Development of reduced graphene oxide (rGO) reinforced poly(lactic) acid/ cellulose nanocrystal composite through melt mixing: Effect of nanofiller on thermal, structural, biodegradation and antibacterial properties

Abstract

The intent of this research work was to synthesised a synthetic polymer that is biodegradable, bioresorbable, and biocompatible, while also exhibiting favorable thermal characteristics. The present study reports the successful fabrication of bionanocomposites by incorporating Cellulose nanocrystals (CNCs) and Reduced graphene oxide (rGO) into host matrix (PLA) using the melt-mixing technique. Various weight percentages (wt%) of rGO were employed in the process and various characterization techniques, including BET analysis, XRD, FTIR and field emission scanning electron microscopy (FE-SEM) were used to verify the efficient fabrication of a number of nanoformulations and nanofiller's effect. Introduction of CNC and rGO in PLA matrix increases the surface area as well as porosity of the composites, established by BET analysis. DSC results indicate that the assimilation of rGO into the polymer matrix improved thermal stability of the composite material and leads to boost in the degree of crystallinity which was supported by XRD analysis. TGA results found no noticeable change in glass transition temperature (Tg) due to the addition of Nanofiller (rGO). The wettability analysis was done by contact angle measurement to determine the hydrophilicity of the composite and it is shown that with the increasing amount of rGO, hydrophilicity increases and contact angle reaches to 69 degrees for 0.75 wt% of rGO in composite in comparision to 100 degrees Neat PLA. The rGO/CNC/PLA nanocomposites exhibit a unique antibacterial effectiveness against both the S. aureus (Gram-positive) and E. coli (Gram-negative) bacterial strains. The highest antimicrobial activity was obtained in the nanocomposite tested against S. aureus. Biodegradation through Lysozyme in PBS solution shows promising result after incorporation of nanofillers. Hence, the nanocomposite manufactured through melt mixing process has promising uses in the biomedical and food packaging industries.