New sol–gel synthesis of NiO antibacterial nano-pigment and its application as healthcare coating

This report deals with the fabrication of NiO nanoparticle (NiO Nps) dispersed alkyd coating and its antimicrobial activity. NiO Nps is prepared by novel sol–gel technique using pectic polysaccharides as a gelling agent. The gelling agent converts the hydroxo-metal network into a gel within 4 h of time. After calcination, the FESEM and TEM micrograph of the obtained NiO Nps shows cubic and irregular shaped structures with size ranging from 30 to 200 nm. The structural characterizations have been evaluated through XRD, FTIR, UV–vis and VSM studies. The antimicrobial activity of NiO Nps has been carried out against both gram negative and gram positive bacteria namely Escherichia coli, Klebsiella pneumonia and Proteus vulgaris, Streptococcus mutans, Bacillus subtilis, and Staphylococcus aureus. The findings of the present study indicate that the NiO Nps permeate the bacterial cell wall, accumulated inside thereby facilitating the synergistic impact against the growth of bacterial strains. The experimental outcomes suggest the potential use of NiO as pigments in the alkyd coating. Alkyd coating consisting of NiO Nps exhibits considerable reduction in bacterial viability when it comes in contact against microbial strains, proving the efficacy of the coating.