Controlled release of organic substances using polymer membrane with responsive function for amino compounds

In order to regulate the release of a water‐soluble organic substance from a polymer device, an amphiphilic polymer membrane having a dinitrophenyl group was prepared and the effects of an amino compound on the release of such a substance in an aqueous medium were investigated. When the amino compound, triethylamine (TEA), was added to the medium, the release rate of methyl orange (MO) in solution from the polymer device increased; the same was noted with an increase in the concentration of TEA. However, on removal of the TEA from solution, the rate resumed its initial level of that in water. These results were explained by the change in the swelling degree of the polymer membrane induced by the addition of TEA. This change was considered to result from the formation of a charge transfer complex between the dinitrophenyl group in the polymer membrane and the added TEA, since a charge transfer spectrum was observed in the polymer membrane–TEA system.