DN strategy constructed photo-crosslinked PVA/CNC/P(NIPPAm-co-AA) hydrogels with temperature-sensitive and pH-sensitive properties

In this paper, poly(N-isopropylacrylamide) (PNIPPAm), polyacrylic acid (PAA), polyvinyl alcohol (PVA) and cellulose nanocrystals (CNC) were used to prepare double-network hydrogels by the photo-crosslinking technology. The results from mechanical and swelling tests indicated that photo-crosslinked PVA/CNC/P(NIPPAm-co-AA) hydrogels exhibited temperature-sensitive, pH-sensitive behaviors and good mechanical strengths. We prepared DN hydrogels, which combined the advantages of PNIPAAm, PAA and photo-crosslinking collectively in the PVA/CNC system, leading to controllable temperature and pH responses and improvement in physical properties. A simple and green method for the preparation of DN hydrogels was demonstrated, offering photo-crosslinked PVA/CNC/P(NIPPAm-co-AA) hydrogels as excellent prospects for applications in the medical field.