Self-healing and acidochromic polyvinyl alcohol hydrogel reinforced by regenerated cellulose.

Recently, integration of self-healing, color-tunable, sol-gel converted properties into hydrogel has attracted interest for preparing a reinforced multifunctional hydrogel. Herein, acidochromic regenerated cellulose (ARC) was incorporated into the polyvinyl alcohol/borax (PB) matrix for constructing a tough, self-healing, multicolor and sol-gel converted smart hydrogel (PB/ARC). The mechanical properties of PB/ARC hydrogel were improved after introducing ARC, which could bear a weight of 200 g and had high maximum tensile strength (6.8 times) and compressive strength (2.3 times). PB/ARC hydrogel automatically fused within 15 s after being cut and quickly recovered to the original state after being subjected to high shear strain, showing excellent self-healing ability. The color of hydrogel could be tuned between yellow and purple by altering pH values (5-12). In addition, PB/ARC hydrogel exhibited reversible sol-gel conversion in response to the change of acidity and alkalinity. This study offers a new and facile strategy for developing multifunctional smart hydrogel.