Role of Zno Nanoparticles in Enhancing the Antimicrobial Property of Nitrocellulose Lacquer Wood Finish

Abstract

Background: Mould growth on coated wood products during shipment is the foremost apprehension for most of the wood industries in India. Well finished wood products tend to get deposited by staining moulds superficially in high humidity conditions during shipment. Though wood disfiguring fungi (stain moulds) normally have no significant effect on the mechanical properties of timber, they only affect the aesthetic appearance of the material without destructing the wood cell wall. This causes a huge economic loss to the manufacturer due to disfigurement of the appearance of wood products. Methods: The aim of this work is to test and enhance antimicrobial property of Nitrocellulose lacquer wood finish to prevent mould deposition on coated wood products. The work was carried out to screen and evaluate the antimicrobial activity of commercial Nitrocellulose lacquer. Several patents regarding antimicrobial activity of nano metal oxides have been visited. In order to enhance the mould resistance of this coating, its combinations with neem oil and ZnO nanoparticles were prepared and tested against the growth of staining moulds: Aspergillus niger and Penicillium sp. on the wood substrate of Melia dubia. The study was carried out for 500 hours under favorable conditions (Temperature and Relative Humidity (RH)) for the mould growth. The growth was analysed on the basis of surface area affected by stain moulds on coated wood samples. Results: The growth analysis data inferred that the ZnO nanoparticles had significant effect against the growth of stain moulds. The presence of ZnO nanoparticles increased the mould growth resistance of Nitrocellulose lacquer coating to a great extent compared to the ability of neem oil for the same. This finding demonstrates the potential use of nano ZnO for increasing the effectiveness of NC lacquer against mould growth without hampering its other properties. Conclusion: 1 % nano ZnO concentration in Nitrocellulose lacquer wood coating increased its efficacy against staining mould growth by 95 %.