Pattern formation in the polyacrylamide-methylene bluesulfide-oxygen system

摘要

In an experimental study of the polyacrylamide-methylene bluesulfide-oxygen (PA-MBO) system a variety of complex concentration patterns have been observed. Chevron and white-eye patterns develop from hexagons in a slow, continuous transition process. Honeycombs form a third type of structure that develops from either white-eye or hexagonal patterns. The motion of suspended tracer particles during the process of pattern formation was recorded under a microscope. This motion provides information about the possible role of hydrodynamic convection and/or mechanical deformation of the gel matrix. Quantitative data on surface undulations of the gel are also presented. The structure of the gel surface resembles the structure of the observed methylene blue patterns. It is concluded that plastic or elastic phenomena may play a role in later stages of the pattern formation. [References: 14]