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Composite Electrodes for Electrochemical Supercapacitors  [cached]
Li Jun,Yang QuanMin,Zhitomirsky Igor
Nanoscale Research Letters , 2010,
Abstract: Manganese dioxide nanofibers with length ranged from 0.1 to 1 μm and a diameter of about 4–6 nm were prepared by a chemical precipitation method. Composite electrodes for electrochemical supercapacitors were fabricated by impregnation of the manganese dioxide nanofibers and multiwalled carbon nanotubes (MWCNT) into porous Ni plaque current collectors. Obtained composite electrodes, containing 85% of manganese dioxide and 15 mass% of MWCNT, as a conductive additive, with total mass loading of 7–15 mg cm 2, showed a capacitive behavior in 0.5-M Na2SO4 solutions. The decrease in stirring time during precipitation of the nanofibers resulted in reduced agglomeration and higher specific capacitance (SC). The highest SC of 185 F g 1 was obtained at a scan rate of 2 mV s 1 for mass loading of 7 mg cm 2. The SC decreased with increasing scan rate and increasing electrode mass.
Synergistic Nanophotonics of Fullerene  [PDF]
E. F. Sheka
Physics , 2010,
Abstract: A deep similarity of photo-stimulated effects occurring in physical and biological objects involving fullerene forces to raise the question: what is meant under nanophotonics of fullerene and if should we not imply under this conventional term, usually restricted to optical events, something more general? Discussed in the paper, makes it possible to suggest that the formation of positive-negative fullerene ion pair at each photon absorption act is common for photo stimulated events in chemistry, medicine, and optics thus providing their common origin.
Electrodeposition and Capacitive Behavior of Films for Electrodes of Electrochemical Supercapacitors  [cached]
Shi C,Zhitomirsky I
Nanoscale Research Letters , 2010,
Abstract: Polypyrrole films were deposited by anodic electropolymerization on stainless steel substrates from aqueous pyrrole solutions containing sodium salicylate and tiron additives. The deposition yield was studied under galvanostatic conditions. The amount of the deposited material was varied by the variation of deposition time at a constant current density. SEM studies showed the formation of porous films with thicknesses in the range of 0–3 μm. Cyclic voltammetry data for the films tested in 0.5 M Na2SO4 solutions showed capacitive behavior and high specific capacitance (SC) in a voltage window of 0.9 V. The films prepared from pyrrole solutions containing tiron showed better capacitive behavior compared to the films prepared from the solutions containing sodium salicylate. A highest SC of 254 F g 1 was observed for the sample with a specific mass of 89 μg cm 2 at a scan rate of 2 mV s 1. The SC decreased with an increasing film thickness and scan rate. The results indicated that the polypyrrole films deposited on the stainless steel substrates by anodic electropolymerization can be used as electrodes for electrochemical supercapacitors (ES).
Degradation of a fullerene end-capped polycaprolactone by lipase AK
QiYun Peng,Feng Kang,Juan Li,XinLin Yang
Chinese Science Bulletin , 2010, DOI: 10.1007/s11434-010-4058-7
Abstract: Using titrimetric method, enzymatic behavior of lipase AK against fullerene end-capped polycaprolactone (C60-PCL) was studied for the first time, compared with polycaprolactone (PCL). The results showed that degradation of both C60-PCL and PCL by lipase followed Mechaelis-Menten equation, with the degradation parameters of PCL and C60-PCL were 0.75 mg mL 1 and 0.16 mg mL 1 for K m, and 0.90 mL h 1 and 0.43 mL h 1 for V max, respectively. C60-PCL had a slower degradation rate than PCL under the same conditions. These data indicated that the introduction of fullerene enabled PCL hard to be degraded by lipase.
Progress of Research on Electrode Materials for Electrochemical Supercapacitors
电化学超级电容器电极材料的研究进展

JIANG Qi,QU Mei-Zhen,ZHANG Bo-Lan,YU Zuo-Long,
江奇
,瞿美臻,张伯兰,于作龙

无机材料学报 , 2002,
Abstract: Electrochemical supercapacitors have been focused for their great capacitance, fast charging-discharging with big current, and very long cycle life since they were born. In recent years, with their applications in national security science technology, environmental reservation and so on, the studies on them have become one of the hot spots in the strategic field. In this paper, the authors outlined the recent progress of research on electrode material for the electrochemical supercapacitors and classed them into four kinds: carbon materials series, transition metal oxides series, electronically conducting organic polymers series and others. At the same time, the authors analyzed the development orientations of the four kinds of electrode materials and brought out the research emphasis of the four kinds of electrochemical supercapacitors electrode materials in future.
Optical Polarizability of Zigzag Single-Walled Carbon Nanotubes Fullerene-Capped at One End and Covalently Bonded with Benzene Rings at the Other End  [PDF]
O. V. Ogloblya,D. Hui,Y. M. Strzhemechny,Yu. I. Prylutskyy
Journal of Nanomaterials , 2007, DOI: 10.1155/2007/13617
Abstract: We report on the results of numerical simulations for the linear optical polarizability of single-walled zigzag (9,0) carbon nanotubes with modified ends. The nanotubes of a variable length are fullerene-capped at one end and covalently bonded to a hydrophobic cluster of nine benzene rings at the other end. We investigate electronic and optical properties of such structures within a framework of the Su-Schrieffer-Heeger model. We demonstrated that the localized states in this system exhibit nonlinear characteristics of excited states. The nanotubes have a strongly oscillating dependence of their optical polarizability on the energy of incident light. Spectral features of the optical polarizability drop in intensity and shift towards higher energies with a decrease in the length of a nanotube or upon fullerene-uncapping. The length dependence is similar for the nanotubes without benzene rings, capped either at one or both ends. Potential applications are suggested for hydrophobic pollutant control in liquid-purification systems.
