lv, Hongke Wang, Yu Liu, Ya Peng, Zhiyu Qian, Guo Fu, Liming Nie
      Abstract: Stem cell migration and interaction with pathology are critical to understand the complexity and status of disease recovery progress. However, the dynamic visualization still remains a great challenge due to imaging technical limitation, cell labeling difficulty, or blood–brain barrier (BBB). Herein, fast photoacoustic tomography (PAT) with optical molecular probes is applied to noninvasively monitor traumatic brain injury (TBI) and its rehabilitation. The vascular distribution and TBI hemorrhage are clearly imaged, longitudinally monitored, and quantified. Bone mesenchymal stem cells (BMSCs) labeled with modified Prussian blue particles (PBPs), excellent near-infrared dyes and photoacoustic contrasts, are intravenously injected to the mice for improved observation and efficient therapy. BMSCs are demonstrated to be capable of overcoming BBB with enhanced delivery of PBPs to the brain parenchyma. Notably, the versatile BMSCs are observed by PAT to home to the damage region and repair the ruptured vasculature. Moreover, the wound treated by BMSCs exhibits much faster recovery speed than that without treatment. These findings can potentially provide a new noninvasive and high-resolution approach to image TBI, monitor recovery process, and especially trace BMSCs. This study will stimulate extensive researches on brain diseases and provide promising strategies of dye labeled BMSCs in regenerative medicine.Photoacoustic tomography (PAT) with optical molecular probes is applied to noninvasively monitor on-the-spot traumatic brain injury (TBI) and its recovery process with bone mesenchymal stem cell (BMSC) therapy. TBI hemorrhage is clearly imaged and BMSCs labeled with modified Prussian blue particles are successfully visualized in vivo by PAT. Significantly, stem cell therapy contributes to the rehabilitation of brain injury.
      PubDate: 2017-12-05T00:06:53.522866-05:
      DOI: 10.1002/advs.201700277
       
  • Graphene-Based MicroRNA Transfection Blocks Preosteoclast Fusion to
           Increase Bone Formation and Vascularization

    • Authors: Ce Dou; Ning Ding, Fei Luo, Tianyong Hou, Zhen Cao, Yun Bai, Chuan Liu, Jianzhong Xu, Shiwu Dong
      Abstract: The objective of this study is to design a graphene-based miRNA transfection drug delivery system for antiresorptive therapy. An efficient nonviral gene delivery system is developed using polyethylenimine (PEI) functionalized graphene oxide (GO) complex loaded with miR-7b overexpression plasmid. GO-PEI complex exhibits excellent transfection efficiency within the acceptable range of cytotoxicity. The overexpression of miR-7b after GO-PEI-miR-7b transfection significantly abrogates osteoclast (OC) fusion and bone resorption activity by hampering the expression of an essential fusogenic molecule dendritic cell-specific transmembrane protein. However, osteoclastogenesis occurs without cell–cell fusion and preosteoclast (POC) is preserved. Through preservation of POC, GO-PEI-miR-7b transfection promotes mesenchymal stem cell osteogenesis and endothelial progenitor cells angiogenesis in the coculture system. Platelet-derived growth factor-BB secreted by POC is increased by GO-PEI-miR-7b both in vitro and in vivo. In treating osteoporotic ovariectomized mice, GO-PEI-miR-7b significantly enhances bone mineral density, bone volume as well as bone vascularization through increasing CD31hiEmcnhi cell number. This study provides a cell–cell fusion targeted miRNA transfection drug delivery strategy in treating bone disorders with excessive osteoclastic bone resorption.A graphene based miRNA transfection system is developed using graphene oxide (GO)-PEI loaded with miR-7b plasmid. GO-PEI-miR-7b efficiently delivers miR-7b plasmid into bone marrow macrophages and reduces the expression of target protein dendritic cell-specific transmembrane protein (DC-STAMP) thus blocking cell-cell fusion to preserve pre-osteoclasts for better osteogenesis and angiogenesis.
      PubDate: 2017-12-04T09:26:25.358086-05:
      DOI: 10.1002/advs.201700578
       
  • Dopant-Free and Carrier-Selective Heterocontacts for Silicon Solar Cells:
           Recent Advances and Perspectives

    • Authors: Pingqi Gao; Zhenhai Yang, Jian He, Jing Yu, Peipei Liu, Juye Zhu, Ziyi Ge, Jichun Ye
      Abstract: By combining the most successful heterojunctions (HJ) with interdigitated back contacts, crystalline silicon (c-Si) solar cells (SCs) have recently demonstrated a record efficiency of 26.6%. However, such SCs still introduce optical/electrical losses and technological issues due to parasitic absorption/Auger recombination inherent to the doped films and the complex process of integrating discrete p+- and n+-HJ contacts. These issues have motivated the search for alternative new functional materials and simplified deposition technologies, whereby carrier-selective contacts (CSCs) can be formed directly with c-Si substrates, and thereafter form IBC cells, via a dopant-free method. Screening and modifying CSC materials in a wider context is beneficial for building dopant-free HJ contacts with better performance, shedding new light on the relatively mature Si photovoltaic field. In this review, a significant number of achievements in two representative dopant-free hole-selective CSCs, i.e., poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate)/Si and transition metal oxides/Si, have been systemically presented and surveyed. The focus herein is on the latest advances in hole-selective materials modification, interfacial passivation, contact resistivity, light-trapping structure and device architecture design, etc. By analyzing the structure–property relationships of hole-selective materials and assessing their electrical transport properties, promising functional materials as well as important design concepts for such CSCs toward high-performance SCs have been highlighted.Carrier-selective dopant-free contacts with Si are of great interest to both fundamental researchers and the photovoltaic industry due to the extreme simplifications in device structure and manufacturing procedure. Here, recent advances and open challenges in two typical hole-selective designs of organic poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and transition metal oxides are reported, examining the topic from both the materials and device engineering.
      PubDate: 2017-12-04T02:17:39.819918-05:
      DOI: 10.1002/advs.201700547
       
