Surface Modification and Characterization of Dichloromethane Plasma Treated Polypropylene Film

Surface of polypropylene (PP) film was modified in plasma of dichloromethane (CH₂Cl₂). The nature of surface modifications and formation of cross-linked layer due to plasma polymerization was studied by surface energy measurements and solubility test. Surface modification achieved by CH₂Cl₂ plasma was compared with the reported work on chloroform (CHCl₃) and carbontetrachloride (CCl₄) plasma modifications. Modified surface characterized by ATR-FTIR technique indicated formation of saturated and unsaturated cross-linked product. On the basis of relative intensity change of the specific bands, the site of attachment of chlorine on PP surface was investigated. Adhesive strength of modified film was measured by T-peel test method. Stability of modified surface was studied by measuring surface energy and peel strength after two months.     

Adhesion Aspects of Plasma Polymerized Acetonitrile and Acrylonitrile on Polypropylene Surface

Acetonitrile and acrylonitrile were plasma polymerized on Polypropylene (PP) surface. Surface modifications were characterized by surface energy measurements and ATR-FTIR spectroscopy. Surface energy measurement showed incorporation of hydrophilic groups along with deposition of cross-linked network of plasma-polymerized product. ATR-FTIR analysis of modified films showed incorporation of conjugated imine and amine groups. Using change in the relative intensities of C—H stretch bands of polypropylene surface, site of attachment of hydrophilic group and most predominant surface chemical reaction could be inferred. Chemical nature of plasma polymerized product was studied using FTIR by KBr disc method. Adhesion test was performed on modified surface by peel test method. Surface energy and peel strength measurements were performed for the samples aged for 2 months in order to check the durability of surface modification.     

Integral Isobaric Heats of Vaporization of Methanol + 1,2-Dichloroethane, + 1,1,1-Trichloroethane Mixtures

Abstract

A modified form of Dana's apparatus is employed to measure the integral isobaric heats of vaporization of methanol-1,2-dichloroethane and methanol-1,1,1-trichloroethane mixtures at 720 mm Hg. The results are in good agreement with the values calculated from Gambill's equation.     

等离子体聚合四丁基锡薄膜的制备和结构

研究了Ａｒ和Ａｒ／Ｏ＿２混合气携带四丁基锡的等离子体聚合规律和膜的组成、结构，分别得到低碳氢含量的金属Ｓｎ和ＳｎＯ＿ｘ共混膜。     

Characterization of Polypropylene Surface Treated in a CO2 Plasma

The polypropylene modification in CO₂ plasma mainly contributes to degradation, functionalization, and cross-linking. The degradation, whose rate is depending on CO₂ dissociation and oxygen atom formation, is a quite slow reaction and it is associated with surface topography alteration, especially of the amorphous phase of the polypropylene. The surface roughness increases with the treatment duration and the amorphous phase is more degraded than the crystallized part. The functionalization, corresponding to an increase of the surface energy (57.3 mJ m ^{– 2} in 30 s), and to an oxidation (23 oxygen at.%) with the appearance of alcohol, ketone, and acid functions is a much faster phenomenon. Cross-linking takes also place during this type of treatment and will reinforce the stability of the modified surface.     

Thermophysical Properties of the Ternary System 2-Methoxyethanol + Acetonitrile + 1,2-Dichloroethane, and the Binary Systems at 25°C

Excess molar volumes, change of refractive indexes, and deviation of dynamic viscosity of the 2-methoxyethanol + acetonitrile, 2-methoxyethanol + 1,2-dichloroethane, and acetonitrile + 1,2-dichloroethane binary systems and the excess molar volumes of 2-methoxyethanol + acetonitrile + 1,2-dichloroethane ternary system have been determined at 25°C and at atmospheric pressure, by measuring densities, refractive indexes, and viscosities over the entire range of composition. These derived data of binary and ternary mixtures were fitted to Redlich–Kister and Cibulka equations, respectively. An estimation of excess volumes is also evaluated using a modified Heller equation, which depends on the refractive indexes of the mixture. A comparison of the predictions by different methods with the experimental values of the physical properties has been made.     

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.     

氯喹药物在水／1,2—二氯乙烷界面上的传输机理研究

用滴电解液电极(EDE)极谱法、电流环扫伏安法和计时电位法研究了水相中氯喹离子、有机相中非离子化氯喹及以缔合物形式存在的氯喹在水/1,2-二氯乙烷界面上的传输过程.探讨了水相pH、氯喹浓度、EDE速度和扫描速度对传输行为的影响.提出了相应的传输机理.     

