High-strength and pH-responsive self-healing polyvinyl alcohol/poly 6-acrylamidohexanoic acid hydrogel based on dual physically cross-linked network

The fabrications of hydrogel with both good mechanical properties and self-healing ability are still challenging issues. Herein, we report a high strength and pH responsive hydrogel based on polyvinyl alcohol (PVA) and poly 6-acrylamidohexanoic acid (PAACA) using dual physically cross-linking strategy. Owing to the H-bonds and the crystallites domains, the prepared hydrogel present considerable tensile strength . Meanwhile, the PAACA could facilitate the crystallization behavior of PVA, resulting in the fabrication of hydrogel through one simple freezing step instead of repeated freeze/thaw cycles. Furthermore, the hydrogel exhibit reversible pH responsive self-healing and swelling property stemming from protonated and deprotonated of the carboxyl groups in PAACA side chains, allowing external control over the healing and swelling process.