高分子量聚合物对溶剂诱导低分子量聚合物薄膜去润湿动力学的影响

采用偏光显微镜及椭偏仪等研究了单分散低分子量聚苯乙烯(PS)薄膜、 单分散高分子量PS薄膜以及将二者按不同质量比共混制备的PS薄膜, 在室温下用丙酮溶剂诱导其去润湿的过程. 实验发现, 按不同质量比共混的PS薄膜的去润湿动力学与单分散的PS薄膜去润湿动力学有较大区别. 按不同质量比共混的PS薄膜, 低分子量的PS更易于富集在薄膜的表面, 其去润湿的速度介于单分散低分子量PS薄膜与单分散高分子量PS薄膜的去润湿速度之间. 但共混薄膜的去润湿速率并非随着高分子量PS的加入呈现单调的变化, 这是由大量接触分子的形成抑制了去润湿所致.

Influence of the Polymer with High Molecular Weight on the Solvent-induced Dewetting Dynamics of the Polymer Thin Film with Low Molecular Weight†

The dewetting dynamics of the polystyrene(PS) thin film induced by the solvent of acetone with the method of optical microscopy(OM) and Ellipsometer were investigated. We compared the dewetting dynamics of the monodiperse PS with low molecular weight(PSL), that with high molecular weight(PSH) and the mixture of the PSL and PSH(PSM). It was observed that their dewetting behavior was different although the radius of the holes vs. time exhibited exponential behavior for all samples. As for monodiperse PS, there is the difference in rim morphologies because of the viscosity difference between the PSL and the PSH. As for the PSM, the anomaly of the deweting velocity with the addition of PSH happens due to effect of the chain connectors which were partially in the entangle polymer film and partially in the top film.