原位测量聚苯乙烯薄膜在溶剂气氛下的动态变化过程

In-Situ Measurements for Dynamic Process of the PS Film in Solvent Atmosphere

采用旋涂法制得聚苯乙烯(PS)薄膜样品,在四氢呋喃(THF)溶剂饱和气氛下,通过原位椭偏仪和光学显微镜同步联用的方法观测了2种不同相对分子质量的薄膜体系,当初始薄膜厚度不同时所发生的从溶胀到去润湿的动态全过程。结果表明,在溶剂气氛环境中聚苯乙烯薄膜的动力学变化过程可以从溶胀厚度的变化和去润湿发生的时间及程度反映出来。这个过程的变化不仅与薄膜的初始厚度相关,还受相对分子质量的影响,并且这两方面的作用是相互交叉在一起的。溶胀厚度的变化可以预测出去润湿的可能状况,同样去润湿的过程可以验证溶胀厚度所反映的动力学变化的快慢。证实了联用2种测试手段观测和分析薄膜从溶胀到去润湿全过程的可行性和有效性。

Thin polystyrene （PS） films were prepared onto silicon wafer by spin coating method. The films were subjected to a tetrahydrofuran （THF） solvent atmosphere at its saturated pressure where swelling and dewetting of the film occurred. Such swelling and dewetting processes of PS films with different initial thickness and molecular weight were investigated in situ via a combination of ellipsometer and optical microscope measurements. The results show that the dynamic process can be characterized by the evolution behavior of swollen thickness and dewetting morphology. The dynamic process is influenced by both molecule weights of the polymer and initial thickness of films. The evolution behavior of film swollen thickness can predict the possible dewetting situation subsequently, and the dewetting process can verify the consistence between the tendency of film swollen thickness and dynamics process. All results demonstrate the feasibility and effectiveness of this combined measuring method.