Enhanced water‐induced shape memory and swelling characteristics of graphene oxide‐cellulose nanofiber reinforced polyvinyl alcohol nanocomposites

Abstract An efficient water‐induced shape memory polymer (SMP) has been developed by incorporating graphene oxide (GO) and cellulose nanofibers (CNF) into polyvinyl alcohol (PVA) matrix. The resulting PVA/GO‐CNF hybrid nanocomposite films at 1 wt% exhibit synergistic effect with superior water‐induced shape memory performance, with 100% shape recovery within 37 sec. Moreover, these hybrid nanocomposite films at 1 wt% demonstrate superior mechanical strength of 77.9 MPa and an improved glass transition temperature ( T g ) of 61.4°C in dry conditions. The synergetic effect of GO and CNF in PVA overcomes the limitations of other PVA‐based SMPs in terms of mechanical properties, dimensional stability, and resistance to excessive swelling. Exposure to water significantly reduces T g to 24.2°C, as confirmed by DSC analysis, which is attributed to the decrease in hydrogen bonding between PVA and 1 wt% GO‐CNF caused by the swelling and plasticizing effect of water. Consequently, the shape recovery of the PVA/1 wt% GO‐CNF occurs with a switching temperature activation due to the polymer chains' released strain energy. These findings suggest that these hybrid films hold the potential for expanding the applications of SMPs in biomedical and moisture‐responsive application such as soft robotics and smart textiles, where water serves as the primary stimulus. Highlights PVA/1 wt% GO‐CNF hybrid film demonstrates 100% shape recovery in 37 sec. Water immersed PVA/1 wt% GO‐CNF nanocomposites show a reduction in T g to 24.2°C. PVA/1 wt% GO‐CNF nanocomposite shows superior mechanical strength in dry conditions. Shape memory behavior is due to reduction in hydrogen bonding and plasticizing effect.