Multiresponsive reversible gels based on a carboxylic azo polymer

Multiresponsive reversible gels were prepared with a carboxylic azo polymer (PM6AzCOOH) in dimethyl sulfoxide (DMSO) based on formation of H-aggregation and hydrogen bonds. Due to the specifically designed molecular structure of the polymer PM6AzCOOH, the obtained gel showed multiresponse behaviours to several stimuli, such as temperature, solvent polarity, and light. Their reversibly multiresponsive behaviours were systematically studied. It was found that the resulting gels could be destroyed by heating, adding a solvent with lower polarity, or irradiating with UV light. The gel could then be reformed by reverse processes with full reproducibility.