常压辉光放电等离子体对化纤及其它聚合物材料的表面处理研究进展

常压辉光放电等离子体(APGDP)具有不需要在低气压下运行、可实现连续生产、能产生大面积均匀放电且面功率密度合适等优点,其在化纤及其它聚合物的表面改性上有很好的应用前景,是近期等离子体应用研究中的一个热点。主要综述了APGDP对化纤及其它聚合物的表面处理,并扼要地介绍了APGDP对化纤及其它聚合物的等离子体聚合和等离子体引发的聚合或表面接枝,以及有关化纤染色性的研究。     

低温等离子体技术在高分子材料变性中的应用

<正> 低温等离子体,是以辉光放电、电晕放电或微波放电方式产生的电离气体,其中包含着大量的高能电子、离子、激发态原子等活性粒子,从而能引发种种化学反应。因为低温等离子体是非热平衡的,其气体温度远比电子温度低,通常略高于室温,这对于热敏感的有机高分子材料来说是非常适宜的。以往高分子材料表面改性大都借助于热     

高分子材料的等离子体表面改性

概述了低温等离子体技术在高分子材料表面改性方面的应用,主要包括以下三方面内容:在Ar、He、N_2、O_2、NH_3等气体辉光放电过程中对聚合物表面的等离子体处理;等离子体表面接枝;在聚合物表面淀积超薄等离子体聚合膜.并对这一技术的应用领域进行了介绍。     

非平衡等离子体合成氨研究综述

非平衡等离子体技术是一种能有效降低反应压力和温度的新型合成氨方法。综述了非平衡等离子体合成氨技术的研究历程,包括在低压下采用微波、射频或交、直流高压激发辉光放电和常压下采用介质阻挡放电产生非平衡等离子体进行合成氨研究。此外,针对目前国内外研究现状,对常压介质阻挡放电等离子体合成氨发展方向进行了展望。     

辉光放电等离子体处理有机废水研究进展

辉光放电是一种环境友好的、新兴的电化学高级氧化技术,等离子体是由电极与其周围的电解液产生直流辉光来维持。本文综述了辉光放电等离子体在生物难降解有机废水处理方面的实验装置、特点及机理,介绍了辉光放电等离子体技术的国内外研究现状,探讨了该技术在有机废水处理中存在的问题及其应用前景。     

介质阻挡放电在芳纶表面改性中的应用

综述了介质阻挡放电应用于芳纶表面改性研究的最新进展;介绍了介质阻挡放电的机理、特点以及国内主要的介质阻挡放电等离子体的设备;阐述了介质阻挡放电对芳纶亲水性能和粘结性能等表面性能的改善。指出芳纶等离子体表面改性的时间效应限制了其广泛应用,应进一步加强纤维表面等离子体改性的机理研究。     

染料废水等离子体处理技术的研究进展

综述了产生等离子体的方法,除高压脉冲放电法以及辉光放电法以外,还有电弧放电法,客观认为介质阻挡放电更具潜力。阐明了等离子体的本质,以及降解染料废水的原理和优缺点,简单介绍了各类方法的发展现状以及应用前景,同时在查阅国内外资料的基础上列举了相关实验实例。     

等离子体优化修饰技术在固定化酶载体材料中的应用进展

运用等离子体聚合或表面处理技术改变载体材料的表面性质,进而固定酶蛋白的方法主要有4类:等离子体表面处理、等离子体聚合、等离子体接枝共聚和等离子体化学气相沉积。综述了近年来用等离子体优化修饰技术处理载体材料进行固定化酶研究的新进展,指出今后应加强等离子体体系表面改性规律及机理、等离子体单体气体种类、放电条件及底衬材料等方面的研究。     

低温等离子体法直接分解硫化氢制氢的研究进展

总结了包括电晕放电、辉光放电、滑动弧光放电、微波等离子体、射频等离子体及介质阻挡在内的多种放电形式在分解硫化氢领域的研究现状.当前低温等离子体技术应用于硫化氢分解的研究仍停留于实验室阶段,实现工业应用仍有很多理论及工程问题有待解决.提高硫化氢转化率,降低产氢能耗将是该技术走向工业化和实用化的研究重点和方向.     

