Paper PS2-ThA8
Plasma Polymerization on Textiles: Deposition of Functional Nanostructured Thin Films

Thursday, October 23, 2008, 4:20 pm, Room 306

A shift towards highly functional and added-value textiles is now recognized as being essential to the sustainable growth of the textile and clothing industry in developed countries. The demand for tailored surface modifications for water repellence, long-term hydrophilicity, anti-bacterial properties, etc, is therefore increasing. At the same time, the environmental restrictions concerning the waste water produced by conventional textile finishing techniques are getting more and more severe. In this context, plasma processing is seen as an attractive alternative method to add new functionalities to textiles since it is a versatile and eco-friendly (dry) technology. Because plasma processing results in a nano-scaled surface modification, it also has the advantage of preserving the bulk properties as well as the touch of the textiles. In this study, plasma polymer thin films have been deposited on various polyester fabrics of defined structure using NH₃/C₂H₄/Ar low pressure RF glow discharges. The films were first characterized using XPS, FTIR and AFM as a function of the plasma process parameters. For a defined range of energy input and NH₃/C₂H₄ gas flow ratio, the coatings are nanostructured and contain predominantly amine functional groups. Interestingly, these films can thus serve as nanostructured templates for further surface functionalization. For example, they can be used to selectively bind acid dyestuff molecules, allowing a very efficient low temperature and substrate independent dyeing. The amine groups contained in the films were also derivatized with molecules containing OH and CF₃ groups. Due to the nano roughness and the high specific surface area of the films, super-hydrophilic or -hydrophobic properties are obtained. The hydrophilicity of the various coated fabrics was compared by monitoring the spreading of water droplets with infrared thermography. Results show that the textile structure has an important influence on the final properties. This is discussed in terms of capillary effects and accessibility of the textiles structures to the plasma species. Finally, the properties of the coated fabrics remain generally rather stable during abrasion tests, presumably due to the high crosslinking degree of the films. The scalability of the process investigated in this work has been demonstrated using a pilot-scale continuous web coater.