Monte Carlo simulation of AB diblock copolymer between surface and substrate and comparison of experimental results

Abstract

The morphologies of AB diblock copolymer film between the substrate and surface were investigated via Monte Carlo simulations on simple cubic lattices. The morphological dependence of the diblock copolymer thin film on the thickness, as well as the composition and interactive intensity has been mainly studied. With the increase of A-segments fraction, various microdomain morphologies including regular parallel stripe-like, mesh-like, and normal lamella near the region of the surface were generated in this work. The morphology of thin films of asymmetric diblock copolymer was found to form cylinders in a bulk system when Lz was equal to 30. The morphologies of PS-b-PDMS diblock copolymer films have been studied via atomic force microscopy (AFM) and transition electron microscopy (TEM) measurements. The surface morphology of the PS-b-PDMS copolymer thin film shows a mesh-like microphase separated structure, and PDMS continuous phase protruded on the PS dispersed phase. The surface composition of PS-b-PDMS copolymer thin films was measured by means of X-ray photoelectron spectroscopy (XPS) and ATR-IR. The comparison results show that the experimental observations are in good agreement with the simulation results. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1835–1845, 2006