ESEM Study of Wetting of Untreated and Plasma Treated Polypropylene Fibers

Polypropylene (PP) fibers have been increasingly used in the technical textile industry for a variety of applications. Wetting behavior of PP fibers is of importance in these applications. The wetting behavior of the untreated and oxygen plasma treated polypropylene fibers was studied by the environmental scanning electron microscope (ESEM) in this work. Water droplets were formed on the cooled fibers by directly condensing water from the vapor phase. This was achieved by slowly increasing the vapor pressure inside the chamber towards the dew point for water at the appropriate specimen temperature. By this method small droplets in the micron range were condensed onto fiber surfaces. Contact angles of water on fiber surfaces were measured from the ESEM micrographs. The investigations have shown that the plasma treatment significantly altered the surface wettability of polypropylene fibers and that the ESEM provides a new approach to wetting and contact angle of fibers on the micron scale.