  • Magnetic Sponge with Neutral–Ionic Phase Transitions

    • Authors: Wataru Kosaka; Yusuke Takahashi, Masaki Nishio, Keisuke Narushima, Hiroki Fukunaga, Hitoshi Miyasaka
      Abstract: Phase transitions caused by the charge instability between the neutral and ionic phases of compounds, i.e., N–I phase transitions, provide avenues for switching the intrinsic properties of compounds related to electron/spin correlation and dipole generation as well as charge distribution. However, it is extremely difficult to control the transition temperature (Tc) for the N–I phase transition, and only chemical modification based on the original material have been investigated. Here, a design overview of the tuning of N–I phase transition by interstitial guest molecules is presented. This study reports a new chain coordination-polymer [Ru2(3,4-Cl2PhCO2)4TCNQ(EtO)2]∙DCE (1-DCE; 3,4-Cl2PhCO2− = 3,4-dichlorobenzoate; TCNQ(EtO)2 2,5-diethoxy-7,7,8,8-tetracyanoquinodimethane; and DCE = 1,2-dichloroethane) that exhibits a one-step N–I transition at 230 K (= Tc) with the N- and I-states possessing a simple paramagnetic state and a ferrimagnetically correlated state for the high- and low-temperature phases, respectively. The Tc continuously decreases depending on the content of DCE, which eventually disappears with the complete evacuation of DCE, affording solvent-free compound 1 with the N-state in the entire temperature range (this behavior is reversible). This is an example of tuning the in situ Tc for the N–I phase transition via the control of the interstitial guest molecules.A chain coordination polymer, exhibiting a one-step neutral–ionic (N–I) transition is reported. The transition temperature decreases with the gradual evacuation of the crystallization solvent and eventually vanishes. Desolvated compound is neutral in the entire temperature range. The transition behavior is completely recovered by solvent adsorption and therefore the N–I transition synergistically occurs by linking with the degree of solvation.
      PubDate: 2017-12-04T02:11:54.741378-05:
      DOI: 10.1002/advs.201700526
       
  • Toward Aerogel Electrodes of Superior Rate Performance in Supercapacitors
           through Engineered Hollow Nanoparticles of NiCo2O4

    • Authors: Jianjiang Li; Shuai Chen, Xiaoyi Zhu, Xilin She, Tongchao Liu, Huawei Zhang, Sridhar Komarneni, Dongjiang Yang, Xiangdong Yao
      Abstract: A biomass-templated pathway is developed for scalable synthesis of NiCo2O4@carbon aerogel electrodes for supercapacitors, where NiCo2O4 hollow nanoparticles with an average outer diameter of 30–40 nm are conjoined by graphitic carbon forming a 3D aerogel structure. This kind of NiCo2O4 aerogel structure shows large specific surface area (167.8 m2 g−1), high specific capacitance (903.2 F g−1 at a current density of 1 A g−1), outstanding rate performance (96.2% capacity retention from 1 to 10 A g−1), and excellent cycling stability (nearly without capacitance loss after 3000 cycles at 10 A g−1). The unique structure of the 3D hollow aerogel synergistically contributes to the high performance. For instance, the 3D interconnected porous structure of the aerogel is beneficial for electrolyte ion diffusion and for shortening the electron transport pathways, and thus can improve the rate performance. The conductive carbon joint greatly enhances the specific capacity, and the hollow structure prohibits the volume changes during the charge–discharge process to significantly improve the cycling stability. This work represents a giant step toward the preparation of high-performance commercial supercapacitors.Hollow NiCo2O4@carbon aerogel is synthesized by a biomass-template approach utilizing the ion-exchange process between metal ion and sodium alginate solution. This kind of NiCo2O4@carbon aerogel shows large specific surface area, high specific capacitance, outstanding rate performance, and excellent cycling stability for the supercapacitor.
      PubDate: 2017-11-08T00:07:26.358777-05:
      DOI: 10.1002/advs.201700345
       
  • Through-Bond Energy Transfer Cassette with Dual-Stokes Shifts for
           “Double Checked” Cell Imaging

