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31.
《Surface and interface analysis : SIA》2003,35(12):1015-1017
Material surface properties of polymers, plastics, ceramics and textiles can be modified by atmospheric or low‐pressure glow discharge plasma. The aim of the present work is to study the surface modification of biaxially oriented polypropylene (BOPP) film in order to improve its hydrophilic and wetting properties. In this article we used low‐pressure, low‐temperature oxygen plasma for the surface treatment of BOPP. Scanning electron microscopy indicates that plasma treatment causes mainly physical changes by creating microcraters and roughness on the surface and increasing surface friction. Attenuated total reflectance infrared spectra show oxygen‐containing groups such as ? OH at 3513 cm?1 and C?O at 1695 cm?1. Microscopic investigations of water droplets on BOPP (treated, untreated) show that the interfacial adhesion of treated surfaces is increased. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
32.
G. Gousset M. Touzeau M. Vialle C. M. Ferreira 《Plasma Chemistry and Plasma Processing》1989,9(2):189-206
A simple kinetic model predicting the concentration of oxygen atoms, metastable singlet molecules O2(a
1) and negative ions O — in the positive column of a DC glow discharge is developed. The calculated O and O2(a
1) concentrations are compared to previously reported measurements for pressuresp=0.2–2 Torr and discharge currentsI=10–80 mA. The electron density calculated from the continuity equationj=n
e
e v
d agrees well with experiment. The rate coefficients for electron impact processes used in the balance equations of O, O2(a
1), and O– were taken from the literature as a function of the reduced electric fieldE/N forE/N=40–80 Td. A reasonable agreement is obtained between the model and the experiment with a set of 10 reactions for the production and destruction of the above-mentioned species 相似文献
33.
34.
Microwave discharges of HBr/H2/Ar and H/H2/Ar with additional do biasing of the sample were used to etch InP, GaAs, and AlGaAs at temperatures between 50–250°C. The etch rates increase by factors of 3–50 and 5–9, respectively, for HBr-and HI-based discharges over this temperature range, but display non-Arrhenius behavior. The etched surfaces became very rough above 100°C for InP with either discharge chemistry due to preferential loss of P, while GaAs and AlGaAs are more tolerant of the elevated temperature etching. The near-surface electrical properties of InP are severely degraded by etch temperatures above 100°C, while extensive hydrogen in-diffusion occurs in GaAs and AlGaAs under these conditions, leading to dopant passivation which can be reversed by annealing at 400°C. 相似文献
35.
Kulova T. L. Karseeva E. I. Skundin A. M. Kachibaya E. I. Imnadze R. A. Paikidze T. V. 《Russian Journal of Electrochemistry》2004,40(5):494-499
A series of compounds with the general formula LiMn2 - x - y
Cr
x
Ni
y
O4, where x + y = 0.05, 0.5, or 1.0, is synthesized. It is shown that all these compounds are pure-phase spinels with parameter aequal to 0.8193-0.8236 nm. Doping a stoichiometric lithium-manganese spinel simultaneously with chromium and nickel makes the spinel structure stable. The initial specific capacity of a spinel depends on its doping degree. Doping LiMn2O4 with chromium and nickel simultaneously at an Mn : Cr : Ni ratio of 195 : 3 : 2 raises the spinel's specific capacity and reduces the cycling degradation. The change in the discharge capacity of LiMn1.95Cr0.03Ni0.02O4 electrodes cycled at 20, 0, and -14°C is determined. 相似文献
36.
Jin Ho Lee Heoung Woo Kim Pyong Ki Pak Hai Bang Lee 《Journal of polymer science. Part A, Polymer chemistry》1994,32(8):1569-1579
Functional group gradient surfaces where the density of functional groups changes gradually along the sample length were prepared. The functional group (? COOH, ? CONH2, and ? OH group) gradient surfaces were produced by the treatment of low-density PE sheets using a corona with gradually increasing power, followed by the graft copolymerization of acrylic acid and subsequent substitution reaction of carboxylic acid groups to amide or hydroxyl groups. The prepared gradient surfaces were characterized by the measurement of water contact angle, FTIR-ATR, and ESCA. The gradient surfaces prepared can be used to systematically investigate the interactions of biological or other species in terms of the surface functional groups and their density of polymeric materials. © 1994 John Wiley & Sons, Inc. 相似文献
37.
