Engineering of H‐Bonding Interactions in PVA/g‐C3N4 Hybrids for Enhanced Structural, Thermal, and Mechanical Properties: Toward Water‐Responsive Shape Memory Nanocomposites

Abstract New water‐triggered shape memory nanocomposites are developed by incorporating graphitic carbon nitride nanosheets (g‐C 3 N 4 ) in polyvinyl alcohol (PVA) films. The findings demonstrate that the water‐triggered shape memory effect of PVA‐filled g‐C 3 N 4 nanocomposites (PVA/g‐C 3 N 4 ) is largely enhanced via the establishment of strong H‐bonding interactions between the uncondensed amine groups of g‐C 3 N 4 and hydroxyl groups of PVA (–OH) which induce supplementary physically cross‐linked sites in the formed nanocomposites. Additionally, the designed PVA/g‐C 3 N 4 nanocomposites reveal the achievement of improved physicochemical properties including thermal and mechanical characteristics compared to the neat PVA. Tensile testing displays a significant increment of tensile strength (by 58%) along with an increment of the Young's modulus (by 357%), owing to the existing of noncovalent interactions in the form of H‐bonds established between the PVA matrix and g‐C 3 N 4 functional groups. Furthermore, a shape memory mechanism is suggested to highlight the water‐triggered shape memory behaviors of the PVA/g‐C 3 N 4 nanocomposites. The obtained results are very propitious in terms of plotting and manufacturing g‐C 3 N 4 ‐based nanocomposites with enhanced mechanical, thermal, and swelling features, providing a framework for designing g‐C 3 N 4 ‐derived shape memory polymers (gSMP) toward better comprehension of the shape recovery mechanism in water‐triggered gSMP nanocomposites.