    • Authors: Xiangdong Xue; Shubin Jin, Zhipeng Li, Chunqiu Zhang, Weisheng Guo, Liming Hu, Paul C. Wang, Jinchao Zhang, Xing-Jie Liang
      Abstract: Organic dyes generally suffer from small Stokes shift that usually leads to self-quenching and -gaining errors during the fluorescent imaging process. Here, a through-bond energy transfer (TBET) cassette is developed with large Stokes shift to pursue precise cell imaging. The TBET is constructed by covalently conjugated tetraphenylethene (acts as donor) and rhodamine (acceptor) through an acetylene bond. The constructed TBET cassette distinctly behaves as dual-Stokes shifts, including a large pseudo-Stokes shift caused by energy transfer, from donor's absorption to acceptor's emission (up to 260 nm) and a smaller Stokes shift of acceptor molecules itself. Due to the intrinsic dual-Stokes shifts, TBET cassette exhibits specific “dual distinct absorbances, single shared emission” properties, which can be excitated under two different laser channels. By colocalization of the imaging readouts of these two channels, the precisely “double checked” fluorescent imaging is achieved in living cells.Through-bond energy transfer (TBET) cassette is constructed with intrinsically “dual distinct absorbances, single shared emission” properties and realized precisely, “double checked” fluorescent imaging in living cells.
      PubDate: 2017-10-27T23:06:52.675929-05:
      DOI: 10.1002/advs.201700229
       
  • Enhanced Proton Conductivity in Y-Doped BaZrO3 via Strain Engineering

    • Authors: Aline Fluri; Aris Marcolongo, Vladimir Roddatis, Alexander Wokaun, Daniele Pergolesi, Nicola Marzari, Thomas Lippert
      Abstract: The effects of stress-induced lattice distortions (strain) on the conductivity of Y-doped BaZrO3, a high-temperature proton conductor with key technological applications for sustainable electrochemical energy conversion, are studied. Highly ordered epitaxial thin films are grown in different strain states while monitoring the stress generation and evolution in situ. Enhanced proton conductivity due to lower activation energies is discovered under controlled conditions of tensile strain. In particular, a twofold increased conductivity is measured at 200 °C along a 0.7% tensile strained lattice. This is at variance with conclusions coming from force-field simulations or the static calculations of diffusion barriers. Here, extensive first-principles molecular dynamic simulations of proton diffusivity in the proton-trapping regime are therefore performed and found to agree with the experiments. The simulations highlight that compressive strain confines protons in planes parallel to the substrate, while tensile strain boosts diffusivity in the perpendicular direction, with the net result that the overall conductivity is enhanced. It is indeed the presence of the dopant and the proton-trapping effect that makes tensile strain favorable for proton conduction.Tensile lattice strain is shown for the first time to enhance the proton conduction in the grain interior, which is in contradiction to previous theoretical simulations. Through the synergy of experiment and theory, a new approach to the theoretical modeling of the proton conduction mechanism is developed, which is capable of explaining the experimental results.
      PubDate: 2017-10-27T06:16:51.712744-05:
      DOI: 10.1002/advs.201700467
       
  • Overcoming the Limitations of Sputtered Nickel Oxide for High-Efficiency
           and Large-Area Perovskite Solar Cells

    • Authors: Guijun Li; Yibin Jiang, Sunbin Deng, Alwin Tam, Ping Xu, Man Wong, Hoi-Sing Kwok
      Abstract: Perovskite solar cells (PSCs) are one of the promising photovoltaic technologies for solar electricity generation. NiOx is an inorganic p-type semiconductor widely used to address the stability issue of PSCs. Although high efficiency is obtained for the devices employing NiOx as the hole transport layer, the fabrication methods have yet to be demonstrated for industrially relevant manufacturing of large-area and high-performance devices. Here, it is shown that these requirements can be satisfied by using the magnetron sputtering, which is well established in the industry. The limitations of low fill factor and short-circuit current commonly observed in sputtered NiOx-derived PSCs can be overcome through magnesium doping and low oxygen partial pressure deposition. The fabricated PSCs show a high power conversion efficiency of up to 18.5%, along with negligible hysteresis, improved ambient stability, and high reproducibility. In addition, good uniformity is also demonstrated over an area of 100 cm2. The simple and well-established approach constitutes a reliable and scale method paving the way for the commercialization of PSCs.An industrially relevant manufacturing of perovskite solar cells is demonstrated with the magnetron sputtered NiMgOx, and the limitations of low fill factor and short-circuit current commonly observed in sputtered NiOx-derived devices can be overcome through magnesium doping and low oxygen partial pressure deposition. The as fabricated devices show a high efficiency of up to 18.5%, along with good uniformity over a large-area of 100 cm2.
      PubDate: 2017-10-26T03:56:03.945905-05:
      DOI: 10.1002/advs.201700463
       
  • 3D Printing of Lotus Root-Like Biomimetic Materials for Cell Delivery and
           Tissue Regeneration

