Wetting by Polymer Solutions
Very small droplets of polystyrene dissolved in toluene were placed on a glass slide and studied under a goniometer microscope. The drops were allowed to spread and dry and their extent of spreading is plotted as a variation of the concentration of the polymer in the solution. It was observed that drops of polystyrene in a volatile solvent such as toluene, spread to some extent and then gets dried up thus preventing the contact line from moving further. when liquid PDMS in non-volatile solvent, HMDS, and in volatile solvent, toluene, was used, the droplets continued to spread. One conclusion among others, is that even if the droplet dries but leaves behind a mobile contact line then the solution spreads out, on the other hand if the droplet dries and the contact line loses its mobility, the spreading automatically comes to a stop.
S. Saritha et al., "Wetting by Polymer Solutions," Polymer, Elsevier, Aug 2006.
The definitive version is available at http://dx.doi.org/10.1016/j.polymer.2006.06.069
Chemical and Biochemical Engineering
National Science Foundation (U.S.)
Keywords and Phrases
PDMS; Polymer Solutions; Wetting
Article - Journal
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