Constrained dewetting of polymers grafted onto a nonadsorbing surface in poor solvents: From pancake micelles to the holey layer

Using both theory and computer simulation, we study the dewetting problem of a polymer layer grafted on a surface in a poor solvent. We find that in the regime of moderate grafting density the layer is unstable to the formation of finite-sized holes. The formation of these holes is a result of the tradeoff between minimal layer surface energy and minimal tether penalty, thus giving an example of dewetting constrained by polymer stretching. We also examine the low-density case and find a new micellar regime where the nuclei of surface micelles are strongly flattened, forming "pancake micelles". The theoretical prediction qualitatively agrees with Monte Carlo simulations.