    • Authors: Chun Feng; Wenjie Zhang, Cuijun Deng, Guanglong Li, Jiang Chang, Zhiyuan Zhang, Xinquan Jiang, Chengtie Wu
      Abstract: Biomimetic materials have drawn more and more attention in recent years. Regeneration of large bone defects is still a major clinical challenge. In addition, vascularization plays an important role in the process of large bone regeneration and microchannel structure can induce endothelial cells to form rudimentary vasculature. In recent years, 3D printing scaffolds are major materials for large bone defect repair. However, these traditional 3D scaffolds have low porosity and nonchannel structure, which impede angiogenesis and osteogenesis. In this study, inspired by the microstructure of natural plant lotus root, biomimetic materials with lotus root-like structures are successfully prepared via a modified 3D printing strategy. Compared with traditional 3D materials, these biomimetic materials can significantly improve in vitro cell attachment and proliferation as well as promote in vivo osteogenesis, indicating potential application for cell delivery and bone regeneration.Inspired by the microstructure of lotus root, lotus root-like biomimetic materials are successfully prepared via a modified 3D printing strategy with different kinds of materials, channel numbers, shapes, porosity, surface area, and mechanical properties. The biomimetic materials significantly improve in vitro cell attachment and proliferation as well as in vivo osteogenesis, indicating potential application for cell delivery and bone regeneration.
      PubDate: 2017-10-26T02:01:35.809572-05:
      DOI: 10.1002/advs.201700401
       
  • An Aqueous Ca-Ion Battery

    • Authors: Saman Gheytani; Yanliang Liang, Feilong Wu, Yan Jing, Hui Dong, Karun K. Rao, Xiaowei Chi, Fang Fang, Yan Yao
      Abstract: Multivalent-ion batteries are emerging as low-cost, high energy density, and safe alternatives to Li-ion batteries but are challenged by slow cation diffusion in electrode materials due to the high polarization strength of Mg- and Al-ions. In contrast, Ca-ion has a low polarization strength similar to that of Li-ion, therefore a Ca-ion battery will share the advantages while avoiding the kinetics issues related to multivalent batteries. However, there is no battery known that utilizes the Ca-ion chemistry due to the limited success in Ca-ion storage materials. Here, a safe and low-cost aqueous Ca-ion battery based on a highly reversible polyimide anode and a high-potential open framework copper hexacyanoferrate cathode is demonstrated. The prototype cell shows a stable capacity and high efficiency at both high and low current rates, with an 88% capacity retention and an average 99% coloumbic efficiency after cycling at 10C for 1000 cycles. The Ca-ion storage mechanism for both electrodes as well as the origin of the fast kinetics have been investigated. Additional comparison with a Mg-ion cell with identical electrodes reveals clear kinetics advantages for the Ca-ion system, which is explained by the smaller ionic radii and more facile desolvation of hydrated Ca-ions.An aqueous Ca-ion battery is demonstrated using two low-cost materials as the electrodes. The battery shows specific energy of 54 Wh kg−1, high-rate capability, and stable cycling performance with high coulombic efficiency and is a promising energy storage system for large-scale applications.
      PubDate: 2017-10-26T02:00:42.480278-05:
      DOI: 10.1002/advs.201700465
       
  • Nonlocal Response in Infrared Detector with Semiconducting Carbon
           Nanotubes and Graphdiyne

    • Authors: Zhe Zheng; Hehai Fang, Dan Liu, Zhenjun Tan, Xin Gao, Weida Hu, Hailin Peng, Lianming Tong, Wenping Hu, Jin Zhang
      Abstract: Semiconducting single-walled carbon nanotubes (s-SWNTs) are regarded as an important candidate for infrared (IR) optical detection due to their excellent intrinsic properties. However, the strong binding energy of excitons in s-SWNTs seriously impedes the development of s-SWNTs IR photodetector. This Communication reports an IR photodetector with highly pure s-SWNTs and γ-graphdiyne. The heterojunctions between the two materials can efficiently separate the photogenerated excitons. In comparison to device fabricated only with s-SWNTs, this IR detector shows a uniform response in the whole channel of the device. The response time is demonstrated to be below 1 ms. The optimal responsivity and detectivity approximately reach 0.4 mA W−1 and 5 × 106 cmHz1/2 W−1, respectively.The uniform response is gotten through the combination of semiconducting single-walled carbon nanotubes and γ-graphdiyne without decrease of electrical transport property of the device. The signal can be collected in the whole channel area and the responsivity and detectivity approximately reach 0.4 mA W−1 and 5 × 106 cmHz1/2 W−1, respectively. The response time is below 1 ms.
      PubDate: 2017-10-25T23:07:33.168083-05:
      DOI: 10.1002/advs.201700472
       
  • Pursuing Polymer Dielectric Interfacial Effect in Organic Transistors for
           Photosensing Performance Optimization

    • Authors: Xiaohan Wu; Yingli Chu, Rui Liu, Howard E. Katz, Jia Huang
      Abstract: Polymer dielectrics in organic field-effect transistors (OFETs) are essential to provide the devices with overall flexibility, stretchability, and printability and simultaneously introduce charge interaction on the interface with organic semiconductors (OSCs). The interfacial effect between various polymer dielectrics and OSCs significantly and intricately influences device performance. However, understanding of this effect is limited because the interface is buried and the interfacial charge interaction is difficult to stimulate and characterize. Here, this challenge is overcome by utilizing illumination to stimulate the interfacial effect in various OFETs and to characterize the responses of the effect by measuring photoinduced changes of the OFETs performances. This systemic investigation reveals the mechanism of the intricate interfacial effect in detail, and mathematically explains how the photosensitive OFETs characteristics are determined by parameters including polar group of the polymer dielectric and the OSC side chain. By utilizing this mechanism, performance of organic electronics can be precisely controlled and optimized. OFETs with strong interfacial effect can also show a signal additivity caused by repeated light pulses, which is applicable for photostimulated synapse emulator. Therefore, this work enlightens a detailed understanding on the interface effect and provides novel strategies for optimizing OFET photosensory performances.The significant and intricate semiconductor/dielectric interfacial effect in flexbile organic transistors is systematically investigated, giving a mechanism that mathematically explains how the photosensitive device characteristics are determined by parameters including polar group of the polymer dielectrics and side chain of the organic semiconductors. By utilizing the mechanism, performance of the organic electronics can be optimized, and photostimulated synapse emulators are obtained.
      PubDate: 2017-10-16T01:31:44.717918-05:
      DOI: 10.1002/advs.201700442
       
