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

Abstract

AbstractNew water‐triggered shape memory nanocomposites are developed by incorporating graphitic carbon nitride nanosheets (g‐C3N4) in polyvinyl alcohol (PVA) films. The findings demonstrate that the water‐triggered shape memory effect of PVA‐filled g‐C3N4 nanocomposites (PVA/g‐C3N4) is largely enhanced via the establishment of strong H‐bonding interactions between the uncondensed amine groups of g‐C3N4 and hydroxyl groups of PVA (–OH) which induce supplementary physically cross‐linked sites in the formed nanocomposites. Additionally, the designed PVA/g‐C3N4 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‐C3N4 functional groups. Furthermore, a shape memory mechanism is suggested to highlight the water‐triggered shape memory behaviors of the PVA/g‐C3N4 nanocomposites. The obtained results are very propitious in terms of plotting and manufacturing g‐C3N4‐based nanocomposites with enhanced mechanical, thermal, and swelling features, providing a framework for designing g‐C3N4‐derived shape memory polymers (gSMP) toward better comprehension of the shape recovery mechanism in water‐triggered gSMP nanocomposites.