Simulation study on the coil-globule transition of adsorbed polymers

ABSTRACT Coil‐globule transition of adsorbed polymers on attractive surface is simulated by using dynamic Monte Carlo simulation. The effect of surface attraction strength EPS and intrachain attraction strength EPP on polymer phases is investigated. The coil‐globule transition point is dependent on EPS, while the globule conformation is dependent on both EPS and EPP. At small EPS, the conformation of adsorbed polymer is three‐dimensional layer structure. While at large EPS, the conformation of adsorbed polymer is roughly two‐dimensional (2D) at EPP = 0, and we observe a 2D coil‐globule transition at E*PP and a layer‐forming transition from 2D conformation to three‐dimensional layer structure at E*PP,L > E*PP. The layer‐forming transition point E*PP,L increases with EPS as E*PP,L = EPS − 1.4. In addition, we find that the adsorption suppresses the coil‐globule transition, i.e., the coil‐globule transition point E*PP increases with the increase in EPS. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 2359–2367 The coil‐globule transition of adsorbed polymers on an attractive surface is simulated. A phase diagram of the polymer state against surface attraction strength and intrachain attraction strength is presented. For the adsorbed polymer, a three‐dimensional coil‐globule transition is observed at weak surface attraction and a 2D one is seen at strong surface attraction. The phase boundary for the transition between three‐dimensional adsorbed layer structure and 2D adsorbed globule structure is a straight line. The adsorption of polymer suppresses the three‐dimensional coil‐globule transition.