Thermal, morphology and bacterial analysis of pH-responsive sodium carboxyl methylcellulose/ fumaric acid/ acrylamide nanocomposite hydrogels: Synthesis and characterization

In this present investigation, sodium carboxymethyl cellulose grafted with Fumaric acid/Acrylamide (CMC/FA/AAm=CFA) hydrogel and their silver nanocomposite hydrogels (CFA-Ag (x), x = 5, 10 and 20) were developed by simple, cost effective and ecofriendly greener method. Mint leaf extract was used as an efficient natural reducing agent due to presence of active and antioxidant potential of polyphenol and flavonoid components. Swelling equilibrium of CFA hydrogel showed S(eq)% 3000 both in pH medium and distilled water. CFA (90:10) hydrogel has been produced greater than S(eq)% 6000. The synthesized CFA (90:10)-Ag-5, CFA (90:10)-Ag-10 and CFA (90:10)-Ag-20 nanocomposite hydrogels have been observed lower S(eq)% 2000–3000 than the CFA hydrogel. The homogeneous distribution of AgNPs throughout the CFA hydrogel and nanocomposites has been explored by SEM analysis. The interaction of network heteroatoms with AgNPs has been strongly revealed by the FTIR spectra and XRD analysis. The thermal stability of CFA (90:10)-Ag-5, 10, and 20 nanocomposite hydrogels have showed greater stability than CFA hydrogel which is confirmed by TGA/DSC thermogram analysis. The TEM analysis was used to explore a uniform distribution of spherical AgNPs (10 nm–50 nm) embedded on the CFA composite hydrogel. The CFA (90:10)-Ag-20 nanocomposite hydrogel has showed good antibacterial activity beside E. coli (Gram positive) and S. aureus (Gram negative) pathogens. Based on the antibacterial activity and swelling properties of CFA-Ag nanocomposite hydrogels have the ability to accelerate the antibacterial activity and are potential candidates for medical and environmental applications.