Effect of AgNP distribution on the cotton fiber on the durability of antibacterial cotton fabrics

Abstract

Silver nanoparticles (AgNPs) loaded on the cotton fiber can endow the fiber with good antibacterial activity, but the AgNPs on the surface of cotton fiber will leach out with the increase of washing times, which will not only greatly reduce the antibacterial properties of cotton fiber, but also cause pollution to the environment. In this paper, carboxyl groups were introduced into cotton fiber by three methods, namely selective oxidation, butane tetracarboxylic acid (BTCA) grafting and polyacrylic acid (PAA) adsorption. The silver ions (Ag+) were adsorbed on the cotton fibers through electrostatic attraction, and after reduction, the AgNPs were loaded onto the cotton fibers, and the AgNP distribution on the fiber and its effect to the washing resistance of AgNPs were studied. The results showed that the carboxyl groups can be introduced onto the cotton fibers by all the three methods, and the reaction only occurred in the amorphous region of the fibers. The selective oxidation and the BTCA grafting can introduce carboxylic groups into the interior of cotton fibers while the PAA adsorption only imports carboxyl groups on the surface of the fiber. As a consequence, AgNPs were formed inside of the cotton fiber when the selective oxidation and the BTCA grafting were employed, while AgNPs can only be loaded on the surface of the fiber by the PAA adsorption method. AgNPs inside of the fiber have high energetic adherence, resulting in silver-cotton fabric nanocomposites with strong slow-release property and long-term antibacterial ability. The fabric nanocomposites prepared by selective oxidation and BTCA grafting exhibited high AgNP retention rate and excellent antibacterial activity even after 80 washing cycles.