  • Electroionic Antagonistic Muscles Based on Nitrogen-Doped Carbons Derived
           from Poly(Triazine-Triptycene)

    • Authors: Sandipan Roy; Jaehwan Kim, Moumita Kotal, Kwang Jin Kim, Il-Kwon Oh
      Abstract: Electroactive soft actuators and bioinspired artificial muscles have received burgeoning interest as essential components in future electronic devices such as soft haptic-feedback systems, human-friendly wearable electronics, and active biomedical devices. However, important challenging issues including fast response time, ultralow input power, robust operation in harsh environments, high-resolution controllability, and cost-effectiveness remain to be resolved for more practical applications. Here, an electroionic antagonistic artificial muscle is reported based on hierarchically porous nitrogen-doped carbon (HPNC) electrodes derived from a microporous poly(triazine-triptycene) organic framework (PtztpOF). The HPNC, which exhibits hierarchically micro- and mesoporous structures, high specific capacitance of 330 F g−1 in aqueous solution, large specific surface area of 830.46 m2 g−1, and graphitic nitrogen doping, offers high electrical conductivity of 0.073 MS m−1 and outstanding volumetric capacitance of 10.4 MF m−3. Furthermore, it is demonstrated that a novel electroionic antagonistic muscle based on HPNC electrodes successfully displays extremely reliable and large bending deformations and long-term durability under ultralow input voltages. Therefore, microporous polymer or covalent organic frameworks can be applied to provide significant improvements in electroactive artificial muscles, which can play key roles as technological advances toward bioinspired actuating devices required for next-generation soft and wearable electronics.Ultrasensitive bioinspired ionic actuators are newly developed using hierarchically porous nitrogen-doped carbon electrodes derived from poly(triazine-triptycene) organic framework. Owing to remarkable electro-chemomechanical properties of the electrodes such as high specific capacitance and electrical conductivity, and large surface area with hierarchical porosity, the bioinspired actuators exhibit large bending actuation and long-term durability under ultralow input voltages.
      PubDate: 2017-10-11T10:50:59.143801-05:
      DOI: 10.1002/advs.201700410
       
  • Electronic and Optoelectronic Applications Based on 2D Novel Anisotropic
           Transition Metal Dichalcogenides

    • Authors: Chuanhui Gong; Yuxi Zhang, Wei Chen, Junwei Chu, Tianyu Lei, Junru Pu, Liping Dai, Chunyang Wu, Yuhua Cheng, Tianyou Zhai, Liang Li, Jie Xiong
      Abstract: With the continuous exploration of 2D transition metal dichalcogenides (TMDs), novel high-performance devices based on the remarkable electronic and optoelectronic natures of 2D TMDs are increasingly emerging. As fresh blood of 2D TMD family, anisotropic MTe2 and ReX2 (M = Mo, W, and X = S, Se) have drawn increasing attention owing to their low-symmetry structures and charming properties of mechanics, electronics, and optoelectronics, which are suitable for the applications of field-effect transistors (FETs), photodetectors, thermoelectric and piezoelectric applications, especially catering to anisotropic devices. Herein, a comprehensive review is introduced, concentrating on their recent progresses and various applications in recent years. First, the crystalline structure and the origin of the strong anisotropy characterized by various techniques are discussed. Specifically, the preparation of these 2D materials is presented and various growth methods are summarized. Then, high-performance applications of these anisotropic TMDs, including FETs, photodetectors, and thermoelectric and piezoelectric applications are discussed. Finally, the conclusion and outlook of these applications are proposed.The recent research progresses of low-symmetry MTe2 (M = Mo, W) and ReX2 (X = S, Se) are presented with an emphasis on the crystalline structure, preparation methods, and novel electronic and optoelectronic applications.
      PubDate: 2017-10-06T08:46:24.291743-05:
      DOI: 10.1002/advs.201700231
       