Reactions in a Mixture of CH4 and CO2 under the Aciton of Microwave Discharge at Atmospheric Pressure 下载免费PDF全文
Reactions between CH4 and CO2 under the action of continuous microwave discharge at atmospheric pressure were studied in a special homemade reactor,The main products were CO and H2,while acetylene and ethylene were also found in the products.Experimental results show that conversions of CH4 and CO2 could be higher than 90% without the presence of any catalyst,Effects of CO2/CH4 molar ratio and total flow rate of the feed gas on the reaction were also investigated. 相似文献
38.
PbO~2纳米粉体的固相合成及其对MnO~2电极材料的改性作用 总被引:17,自引:1,他引:17
利用固相氧化反应制备了PbO~2纳米粉体样品,借助XRD,TEM以及循环伏安测试对其性质进行了表征。同时,对反应条件的选择进行了讨论。将所得样品用于改性MnO~2电极,恒流放电测试结果表明,样品掺杂量在1.25%~5.00%间对MnO~2有良好的改性效果,可使改性MnO~2的放电容量得到极大提高。循环伏安测试结果表明,铅的掺入改变了MnO~2的放电机理。在循环扫描过程中,掺杂物与MnO~2均不再以单纯氧化物的形式存在,而是形成了一系列Pb(X)(X=0,Ⅱ)Mn(Y)(Y=Ⅳ,Ⅲ,Ⅱ)复合物的共氧化与共还原,抑制了电化学惰性物质Mn~3O~4的生成和积累,从而有望改善MnO~2的可充性能。纳米PbO~2与常粒径PbO~2与常粒径PbO~2(标记为S)对MnO~2的改性机理类似。但前者对MnO~2的改性效果明显优于后者,当恒流放电至-1.0V时,其放电容量较S样改性MnO~2的放电容量平均高出约30%。 相似文献
39.
A. G. Bubnov E. Yu. Burova V. I. Grinevich V. V. Rybkin J.-K. Kim H.-S. Choi 《Plasma Chemistry and Plasma Processing》2006,26(1):19-30
This study investigated the processes for the destruction of phenol and its derivatives (resorcin and pyrocatechol) in aqueous
solutions under the action of an oxygen dielectric barrier discharge (DBD) at atmospheric pressure in the presence or absence
of catalysts in the plasma zone. It was shown that the DBD had a high decomposition efficiency for phenol and its derivatives
(up to 99%). Phenol was the most stable and pyrocatechol was the least. In a plasma-catalytic hybrid process, the effective
rate constants for phenol, resorcin and pyrocatechol decomposition were 11, 4 and 2.5 times higher, respectively, than those
for the DBD treatment without catalysts. The process also resulted in a 1.4, 1.6 and 1.2 times higher rate of carboxylic acid
formation for phenol, resorcin and pyrocatechol, respectively. The fractional conversion into the respective carboxylic acids
reached 56% for phenol and 68% for resorcin and pyrocatechol. 相似文献
40.
Densities of N, H, and NH active species have been detected by laser-induced fluorescence (LIF) in N2-xH2 dc flowing discharges. A peak value of N atom densities far x = 0.2–0.5% and a plateau value of H atom densities between x = 1% and 90% in post-discharge conditions (0.05 sec, p = 2 torr) has been found. Comparison between LIF measurements of N atoms and the trend of the N2(B, v = II) population shows that the emission from this state can be used for monitoring N atoms. The NH radical has only been detected inside the discharge region.On leave from Instituto Tecnológico de Aeronáutica, CNPq, Brazil. 相似文献