- Author
- Sung, L. P. | Douglas, J. F. | Han, C. C. | Karim, A.
- Title
- Suppression of Phase Separation Pattern Formation in Blend Films With Block Copolymer Compatibilizer.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Journal
- Journal of Polymer Science: Part B: Polymer Physics, Vol. 41, No. 14, 1697-1700, July 15, 2003
- Keywords
- copolymers | thin film | polymer blend | phase separation | surfactant | surface pattern formation | block copolymer | Marangoni pattern
- Abstract
- The structure of thin films is sensitive to surface-tension variations that can cause the free surface of films to buckle.14 Many different types of film perturbations cause surface-tension variations and thus film-surface pattern formation. Recent studies2,3 have shown that phase separation within very thin polymer blend films leads to a range of surface patterns (bumps, holes, and labyrinthine ridges and valleys) that depend on the polymer composition. These patterns disappear when the films are returned into the one-phase region of the fluid mixture, verifying their phase-separation origin. 2,3 Although in some situations the surface patterns are beneficial, the surface patterns can sometimes compromise film-barrier properties or create other undesirable changes in polymer-coating properties (optical appearance, friction, tendency to attract impurities from the atmosphere, etc.). This technological problem led us to seek methods of inhibiting surface-pattern formation in thin-blend films.