  • Photogating in Low Dimensional Photodetectors

    • Authors: Hehai Fang; Weida Hu
      Abstract: Low dimensional materials including quantum dots, nanowires, 2D materials, and so forth have attracted increasing research interests for electronic and optoelectronic devices in recent years. Photogating, which is usually observed in photodetectors based on low dimensional materials and their hybrid structures, is demonstrated to play an important role. Photogating is considered as a way of conductance modulation through photoinduced gate voltage instead of simply and totally attributing it to trap states. This review first focuses on the gain of photogating and reveals the distinction from conventional photoconductive effect. The trap- and hybrid-induced photogating including their origins, formations, and characteristics are subsequently discussed. Then, the recent progress on trap- and hybrid-induced photogating in low dimensional photodetectors is elaborated. Though a high gain bandwidth product as high as 109 Hz is reported in several cases, a trade-off between gain and bandwidth has to be made for this type of photogating. The general photogating is put forward according to another three reported studies very recently. General photogating may enable simultaneous high gain and high bandwidth, paving the way to explore novel high-performance photodetectors.Photogating is considered as a way of conductance modulation through photoinduced voltage. The origins, formations, and characteristics of the trap- and hybrid-induced photogating are discussed. This type of photogating enables a trade-off between gain and bandwidth. However, general photogating may enable simultaneous high gain and high bandwidth, paving the way to explore novel high-performance photodetectors.
      PubDate: 2017-10-04T04:37:03.159617-05:
      DOI: 10.1002/advs.201700323
       
  • Simultaneous Optimization of Carrier Concentration and Alloy Scattering
           for Ultrahigh Performance GeTe Thermoelectrics

    • Authors: Juan Li; Zhiwei Chen, Xinyue Zhang, Hulei Yu, Zihua Wu, Huaqing Xie, Yue Chen, Yanzhong Pei
      Abstract: In order to locate the optimal carrier concentrations for peaking the thermoelectric performance in p-type group IV monotellurides, existing efforts focus on aliovalent doping, either to increase (in PbTe) or to decrease (in SnTe and GeTe) the hole concentration. The limited solubility of aliovalent dopants usually introduces insufficient phonon scattering for thermoelectric performance maximization. With a decrease in the size of cation, the concentration of holes, induced by cation vacancies in intrinsic compounds, increases rapidly from ≈1018 cm−3 in PbTe to ≈1020 cm−3 in SnTe and then to ≈1021 cm−3 in GeTe. This motivates a strategy here for reducing the carrier concentration in GeTe, by increasing the mean size of cations and vice-versa decreasing the average size of anions through isovalent substitutions for increased formation energy of cation vacancy. A combination of the simultaneously resulting strong phonon scattering due to the high solubility of isovalent impurities, an ultrahigh thermoelectric figure of merit, zT of 2.2 is achieved in GeTe–PbSe alloys. This corresponds to a 300% enhancement in average zT as compared to pristine GeTe. This work not only demonstrates GeTe as a promising thermoelectric material but also paves the way for enhancing the thermoelectric performance in similar materials.Apart from aliovalent doping, alloying GeTe with PbSe controls carrier concentration precisely through controlling the intrinsic cation vacancies. The isovalent point defects at cation and anion sites simultaneously decrease the lattice thermal conductivity to ≈0.5 W (m K)−1, and eventually thermoelectric figure of merit, zT ≈ 2.2 is achieved, which corresponds to a 300% improvement in the average zT compared to pristine GeTe.
      PubDate: 2017-09-30T23:06:28.193984-05:
      DOI: 10.1002/advs.201700341
       
  • Netrin-1 Promotes Inflammation Resolution to Achieve Endothelialization of
           Small-Diameter Tissue Engineering Blood Vessels by Improving Endothelial
           Progenitor Cells Function In Situ

    • Authors: Yanzhao Li; Simin Wan, Ge Liu, Wang Cai, Da Huo, Gang Li, Mingcan Yang, Yuxin Wang, Ge Guan, Ning Ding, Feila Liu, Wen Zeng, Chuhong Zhu
      Abstract: The transplant of small-diameter tissue engineering blood vessels (small-diameter TEBVs) (
      PubDate: 2017-09-28T11:29:15.168634-05:
      DOI: 10.1002/advs.201700278
       
  • Full-Color Emission Polymer Carbon Dots with Quench-Resistant Solid-State
           Fluorescence

    • Authors: Jieren Shao; Shoujun Zhu, Huiwen Liu, Yubin Song, Songyuan Tao, Bai Yang
      Abstract: Polymer carbon dots (PCDs) represent a new class of carbon dots (CDs) possessing sub-fluorophores and unique polymer-like structures. However, like small molecule dyes and traditional CDs, PCDs often suffer from self-quenching effect in solid state, limiting their potential applications. Moreover, it is hard to prepare PCDs that have the same chemical structure, exhibiting full-color emission under one fixed excitation wavelength by only modulating the concentration of the PCDs. Herein, self-quenching-resistant solid-state fluorescent polymer carbon dots (SSFPCDs) are prepared, which exhibit strong red SSF without any other additional solid matrices, while having a large production yield (≈89%) and a considerable quantum yield of 8.50%. When dispersed in water or solid matrices in gradient concentrations, they can exhibit yellow, green, and blue fluorescence, realizing the first SSFPCDs with the same chemical structure emitting in full-color range by changing the ratio of SSFPCDs to the solid matrices.A new type of polymer carbon dots (PCDs), possessing red quench-resistant solid state fluorescence, is developed, providing us a new way of achieving solid emission in the field of carbon dots. Moreover, these PCDs also exhibit full-color concentration-dependent emission, contributing to the realization of efficient full-color solid state fluorescence.
      PubDate: 2017-09-28T11:27:28.053202-05:
      DOI: 10.1002/advs.201700395
       
