Supramolecular microgel from cellulose and gelatin via host–guest interaction: Formation and sustained release application

Abstract

Herein, β-cyclodextrin-coupled cellulose (β-CD-Cel) copolymer microgel was synthesized by cross-linking copolymerization in the NaOH/urea water system. Then, cellulose/gelatin supramolecular microgel (CGSM) with vesicle morphology was obtained by utilizing the host–guest interaction between β-CD cavity and phenylalanine, tryptophan, and tyrosine of gelatin structure. Furthermore, the hydrophobic active substance vanillin was encapsulated into CGSM supramolecular microgel by ultrasonic method to obtain a long-lasting fragrance-released microgel. FTIR, XRD, UV–vis, fluorescence spectra, and ¹H NMR provided evidences for the formation of CGSM supramolecular microgel and the supramolecular interaction between cellulose and gelatin molecules. SEM and DLS confirmed the formation of supramolecular microgel with vesicle structure. Benefiting from the core, residual β-CD cavity, and rich network structure of CGSM supramolecular microgel, the efficient loading and long-lasting release for vanillin was achieved. Compared with β-CD-Cel microgel, CGSM supramolecular microgel showed a higher loading efficiency (98.58 %) for vanillin, and the vanillin retention rate still reached 53.87 % after 196 h of release. After being sprayed on the fabric surface, the fragrance release time of long-lasting fragrance-released CGSM microgel is more than 60 days, and 20 % vanillin is still retained on fabric after washing ten times.