聚乙烯吡咯烷酮纳米薄膜非平衡行为的研究

Study on Non-equilibrium Behavior of Polyvinylpyrrolidone Nano Films

通过旋涂法制备了聚乙烯吡咯烷酮(PVP)纳米薄膜(厚度h<100 nm),利用饱和水气诱导PVP纳米薄膜发生去润湿现象,通过观察薄膜中孔洞生长过程和形态研究薄膜中存在的非平衡态现象。我们发现在室温条件下,薄膜中孔洞的生长速率随退火时间的增加不断减慢,直至不随时间变化。这表明新制的纳米薄膜处于非平衡态,存在着一定的残余应力,室温条件下退火可使薄膜趋于平衡。

Metastable polyvinylpyrrolidone(PVP) nano films(h<100 nm) were prepared by spin coating. In order to explore the non-equilibrium behavior of the PVP nano film, water vapor was used to induce dewetting of the films and the mechanism of the hole nucleation and growth was studied. The results showed that with increasing of annealing time at ambient condition, growth rate of holes in the film was continuously reduced to an equilibrium value. It demonstrated that certain amount of residual stress existed in the new prepared nano films, which was released during annealing.