From bellow images it is seen that no new chemical bonds on Kevlar or Nomex fibers are created after plasma treatment at atmospheric pressure in the air. FT-IR results PLASMA TREATMENT OF KEVLAR AND NOMEX Marie Štěpánková 1, Jan Grégr 2, Jakub Wiener 3, Jana Müllerová 4, Jana Grabmüllerová 5 1,3 Technical University of Liberec, Department of Textile Chemistry, Textile Faculty, Czech Republic 2,4 Technical University of Liberec,Department of Chemistry, Faculty of Education, Czech Republic 5 Technical University of Liberec, Department of Textile Materials untreated Nomex plasma treated Nomex (2 min)plasma treated Nomex (5 min) untreated Kevlar plasma treated Kevlar (2 min) plasma treated Kevlar (5 min) Plasma technology performed under atmospheric pressure is used to modify the chemical structure and also topography of the surface of the material. Fields of application can be: desizing, funcionalizing, and design of surface properties of textile fibers. Dielectric barrier discharge is broadly used for atmospheric pressure treatment of large movable materials. Surfaces of textile fibers can be modify with dielectric barrier discharge without modifying the bulk properties. This paper is focused on plasma application on Kevlar and Nomex fibers. These fibres are typical species of aromatic polyamide. They assert the using in large field – reinforcing of composites, reinforcing of tires, bullet proof application and so on. Most of these applications require. The influence of plasma treatment on Kevlar and Nomex fibers is discussed. Introduction Kevlar and Nomex fibers were treated by means of the plasma source of Diffuse Coplanar Surface Barrier Discharge (DCSBD). Model of used equipment is DSCBD A4-LIN, which means that is device with linear displace working at atmospheric pressure. The power of generated discharge was 300 W and frequency 15 kHz. Before plasma treatment Kevlar and Nomex fibers were rinsed twice in iso-propyl alcohol. Flocks of fibres were exposed to plasma ranging from 2 to 5 minutes. In this case the air was the operational gas. The structure and the appearance of fibres surfaces was observed with using of scanning electron microscope (SEM) on device VEGA. The alternative method to value fibre surface is infrared spectroscopy. For this analysis we used device FT-IR Spectrometer One by Perkin Elmer – ATR Technique on ZnSe crystals. Experiment This analysis was performed to detect changes in chemical composition of fiber surfaces. After plasma treatment, the concentrations of oxygen increased for plasma treated Kevlar and Nomex fibers. The concentrations of nitrogen increased at two minutes plasma treated Kevlar and Nomex fibers and decreased at five minutes plasma treated Kevlar and Nomex fibers. Surface oxidation is possible due to the existence of reactive species from the plasma. XPS results This research has been supported by KAN Nomex fiber Kevlar fiber T here are presented results of surface properties of Kevlar and Nomex fibers before and after plasma treatment. For plasma treatment of samples source of Diffuse Coplanar Surface Barrier Discharge (DCSBD) was used at atmospheric pressure. According obtained results changes in fibre surfaces relates to formation or extinction of chemical groups. Due to the existence of reactive species from plasma, there is possibility of surface oxidation. Conclusion untreated Nomex plasma treated Nomex (2 min) plasma treated Nomex (5 min) untreated Kevlar plasma treated Kevlar (2 min) plasma treated Kevlar (5 min) C1s spectra analysis of Nomex fibers: FT-IR spectrum of Kevlar fiber FT-IR spectrum of Nomex fiber C1s spectra analysis of Kevlar fibers: Chemical changes of fibre surface after application of plasma in the air are visible. From bellow SEM images it is seen that samples of plasma modified Kevlar fiber have rougher surface than untreated Kevlar fiber. As shown in bellow images, apparently Nomex fiber is smoother than samples of plasma treated Nomex fibers. SEM results