磁控溅射法制备直接甲醇燃料电池阴极

等离子体溅射沉积是制备直接甲醇燃料电池电极的非常好的方法。采用磁控溅射,Pt被成功溅射在气体扩散层上。在不同的溅射功率和气压下制备了具有相同Pt负载量(0.1mg/cm2)的电极。X射线衍射测试显示Pt以面心立方结构存在。X射线光电子能谱证明了电极中的Pt以Pt(0)态的形式存在。扫描电镜观测显示Pt催化剂以纳米粒子和纳米团簇的形式存在。溅射电极的循环伏安曲线都具有Pt金属的典型性质。将用溅射方法制备的阴极与商用催化剂制备的阳极组装成膜电极一体化,并测试了单电池的性能。结果显示,在5.3Pa,110W条件下制备的阴极相比其他溅射参数下制备的电极具有较好的电性能,这主要是由于Pt粒径的降低以及多孔催化剂层的形成。     

Microstructure,Hardness and Corrosion Resistance of ZrN Films Prepared by Inductively Coupled Plasma Enhanced RF Magnetron Sputtering

ZrN fihns were deposited on Si（111） and M2 steel by inductively coupled plasma （ICP）-enhanced RF magnetron sputtering. The effect of ICP power on the microstructure, mechanical properties and corrosion resistance of ZrN films was investigated. When the ICP power is below 300 W, the ZrN films show a columnar structure. With the increase of ICP power, the texture coefficient （To） of the （111） plane, the nanohardness and elastic modulus of the films increase and reach the maximum at a power of 300 W. As the ICP Power exceeds 300 W, the films exhibit a ZrN and ZrNx mixed crystal structure without columnar grain while the nanohardness and elastic modulus of the films decrease. All the ZrN coated samples show a higher corrosion resistance than that of the bare M2 steel substrate in 3.5% NaCl electrolyte. The nanohardness and elastic modulus mostly depend on the crystalline structure and Tc of ZrN（111）.     

Plasma Induced Grafting of PMMA onto Titanium Dioxide Powder

Grafting of polymer of methyl methacrylate （PMMA） onto titanium dioxide powder is investigated in this paper. The graft polymerization reaction is induced by dielectric-barrier- discharge produced N2 plasma treatment of titanium dioxide surfaces. IR, XPS and TGA results show that PMMA is grafted onto the surfaces of titanium dioxide powder. And crystal structure of the titanium dioxide powder observed with XRD spectra is unchanged after plasma graft polymerization.     

Degradation of Alizarin Red by Hybrid Gas-Liquid Dielectric Barrier Discharge

A system based on dielectric barrier discharge （DBD） with improved discharge sta- bility and homogeneity was used for the degradation of Alizarin Red （AR）. This special structure of the DBD system is characterized by the high voltage electrode, which is covered with a quartz tube and partially immersed in water, and by directly using the water as the ground electrode. A transition was realized from the filamentary mode for the conventional structure of the DBD to the semi-homogeneous mode for such a configuration of the plasma discharge. The spectra of plasma are dominated by N2 molecular lines in the ultraviolet-A radiation region. Plasma degra- dation of AR in this system exhibited pseudo-first-order reaction kinetics. The degradation rate of AR reached 95% or so after 14 min treatment under favorable conditions. Alkaline conditions are favorable for the degradation of AR. The increase of conductivity of the solution, input power and usage of oxygen bubbling could enhance AR degradation.     

低温等离子体气相法制备氯化聚氯乙烯

介绍了氯化聚氯乙烯树脂的生产方法,研究了低温等离子体气相法制备氯化聚氯乙烯的新方法;试验结果表明:低温等离子体氯化工艺能够使聚氯乙烯快速氯化。     

喷涂距离对感应耦合等离子体喷涂B4C/W涂层 结合强度的影响

B_4C材料可用作原位保护涂层防止托卡马克面向等离子体部件中的钨块受到诸如腐蚀、开裂以及颗粒溅射等损伤。本文采用感应耦合等离子体(ICP)喷涂法在惰性气氛下制备B_4C/W涂层,对不同喷涂距离下的涂层进行结合力研究,并对其表面形貌进行分析,同时还对涂层的物相及组成成分进行了分析。不同喷涂距离下的拉伸测试结果展示了涂层结合强度的变化趋势,结果表明,在喷涂距离比较近时涂层的结合强度反而较弱。优化条件下的涂层结合强度值为5.32MPa。涂层表面形貌的SEM图像分析,进一步验证了结合强度的研究结果。与初始B_4C粉末相比,涂层的主要相成分和化学成分没有发生改变。     

Numerical Analysis of Plasma Initiated Polymerization

Plasma initiated polymerization is a kind of well-known radical polymerization mechanism, but it has the ＇living＇ polymerization feature and produces ultra-high molecular weight polymer. In order to explain such phenomena, we calculate the basic data of plasma initiated polymerization of methylmethacrylate （MMA） according to the principle of polymer physics and chemistry. It results in that the radical concentration ranges from 10^-12mol/L to 10^-16mol/L corresponding to the radical life in 10^4s to 10^8s, which means the radicals have a long lifetime. Moreover because of the long lifetime radicals it causes a unique feature rather than the common radical polymerization, and also shows no ＂living polymerization＂. It is noticed in experiments that there are two key factors playing important roles. One is the effective radical amount produced during the plasma discharging while the another is the diffusion factor.     

低温等离子体对聚合物表面改性的研究(续)

3　低温等离子体在聚合物表面改性中的应用3 1　塑料薄膜的表面改性3 1 1　工业包装膜目前的PP、BOPE、PVC、PET等塑料薄膜,在实际应用中均存在着难印刷和难粘接问题,因此工业包装膜在印刷之前一般要进行电晕处理。更多的塑料薄膜在使用之前要涂以特种底漆,如氯化聚氯乙烯、氯化聚丙烯为主要成分的底涂剂,然后使用溶剂型的印刷油墨进行印刷。成本高是一方面,高质量高标准的印刷控制也十分不容易稳定,还有许多凹版印刷的薄膜直接应用于食品包装和日常生活用品的包装,残留的溶剂及含氯树脂所造成的污染也是不容忽视的。低温等离子体表面…     

共溅射法制备的Pt-C薄膜的微观结构和电化学性能的研究

用共溅射的方法制备了Pt-C薄膜,薄膜由Pt纳米粒子和非晶C组成。电子显微镜和X射线衍射的测试结果显示Pt纳米粒子镶嵌在非晶C之中。高分辨率透射电子显微图像证实了2~3 nm的Pt粒子镶嵌于非晶C层中。Pt和Pt-C薄膜的电化学特性是通过循环伏安法来研究的,电解液为氮气饱和的0.5g/mol的硫酸溶液。与纯Pt薄膜相比,Pt-C薄膜显示了更高的电化学活性面积,这主要是由于非晶C支撑基材的存在降低了Pt纳米颗粒的粒径。