In this paper we discuss cadmium hydroxide pattern formation in polyacrylamide gel containing carboxyl groups.<br/>Liesegang phenomenon is a peculiar type of precipitate formation first published by a German chemist and photographer, R. E. Liesegang in 1896 [1]. During a standard Liesegang experiment performed in a test tube, an aqueous outer electrolyte diffuses into a gel containing an inner electrolyte. Providing that the concentration gradient between the two electrolytes is sufficiently large, precipitate bands (stripes) propagate perpendicularly to the reaction front.<br/>In the cadmium hydroxide 2-D Liesegang pattern, further depletion zones occurs perpendicularly to the stripes, which results in the formation of spots regularly arranged in hexagonal symmetry [2]. We have tailored this transition from stripes to spots using systematically modified polyacrylamide gels. Our results have shown that the carboxyl content of the medium might contribute to or hinder the development of depletion zones. Characterizing the geometrical features (position, width) of the patterns as well as the front propagation, data have been collected from grayscale intensity data.<br/>Our results support the following conception: the gel matrix can actively influence the precipitate pattern.<br/>

Unusual pattern formation in the cadmium hydroxide system

253rd National Meeting (2017)

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