Sustainable Finished Leather Preservation Part II - Wattle Tannin Capped Copper Nanoparticles

Abstract

Part 1 of the current paper described the green synthesis of myrobalan capped copper nanoparticles for the preservation of the finished leather. In Part II of the current study, Copper Nanoparticles (CuNPs) were synthesized using green synthesis with wattle (tannin) extract as a reducing agent. Green synthesis is the preferred approach for the synthesis of metal nanoparticles due to its eco-friendly and cost-effectiveness for the preservation of finished leather. To improve the antibacterial qualities of leather with different types of finishes, the resin finished leather was coated with synthesized wattle copper nanoparticles (W-CuNPs). The chemical constituents of wattle induce the reduction of Cu2+ ions to CuNPs with the capping process and also remain as a stabilizing agent for the capping process. The formation of W-CuNPs was confirmed by UV-Spectroscopy at an absorbance of 467 nm. The identified functional groups such as -OH, C=C, and C-N were analyzed by Fourier transform infrared spectrum (FT-IR) which are responsible for the reduction and stabilization of copper nanoparticles. The spherical shape of the nanoparticles was ascertained by Scanning Electron Microscope (SEM), whereas Energy dispersive X-ray (EDX) studies confirmed the presence of copper with 65%. The average particle size of W-CuNPs was found to be 96 nm. The zeta potential value of -24 mv affirmed the stability of the W-CuNPs. The maximum zone of inhibition was 12 mm against Gram-positive (Bacillus subtilis) and 11 mm against Gram-negative (Serratia marcescens) bacteria on W-CuNPs coated finished leather, which exhibits strong antimicrobial activity. Hence, CuNPs synthesized by wattle extract have the potential to preserve the finished leather and its products as an antibacterial agent.