Self-assembling graphene oxide/modified amphipathic hydroxyethyl cellulose hybrid stabilized Pickering emulsion polymerization for functional hydrogel

Herein, a self-assembled hybrid from bromoacetic acid (BA) modified amphipathic hydroxyethyl cellulose (MAHEC) and graphene oxide (GO) was prepared and used as Pickering emulsifiers to synthesizing functional porous hydrogel by removing the oil phase after emulsion templating polymerization. The MAHEC grafted with the 1-bromododecane was prepared by the phase-transfer method, and the graphene oxide was prepared by Hummers' method. The interaction between the GO nanosheets and MAHEC molecular chain was investigated by X-Ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The amphipathy of the GO and MAHEC was measured by the water contact angle, which was 74.0 degrees and 103.0 degrees, respectively. A stable, low cost, and biocompatible Pickering emulsion was fabricated by a low concentration of GO and MAHEC hybrid. Stabilization of Pickering emulsion prepared by the nanohybrid emulsifier GO and MAHEC at different conditions was investigated, such as different electrolyte concentration, pH, and oil/water ratio. The polyacrylamide (PAM) organo-hydrogel was polymerized by the stable Pickering emulsion template. After removing the olive oil, the inner wall of the porous hydrogel was coated by the MAHEC and GO for the pH-sensitive release. The strategy of Pickering emulsion templating polymerization by utilizing functional emulsifiers could be applied for the preparation of various smart materials.

Automated summary

A hybrid material of amphipathic hydroxyethyl cellulose modified with bromoacetic acid and graphene oxide was successfully prepared and utilized as Pickering emulsifiers to synthesize a functional porous hydrogel for pH-sensitive release. The stable, low cost, and biocompatible Pickering emulsion facilitated the polymerization of polyacrylamide organo-hydrogel with a stable template, demonstrating its potential for smart material preparation.