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Siyu Yu Nianjun Yang Michael Vogel Soumen Mandal Oliver A. Williams Siyu Jiang Holger Schönherr Bing Yang Xin Jiang 《Liver Transplantation》2018,8(12)
To fabricate battery‐like supercapacitors with high power and energy densities, big capacitances, as well as long‐term capacitance retention, vertically aligned carbon nanofibers (CNFs) grown on boron doped diamond (BDD) films are employed as the capacitor electrodes. They possess large surface areas, high conductivity, high stability, and importantly are free of binder. The large surface areas result from their porous structures. The containment of graphene layers and copper metal catalysts inside CNFs leads to their high conductivity. Both electrical double layer capacitors (EDLCs) in inert solutions and pseudocapacitors (PCs) using Fe(CN)63?/4? redox‐active electrolytes are constructed with three‐ and two‐electrode systems. The assembled two‐electrode symmetrical supercapacitor devices exhibit capacitances of 30 and 48 mF cm?2 at 10 mV s?1 for EDLC and PC devices, respectively. They remain constant even after 10 000 charging/discharging cycles. The power densities are 27.3 and 25.3 kW kg?1 for EDLC and PC devices, together with their energy densities of 22.9 and 44.1 W h kg?1, respectively. The performance of these devices is superior to most of the reported supercapacitors and batteries. Vertically aligned CNF/BDD hybrid films are thus useful to construct high‐performance battery‐like and industry‐orientated supercapacitors for future power devices. 相似文献
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Supercapacitors: Battery‐like Supercapacitors from Vertically Aligned Carbon Nanofiber Coated Diamond: Design and Demonstrator (Adv. Energy Mater. 12/2018) 
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下载免费PDF全文 Siyu Yu Nianjun Yang Michael Vogel Soumen Mandal Oliver A. Williams Siyu Jiang Holger Schönherr Bing Yang Xin Jiang 《Liver Transplantation》2018,8(12)
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Highly flexible and conductive fabric (CF)‐supported cauliflower‐like nickel selenide nanostructures (Ni3Se2 NSs) are facilely synthesized by a single‐step chronoamperometry voltage‐assisted electrochemical deposition (ECD) method and used as a positive electrode in supercapacitors (SCs). The CF substrate composed of multi‐layered metallic films on the surface of polyester fibers enables to provide high electrical conductivity as a working electrode in ECD process. Owing to good electrical conductivity, high porosity and intertwined fibrous framework of CF, cauliflower‐like Ni3Se2 NSs are densely integrated onto the entire surface of CF (Ni3Se2 NSs@CF) substrate with reliable adhesion by applying a chronoamperometry voltage of ?1.0 V for 240 s. The electrochemical performance of the synthesized cauliflower‐like Ni3Se2 NSs@CF electrode exhibits a maximum specific capacity (C SC) of 119.6 mA h g?1 at a discharge current density of 2 A g?1 in aqueous 1 m KOH electrolyte solution. Remarkably, the specific capacity of the same electrode is greatly enhanced by introducing a small quantity of redox‐additive electrolyte into the aqueous KOH solution, indicating the C SC≈251.82 mA h g?1 at 2 A g?1 with good capacity retention. Furthermore, the assembled textile‐based asymmetric SCs achieve remarkable electrochemical performance such as higher energy and power densities, which are able to light up different colored light‐emitting diodes. 相似文献
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Electrospinning of natural polymer nanofibers useful for biomedical applications often requires the use of cytotoxic organic solvents. In this study, gelatin nanofibers are electrospun from phosphate buffer saline/ethanol binary mixtures as a benign solvent at ambient temperature. The influences of ionic strength, ethanol concentration, and gelatin concentration on the electrospinnability of gelatin solutions and the fiber microarchitectures are analyzed. The electrospun scaffolds retain their morphologies during vapor‐phase crosslinking with glutaraldehyde in ethanol and the subsequent removal of salts contained in the nanofibers via water rinsing. When fully hydrated, the mechanically preconditioned scaffolds display a Young's modulus of 25.5 ± 5.3 kPa, tensile strength of 55.5 ± 13.9 kPa, deformability of 160 ± 15%, and resilience of 89.9 ± 1.8%. When cultured on the gelatin scaffolds, 3T3 fibroblasts displayed spindle‐like morphology, similar to the cell's normal morphology in a 3D extracellular matrix. © 2012 Wiley Periodicals, Inc. Biopolymers 97:1026–1036, 2012. 相似文献
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Bote Zhao Lei Zhang Qiaobao Zhang Dongchang Chen Yong Cheng Xiang Deng Yu Chen Ryan Murphy Xunhui Xiong Bo Song Ching‐Ping Wong Ming‐Sheng Wang Meilin Liu 《Liver Transplantation》2018,8(9)
Compact, light, and powerful energy storage devices are urgently needed for many emerging applications; however, the development of advanced power sources relies heavily on advances in materials innovation. Here, the findings in rational design, one‐pot synthesis, and characterization of a series of Ni hydroxide‐based electrode materials in alkaline media for fast energy storage are reported. Under the guidance of density functional theory calculations and experimental investigations, a composite electrode composed of Co‐/Mn‐substituted Ni hydroxides grown on reduced graphene oxide (rGO) is designed and prepared, demonstrating capacities of 665 and 427 C g?1 at current densities of 2 and 20 A g?1, respectively. The superior performance is attributed mainly to the low deprotonation energy and the facile electron transport, as elaborated by theoretical calculations. When coupled with an electrode based on organic molecular‐modified rGO, the resulting hybrid device demonstrates an energy density of 74.7 W h kg?1 at a power density of 1.68 kW kg?1 while maintaining capacity retention of 91% after 10,000 cycles (20 A g?1). The findings not only provide a promising electrode material for high‐performance hybrid capacitors but also open a new avenue toward knowledge‐based design of efficient electrode materials for other energy storage applications. 相似文献
