Preparation and characterization of a multistimuli-responsive photoluminescent monomer and its corresponding polymer

Abstract

Recently, multistimuli-responsive photo-luminescent materials have received more and more attention due to the basic theoretical research on them and their wide potential applications. In this article, we reported a new multistimuli-responsive luminescent monomer and its corresponding polymer materials based on an α-cyanostilbenic derivative. The prepared monomer and polymer exhibited aggregation-induced emission enhancement characteristics (AIEE). More importantly, they showed responsive behavior to temperature, UV irradiation and ionic strength. Their aqueous solution showed fluorescence thermosensitivity. At first, their luminescence intensity decreased slightly with the increasing temperature, and then their luminescence intensity enhanced greatly when the temperature increased to their lower critical solution temperature (LCST). With the further increasing of temperature, there was a significant decline in their luminescence intensity. They also exhibited different UV irradiation responsive behaviors in aqueous solution and THF solution. In aqueous solution, the LCST of their aqueous solution also changed after UV irradiation and their luminescence intensity increased first and then remained unchanged with increasing irradiation time. While in THF solution, their emission intensity decreased with UV irradiation time. The aqueous solution of the monomer and its corresponding polymer also exhibited obvious ionic strength response behavior. The LCST of their aqueous solution varied with the addition of different salts and the change rule was in good agreement with the Hofmeister effect and the emission intensity changed with the addition of salts.