Comparison of nanostructured blend homopolymers and diblock copolymers by AFM and TOF-SIMS

Abstract

Poly(styrene-b-methyl methacrylate) (PS-b-PMMA) and poly(styrene-b-ethyl hexylacrylate) (PS-b-PEHA) were used to investigate microphase separation in block copolymer films. Blend homopolymers were also used to compare their nanostructures on the surface with those of diblock copolymers. Atomic force microscopy (AFM) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) were used to obtain the nanostructural information of the diblock copolymers and the blend homopolymers. The tapping mode AFM results provided information about the surface morphology, microphase-separated structure, and thickness of the films according to the annealing condition and concentration. TOF-SIMS was used to determine the lamellar nanostructures of the block copolymer films. The TOF-SIMS depth profiles demonstrate variations in the hydrogen, deuterium, carbon, oxygen, and molecular fragment ions of the block copolymer according to the depth. Accurate surface structure information on the block copolymers and blend homopolymers was obtained by the combined images of TOF-SIMS and AFM. Copyright (c) 2014 John Wiley & Sons, Ltd.