Effects of solvent vapor annealing duration on the dewetting of two kinds of spin-coated bilayer films of polystyrene-block-poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) (PS-b-PMMA/SAN, upper/lower) and SAN/PS-b-PMMA were mainly studied by atomic force microscopy and contact angle measurement technique. In the PS-b-PMMA/SAN bilayer film, the continuous upper film first appears holes and then ruptures into droplets which fuse and break periodically, which is different from the single increase and decrease evolution in the spin-coated PS-b-PMMA monolayer film. The periodic droplet evolution is due to the preferred affinity with acetone to PMMA blocks and the change of the film surface energy. The droplet diameters are smaller than those in our previous PS-b-PMMA monolayer films. This illustrates that the interactions between PS blocks of PS-b-PMMA layer and styrene segments of SAN layer are stronger than those between PMMA blocks of monolayer film and the substrate. In the SAN/PS-b-PMMA bilayer film, on the other hand, the SAN upper layer does not form the continuous film during the spin-coating process and occurs microphase separation due to the surface energy difference of AN and styrene segments and their thermodynamic incompatibility. The dewetting behavior occurs in the bilayer films induced by acetone vapor, and the droplet sizes are not uniform.

溶剂蒸汽退火时间对聚苯乙烯-嵌段-聚甲基丙烯酸甲酯/聚苯乙烯-共聚-丙烯腈两种旋涂双层膜去润湿的影响(PS- b -PMMA/SAN, upper/lower)和SAN/PS- b - PMMA主要通过原子力显微镜和接触角测量技术进行了研究。在PS- b - PMMA/SAN双层薄膜中，连续的上层薄膜首先出现孔洞，然后破裂成液滴，液滴周期性地融合和破裂，这与旋涂PS- b中的单一增加和减少演变不同-PMMA单层膜。周期性液滴演变是由于丙酮对 PMMA 块的优先亲和力以及薄膜表面能的变化。液滴直径小于我们之前的 PS- b - PMMA 单层膜。这说明 PS- b -PMMA 层的 PS 块与SAN 层的苯乙烯段之间的相互作用强于单层膜的 PMMA 块与基材之间的相互作用。在 SAN/PS- b-PMMA 双层膜，另一方面，SAN 上层在旋涂过程中不形成连续膜，并且由于 AN 和苯乙烯链段的表面能差异及其热力学不相容性而发生微相分离。丙酮蒸气诱导的双层膜发生去湿行为，液滴尺寸不均匀。