Dewetting Kinetics of Thin Polymer Films with Different Architectures: Effect of Polymer Adsorption

We have investigated the influence of the adsorption process on the dewetting behavior of the linear polystyrene film (LPS), the 3-arm star polystyrene film (3SPS) and the ring polystyrene film (RPS) on the silanized Si substrate. Results show that the adsorption process greatly influences the dewetting behavior of the thin polymer films. On the silanized Si substrate, the 3SPS chains exhibit stronger adsorption compared with the LPS chains and RPS chains; as a result, the wetting layer forms more easily. For LPS films, with the decrease of annealing temperature, the kinetics of polymer film changes from exponential behavior to slip dewetting. As a comparison, the stability of 3SPS and RPS films switches from slip dewetting to unusual dewetting kinetic behavior. The adsorbed nanodroplets on the solid substrate play an important role in the dewetting kinetics by reducing the driving force of dewetting and increase the resistant force of dewetting. Additionally, Brownian dynamics (BD) simulation shows that the absolute values of adsorption energy (epsilon) gradually increase from linear polymer (-0.3896) to ring polymer (-0.4033) and to star polymer (-0.4264), which is consistent with the results of our adsorption experiments.