Two-Dimensional Marangoni-Instability-Induced Periodic Patterns of Polymer Blend Films Cast on Tilted Substrates
✍ Scribed by Kuen-Hua Wu; Shih-Yuan Lu; Hsin-Lung Chen; Yen-Yi Chen
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 438 KB
- Volume
- 209
- Category
- Article
- ISSN
- 1022-1352
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Two‐dimensional periodic patterns were observed for PS/PVP blend films and the corresponding homopolymer films on tilted glass substrates. They were attributed to the Marangoni instability resulting from surface tension non‐uniformity. For the 1:1 PS‐1/PVP‐1 blend films, two‐dimensional regular arrays of the separated phases were observed, similar to those observed on homopolymer films from thickness variations. In addition, for the PS‐2/PVP‐2 blend films of 30/70 composition, one‐dimensional strip patterns of separated phases were observed. The pattern formation mechanism is discussed and a characteristic parameter, defined as the ratio of the final film thickness to initial solution viscosity, is found to correlate well with the pattern regularity through variation in polymer concentration.
magnified image