Enhanced Reactive Dye Inkjet Printing Performance of Antimicrobial Silk Fabrics Surface Modified with Plasma and Chitosan

Abstract

This paper develops a new clean production technology combining atmospheric pressure plasma jets and nano-chitosan to prepare strong and durable bio-based coatings for improving the inkjet printing performance of antimicrobial silk fabrics. The key contribution of this study is to introduce green and environmental friendly production methods, avoiding the use of chemicals and pollution caused by dye hydrolysis in traditional ways. By contradistinctive experiments, we present direct empirical evidence that the plasma-chitosan treatment can significantly improve the hydrophilicity of the silk surfaces. Wettability test indicates that the infiltration time of droplet on the surface of modified silk fabric was only 1/12 of the time spent on the untreated sample. The study of reactive dye inkjet printing illustrates that the antibleeding property on modified samples was evidently enhanced. Meanwhile, in respect of color fixation of reactive dyes, there was also an increase in K/S value on modified samples, ranging from 76 % to 214 % in color depth of the four-color print blocks, even after gas steaming and washing. Scanning electron microscope (SEM) observation reveals that the surface of silk fibers modified with plasma is covered with firmer and more uniform chitosan coatings in terms of morphology change. X-ray photoelectron spectroscopy (XPS) analysis verifies that the content of oxygenous groups on the silk fabric processed by plasma-chitosan increased by more than 42 %. As to the antibacterial effect of nano-chitosan, the photographs of inhibition zone shows that the plasma processing effectively enhanced the durability of chitosan against B. subtilis, and thus prepared long-lasting antibacterial silk fabric. Furthermore, measurements of washing and rubbing color fastness prove that the plasma-chitosan treated fabrics still had excellent inkjet printing effect even after 45 cycles of soa**. Taken together, it turns out that such nontoxic, nonpolluting, low energy-consumed chitosan coating combining with plasma can explicitly provide an innovative option for the production of inkjet printing on natural fabrics.