铝酸酯偶联剂对高岭土表面改性研究

本文报告了ＤＬ－４１１－Ａ铝酸酯偶联剂为改性剂改性高岭土的方法与条件及其性质，并探讨了改性机理。     

Surface Modification of Polycarbonate by Ultraviolet Radiation and Ozone

The effect of ultraviolet (UV) radiation in the presence of ozone as a surface treatment for polycarbonate is examined in regards to changes in the wettability, adhesion, and surface mechanical properties. Standalone, 175-µm-thick films of a commercially available polycarbonate were exposed to UV radiation from sources of different power with various treatment times in the presence of supplemental ozone. Significant decreases in the water contact angle were observed after exposure to UV radiation in the presence of ozone. After several variations in the experimental setup, it was determined that the change in water contact angle is a function of the UV irradiance and the work of adhesion follows a master curve versus UV irradiance. Nanoindentation experiments revealed that the modulus of the top 500 nm of the surface is increased following UV exposure, attributable to surface cross-linking. Adhesion tests to the surface (conducted by a pneumatic adhesion tensile test instrument) showed little change as a function of UV exposure. Analysis of adhesion test failure surfaces with X-ray Photoelectron Spectroscopy (XPS) showed the locus of bond failure lay within the bulk polycarbonate and the measured bond strength is limited by the bulk properties of the polycarbonate and/or the creation of a weak boundary layer within the polymer.     

用微波等离子体改性氟树脂表面

我们发现了用微波炉产生的微波来很简单地进行等离子体处理的新方法。用这种方法处理了聚四氟乙烯(PTFE)和四氯乙烯-六氟丙烯共聚物(FEP)。为了评价等离子体处理了的高分子的润湿特性。用了苯二甲酸二烷酯(DAP)作接触角测定的标准液体。由DAP在聚丙烯上的接触角(θ)根据Fowkes方程求出了DAP的表面张力的色散力成分(γ_L~d)及极性成分(γ)。等离子体处理后,标准液体在 FEP和 PTFE上的cosθ增大,而且γ_L(1+cosθ)/(γ_L~d)~(1/2)与(γ_L~P)~(1/2)/(γ_L~d)~(1/2)之间成直线关系。等离子体处理后的FEP和PTFE的γ_3,γ_5~d,γ_s~P都有所增加。ESCA分析结果显示,经等离子体处理后,有相当量的氧导入了高分子表面。粘合到等离子体处理了的FEP和PTFF上的压敏胶带的剥离强度增加到未处理时的约2～3倍。     

聚乙烯醇—甲醛—脲三元共聚物的合成及掺混改性研究

研究了聚乙烯醇－甲醛－脲三元共聚物的合成及其与聚醋酸乙乳乳液掺混改性的工艺条件和产品性能。     

Super-Hydrophilicity of Stainless Steel Surface Induced by Heat Treatment with Gaseous Ozone

The hydrophilic states of stainless steel surface treated by the separate or combined use of gaseous ozone and heat were investigated by measuring the contact angle of a water droplet, the content of the surface carbon contaminants, and the adsorption isotherm of water vapor. Super-hydrophilic states of stainless steel plates were achieved only by the combined gaseous ozone/heat treatment. The contact angle of a water droplet on the plate decreased from 81° to less than 5° after treating at 120 to 180 °C under 2 vol% ambient gaseous ozone. It was found that the super-hydrophilization proceeded according to two different mechanisms. One is the decomposition of surface contaminants. There was a good correlation between the surface carbon content and the water contact angle over the range of 15 to 81°. The other is the once removal of surface hydroxyl groups followed by chemisorption of water on these dehydroxylated sites. As a result of the removal of contaminants and the rehydration, the total number of surface hydroxyl groups on stainless steel became larger than that on the original surface.     

超滤膜等离子体改性分离大豆蛋白的研究

分别用氧气和氩气等离子体对醋酸纤维素超滤膜进行表面改性,用大豆分离蛋白溶液进行超滤实验,结果表明等离子体处理后膜的接触角变小,亲水性能大大增强,超滤过程可以在保持截留率不变的情况下使膜的透水率增大2～3倍,同时膜的抗污染性能增强。研究发现在相同的等离子体反应条件下,氩气的处理效果优于氧气。