High Strength, Swelling Resistance, Antimicrobial and Conductive Zwitterionic Hydrogel Based on Cellulose Frame

Abstract

A high strength, swelling resistance, and conductive hydrogel with excellent photothermal effect and antimicrobial property is prepared based on a cellulose frame. First, cellulose is dissolved in a NaOH/urea aqueous solution. The cellulose solution is self-assembled in an ethanol environment to form a cellulose frame. The frame is then immersed in the acrylamide (AM) and 2-methylacryloxyethyl phosphocholine (MPC) solution. A Cel-PA_xM_y cellulose hydrogel is prepared by in situ copolymerization of AM and MPC. Lastly, Cel-PA_xM_y hydrogel is soaked in a tannic acid/ferric chloride (TA@Fe³⁺) solution to prepare the TA@Fe³⁺-Cel-PA_xM_y hydrogel. The obtained hydrogel shows excellent mechanical strength (toughness 600 KJ/m³, Young’s modulus 225 KJ/m³) due to the presence of a rigid cellulose frame. The introduction of TA@Fe³⁺ not only increases the cross-linking density of hydrogels, making hydrogels have extraordinary swelling resistance (swelling ratio 50 ± 20%), but also endows the hydrogels with excellent electrical conductivity (conductivity 1.0 S/m, GF 0.75, response time 572.27 ms), good near-infrared photothermal effect, and outstanding antimicrobial property. This work proposes an effective strategy for the development of high strength, swelling resistance, antimicrobial and conductive zwitterionic hydrogel, which exhibits significant promise for wearable sensors and electronic devices.