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Electrospun tubular conduit (4 mm inner diameter) based on blends of polydioxanone (PDS II®) and proteins such as gelatin and elastin having a spatially designed trilayer structure was prepared for arterial scaffolds. SEM analysis of scaffolds showed random nanofibrous morphology and well‐interconnected pore network. Due to protein blending, the fiber diameter was reduced from 800–950 nm range to 300–500 nm range. Fourier‐transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) results confirmed the blended composition and crystallinity of fibers. Pure PDS scaffold under hydrated state exhibited a tensile strength of 5.61 ± 0.42 MPa and a modulus of 17.11 ± 1.13 MPa with a failure strain of 216.7 ± 13%. The blending of PDS with elastin and gelatin has decreased the tensile properties. A trilayer tubular scaffold was fabricated by sequential electrospinning of blends of elastin/gelatin, PDS/elastin/gelatin, and PDS/gelatin (EG/PEG/PG) to mimic the complex matrix structure of native arteries. Under hydrated state, the trilayer conduit exhibited tensile properties (tensile strength of 1.77 ± 0.2 MPa and elastic modulus of 5.74 ± 3 MPa with a failure strain of 75.08 ± 10%) comparable to those of native arteries. In vitro degradation studies for up to 30 days showed about 40% mass loss and increase in crystallinity due to the removal of proteins and “cleavage‐induced crystallization” of PDS. Biotechnol. Bioeng. 2009; 104: 1025–1033. © 2009 Wiley Periodicals, Inc. 相似文献
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Sangeeta Gopichandra Itankar Manjusha Prafulla Dandekar Subhash Baburao Kondawar Bhaskar Marotrao Bahirwar 《Luminescence》2017,32(8):1535-1540
Eu3+‐doped polystyrene and polyvinylidene fluoride (PVDF/Eu3+ and PS/Eu3+) nanofibers were made using electrospinning. These fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT‐IR), energy dispersive spectroscopy (EDX) and photoluminescence (PL). Spectral analysis of PVDF/Eu3+ and PS/Eu3+ nanofibers was based on their emission spectra. A bright red emission was noticed from Eu3+ that was assigned to the hypersensitive 5D0 → 7F2 transition. The enhanced intensity ratios of 5D0 → 7F2 to 5D0 → 7F1 transitions in the nanofibers indicated a more polarized chemical environment for the Eu3+ ions and greater hypersensitivity for the 5D0 → 7F2 transition, which showed the potential for application in various polymer optoelectronic devices. The Eu3+‐doped polymer (PVDF/Eu3+ and PS/Eu3+) nanofibers are suitable for the photoluminescent white light fabric design of smart textiles. This paper focuses on the potential application of smart fabrics to address challenges in human life. 相似文献
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Shujuan Sheng Qianli Ma Xiangting Dong Nan Lv Jinxian Wang Wensheng Yu Guixia Liu 《Luminescence》2015,30(1):26-31
In order to develop new‐type multifunctional composite nanofibers, Eu(BA)3phen/PANI/PVP bifunctional composite nanofibers with simultaneous photoluminescence and electrical conductivity have been successfully fabricated via electrospinning technology. Polyvinyl pyrrolidone (PVP) is used as a matrix to construct composite nanofibers containing different amounts of Eu(BA)3phen and polyaniline (PANI). X‐Ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), fluorescence spectroscopy and a Hall effect measurement system are used to characterize the morphology and properties of the composite nanofibers. The results indicate that the bifunctional composite nanofibers simultaneously possess excellent photoluminescence and electrical conductivity. Fluorescence emission peaks of Eu3+ ions are observed in the Eu(BA)3phen/PANI/PVP photoluminescence–electrical conductivity bifunctional composite nanofibers. The electrical conductivity reaches up to the order of 10−3 S/cm. The luminescent intensity and electrical conductivity of the composite nanofibers can be tuned by adjusting the amounts of Eu(BA)3phen and PANI. The obtained photoluminescence–electrical conductivity bifunctional composite nanofibers are expected to possess many potential applications in areas such as microwave absorption, molecular electronics, biomedicine and future nanomechanics. More importantly, the design concept and construction technique are of universal significance to fabricate other bifunctional one‐dimensional naonomaterials. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Serap Gül;Şeyda Kara;Hanene Talhi;Ali Adem Bahar;Orhan Murat Kalfa;Muharrem Akcan; 《Peptide Science》2024,116(5):e24350
