RUPTURING OF POLYMER FILMS WITH RUBBING-INDUCED SURFACE DEFECTS  

作　　者：B.Du F.C.Xie Y.J.Wang O.K.C.Tsui O.K.C.Tsui 

机构地区：[1]InstituteofNanoScienceandTechnologyandPhysicsDepartment,HongKongUniversityofScienceandTechnology,ClearWaterBay,Kowloon,HongKong [2]InvitedlecturepresentedattheInternationalSymposiumonPolymerPhysics,2002,Qingdao,ChinaReceivedJuly9，2002

出　　处：《Chinese Journal of Polymer Science》2003年第2期123-128,共6页高分子科学（英文版）

基　　金：This work was supported by the Institute of Nano Science and Technology and the Hong Kong University of Science and Technology through the Postdoctoral Matching Fund.

摘　　要：It has been a long-standing question whether dewetting of polymer film from non-wettable substrate surfaceswherein the bicontinuous morphology never forms in the dewetting film is due to spinodal instability or heterogeneousnucleation. In this experiment, we use a simple method to make the distinction through introduction of topographical defectsof the films by rubbing the sample surface with a rayon cloth. Spinodal dewetting is identified for those films that dewet by acharateristic wavevector, q, independent of the density of rubbing-induced defects. Heterogeneous nucleation, on the otherhand, is identified for those with q increasing with increasing density of defects. Our result shows that PS films on oxidecoated silicon with thickness less than ≈ 13 nm are dominated by spinodal dewetting, but the thicker films are dominated bynucleation dewetting. We also confirm that spinodal dewetting does not necessarily lead to a bicontinuous morphology in thedewetting film, contrary to the classic theory of Cahn.It has been a long-standing question whether dewetting of polymer film from non-wettable substrate surfaceswherein the bicontinuous morphology never forms in the dewetting film is due to spinodal instability or heterogeneousnucleation. In this experiment, we use a simple method to make the distinction through introduction of topographical defectsof the films by rubbing the sample surface with a rayon cloth. Spinodal dewetting is identified for those films that dewet by acharateristic wavevector, q, independent of the density of rubbing-induced defects. Heterogeneous nucleation, on the otherhand, is identified for those with q increasing with increasing density of defects. Our result shows that PS films on oxidecoated silicon with thickness less than ≈ 13 nm are dominated by spinodal dewetting, but the thicker films are dominated bynucleation dewetting. We also confirm that spinodal dewetting does not necessarily lead to a bicontinuous morphology in thedewetting film, contrary to the classic theory of Cahn.

关 键 词：DEWETTING Polymer thin films Spinodal instability Heterogeneous nucleation 

分 类 号：O631[理学—高分子化学] O484[理学—化学]