溶液中辉光放电等离子体化学反应研究

分析了溶液中辉光放电等离子体过程中水分子在等离子体层、等离子体-溶液界面和主体溶液中的反应历程;介绍了水溶液体系中辉光放电等离子体电解引发的等离子体合成反应和高级氧化反应;对有机溶剂体系中的辉光放电等离子体电解反应进行了介绍.实验表明甲醇溶液辉光放电等离子体电解主要产物是氢气,还有少量一氧化碳、甲烷、乙烷、丙烷、1,3,5-三(口恶)烷和水等,气相产物中氢气摩尔分数在86%以上.根据甲醇溶液中GDE过程中得到的产物分析,提出了甲醇分解的可能反应历程.     

Effect of electrodeless glow discharge on polymers

The effects of gas plasma generated by electrodeless (inductive coupling) glow discharge on polymers were investigated as functions of gas pressure, discharge power, exposure time, and type of plasma gas. A remarkable similarity between the plasma susceptibilities of low molecular weight organic compounds and polymers was observed; i.e., polymers which have ether, carbonyl, ester, or carboxylic acid attached to a nonaromatic structure are very susceptible to plasma. The weight loss was proportional to the exposure time and exposed area. The discharge power and type of gas were found to have a great influence on both the rate of weight loss and the morphology of the exposed surface. The predominant effect of plasma on polymers was found to be degradation (manifested by weight loss). The crosslinking effect was found to be marginal with many polymers; however, significant crosslinking was observed with double bond-containing polymers. The crosslinking was examined by swelling the treated films. With copolymers of styrene–butadiene, 4-vinylpyridine–butadiene, methacrylic acid-butadiene, and acrylic acid–butadiene, the crosslinking was greatly dependent on the discharge power, the butadiene content of the copolymers, and the exposure time. Both degradation and crosslinking by gas plasma were generally limited to the exposed surface; however, the propagation of crosslinking in the direction of thickness was observed with copolymers of styrene–butadiene. The plasma of organic vapor also cause degradation of plasma-susceptible polymers, particularly at high wattage, although the deposition of polymer occurs simultaneously.     

The initiation of in situ polymerization of vinyl monomers in polyester by glow discharge

Glow discharge initiation of in situ polymerization of acrylic acid and other vinyl monomers incorporated in PET films was investigatigated. The influence of glow discharge conditions such as the gas used, plasma power, discharge current, and plasma treatment time on polymerization yield was determined. Though glow discharge effects are limited to the film surface, in situ polymerization of the vinyl monomers took place and the vinyl polymer could be found all through the film cross section. At short plasma treatment time only surface modification took place, while at longer treatment time bulk modification occurred, too. Good polymerization yields were obtained. Gel effect behavior was observed. Mechanical properties of the modified PET film were not changed, while the contact angle with water improved when polar vinyl monomers were used.     

Dielectric barrier discharge plasma induced surface modification of polyester/cotton blended fabrics to impart water repellency using HMDSO

Continuous treatment of polyester/cotton blended fabric samples was carried with hexamethyldisiloxane (HMDSO) plasma on the pilot scale atmospheric pressure plasma reactor. The mixture of helium and argon was used as carrier gas for generating dielectric barrier discharge plasma. The effect of discharge power and treatment time on the water repellent properties of samples were evaluated with contact angle (CA) and spray test measurements. Spray test and CA results showed improved resistance to wetting with water. The effect of discharge conditions on the surface morphology and surface chemistry of plasma treated samples were investigated by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopic analysis, respectively. The presence of Si‐O‐Si and Si‐CH₃ groups in the structure of plasma polymer deposited at the surface of P/C samples was revealed by FTIR spectroscopy. Further, structural differences in HMDSO plasma polymer deposited under different discharge conditions were reported with reference to organic/inorganic nature of plasma polymer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Adhesion between polymer substrates and plasma films from tetramethylsilane and tetramethyltin by glow discharge polymerization

Adhesion between various polymer substrates and plasma films, which had been prepared from either tetramethylsilane or tetramethyltin by glow discharge polymerization and deposited on the surface of the polymer, was evaluated by the Scotch tape test and by lap-shear strength. It was found that the plasma films exhibited fairly good adhesion to the polymer substrates (with the exception of polypropylene). The position where failure occurred was determined by X-ray fluorescence analysis, scanning electron microscopy and energy diffractive X-ray analysis. This position was at an inner layer of the plasma film (cohesive failure of plasma film), within the polymer substrate (material failure of polymer) or at the interface between polymer substrate and plasma film (adhesive failure) depending upon the polymer substrate. These results indicate an important aspect of durability of surface modification by glow discharge polymerization.     

