Redox-responsive gel-sol/sol-gel transition in poly(acrylic acid) aqueous solution containing Fe(III) ions switched by light

J Am Chem Soc. 2008 Dec 3;130(48):16166-7. doi: 10.1021/ja807087z.

Abstract

Redox-responsive gel-sol/sol-gel transition in aqueous PAA system containing Fe(III)-citrate complex was realized by switching the redox states of Fe(III)/F(II) ions conjugated with photoreduction and oxidation. This reversible transition can be indicated chromatically by the Fe(III) ions and repeated many times as long as there is sufficient citric acid.