Cellulose nanocrystals‑silver nanoparticles-reduced graphene oxide based hybrid PVA nanocomposites and its antimicrobial properties

Abstract

Towards fabricating a hybrid biodegradable multifunctional nanocomposite, cellulose nanocrystal (CNC), reduced graphene oxide (rGO) and silver (Ag) nanoparticles were reinforced into polyvinyl alcohol (PVA) polymer matrix. One-step reduction process was followed, composed of reducing graphene oxide (GO) and silver nitrate (AgNO₃) into rGO and Ag nanoparticles through hydrazine hydrate (chemical reduction method), respectively. Uniformly dispersed CNC, rGO and Ag nanoparticles in PVA matrix led to an increment in modulus by 184% of PVA demonstrating the reinforcement outcome of CNC, rGO and Ag. PVA/CNC/rGO/Ag nanocomposite showed the Ag⁺ ions sustained release from PVA studied using Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The incorporation and elemental composition of CNC, rGO and Ag nanoparticles into nanocomposite were interpreted through FTIR (Fourier Transform Infrared Spectroscopy) and XPS (X-ray photoelectron spectroscopy) technique, respectively. All prepared nanocomposites with different wt% of Ag (PVA, PVA/CNC, PVA/CNC/rGO/Ag) were non-toxic to HEK-293 cell line and exhibited improved antibacterial property against E. coli and S. aureus due to a combination of Ag⁺ ions (release from Ag nanoparticles) and rGO (having antibacterial effect). Thus, the combined effect of CNC, rGO and Ag in PVA matrix distinctively resulted into a multifunctional hybrid nanocomposite for potential use in tissue engineering and packaging applications.

Keywords: Cellulose nanocrystals; Reduced graphene oxide; Silver nanoparticles.