Effect of Plasma Pre-Treatment on the Dyeability of Silk Fabric with Metal-Complex Dye Wenyi Wang 1, a , Hei-Ting Choi 1, b , Chi-Wai Kan 1, c* , Phichitphol Jaroensappayanant 2, d , Pannarai Rug-Ngam 3, e , Kemachart Surakul 4, f and Rattanaphol Mongkholrattanasit 2, g* 1 Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China. 2 Faculty of Industrial Textiles and Fashion Design, Rajamangala University of Technology Phra Nakhon, Bangkok, Thailand. 3 Deapartment of Textile Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi, Pathum thani, Thailand 4 Faculty of Textile Industry, Rajamangala University of Technology Krungthep, Bangkok, Thailand a wangwenyi1111@gmail.com, b 14033602d@connect.polyu.hk, c tccwk@polyu.edu.hk, d phichitphol.j@rmutp.ac.th, e pannarai.r@hotmail.com, f kemachart.s@mail.rmutk.ac.th, g rattanaphol.m@rmutp.ac.th Keywords: Plasma, Pre-treatment, Dyeability, Silk, Metal-complex dye Abstract. Plasma technology is an effective way to modify the physicochemical properties of silk fabric. This study was a preliminary study to explore the dyeability of silk fabric with metal complex dyes after treated with plasma technology, which may improve the processability and broaden the application of silk fabric. This study investigated the optimal plasma treatment condition and evaluated treated silk fabric in terms of wettability, surface modification and dyeability. It was found that plasma treatment can enhance the wettability and dyeability of silk fabric via the formation of hydrophilic functional groups in the structure of silk fiber. Introduction Silk is one of the most popular protein fiber and has become the symbol of royalty in ancient times because of its unique properties like wearing comfort, soft handle, good air permeability and elegant appearance [1]. Silk fiber is constructed with two different protein-based layers-fibroin in an inner layer and a sericin coating in an outer layer. Fibroin is the structural protein of silk fiber, whereas sericin is the water soluble proteinaceous glue that serves to bond the fibers together [2]. Silk processing from cocoons to the finished clothing materials consists of a series of steps, such as reeling, weaving, degumming, dyeing or printing, and finishing. Acid dyes are commonly used for the dyeing of silk fabrics. Nevertheless, the properties of silk fiber are often influenced by acids which are generally used as the additives and auxiliaries in the dyeing process [3]. Moreover, the color fastness to wash is usually unsatisfactory. Thus, surface modifications of silk fiber, such as plasma treatment, is often used to address these questions. Plasma modification is one of the effective ways for the surface treatment of textile materials, since plasma treatment could modify the chemical and the physical properties of the surface of the textile materials without affecting the original bulk properties of the textile materials [4]. Plasma treatment provides possibilities to refine a textile material surface, enabled by the adjustment of parameters like gas flows, power, pressure and treatment time [5]. Plasma treatment of textile material surface causes not only a modification during the plasma exposure, but also leaves active sites at the surfaces which are subject to post-reaction. It has been proved that the hydrophobic characteristic of silk can be promoted with the aid of plasma treatment [6-8]. The present study is to investigate the application of plasma treatment in the surface modification of silk fiber dyed with metal complex dyes. Key Engineering Materials Submitted: 2019-02-19 ISSN: 1662-9795, Vol. 818, pp 21-25 Revised: 2019-05-20 doi:10.4028/www.scientific.net/KEM.818.21 Accepted: 2019-06-03 © 2019 Trans Tech Publications Ltd, Switzerland Online: 2019-08-19 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications Ltd, www.scientific.net. (#507221050-29/07/19,17:15:29)