正丁胺的等离子体聚合膜性质及氢离子响应功能研究

以正丁胺为单体，采用等离子体聚合法，在盖玻片与玻璃碳及一些金属基片上得到附着性和稳定性均良好的聚合膜，红外光谱，元素分析结果和膜性质研究表明，该聚合具膜具有高度支化，交联的结构，具有良好的耐热和耐腐蚀性，以该膜为敏感材料制成的电位型化学传感器在强酸性溶液中对Ｈ＾＋离子具有超能斯特响应，且稳定性和重现性较好。     

NafionTM膜表面改性用等离子体聚合方法提高膜的阳离子选择性

采用辉光放电等离子体聚合方法 ,以 C2 H4 和 NH3 为单体 ,在 Nafion TM膜表面沉积一层含氨基及酰氨基的类聚乙烯阴离子交换膜 ,提高了 Nafion TM膜对阳离子的选择性 ,同时不显著增加膜电阻 .由 SEM确定该等离子体聚合膜厚约 0 .5μm,用红外光谱及 X光电子能谱表征膜结构 .采用四电极法测量膜电阻 ,膜对质子的选择性由 Cu2 + 的迁移数 t Cu表征 ,用二室隔膜装置 (0 .2 5mol/L Cu Cl2 -0 .5mol/L HCl|等离子体处理膜 |1 mol/L HCl)测量 t Cu. O2 等离子体预处理 Nafion TM膜有利于沉积膜在 Nafion TM膜上的沉积并与 Nafion TM膜紧密结合 .经改性后的 Nafion TM膜电阻值仍然很小 ,在 1 mol/L HCl溶液中电阻小于 0 .5Ω· cm2     

Excitation Frequency Dependence of the Surface Properties and Composition of Plasma Polymers from Aldehyde Monomers

The effect was investigated of varying the plasma excitation frequency in the range 125 to 375 kHz upon the air/water contact angles of plasma polymers prepared from the monomers ethylbutyraldehyde (EBA), acetaldehyde (AA), capronaldehyde (CA), and nonyl aldehyde (NA). The surfaces of EBA, CA, and AA plasma films were more hydrophilic when deposited at lower excitation frequencies whereas little frequency dependence was observed in the case of NA plasma polymers. Lower contact angles correlated with increased amounts of C=O and O–C=O groups measured by FTIR and XPS analyses. The effects of storage (aging) in air at room temperature upon the properties of the plasma polymers were also studied. Contact angles of EBA plasma polymers decreased during aging. The contact angles of NA plasma polymers were stable over a 3 months storage period. In the case of CA plasma polymers, the contact angles decreased on aging for films deposited at higher frequencies, whereas CA films deposited at lower frequencies showed increasing contact angles on storage. This aging behavior is interpreted as a result of competition between post-deposition oxidative reactions with atmospheric oxygen and reorientation of polar polymer segments away from the air interface.     

Dielectric Relaxation Study of Chloro Group with Associative Liquids. II. 1,2-Dichloroethane with Methanol, Ethanol, and 1-Propanol

Frequency spectra of the complex permittivity for 1,2-dichloroethane–alcohol binary mixtures have been determined over the frequency range 10 MHz to 20 GHz at 15, 25, 35, and 45°C, using the time-domain reflectometry (TDR) technique, for 11 compositions of each 1,2 dichloroethane–alcohol system. The alcohols used in the study were methanol, ethanol, and 1-propanol. The relaxation in these systems can be described by a single relaxation time using the Debye model. The static dielectric constant, relaxation time, the corresponding excess dielectric properties, Kirkwood correlation factor, and Bruggeman factor of the mixtures have been determined. The static dielectric constants for the mixtures have been fitted with the modified Bruggeman model.     

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。     

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.     

