© 2020 JETIR June 2020, Volume 7, Issue 6 www.jetir.org (ISSN-2349-5162) JETIR2006367 Journal of Emerging Technologies and Innovative Research (JETIR) www.jetir.org 195 STUDY ON THE ANTIMICROBIAL EFFICACY OF FABRICS FINISHED WITH NANO ZINC OXIDE PARTICLES Dr.P.P.GOPALAKRISHNAN Associate Professor, Department of Fashion Apparel Management, NIFT-TEA College of Knitwear Fashion, Tiruppur - 641606, Tamilnadu, India. Abstract: In this paper, knitted fabrics were finished with Zinc Oxide nano particles of 30 nm & 90 nm size. To make knitted fabrics, 100% cotton and 67/33 Polyester / Cotton ring spun yarns made with varying twist factors were selected. Knitted fabrics were finished with nano ZnO particles by Exhaust – dry –cure method and the samples were evaluated for anti microbial efficacy. Test results indicate that in general, anti microbial efficacy of samples increases with increase in yarn twist and decrease in ZnO particle size. Polyester cotton blend samples show better anti microbial efficacy than cotton samples Key words: Anti-microbial efficacy, Knitted fabrics, Ring spun, Particle size, Zinc Oxide nano particles. 1. INTRODUCTION The application of nano particles to textile materials aimed at producing finished fabrics with a variety of functional performances. Nano finishes are processes in which nano particles of metallic origin are synthesized and then applied onto textile substrate to get the desired functional properties, to suit various end use requirements [Gokarneshan et al., 2012]. Nano particles have many advantages over the conventional finishing agents such as high durability, good wash fastness, etc due to their smaller size and increased surface area. The application of nano finishes enable ultra strong, durable, and specific function oriented fabrics to be effectively produced for numerous applications such as military, industrial, medical, domestic, apparel, house hold furnishing and many more [Pan et al., 2001]. Nano finishes have been effectively applied to cotton, wool, silk and polyester fabrics. Antibacterial finishes have been applied on cotton, wool, silk and polyester fabrics as well, with the twin objective of protecting the wearer and fabric too. In the case of nano finishing with synthetic textile materials, the aspects to be considered have been odor elimination, antistatic, and antibacterial properties. Nano particle dispersions have also been used in photonic applications besides textile wet processing. Zinc oxide (ZnO) nano particles have been used for antimicrobial properties and protection against UV radiation [Vigneshwaran et al., 2006 & Yadav et al., 2006]. Zinc oxide has been the most preferred among other types of nano particles owing to their superiority with regard to photo-catalytic, electrical, electronics, optical, dermatological and anti-bacterial properties [Parthasarathy et al., 2011 & Rajendran et al., 2010]. Moreover, it has three unique characteristics, namely, semi conductivity, piezoelectricity, and bio safety compatibility. These special characteristics make zinc oxide the most prospective nano material for future textile research. The effect of coating of nano ZnO particles on Polyester fabrics indicates that the antibacterial efficacy and washing stability of coated polyester samples depends on the composition of the coating solution. It has been found that Particles of ZnO in the range of 50 - 300 nm demonstrate better results with regard to antibacterial efficacy after different washing cycles whereas nanoparticles with a size of 10 nm shows improved optical appearance. ZnO concentration up to 20 μg ZnO/cm2 is found to exhibit suitable antibacterial effect and requires cytocompatibility [Claudia et al., 2015]. The influence of various chemical auxiliaries used in finishing operations, the process temperature, pH and the treatment duration on the anti bacterial efficacy of samples of man-made fibers containing ZnO in blends with cotton shows that the influence of those factors on anti bacterial efficacy is less significant. Anti bacterial properties of surface modified polyamide 6 (PA), polyethylene terephthalate (PET) and polypropylene (PP) textiles using zinc oxide reveals that the amount and structure of antibacterial layer on samples is dependent on roughness and wettability of textile surfaces and rougher and more hydrophilic is the material, the more ZnO were deposited [Popescu et al., 2018]. The biggest amount of ZnO microrods was present on PA, then PET and the least on PP. Crystallite sizes and strain values were highest for PET, PA and least for PP samples. Samples show significant bactericidal activity particularly against Gram-negative bacteria [Marta et al.2018]. The antibacterial effect on cotton fabrics modified with nanosized zinc oxide by in situ method using zinc acetate dihydrate as precursors and