Achieving Both High Power and Energy Density in Electrochemical Supercapacitors with Nanoporous Graphene Materials  [PDF]
Hao Yang,Santhakumar Kannappan,Amaresh S. Pandian,Jae-Hyung Jang,Yun Sung Lee,Wu Lu
Physics , 2013,
Abstract: Supercapacitors, based on the fast ion transportation, are specialized to provide high power, long stability, and efficient energy storage with highly porous electrode materials. However, their low energy density and specific capacitance prevent them from many applications that require long duration. Using a scalable nanoporous graphene synthesis method involving a simple annealing process in hydrogen, here we show graphene supercapacitors capable of achieving a high energy density comparable to what Li-ion batteries can offer, but a much higher power density. Ultra-high specific gravimetric and volumetric capacitances are achieved with highly porous graphene electrodes. Moreover, the supercapacitors assembled with graphene electrodes show excellent stability. Our results demonstrate that by synthesizing graphene materials with an ideal pore size, uniformity, and good ion accessibility, the performance of supercapacitors can be revolutionized.
Comparative Study on the Synergistic Action of Garlic Synthesized and Citrate Capped Silver Nanoparticles with β-Penem Antibiotics  [PDF]
Neethu Hari,Tincy K. Thomas,A. Jayakumaran Nair
ISRN Nanotechnology , 2013, DOI: 10.1155/2013/792105
Abstract: Resistance to antimicrobial agents by pathogenic bacteria has emerged in recent years and is a major challenge for the health care industry. For developing a cheap broad-active agent that can be applicable against different pathogens, it is necessary to develop an alternative source for normal antibacterial agents. This paper mainly focuses on the combined action of green as well as citrate synthesized silver nanoparticles and β-penem antibiotics, which are β-lactam antibiotics with penem rings. These silver nanoparticles synergistic potential helps in the enhancement of antibacterial activity of broad spectrum antibiotics. The synergistic actions of citrate capped silver nanoparticles (Ag-NPs) were compared with that of garlic (Allium sativum) synthesized silver nanoparticles together with action of antibiotics, ampicillin and amoxyclav, and some of the pathogenic organisms showed an increase in the action of antibiotics. 1. Introduction Over the last few years, the β-lactam classes of antibiotics were the most widely used and the most commonly prescribed drugs, which represent more than half of all the antibiotics used in medical field, especially for the treatment of infectious diseases. This is primarily because in general they work perfectly against bacteria, easy to deliver, and are of few side effects. But now most of the bacteria will show wide spread resistance against β-lactam antibiotics by means of production of β-lactam hydrolyzing enzyme (β-lactamases), the utilization of β-lactam-insensitive cell wall transpeptidases, and the active expulsion of β-lactam molecules from Gram-negative cells by way of efflux pumps [1]. Moreover bacteria are capable of producing extended spectrum β-lactamases (ESBLs). Therefore, a new choice of β-lactam antibiotics is necessary to overcome all these problems; thus, new β-lactam penems receive much attention. Recently, silver nanoparticles (Ag-NPs), which are well known for their antimicrobial activity, are also studied intensively due to the growing bacterial resistance to antibiotics. Silver nanoparticles (Ag-NPs) have been known to have inhibitory and bactericidal effects against Gram-negative and Gram positive bacteria especially multiresistant bacteria. It can be expected that the high specific surface area and high fraction of surface atoms of Ag-NPs will lead to high antimicrobial activity as compared with bulk silver metal [2]. Therefore, silver nanoparticles can be exploited in medicine for wound healing, dental materials, catheters, coating stainless steel materials, textile fabrics, water treatment,
Synergistic Effect of Functionalized Nickel Nanoparticles and Quercetin on Inhibition of the SMMC-7721 Cells Proliferation  [cached]
Guo Dadong,Wu Chunhui,Li Jingyuan,Guo Airong
Nanoscale Research Letters , 2009,
Abstract: The effect of functionalized nickel (Ni) nanoparticles capped with positively charged tetraheptylammonium on cellular uptake of drug quercetin into hepatocellular carcinoma cells (SMMC-7721) has been explored in this study via microscopy and electrochemical characterization as well as MTT assay. Meanwhile, the influence of Ni nanoparticles and/or quercetin on cell proliferation has been further evaluated by the real-time cell electronic sensing (RT-CES) study. Our observations indicate that Ni nanoparticles could efficiently improve the permeability of cancer cell membrane, and remarkably enhance the accumulation of quercetin in SMMC-7721 cells, suggesting that Ni nanoparticles and quercetin would facilitate the synergistic effect on inhibiting proliferation of cancer cells.
Transparent, flexible, and solid-state supercapacitors based on graphene electrodes
Y. Gao,Y. S. Zhou,W. Xiong,L. J. Jiang
APL Materials , 2013, DOI: 10.1063/1.4808242
Abstract: In this study, graphene-based supercapacitors with optical transparency and mechanical flexibility have been achieved using a combination of poly(vinyl alcohol)/phosphoric acid gel electrolyte and graphene electrodes. An optical transmittance of ~67% in a wavelength range of 500-800 nm and a 92.4% remnant capacitance under a bending angle of 80° have been achieved for the supercapacitors. The decrease in capacitance under bending is ascribed to the buckling of the graphene electrode in compression. The supercapacitors with high optical transparency, electrochemical stability, and mechanical flexibility hold promises for transparent and flexible electronics.
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