Micro-Scale Cell Patterning on Nonfouling Plasma Polymerized Tetraglyme Coatings by Protein Microcontact Printing

Nonfouling thin films were prepared by the plasma deposition of tetraethylene glycol dimethyl ether (pp4G) on fluorinated ethylene propylene polymer (FEP) and glass substrates. Ordered cell patterns were created on these surfaces by microcontact printing of proteins. Pp4G was found to be stable in aqueous environments and resistant to an ethanol sterilization procedure, as verified by surface analysis. Pp4G also reduced nonspecific protein adsorption by more than 65-fold before and after sterilization. Despite the low adsorption of proteins to pp4G in solution, protein microcontact printing was achieved and we were able to print laminin, an adhesive extracellular matrix protein, from an elastomeric stamp onto pp4G. The printed laminin supported the attachment and spreading of cardiomyocytes and the nonprinted pp4G regions remained cell repulsive in culture conditions. Microscale patterns of cardiomyocytes were maintained on printed pp4G for more than 7 days. This cell patterning process should be viable for other cell types. The potential applications include tissue engineering and microdevices for biosensor, diagnostic, and pharmacological applications.     

成骨细胞在表面酰胺化聚乳酸膜上的黏附和增殖行为

利用紫外光接枝聚合丙烯酰胺(Acrylic amide, AAm)获得表面酰胺化的聚乳酸(PLA)膜, 并考察了成骨细胞在酰胺化表面的黏附和增殖行为. 结果表明, 酰胺基的引入改善了PLA膜的表面亲水性, 其表面水接触角由78°减少到56°, 自由能由42.7 mJ/m²增大到51.4 mJ/m²; 与对照组相比, 成骨细胞在改性表面培养3 d后有大量的丝状伪足伸出, 并且较快地进入了细胞分裂期, 表明PLA膜表面的酰胺化能够促进细胞的黏附和增殖.     

Anode Magnetron Enhanced DC Glow Discharge Processes for Plasma Surface Cleaning and Polymerization

The objective of this study was to examine some fundamental factors involved in the design and construction of the anode magnetron dc glow discharge processes as well as its performance in plasma cleaning and polymerization. Those advantages of anode magnetron include the capability of the magnetron to operate at low pressure, as well as decreasing the thickness of cathode dark space, i.e., the negative glow which contains a higher concentration of ions and active species was more closely to the cathode surface, which makes the plasma surface cleaning and polymerization an effective and uniform processes. The deposition rate at a given discharge power is increased by the presence of anode magnetrons, and is also much higher relative to rf and af. The refractive index of dc plasma film at a given polymer thickness (such as TMS, 70 nm, RI: 2.4) is higher than rf, af, and cascade arc plasma (RI: 1.6–1.7).     

那可汀在水／1，2－二氯乙烷微界面转移的机理研究及分析测定

本文用循环伏安法研究质子化那可汀在水／１，２－二氯乙烷微界面的转移机制，计算了与界面转移有关参数，并且研究了那可汀的界面电位响应，将那可汀液／液界面微电极用于测定人尿中那可汀含量，回收率为９２％～１０６％，检测下限为３×１０－５ｍｏｌ／Ｌ。     

骨髓基质干细胞在等离子体处理PEGDA基凝胶表面的黏附和增殖

通过低温等离子体技术对聚乙二醇双丙烯酸酯(PEGDA)/甲基丙烯酸β-羟乙酯(HEMA)共聚物水凝胶生物材料进行表面改性,以骨髓基质干细胞(BMSc)为细胞模型,考察了细胞在等离子体表面改性前后的水凝胶材料的黏附和增值行为,材料的表面性能通过 X 射线光电子能谱、接触角和扫描电镜进行表征.研究结果表明,材料表面经氩等离...     

利用等离子体技术研究聚苯乙烯表面的接枝聚合反应

用O₂等离子体对聚苯乙烯(PS)进行预处理, 再用Ar等离子体引发N-乙烯基吡咯烷酮(NVP)在其表面接枝聚合. 通过接触角(CA)及表面自由能(SE)分析, 探讨了O₂等离子体预处理条件对PS表面自由能的影响, 确定了预处理的最佳条件. 通过衰减全反射红外光谱(ATR-FTIR)、X射线光电子能谱(XPS)和动态接触角(DCA)分析, 比较了O₂等离子体预处理前后和接枝聚合前后PS的表面组成及表面性能, 实验结果表明, 利用等离子体技术能成功地将NVP接枝聚合于PS表面, 接枝聚合后的PS表面由于极性高分子链和粗糙度的增加, 亲水性增强, 水滴易在其表面铺展. 由于接枝聚合后PS表面的高分子链在水中发生重构, 使后退角降低幅度较大, 接触角滞后现象明显.