A novel pH-sensitive aqueous supramolecular structured photoinitiator comprising of 6-modified per-methylated β-cyclodextrin and 1-hydroxycyclohexyl phenyl ketone

•A novel PM-β-CD derivative (6-acryl-en-PM-β-CD) was synthesized to construct a water-soluble SSPI.•Efficiency of the obtained SSPI can be controlled by pH stimulation with geometry change.•Modification of acryloyl group led to a pH-controllable morphology of the polymeric film.

A novel permethylated β-cyclodextrin (PM-β-CD) derivative, 6I-acryloyl ethylenediamine-6I-deoxy-2I, 3I-di-O-methyl-hexakis (2II−VII, 3II−VII, 6II−VII-tri-O-methyl)-β-cyclodextrin (6-acryl-en-PM-β-CD) was synthesized as host molecule to construct a pH-sensitive water-soluble supramolecular-structured photoinitiator (SSPI) with hydrophobic 1-hydroxycyclohexyl phenyl ketone (HCPK). The conformation, binding behavior and photopolymerization kinetics of 6-acryl-en-PM-β-CD with HCPK were investigated by using FT-IR, 1H NMR, fluorescence spectra titration and UV–vis at various pH values. Experiment results obtained indicated that the polymerization efficiency of the resulting water-soluble SSPI was able to be controlled by pH stimulation where the intrinsic mechanism was discussed from the insight of the binding manner geometry transformation. Moreover, the GPC and SEM results further demonstrated that apparent morphology of polymer product had the potential to be regulated by the pH-sensitive SSPI.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (150 K)Download as PowerPoint slide