Pattern formation of constrained acrylamide/sodium acrylate copolymer gels in acetone/water mixture

作者：Yong Li, Chun-Fang Li, Zhibing Hu · 发表于：The Journal of Chemical Physics · 年份：1994 · DOI：10.1063/1.466296 · 被引用次数：34 · 研究领域：Liquid Crystal Research Advancements、Pickering emulsions and particle stabilization、Hydrogels: synthesis, properties, applications

Pattern formation and evolution in constrained acrylamide/sodium acrylate (PAAM/SA) gels have been investigated in acetone/water mixture. The constraint is achieved by cross linking the gel slabs onto a rigid substrate. All samples are initially kept in water with the hexagonal pattern develop on the surface before being immersed in the acetone/water mixture. Depending on the solvent composition and ionic strength of the sample, different patterns, i.e., hexagonal, grains, and bubbles, have been observed. These patterns are formed at acetone concentration below, near, and above the concentration at which the gel volume phase transition occurs. The wavelengths of hexagonal and bubble patterns are found to be the same, while that of the grain pattern is four times smaller. It is suggested that the shrinking patterns are formed due to the dense gel surface produced during the shrinking process.