丙烯醇等离子体处理聚四氟乙烯的表面结构与润湿性

聚四氟乙烯经丙烯醇等离子体处理后,在其表面形成了一层亲水性的聚合物薄膜。水在表面的接触角为40—60°不等,由等离子体处理时间决定。对表面的全反射红外光谱、ESCA分析和SEM观测发现,等离子体处理后在原表面上形成的聚合物膜包含—CH_3、—CH_2、C=O和C—OH等基团,并且表面光滑、平整。     

氩等离子体后辉光区对聚四氟乙烯膜表面的优化改性

在理想管式反应器中, 采用Langmuir双电子探针和电子自旋共振(ESR)诊断技术分别定量测定了氩等离子体场中各活性物种的轴向分布, 并利用氩等离子体放电区及后辉光区对聚四氟乙烯(PTFE)进行了表面改性. 通过接触角测量、扫描电子显微镜和X 射线光电子能谱分析比较了改性前后常规及后辉光氩等离子体对PTFE表面结构及性能的影响. 结果表明, 氩等离子体中电子及离子浓度随轴向距离的增大迅速降低, 30 cm后接近于0, 而自由基浓度则降低缓慢, 40 cm处仍为初始浓度的96%. 氩等离子体放电功率、处理时间和气体流量强烈影响着PTFE表面润湿性的改善效果. 后辉光区因抑制电子和离子的刻蚀作用, 强化自由基反应, 使改性效果远优于常规氩等离子体. 经氩等离子体后辉光区短时间(30 s)处理后, PTFE表面化学成分发生了变化, F/C原子比从3.27降至2.30, O/C原子比从0.02增至0.09. 脱氟作用和含氧基团(如CO)的引入是有效改善PTFE表面润湿性的关键因素.     

辉光放电处理聚四氟乙烯：Ⅲ.PTFE表面结构的XPS表征

Yasuda等在用XPS研究离子体处理后的PTFE表面结构时,得到一个包络的C_(1s)峰。本文对此进行探讨。 PTFE膜先在蒸馏水中浸泡1小时,再用热异丙醇洗涤5分钟,然后用去离子水清洗三     

乙烯等离子体处理的云母表面结构及表面性质

用元素分析、色-质谱、裂解气相色谱和顺磁共振等方法研究了经乙烯等离子体处理的云母表面化学结构及处理过程。结果表明,云母颗粒表面形成了厚数十埃的等离子体聚乙烯膜,其化学结构与反应体系中无云母时得到的等离子体聚乙烯膜相同。通过扫描电镜观察到云母片表面的聚合膜具有规则的海星状花样,随处理时间的延长花样按比例长大。水与云母表面的接触角数据说明,乙烯等离子体处理使云母表面的疏水性提高到聚乙烯的水平,比氩气等离子体、硅烷偶联剂及钛酸酯偶联剂处理的效果均更为显著。     

通过等离子体表面处理提高聚乙炔稳定性

用等离子体方法对聚乙炔膜进行表面处理发现,其碘掺杂室温电导率与未处理的PA膜相当,但电导在空气中的稳定性及膜自身的抗氧化能力都有了较大提高。ESCA谱证实了在空气等离子体处理后的PA膜表面上接入了O和N原子。另外,IR光谱结果也表明,随着等离子体处理功率的增加,PA膜反式食量逐渐增加,顺式含量相应减少。     

XPS研究等离子体处理的聚苯乙烯表面结构

采用不同功率(10、20、60、100、150W)、时间(0.5、1、3、6、15和30分),在Ar、N_2、O_2、H_2和空气中,对聚苯乙烯(PS)片基进行了等离子体处理。 通过XPS技术、谱图的拟合、差谱分析和Ar~+小功率剖面处理,研究了PS表面组成与结构变化,指出处理的聚苯乙烯表面有C—O、C—NH_2、C=O、COOH和基团嵌入,因而改变了材料特性。     

聚丙烯微孔膜表面的空气等离子体处理

采用空气等离子体对聚丙烯微孔膜进行了处理，膜表面带有了氧元素，表面亲水性增强。微孔膜外表面改性程度较高，而孔内愈往深处改性程度愈弱。空气等离子体处理过的微孔膜力学性能下降。     

