Key points are not available for this paper at this time.
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.
Peng et al. (Tue,) studied this question.