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991.
聚四氟乙烯薄膜等离子体表面改性的研究 总被引:8,自引:0,他引:8
利用等离子体表面处理和化学接枝的方法对聚四氟乙烯(PTFE)薄膜表面进行了化学改性。利用XPS研究了改性后的PTFE薄膜的表面结构和价键状态,并通过接触角的测定研究了表面改性对薄膜亲水性的影响。研究结果发现PTFE薄膜经等离子体处理后,薄膜表面的C-F键发生了断裂,形成了C-C键、C-H键及C-O键;等离子体处理后的薄膜再经丙烯酸化学处理,强亲水性的丙烯酸基被接枝到PTFE表面,使得PTFE薄膜获 相似文献
992.
Deepak Bansilal Akolekar 《Catalysis Letters》1994,28(2-4):249-262
Highly crystalline cobalt aluminophosphates of type 36 have been synthesized and characterized. Investigations on the thermal decomposition of Pr3N-CoAPO-36 and the surface, sorption, acid strength distribution, acidic and catalytic properties of CoAPO-36 were carried out. The XPS analysis indicated that the concentration of cobalt was higher in the bulk of the material than on the surface. The surface of the cobalt aluminophosphate is aluminium rich. The number of strong acid sites is higher on the CoAPO-36 than on CoAPO-5, MAPO-5 and ZAPO-36. The catalytic activities of CoAPO-5, MAPO-5, ZAPO-36, CoAPO-36, MAPO-36 and MAPSO-36 in the 3-methylpentane ando-xylene conversion reactions were compared. The catalytic turnover rate per framework substituted atom in the conversion ofo-xylene for CoAPO-36 is higher than for the MAPO-5, CoAPO-5, ZAPO-36 and MAPSO-36. In the ethylbenzene conversion reaction, the deactivation of the cobalt aluminophosphate and magnesium aluminophosphates of type 36 were studied. 相似文献
993.
994.
YANG Jian-hua'''' GONG Yun-guo'''' CHENG Ming-fei> ZHANG Tong-he .Department of Physics Nantong University Jiangsu China .Department of Physics Nantong Institute of Technology Jiangsu China . Radiation Beam Materials Engineering Lab Beijing Normal University Beijing China 《材料热处理学报》2004,25(5)
IN severe working and operating conditions tin filmsfabricated by conventional methods may also fail.Therefore,the investigations were towards furthersurface treatments,aiming at modifying the wearresistance of TiN films.Among the post surfacetreatment methods,MEVVA ion implantation hasshown to be particularly promising for surfacemodification|2l Some studies have shown that the wearand friction of implanted TiN films were improved afterMEVVA ion implantation,irrespective of the type ofi… 相似文献
995.
L. Cizaire B. Vacher T. Le Mogne J. M. Martin L. Rapoport A. Margolin R. Tenne 《Surface & coatings technology》2002,160(2-3):282-287
Inorganic Fullerene-like (IF)-MoS2 nanoparticles were tested under boundary lubrication and ultra-high vacuum (UHV) and were found to give an ultra-low friction coefficient in both cases compared to hexagonal (h)-MoS2 material. Previous works made by Rapoport et al. with IF-WS2 revealed that the benefit effect of the inorganic fullerene-like materials decreases at high loads and sliding velocities. Nevertheless, under the conditions used in our experiments using high contact pressure (maximum pressure above 1.1 GPa in oil and 400 MPa in high vacuum) and slow sliding velocities (1.7 mm/s in oil test and 1 mm/s in high vacuum), friction always decreases and stabilizes at about 0.04 for 800 cycles in both cases. Therefore, IF-MoS2 material appears to be a good candidate for use in various environments in regard to other MoS2 crystal structures. Wear mechanisms were investigated using both High Resolution TEM and surface analyses (XPS) on the wear tracks. Wear particles collected from the flat wear scar show several morphologies, suggesting at least two lubricating mechanisms. As spherical particles are found in the wear debris, rolling may be a possible event. However, flattened and unwrapped IF-MoS2 particles are often observed after friction. In this case, low friction is thought to be due either to sliding between IF-MoS2 external flattened planes or to slip between individual unwrapped MoS2 sheets. 相似文献
996.
C.-O.A. Olsson 《Corrosion Science》2004,46(1):213-224
The long term atmospheric oxidation of a Nb-Zr alloy was studied by XPS. Curve fit parameters were defined and strictly constrained to obtain a consistent evaluation of film thickness and chemistry. A formalism was introduced to distinguish between the water, hydroxide and oxide contributions to the surface oxide.Ageing experiments were carried out simultaneously exposing one lot of samples to a laboratory atmosphere for 10 months and a second lot to a dry atmosphere in a desiccator. 相似文献
997.
The surface structures of three kinds of poly(ethylene oxide)‐segmented nylon (PEO‐Ny) films prepared by the solvent‐cast method were investigated with electron spectroscopy for chemical analysis (ESCA). The PEO‐Ny's used were high‐crystalline PEO‐segmented poly(iminosebacoyliminohexamethylene), low‐crystalline PEO‐segmented poly(iminosebacoylimino‐m‐xylene), and amorphous PEO‐segmented poly(iminoisophthaloyliminomethylene‐1,3‐cyclohexylenemethylene), and the PEO contents in the bulk polymers were approximately 10 wt %. The ESCA results showed that the PEO segment was enriched on the top surfaces of all the films, and the degrees of enrichment were different. The mechanism of the PEO enrichment was examined. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 10–16, 2002 相似文献
998.
掺杂态聚苯胺的XPS研究 总被引:1,自引:0,他引:1
对经不同质子酸盐酸 (HCl)、对甲基苯磺酸 (TSA)及磺基水杨酸 (SSA)掺杂的聚苯胺 (PAn)进行 3h空气浴的热处理 ,并用电导率和 XPS对其进行了表征。结果表明 ,PAn·HCl在 16 0℃时其电导率下降了六个数量级 ,其表面掺杂率随温度的升高而降低 ,并且具有不同结合能 Cl的相对组成也随之发生了变化 ;PAn·TSA及 PAn·SSA在 2 0 0℃的电导率分别下降了两个和一个数量级 ,但其表面掺杂率未发生明显的变化。随着温度的升高 ,掺杂态 PAn膜的脆性和表面氧化的程度增加 相似文献
999.
氧离子束辅助激光淀积生长ZnO/Si的XPS探究 总被引:1,自引:0,他引:1
为了探究ZnO/Si内部化学成分及有关信息,用氧离子束辅助(O+-assisted)脉冲激光淀积(PLD)法在不同实验条件下生长成ZnO/Si(111)样品.利用X射线光电子能谱(XPS)对长成的ZnO/Si异质结构进行了异位测试.通过对O1s峰及其肩状结构进行拟合、分析,得到了原子数密度比n(O)∶n(Zn),进而探究了原子数密度比与生长质量的关系.结果表明,用氧离子束辅助PLD法,可在较低的衬底温度190℃和适当O+束流条件下,生长出正化学比接近于1,且c轴单一取向最佳的ZnO/Si薄膜.用氧离子束辅助PLD淀积法生长ZnO薄膜,可以改善缺氧状况,能提供一个富氧环境. 相似文献
1000.
聚苯乙烯泡沫塑料是外墙外保温系统应用最广泛的材料之一,水蒸气透湿系数影响其导热性能和耐老化性能,而其产品标准中所采用的检验方法不适合于该材料的检测和结论评定.根据多年的试验证实了试验过程的缺陷,并提出了改进意见. 相似文献