Controllable Construction of Temperature-Sensitive Supramolecular Hydrogel Based on Cellulose and Cyclodextrin

In temperature sensitive hydrogels, the swelling degree or light transmittance of the gel itself changes with variations in ambient temperature, prompting its wide application in controlled drug release, tissue engineering, and material separation. Considering the amphiphilic structure of beta-cyclodextrin (beta-CD), a cellulose-based supramolecular hydrogel with superior temperature sensitivity was synthesized based on a combination of cellulose and beta-CD as well as the host-guest interaction between beta-CD and polypropylene glycol (PPG). In the one-pot tandem reaction process, chemical grafting of beta-CD on cellulose and the inclusion complexation of beta-CD with PPG were performed simultaneously in a NaOH/urea/water system. The obtained supramolecular hydrogel had a lower critical solution temperature (LCST) of 34 degrees C. There existed covalent bonding between the cellulose and beta-CD, host-guest complexation between the beta-CD and PPG, and hydrogen bonding and hydrophobic interactions between the components in the network structure of the supramolecular hydrogel. The combination of various covalent and non-covalent bonds endowed the resulting supramolecular hydrogel with good internal network structure stability and thermal stability, as well as sensitive temperature responsiveness within a certain range-implying its potential as a smart material in the fields of medicine, biology, and textiles. This work is expected to bring new strategies for the fabrication of cellulose-based thermosensitive materials, benefitting the high-value utilization of cellulose.

Automated summary

A temperature sensitive hydrogel based on cellulose and beta-cyclodextrin (beta-CD) was synthesized through a one-pot tandem reaction process. The hydrogel exhibited good internal network structure stability and thermal stability, as well as sensitive temperature responsiveness, making it a potential smart material for medical, biological, and textile applications.