Antibacterial activity on Polyamide and Natural fabrics using Low Temperature Plasma S.Shahidi *,** , A.Rashidi ** , J.Wiener * and M.Ghoranneviss ** * Department of Textile Chemistry, Faculty of Textile, Technical University of Liberec, Liberec, Czech Republic, sheila.shahidi@tul.cz ** Plasma Physics Research Center, Science and Research Campus, Islamic Azad University, P.O.Box: 14665-678, Tehran, Iran ABSTRACT Low-temperature plasma is generated when a gas at low pressure and near ambient temperature is exposed to an electric field and contains radicals, ions, electrons, photons and other excited species. These species can interact either physically or chemically with the substrate surface to a depth of a few tenths of nanometers, due to their high reactivity. The advantages of plasma technology for making suitable implants or medical devices are both technological and administrative. The techniques are easy to implement, reproducible, clean and can be set up in any type of clean room. The techniques are non pollutant, there are no organic residuals. Plasma treatment can be used to create a functionalized surface through attachment of new chemical groups. In the present paper, we have investigated the possibility of obtaining antibacterial fabric with views on their application on dressings by using a single process, plasmas sputtering. Also the other modification investigated consisted of an Oxygen glow discharge pre- functionalization, followed by a one-step wet-treatment in silver nitrate. The surface was first activated by O2 plasma to produce more hydrophilic groups so that silver could be coated more effectively on the surface. Different fabrics such as cotton and polyamide have been treated; their surface properties have been studied by different techniques, and correlated to their antibacterial action. Keywords: Fabric, Antibacterial, Cotton, Polyamide, Low Temperature Plasma 1 INTRODUCTION In recent years, the demand for antibacterial fabrics in domestic and abroad markets has grown significantly because of more awareness of the potential threat of spreading diseases. Bio-protective fabrics such as medical clothes, protective garments, and hygienic textiles are the main application of the antibacterial fibers [1]. Natural textiles such as those made from cellulose and protein fibers are often considered to be more vulnerable to microbe attack than man-made fibers because of their hydrophilic porous structure and moisture transport characteristics. Thus, the use of antibacterial agents to prevent or retard the growth of bacteria is becoming a standard finishing for textile goods. There is, however, an increasing public concern over the possible effects of antibacterial finishing on environmental and biological systems since many antibacterial agents are toxic chemicals. They are also lack of efficiency and durability. Thus, an ideal textile antibacterial finishing should be safe and environmentally benign besides killing undesirable micro-organisms [2]. Also Polyamide (PA) synthetic textiles are among the most used fibers in the biomedical textile field [3]. The formation of nano-structured surfaces gained high interest due to their large surface area which might yield a highly functional surface. The main approach is the incorporation of nano particles into wet-chemical coatings or compounds. However, some difficulties during the handling of nano particles (agglomeration, nano toxicology) and concerning the distribution of nano particles at the surface as well as mechanical durability occur. Nanoporous structures, on the other hand, which can be obtained by plasma polymerization/etching processes might avoid these issues and yield an even higher surface area. Furthermore, nano particles with homogeneous size and spatial distribution can also be embedded in situ by a plasma polymerization/co-sputtering process. Products made with the help of textiles and fibers become more and more sophisticated and multifunctional . Tailored surface modifications are required to meet customer needs and to assure a share in the market. However, conventional finishing techniques applied to textiles (dyeing, stain repellence, flame retardance, antibacterial treatments) generally use wet-chemical process steps and produce a lot of wastewater. Plasma treatment, on the other hand, as a dry and eco-friendly technology, is offering an attractive alternative to add new functionalities such as water repellence, long-term hydrophilicity, mechanical, electrical and antibacterial properties as well as biocompatibility due to the nano-scaled modification on textiles and fiber. At the same time, the bulk properties as well as the touch of the textiles remain unaffected [4-11] In the present paper, we have investigated the possibility of obtaining antibacterial fabric with views on their application on dressings by using a single process, plasmas sputtering. Also the other modification investigated consisted of an Oxygen glow discharge pre-functionalization, followed by a one-step wet-treatment in silver nitrate. The surface was first activated by O2 plasma to produce more hydrophilic groups so that silver could be coated more effectively on the NSTI-Nanotech 2009, www.nsti.org, ISBN 978-1-4398-1784-1 Vol. 3, 2009 210