Surface perturbations on the perfluoropolyether molecules in the melt and the gas-like conditions

A Rouse-like algorithm applied to a simplified bead-spring off-lattice polymer model an NVT [N (number of atoms), V (volume), and T (temperature)] Monte Carlo (MC) simulation for perfluoropolyether (PFPE) Z and Zdol (qualitative) has been performed. Simulation is performed with approximately 4000 g/mol molecular weight under the assumption of room temperature and pressure conditions. Simulations have been carried out for both the ultrathin liquid films (melts) of PFPE on solid surfaces and gas-like states of PFPE molecules. Top solid surfaces at several separation distances (3, 4, 6, and 8 nm) have been activated over the ultrathin films (2-nm film thickness) only on the bottom surfaces. The critical separation distances for the direct perturbations (to destabilize the films) of the top surfaces on the ultrathin liquid films only on the bottom surfaces have been calculated. The statistical critical distances of perturbations of the surfaces on the gas-like states of PFPE molecules have also been calculated. Critical separation distances between the parallel solid surfaces to inhibit the destabilization of the films considering vapor phases over the ultrathin films on solid surfaces have also been proposed. Here, effects of polar interaction have been elucidated. Meniscus bridges between the two parallel solid surfaces have also been calculated for several separation distances.