  • Field-Controlled Electrical Switch with Liquid Metal

    • Authors: James Wissman; Michael D. Dickey, Carmel Majidi
      Abstract: When immersed in an electrolyte, droplets of Ga-based liquid metal (LM) alloy can be manipulated in ways not possible with conventional electrocapillarity or electrowetting. This study demonstrates how LM electrochemistry can be exploited to coalesce and separate droplets under moderate voltages of ~1–10 V. This novel approach to droplet interaction can be explained with a theory that accounts for oxidation and reduction as well as fluidic instabilities. Based on simulations and experimental analysis, this study finds that droplet separation is governed by a unique limit-point instability that arises from gradients in bipolar electrochemical reactions that lead to gradients in interfacial tension. The LM coalescence and separation are used to create a field-programmable electrical switch. As with conventional relays or flip-flop latch circuits, the system can transition between bistable (separated or coalesced) states, making it useful for memory storage, logic, and shape-programmable circuitry using entirely liquids instead of solid-state materials.This study presents a fluidic electrical switch that reversibly changes states in response to moderate applied voltage (≈1–10 V). It comprises two liquid metal droplets anchored to copper pads and immersed in an electrolytic solution. This “liquid transistor” is the first soft-matter electrical switch that operates with voltages similar to that of conventional solid-state transistors.
      PubDate: 2017-09-26T23:07:06.137505-05:
      DOI: 10.1002/advs.201700169
       
  • Hematological Effects of Gold Nanorods on Erythrocytes: Hemolysis and
           Hemoglobin Conformational and Functional Changes

    • Authors: Xingchen Zhao; Dawei Lu, S. Qian Liu, Yiling Li, Rui Feng, Fang Hao, Guangbo Qu, Qunfang Zhou, Guibin Jiang
      Abstract: Gold nanorods (GNRs) are a unique class of metal nanostructures that have attractive potentials in biomedical applications, and the concern on their biological safety is concomitantly increasing. Hemocompatibility is extremely important as their contact with blood circulation is unavoidable during in vivo delivery. Herein, two kinds of GNRs coated with hexadecyltrimethylammonium bromide (C-GNRs) or poly(sodium-p-styrenesulfonate) are used to test their potential toxicological effects in blood. C-GNRs with positive surface charges efficiently induce hemolysis when encountering erythrocytes. Cellular internalization of C-GNRs is found, and they subsequently bind with hemoglobin, forming bioconjugates. The interaction between hemoglobin and C-GNR (stoichiometry 32.7:1) is regulated by electrostatic forces. Chromophores like tryptophan (Trp) are found to interact with C-GNRs, causing enhancement in fluorescence intensity. The conformation of protein is partially altered, evidenced by decrease in α-helical, increase in β-sheet and random coil of hemoglobin. Although C-GNRs do not essentially decrease oxygen binding capacity of hemoglobin, they hamper oxygen release from the protein. Heme, the oxygen binding unit, releases from hemoglobin upon C-GNR treatment, which could contribute to C-GNR-induced hemolysis. This study demonstrates the hematological effects of GNRs, revealing their potential risk in biomedical applications.The hematological effects are investigated for positively charged gold nanorods (C-GNRs) and negatively charged ones (P-GNRs). In contrast to P-GNRs, C-GNRs efficiently induce hemolysis when encountering erythrocytes. C-GNRs subsequently bind with hemoglobin after being encapsulated, inducing conformational and functional changes of the protein. The bound hemoglobin partially loses its function of oxygen release while retains the oxygen binding capacity.
      PubDate: 2017-09-25T11:10:59.116856-05:
      DOI: 10.1002/advs.201700296
       
  • Exploitation of the Large-Area Basal Plane of MoS2 and Preparation of
           Bifunctional Catalysts through On-Surface Self-Assembly

    • Authors: Yinghe Zhao; Qiang Li, Li Shi, Jinlan Wang
      Abstract: The development of nonprecious electrochemical catalysts for water splitting is a key step to achieve a sustainable energy supply for the future. Molybdenum disulfide (MoS2) has been extensively studied as a promising low-cost catalyst for hydrogen evolution reaction (HER), whereas HER is only catalyzed at the edge for pristine MoS2, leaving a large area of basal plane useless. Herein, on-surface self-assembly is demonstrated to be an effective, facile, and damage-free method to take full advantage of the large ratio surface of MoS2 for HER by using multiscale simulations. It is found that as supplement of edge sites of MoS2, on-MoS2 M(abt)2 (M = Ni, Co; abt = 2-aminobenzenethiolate) owns high HER activity, and the self-assembled M(abt)2 monolayers on MoS2 can be obtained through a simple liquid-deposition method. More importantly, on-surface self-assembly provides potential application for overall water splitting once the self-assembled systems prove to be of both HER and oxygen evolution reaction activities, for example, on-MoS2 Co(abt)2. This work opens up a new and promising avenue (on-surface self-assembly) toward the full exploitation of the basal plane of MoS2 for HER and the preparation of bifunctional catalysts for overall water splitting.On-surface self-assembly is demonstrated to be an effective, facile, and damage-free method to exploit the large-area basal plane of MoS2 for hydrogen evolution reaction (HER). Efficient exploitation for the basal plane of MoS2 is achieved based on significantly increased HER active sites by on-surface self-assembly. Moreover, on-surface self-assembly can serve for the preparation of bifunctional catalysts toward overall water splitting.
      PubDate: 2017-09-23T23:06:25.892835-05:
      DOI: 10.1002/advs.201700356
       
