Restructuring-induced dewetting and re-entrant wetting of thin glassy films

¹ FOM-Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ, Amsterdam, The Netherlands
² Koç University, Chemistry Department, Çayir Cad. No: 5 Istinye 80860 Istanbul, Turkey
³ University of Amsterdam, Department of Chemical Engineering, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands

Received: 15 September 1998
Accepted: 29 October 1998

Abstract

Thin films of glass-forming liquid crystalline molecules on float glass substrates showed restructuring-induced dewetting in the film thickness range of 40–100 Å  upon increasing temperature after spin coating. This dewetting proceeded by the appearance of fluctuations at the free surface caused by restructuring taking place at the interface with the supporting substrate. Films thicker than 100 Å  did not dewet despite significant modulations of the free surface. The amplitude of surface fluctuations with respect to the film thickness is shown to determine the film thickness range for dewetting.