Xu Xiaofei, Dai Yibing
Center for Soft Condensed Matter Physics and Interdisciplinary Research, and ‡College of Physics, Optoelectronics and Energy, Soochow University , Suzhou, Jiangsu 215006, China.
J Phys Chem B. 2017 Jan 12;121(1):314-321. doi: 10.1021/acs.jpcb.6b11975. Epub 2017 Jan 4.
In this article, we study the dewetting phenomenon of a polymer and carbon dioxide (CO) mixture on a planar surface by combining density functional theory and the string method. It is found that dewetting is a first-order discontinuous phase transition. When the pressure is lower than the completely dewetting pressure (P), CO stabilizes the polymer films. The density fluctuation of the polymer decreases significantly with the inclusion of CO. When the pressure is above P, the polymer film is depleted far away from the surface, leaving a thick layer of pure CO in the region near the surface. P is proportional to the surface energy strength. The CO molecules enhance the density fluctuation of the polymer during the dewetting process. The polymer-rich phase at the triple point dewets to a CO-rich vapor film, as the CO-rich liquid film near the surface is metastable. These results have promising application in the industry of fabricating polymer films and antifouling polymers on attractive surfaces.
