Progress in Organic Coatings 58 (2007) 237–240 Nanostructured plasma coatings to obtain multifunctional textile surfaces Dirk Hegemann ∗ , M. Mokbul Hossain, Dawn J. Balazs Empa, Swiss Materials Science & Technology, Lerchenfeldstrasse 5, CH-9014 St.Gallen, Switzerland Received 1 June 2006; accepted 30 August 2006 Abstract Nanostructured surfaces are of great interest, since they provide a high surface area. A high functionality can thus be obtained by ultrathin coatings. Plasma polymerization of acetylene mixed with ammonia (C 2 H 2 /NH 3 ) was used in a regime where both deposition and etching processes took place yielding a nanoporous, crosslinked network with accessible functional groups. These plasma coatings can be used as permanent hydrophilic treatment or for substrate-independent dyeing when deposited on textile fabrics. Increasing color intensity with film thickness proved that accessible amine groups were deposited within a nanoporous hydrocarbon matrix. Using plasma co-sputtering of a silver target, Ag nano particles can be in situ embedded within the growing plasma polymer yielding a well-defined size and distribution of nano particles at the coating surface. Hence, an anti-microbial activity was achieved. Multifunctional textile surfaces can thus be obtained by adjusting combined properties such as wettability, functional group density as well as anti-bacterial and bio-responsive surfaces. Scale-up of these combined plasma processes is enabled by control of plasma chemistry regarding energy input into the plasma zone and plasma physics by surface interaction with energetic particles. © 2006 Elsevier B.V. All rights reserved. Keywords: Plasma polymerization; Functionalization; Nano structuring; Nano particles; Textiles 1. Introduction The formation of nanostructured surfaces gained high interest due to their large surface area which might yield a highly func- tional surface [1]. The main approach is the incorporation of nano particles into wet-chemical coatings or compounds. How- ever, some difficulties during the handling of nano particles (agglomeration, nano toxicology) and concerning the distri- bution 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 pro- cesses might avoid these issues and yield an even higher surface area [2,3]. 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 ∗ Corresponding author. Tel.: +41 71 274 7268; fax: +41 71 274 7569. E-mail address: dirk.hegemann@empa.ch (D. Hegemann). 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 func- tionalities such as water repellence, long-term hydrophilicity, mechanical, electrical and antibacterial properties as well as bio- compatibility due to the nano-scaled modification on textiles and fibers [2]. At the same time, the bulk properties as well as the touch of the textiles remain unaffected. Plasma polymerization can be used to obtain highly crosslinked plasma coatings, e.g. by using simple hydrocar- bons. When non-polymerizable gases such as Ar, CO 2 or NH 3 are added to the gas discharge chemical etching and sputter- ing effects can be used to modify the film growth [4]. Thus, interconnected voids could be obtained within a-C:H:N films [5]. Therefore, we investigated gases mixtures of C 2 H 2 /NH 3 /Ar within low pressure RF discharges to obtain nanoporous coat- ings and to incorporate Ag nano particles from a silver target during film growth. 2. Experimental RF plasma reactors working at 13.56 MHz coupled to an internal electrode were used for plasma polymerization. Beside 0300-9440/$ – see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.porgcoat.2006.08.027