商品聚氯乙烯膜的等离子体表面处理改性的研究

利用辉光放电技术,将C_2H_2/CO_2/H_2的等离子体聚合物沉积处理聚氯乙烯商品膜表面进行改性。用红外光声光谱和扫描电子显微镜分析观察了等离子体改性的聚氯乙烯膜的结构和表面形态。测量了改性膜的水接触角,计算了它们的表面自由能,界面自由能以及表面功,从而研究了改性膜的亲水性。同时,利用热重分析仪(TGA)研究了改性膜的热稳定性。     

木粉/聚乙烯复合材料的等离子体表面处理——等离子体处理时间对复合材料表面特性的影响

为改善木粉/聚乙烯复合材料的表面粘接性,实现木粉/聚乙烯复合材料的无缝连接,利用低温等离子体处理技术,对木粉/聚乙烯复合材料进行了表面处理.采用接触角测试、傅立叶变换红外光谱分析(FTIR)以及X射线光电子能谱分析(XPS)研究了等离子体处理前后复合材料表面性能的变化.试验结果表明,经等离子体处理后,复合材料表面的接触角减小,表面润湿性得以改善;FTIR分析结果表明,经等离子体处理后,复合材料表面有—OH、—C=O和—O—C=O基团生成;XPS分析表明,经等离子体处理后,复合材料表面含氧基团的含量增加,在较短的时间内表面氧元素含量增加会达到平衡,且生成大量的—O—C=O基团。     

用低温等离子体处理方法改性高分子材料表面

综述了利用等离子体改性高分子材料表面的最新进展,其应用与机理。     

聚对苯二甲酸乙二酯的等离子体表面改性研究

阐述了等离子体原理,综述了等离子体对聚对苯二甲酸乙二酯表面改性的研究工作,大量的实验数据表明了这种方法可以成功改善各种性能。等离子体处理后PET材料表面粗糙度增加,并产生化学基团,因此可改善以下各种性能:润湿性、粘接性、染色性、抗静电性,对人体的生物相容性,添加TiO2的杀菌性,PET表面化学镀金属的性能。PET表面的刻蚀作用,导致其重量的减轻,可替代部分碱减量处理。     

空气等离子法处理超高分子量聚乙烯纤维

用空气等离子法对高分子量聚乙烯纤维进行了表面处理,利用1,1－二苯基,二－苦基肼检测纤维表面自由基的产生、变化,并用亚甲基蓝、XPS表面元素分析、SEM等方法了纤维表面性能处理前后的变化。实验发现通过等离子离子处理后,纤维复合材料的剪强度从未处理的5．98MPa提高到了18．1MPa。     

Underwater Oil Wettability on Nanostructured Superamphiphobic Surface Tuned by Trapped Air Layer Continuity

When the superamphiphobic meshes are immersed in water, the rough structures on steel wires are filled with air. The nanostructured superamphiphobic surfaces were prepared on the stainless-steel mesh. By adjusting the mesh size of the surface, the continuity of trapped air layer on the superamphiphobic surface underwater could be controlled. Then the underwater oil-wetting behavior on the prepared superamphiphobic mesh was investigated. The oil droplet spread out on the superamphiphobic surface without mesh and exhibited an oil contact angle of about 0° under water. But the oil contact angle formed on the superamphiphobic mesh surfaces and extended with increasing mesh size. We thought the discontinuity of trapped air layer on the surface and the entry of water into interval between the steel wires should be responsible for these behaviors.     

The Surface Modification of Pure Cellulose Paper Induced by Low-Pressure Nitrogen Plasma Treatment

We have used Time of Flight Secondary Ion Mass Spectroscopy (TOF-SIMS) in combination with X-ray photoelectron spectroscopy (XPS) to study chemical changes taking place at the surface of pure cellulose paper samples treated in N₂ plasma for periods of time up to 60 seconds. High resolution TOF-SIMS spectra permit the detection of various functionalities containing nitrogen, even following very brief (2s) plasma exposure. Correlations between chemistry and surface properties, such as water wettability, are presented and discussed.     