The increased usage and misuse of antibiotics cause antimicrobial resistance, which makes it necessary to develop new antibiotic agents. Antimicrobial peptides (AMPs) could be a significant solution to addressing this issue. Antimicrobial temporin 1Ta and temporin 1Tb peptides, derived from frog skin secretions, exhibit notable activity against Gram (+) bacteria; on the other hand, apidaecin 1b peptide, obtained from honeybees, is effective against Gram (−) bacteria. In this study, hybrid AMPs were synthesized by merging temporin 1Ta and temporin 1Tb with apidaecin 1b to produce peptides that are active against a broad spectrum of microorganisms. Furthermore, the hybrid peptides were mixed with polyvinyl alcohol (PVA) polymer to produce bioactive nanofibers by electrospinning. The synthesized peptides and the nanofibers were tested on various Gram (+) and Gram (−) bacteria (E. coli ATCC 25922, P. aeruginosa ATCC 27853, S. aureus ATCC 29213, and E. faecalis ATCC 29212). As a result, the hybrid peptides were found to have a reasonable antibacterial effect on both bacterial groups. In addition, peptide-containing nanofibers preserved the antibacterial activity as well. The hemolytic activities of the peptides were also examined, and it was found that the hybrid peptides were not lethal to red blood cells at a concentration of 16 μM. 相似文献
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Molamma P. Prabhakaran Elham Vatankhah Seeram Ramakrishna 《Biotechnology and bioengineering》2013,110(10):2775-2784
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Michelle K. Leach Zhang-Qi Feng Samuel J. Tuck Joseph M. Corey 《Journal of visualized experiments : JoVE》2011,(47)
Electrospun nanofiber scaffolds have been shown to accelerate the maturation, improve the growth, and direct the migration of cells in vitro. Electrospinning is a process in which a charged polymer jet is collected on a grounded collector; a rapidly rotating collector results in aligned nanofibers while stationary collectors result in randomly oriented fiber mats. The polymer jet is formed when an applied electrostatic charge overcomes the surface tension of the solution. There is a minimum concentration for a given polymer, termed the critical entanglement concentration, below which a stable jet cannot be achieved and no nanofibers will form - although nanoparticles may be achieved (electrospray). A stable jet has two domains, a streaming segment and a whipping segment. While the whipping jet is usually invisible to the naked eye, the streaming segment is often visible under appropriate lighting conditions. Observing the length, thickness, consistency and movement of the stream is useful to predict the alignment and morphology of the nanofibers being formed. A short, non-uniform, inconsistent, and/or oscillating stream is indicative of a variety of problems, including poor fiber alignment, beading, splattering, and curlicue or wavy patterns. The stream can be optimized by adjusting the composition of the solution and the configuration of the electrospinning apparatus, thus optimizing the alignment and morphology of the fibers being produced. In this protocol, we present a procedure for setting up a basic electrospinning apparatus, empirically approximating the critical entanglement concentration of a polymer solution and optimizing the electrospinning process. In addition, we discuss some common problems and troubleshooting techniques. 相似文献
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Mixed metal sulfides (MMSs) have attracted increased attention as promising electrode materials for electrochemical energy storage and conversion systems including lithium‐ion batteries (LIBs), sodium‐ion batteries (SIBs), hybrid supercapacitors (HSCs), metal–air batteries (MABs), and water splitting. Compared with monometal sulfides, MMSs exhibit greatly enhanced electrochemical performance, which is largely originated from their higher electronic conductivity and richer redox reactions. In this review, recent progresses in the rational design and synthesis of diverse MMS‐based micro/nanostructures with controlled morphologies, sizes, and compositions for LIBs, SIBs, HSCs, MABs, and water splitting are summarized. In particular, nanostructuring, synthesis of nanocomposites with carbonaceous materials and fabrication of 3D MMS‐based electrodes are demonstrated to be three effective approaches for improving the electrochemical performance of MMS‐based electrode materials. Furthermore, some potential challenges as well as prospects are discussed to further advance the development of MMS‐based electrode materials for next‐generation electrochemical energy storage and conversion systems. 相似文献
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Electrode/electrolyte interfacial properties of flexible supercapacitors assembled with nanostructured activated carbon fabric (ACF) electrodes can be tailored by applying a pressure and tuning electrolyte ion size relative to electrode pore size. Experimental results reveal that increasing pressure between the supercapacitor electrodes can significantly improve capacitive performance. The ratio of solvated ion size in the electrolyte to the pore size on the electrodes determines the minimum pressure necessary to achieve an optimum performance. For a specific electrode material, this minimum pressure for optimum performance is primarily governed by the size of the larger solvated ions (either the anions or cations), and is lower (～689 KPa) when the ratio of the solvated ion size to the pore size is higher than 0.6, and is higher (at least 1379 KPa) when the ratio is lower than 0.6. An analytical model capable of predicting the experimental performance data has been developed. These results together provide a fundamental understanding of pressure dependence of electrode/electrolyte interfacial properties and pave the way for practical applications of flexible supercapacitors. 相似文献
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