10.1021/acs.langmuir.9b00923.s001 Yueyue Qi Yueyue Qi Haimi Nguyen Haimi Nguyen Kelly Sin Ee Lim Kelly Sin Ee Lim Wenyun Wang Wenyun Wang Wei Chen Wei Chen Adsorptive Spin Coating To Study Thin-Film Stability in Both Wetting and Nonwetting Regimes American Chemical Society 2019 exhibit dewetted fractal morphologies Stepwise dewetting dynamics thin-film fabrication method PVOH films Adsorptive Spin Coating adsorptive spin-coating method 2 kDa PDMS substrate dip coating adsorption Study Thin-Film Stability 2019-05-13 15:33:36 Media https://acs.figshare.com/articles/media/Adsorptive_Spin_Coating_To_Study_Thin-Film_Stability_in_Both_Wetting_and_Nonwetting_Regimes/8118929 A new thin-film fabrication method, adsorptive spin coating, was evaluated in the preparation of poly­(vinyl alcohol) (PVOH) thin films on silicon-wafer-supported poly­(dimethylsiloxane) (PDMS) substrates. This method takes advantage of the rapid spontaneous adsorption of PVOH at the substrate–solution interface during the brief contact period and the directionality of drying during spinning. Similar to the results obtained using dip coating, the PVOH thin films wet the 2 kDa PDMS substrate and exhibit dewetted fractal morphologies on thicker PDMS substrates. This method generated PVOH films with thicknesses that were comparable to those prepared by dip coating except that thicker PVOH films were obtained at lower spin rates, following the Meyerhofer relationship in the wetting regime. Stepwise dewetting dynamics of confined PVOH drops were captured using high-speed photography. Drying and polymer aggregation initiate at the periphery of the drop and propagate toward the center of the drop. Each dewetted thin film adopts the footprint of the original drop and shows globally ordered patterns, which depend on both initial drop size and spin rate. The PVOH thin films have excellent stability toward water rinse if they are continuous and are given sufficient time to dry. This new adsorptive spin-coating method is not only straightforward but also unique in its ability to generate globally ordered morphologies that are the outcome of fast spontaneous adsorption, spin symmetry, and temporally and spatially adjustable drying rates. It is a valuable tool for fabricating a wide range of thin-film systems where surface adsorption/reaction is rapid, in both wetting and nonwetting regimes.