Suppression of Surface Pattern Formation in Blend Films With Block Copolymer Surfactant

Published

July 1, 2003

Author(s)

Li Piin Sung, Jack F. Douglas, Charles C. Han, Alamgir Karim

Abstract

We show that the addition of a small concentration of a block copolymer surfactant to a thin phase separating blend film can supppress the pattern formation that occurs in the blend films without block copolymer. This effect is obseved even at very low block copolymer concentrations which are below the bulk critical micelle concentration. The block is distributed uniformly on average in the direction normal to the substrate, but we observe large scale fluctuations in the film darkness in optical micrographs that has the appearance of large scale critical fluctuations. We attribute the film thickness to a reductuction of the interfacial tension that gives rise to the suface pattern formation in the absence of the surfactant and the diffuse intensity patterns are ascribed to fluctuations in the block copolymer concentration within the film.

Citation

Macromolecules

Volume

41 No. 14

Pub Type

Journals

Keywords

block copolymer, Film, Marangoni pattern, phase separation, polymer blend, surface pattern formation, surfactant

Citation

Sung, L. , Douglas, J. , Han, C. and Karim, A. (2003), Suppression of Surface Pattern Formation in Blend Films With Block Copolymer Surfactant, Macromolecules (Accessed July 30, 2025)