Use of Nano Silver as an Antimicrobial Agent for Cotton

In the present study, an attempt has been made to impart antimicrobial finishing on cotton woven fabric using nano silver solution, at various concentrations: 5 gpl, 10 gpl, 15 gpl, 20 gpl, and 25 gpl in the presence of PVOH (5 gpl, 7.5 gpl and 10 gpl) and an eco-friendly cross linking agent, namely 100gpl glyoxal/65 gpl Appretan N 92111 (binder) applied by the pad-dry-cure technique. Curing conditions were varied, keeping curing temperatures at 140 oC, 150 oC, and 160 oC and curing times to 1 min., 2 mins., and 3 mins. To assess the quality of the finished fabric, various properties like tensile strength, bending length, crease recovery angle, and zone of inhibition were studied. The zones of inhibition have been studied using Staphylococcus aureus and Escherichia coli bacteria to determine antimicrobial activity. To observe the polymer formation in the finished fabric, the surface characteristics of these fabrics have been studied using Scanning Electron Microscopy (SEM). In the case of commercial Product A (Sanitized® T 27-22 Silver) treated cotton fabric, the zones of inhibition are a minimum of 24 mm and maximum of 29 mm for Gram-positive bacteria and a minimum of 14 mm and a maximum of 18 mm for Gram-negative bacteria. In the case of commercial Product-B (Sanitized® T 25-25 Silver) treated cotton fabric, the zones of inhibition are a minimum of 24 mm and a maximum of 29.5 mm for Gram-positive bacteria and a minimum 14 mm and a maximum of 18.6 mm for Gram-negative bacteria. SEM study of antimicrobial finished fabric reveals that a continuous polymer film has been formed on the fabric. The concentration of PVOH controls the bending length and crease recovery angle. The higher the concentration of PVOH, the higher will be the bending length and crease recovery angle. Curing temperature and time have a profound impact on tensile strength. The higher the curing temperature and time, the lower the tensile strength.