  • Steering Photoelectrons Excited in Carbon Dots into Platinum Cluster
           Catalyst for Solar-Driven Hydrogen Production

    • Authors: Xiaoyong Xu; Wenshuai Tang, Yiting Zhou, Zhijia Bao, Yuanchang Su, Jingguo Hu, Haibo Zeng
      Abstract: In composite photosynthetic systems, one most primary promise is to pursue the effect coupling among light harvesting, charge transfer, and catalytic kinetics. Herein, this study designs the reduced carbon dots (r-CDs) as both photon harvesters and photoelectron donors in combination with the platinum (Pt) clusters and fabricated the function-integrated r-CD/Pt photocatalyst through a photochemical route to control the anchoring of Pt clusters on r-CDs' surface for solar-driven hydrogen (H2) generation. In the obtained r-CD/Pt composite, the r-CDs absorb solar photons and transform them into energetic electrons, which transfer to the Pt clusters with favorable charge separation for H2 evolution reaction (HER). As a result, the efficient coupling of respective natures from r-CDs in photon harvesting and Pt in proton reduction is achieved through well-steered photoelectron transfer in the r-CD/Pt system to cultivate a remarkable and stable photocatalytic H2 evolution activity with an average rate of 681 µmol g−1 h−1. This work integrates two functional components into an effective HER photocatalyst and gains deep insights into the regulation of the function coupling in composite photosynthetic systems.This study reports an effective r-CD/Pt composite photocatalyst based on the combination of two superior function components for solar H2 production. The efficient coupling of respective natures from r-CDs in photon harvesting and Pt in proton reduction is achieved to cultivate a remarkable and stable photocatalytic H2 evolution activity.
      PubDate: 2017-09-21T04:01:06.920851-05:
      DOI: 10.1002/advs.201700273
       
  • Corrosion-Protected Hybrid Nanoparticles

    • Authors: Hyeon-Ho Jeong; Mariana Alarcón-Correa, Andrew G. Mark, Kwanghyo Son, Tung-Chun Lee, Peer Fischer
      Abstract: Nanoparticles composed of functional materials hold great promise for applications due to their unique electronic, optical, magnetic, and catalytic properties. However, a number of functional materials are not only difficult to fabricate at the nanoscale, but are also chemically unstable in solution. Hence, protecting nanoparticles from corrosion is a major challenge for those applications that require stability in aqueous solutions and biological fluids. Here, this study presents a generic scheme to grow hybrid 3D nanoparticles that are completely encapsulated by a nm thick protective shell. The method consists of vacuum-based growth and protection, and combines oblique physical vapor deposition with atomic layer deposition. It provides wide flexibility in the shape and composition of the nanoparticles, and the environments against which particles are protected. The work demonstrates the approach with multifunctional nanoparticles possessing ferromagnetic, plasmonic, and chiral properties. The present scheme allows nanocolloids, which immediately corrode without protection, to remain functional, at least for a week, in acidic solutions.A growth scheme is presented that enables the complete encapsulation of nanoparticles and nanostructures. Nanomaterials that are chemically unstable and prone to corrosion can be encapsulated with a nm thick shell and stabilized for days in corrosive environments.
      PubDate: 2017-09-15T13:11:04.284382-05:
      DOI: 10.1002/advs.201700234
       
  • Ultrahigh Electrocatalytic Conversion of Methane at Room Temperature

    • Authors: Ming Ma; Bing Jun Jin, Ping Li, Myung Sun Jung, Jin Il Kim, Yoonjun Cho, Sungsoon Kim, Jun Hyuk Moon, Jong Hyeok Park
      Abstract: Due to the greenhouse effect, enormous efforts are done for carbon dioxide reduction. By contrast, more attention should be paid for the methane oxidation and conversion, which can help the effective utilization of methane without emission. However, methane conversion and utilization under ambient conditions remains a challenge. Here, this study designs a Co3O4/ZrO2 nanocomposite for the electrochemical oxidation of methane gas using a carbonate electrolyte at room temperature. Co3O4 activated the highly efficient oxidation of methane under mild electric energy with the help of carbonate as an oxidant, which is delivered by ZrO2. Based on the experimental results, acetaldehyde is the key intermediate product. Subsequent nucleophilic addition and free radical addition reactions accounted for the generation of 2-propanol and 1-propanol, respectively. Surprisingly, this work achieves a production efficiency of over 60% in the conversion of methane to produce these long-term stable products. The as-proposed regional electrochemical methane oxidation provides a new pathway for the synthesis of higher alcohols with high production efficiencies under ambient conditions.Efficient conversion of methane to 1-propanol and 2-propanol is realized by direct electrochemical oxidation using ZrO2/Co3O4 as the anode and carbonate solution as the electrolyte. The production of 2-propanol is attributed to the nucleophilic addition reaction and the free radical addition reaction should be responsible for the formation of 1-propanol.
      PubDate: 2017-09-11T02:06:35.139187-05:
      DOI: 10.1002/advs.201700379
       
 
 
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