不同气氛低气压电容耦合放电等离子体对聚甲基丙烯酸甲酯表面的改性

利用低气压电容耦合放电等离子体对聚甲基丙烯酸甲酯(PMMA)表面进行亲水改性,对比分析了Ar、N₂、Air和O₂四种等离子体放电气体和不同放电功率对其表面的影响。采用静态接触角、原子力显微镜、X射线光电子能谱分别对PMMA表面亲水性、粗糙程度以及元素和官能团的组成进行了表征。以牛血清蛋白作为标准蛋白,检测处理后PMMA表面蛋白吸附量。结果表明,经等离子体处理后的PMMA表面亲水性和抗蛋白性能均有不同程度的改善,其中Ar等离子体主要起刻蚀的作用,N₂、Air和O₂等离子体在对PMMA刻蚀的同时,接枝的官能团对其表面性能的改变起到主导作用。当等离子体放电功率较低时,增加功率可以显著提高表面亲水性,且亲水性能的提高带动抗蛋白性能的增强。

Surface Modification of Polymethyl Methacrylate by Capacitive-Coupled Plasmas

Surfaces of polymethyl methacrylate (PMMA) plate, an artificial biomedical material, were modified with low pressure RF capacitive-coupled plasma.The influence of the plasma power and gas-type on the surface properties, including the wettability, functional groups and protein absorption resistance, was investigated with atomic force microscopy, X-ray photoelectron spectroscopy and water contact angle measurement.The results show that the plasma power and gas-type had a major impact.For instance, while etching the surface, N₂, air and O₂ plasma produced quite a few grafting functional groups.An increase of the power in lower range significantly improved the wettability and protein adsorption resistance of PMMA surfaces.As the power increased, the adsorption capacity of bovine serum protein decreased, and the two variables followed a descending order:Ar>N₂>Air>O₂.Possible mechanisms were also tentatively discussed.