pH-Dependent reversible transformation of TPPS4 anchored on mesoporous TiO2 film between monomers and J-aggregates

Abstract

Protonated TPPS₄ monomer and its J-aggregate were formed simultaneously from TPPS₄ adsorbed through its sulfonic acid groups on TiO₂ porous film by decreasing the pH of the surrounding water and this behavior on TiO₂ film can be reversibly repeated depending on pH, indicating a flexible and stable arrangement of TPPS₄ through chemical bonds between the sulfonic acid groups and the TiO₂ surface.