聚酰亚胺膜气体渗透性的改性进展

聚酰亚胺分离膜(PI)是由芳香二酐和二胺单体缩聚而成的,它是主链含有酰亚胺环的一类高聚物。因其具有良好的气体分离性能、热稳定性、耐溶剂性等特性而受到人们的广泛关注。但是,其气体渗透-选择性的平衡问题限制了其在气体分离领域的广泛应用。因此,研究者们将目光转向了聚酰亚胺膜气体渗透性的改性方面,使其具有良好的气体渗透性,用于混合气体的高效分离。文章综述了近年来研究者对聚酰亚胺气体渗透性的研究进展,详细介绍了共混改性、交联改性和分子结构改性方面的最新研究成果,并总结展望了聚酰亚胺膜今后的研究趋势。为未来高效分离膜的研发提供了参考。     

A Downer Reactor for Short‐time Plasma Surface Modification of Polymer Powders

This paper introduces a plasma reactor for short‐time plasma surface modification of polymer powders. This reactor type, the so‐called plasma downer reactor (PDR), provides a high reaction rate, which is forced by the high gas velocity and high particle dispersion in the plasma. It combines the advantageous characteristics of the downer principle for the fluid dynamics of gas‐solid phases with plasma surface modification. This work demonstrates that a very short plasma exposure time of 0.1 s effectively improves the wettability of HDPE and Co‐PA powders. The water contact angles of HDPE and Co‐PA powder can be reduced to 72° and 76°, respectively. The surface tensions of both polymer powders could be increased by a factor of 2 up to 43 mN/m. Water/polymer suspensions and pastes can be made without tensides.     

Argon low‐temperature plasma modification of chopped aramid fiber and its effect on paper performance of aramid sheets

Chopped aramid fiber was modified by an argon low‐temperature plasma treatment to enhance the interfacial strength of aramid paper. The water contact angle of the aramid fiber and the tensile strength, tearing strength, and evenness of the aramid sheets were investigated under different conditions, and the parameters of the argon low‐temperature plasma modification, like gas pressure, discharge power, and discharge time, were optimized. The chemical structure and surface morphology of the fiber after plasma modification were characterized by X‐ray photoelectron spectroscopy, atomic force microscopy, and scanning electron microscopy. The strengthening mechanism of aramid paper by low‐temperature plasma modification was also studied. It was found that the argon low‐temperature plasma treatment introduced some new polar groups onto the fiber surface and increased the fiber surface wettability and roughness. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45215.     

Study on the gas permeabilities in styrene-butadiene rubber by molecular dynamics simulation

In this research, molecular dynamics (MD) simulations were used to study the transport properties of small gas molecules in the butadiene-styrene copolymer (SBR). The condensed-phase optimized molecular potentials for atomistic simulation studies (COMPASS) force field was applied. The diffusion coefficients were obtained from MD (NVT ensemble) and the relationship between gas permeability; the chemical structure and free volume of butadiene-styrene copolymer were investigated. The results indicated that the diffusion coefficient of oxygen declined with increasing styrene content. The fraction of free volume (FFV) in butadiene-styrene copolymer was calculated. It was concluded that diffusion coefficient increased as the FFV increases, which is in accordance with the analysis of the small molecular hop through the free volume in polymer matrix. Subsequently, the glass transition temperatures of these copolymers were calculated by MD. The result showed that the glass transition temperature increased with increasing styrene content in polymer.     

Study on the gas permeabilities in styrene-butadiene rubber by molecular dynamics simulation

In this research, molecular dynamics (MD)simulations were used to study the transport properties of small gas molecules in the butadiene-styrene copolymer(SBR). The condensed-phase optimized molecular potentials for atomistic simulation studies (COMPASS) force field was applied. The diffusion coefficients were obtained from MD (NVT ensemble) and the relationship between gas permeability; the chemical structure and free volume of butadiene-styrene copolymer were investigated. The results indicated that the diffusion coefficient of oxygen declined with increasing styrene content. The fraction of free volume (FFV) in butadiene-styrene copolymer was calculated. It was concluded that diffusion coefficient increased as the FFV increases, which is in accordance with the analysis of the small molecular hop through the free volume in polymer matrix. Subsequently, the glass transition temperatures of these copolymers were calculated by MD. The result showed that the glass transition temperature increased with increasing styrene content in polymer.