Enhancement of mechanical property of polyacrylic acid hydrogel using magnetic nanocomposite based crosslinker

Abstract

Derivatives of cellulose, particularly carboxy methyl cellulose (CMC) is one of the popular physical crosslinkers used to improve the mechanical toughness and self-healing capability of polymeric hydrogels. In addition to good mechanical properties and self-healing properties, hydrogels capable of responsive to magnetic field are promising materials for biomedical applications. In this study, along with CMC as the physical crosslinker, Ni-nanoparticle was used to synthesize polyacrylic acid (PAA)-Ni-Cellulose nanocomposite. Polymerization was carried out using the free radical polymerization (FRP) technique using potassium persulfate (KPS) as initiator under inert atmosphere. The successful incorporation of Ni nanoparticle was confirmed using FTIR spectra as well as FESEM images. The incorporation of Ni-nanoparticle to hydrogel not only improved the mechanical toughness, it also introduced magnetic field to the prepared hydrogel. The amount of Ni-nanoparticle was varied to study the effect of Ni-nanoparticle on the mechanical toughness and self-healing capability of PAA-Ni-Cellulose nanocomposite. It was found that with the increasing amount of Ni-nanoparticle, the tensile strength increases while elongation of the hydrogel decreases. The nanocomposite hydrogel also showed considerable self-healing capability due the ionic and coordination interaction of Ni-nanoparticle with numerous physical interaction sites CMC provides. The prepared nanocomposite hydrogel also demonstrated responsiveness to the magnetic field due to the presence of Ni-nanoparticle. Therefore, PAA-Ni-Cellulose composite hydrogel with excellent mechanical toughness, self-healing capability, and responsiveness to magnetic field possesses immense potential to be applied in biomedical applications, particularly in biosensor, remote-controlled drug delivery etc.