Plasma Surface Modification of Fluoropolymers Studied by ToF-SIMS

Surface modification by plasma treatment is an efficient way of improving metal adhesion to polymers. Here, Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is used to characterize the surfaces of Teflon PFA and Teflon AF1600 films, following plasma treatments in H₂, O₂ and N₂ gases. This work is complementary to our previous study using XPS, and is particularly directed toward the identification of incorporated hydrocarbons which could seriously affect metal adhesion. Plasma treatments strongly modify the surfaces of fluoropolymers, causing the ablation of a part of the fluorocarbon structure, with H₂ being the most effective gas. The hydrocarbon content of such surfaces is not negligible, and a comparison with hydrocarbon levels on untreated surfaces suggests that a substantial fraction of this material was incorporated on plasma treatment; this is particularly so in the case of H₂ plasma treatment. Due to expected strong matrix effects caused by significant changes in surface chemistry and structure following the various plasma treatments, the use of SIMS absolute intensity values is discussed in terms of data treatment artifacts. Moreover, due to the differences in secondary ion yields between characteristic hydrocarbon and fluorocarbon SIMS peaks, the use of peaks normalized to the total intensity is also impractical. Here, positive mode absolute intensities and negative mode peak intensity values, when normalized to I_tot - I(H^–) - I(F^–), give valuable information, as in the comparison of hydrocarbon and N incorporations.     

Development of Atmospheric Pressure Low Temperature Surface Discharge Plasma Torch and Application to Polypropylene Surface Treatment

We have finally succeeded in producing the plasma jet by use of the surface discharge plasma torch that can be expected to make larger the diameter of torch in the comparatively easy way. It can be checked that the active species in the jet obtained are different depending on the direction of connection, and also it was clearly found that much O and N₂ is included in them. Consequently, etching was confirmed at the position of 10 mm from the torch end in the surface treatment of polypropylene film, but etching was not confirmed at the position of 20 mm.     

Plasma Activation of Wood Surface by Diffuse Coplanar Surface Barrier Discharge

Radial cuts of Pedunculate oak (Quercus robur L.) heartwood was activated by Diffuse Coplanar Surface Barrier Discharge (DCSBD) plasma. The plasma treatment resulted in a considerable increase of free surface energy and in the substantial reduction of 50 μl water droplet uptake time. FTIR analysis confirmed the formation of additional polar functional groups on the wood surface due to the plasma treatment. This is consistent with the shift of wood surface pH level towards more acidic values. The energy efficiency of the DCSBD plasma treatment is better comparing to the known volume dielectric barrier discharge treatment method.     

Surface Modification of Nitrile Rubber by Plasma Polymerization

Radio frequency plasma polymerization of vinylidene fluoride was used to modify the surface properties of nitrile rubber. The chemistry and frictional properties of the plasma films were characterized. FTIR transmission spectra and EDX analysis of plasma polymer films deposited on NaCl windows showed that the degree of fluorination of the plasma polymers increased as plasma power was increased from 25 to 50 W, and then decreased monotonically at higher powers. An estimation of the actual F/C ratio from EDX data indicated that the plasma polymer films contained approximately one fluorine atom for every 2–5 carbon atoms. Sliding friction tests on a Delrin countersurface showed that the coefficient of friction of the plasma treated rubbers was lower than untreated rubber, but slighly higher than rubber coated with silicone oil. Repetitive sliding friction testing showed that silicone oil treated samples had a longer lubricating lifetime than plasma treated samples. However, cyclic friction tests conducted with nitrile rubber o-rings yielded similar frictional behavior and lubricating lifetimes for silicone oil and plasma treatments. There was no correlation between chemical composition and the frictional and wear properties of the plasma films. Environmental scanning electron micrographs showed that the plasma films were brittle and tended to crack and flake off during wear testing.     

A Plasma Surface Treatment of Polyester Textile Fabrics Used for Reinforcement of Car Tires

Polyester tire cord surfaces have been modified by plasma at low temperature and atmospheric pressure. The surface treatment has been executed by various nonequilibrium discharges, namely by barrier discharge, atmospheric pressure glow discharge and gliding arc. The polymeric multicord sewing threads treated by this procedure have been used in the same form as in industry, i.e., with the protecting oil films on their surface. The surface properties have been investigated by electron spin resonance spectroscopy and by measuring their contact angle with various liquids; partially the zeta potential measurements have been used, too. Further tests have been done at an industrial testing impregnation line using the common technology and conditions, on both plasma treated and untreated fibers. Finally, the standard H-tests and peel-tests have been used to characterize the fiber adhesion to usual testing rubbers.