Fenglin Huang

Preparation And Characterizations Of Ptfe Gradient Nanostructure On Silk Fabric

Superhydrophobic materials have been extensively studied because of their wonderful array of properties and applications. In this study, normal and superhydrophobic surface of silk fabric have been prepared via deposition of different shapes of PTFE nanostructure using magnetron sputter coating. The effects of PTFE sputter coating on surface morphology and surface chemical properties were characterized using atomic force microscopy (AFM) and ATR-FTIR (attenuated total reflection-Fourier transform infrared spectroscopy). The wettability of the fabric was characterized through measuring the surface contact angle by drop shape analysis apparatus and dynamic contact angle by Wilhelmy technique. As evaluated by water contact angle measurements, all the treatments resulted in a significant enhancement in the hydrophobicity of silk fabric, while larger sputtering pressures brought bigger PTFE nanoparticles, which led to higher contact angles. The results have also revealed that alternant working pressures, could bring gradient nanostructures which generated both high contact angle and less contact angle hysteresis.

Surface Funtionalization of Polymer Fibers by Sputter Coating

Polymer fibers are widely used in many industries, ranging from filtration, composites, tissue engineering, and electronics. The surface properties of polymer fibers are of importance in these applications. The surface properties of polymer fibers can be modified by different techniques. In this study, magnetron sputter coatings are used to generate functional nanostructures on polymer fiber surfaces. Conducting aluminum (Al) film, piezoelectric aluminum nitride (AlN) film, and ceramic film of aluminum oxide (Al2O3) are deposited onto polyethylene terephthalate (PET) fibers at low temperature. The surface topography and compositions of the funtionalized fibers are characterized by optical microscopy, scanning probe microscopy (SPM), and environmental scanning electron microscopy (ESEM). The observations by SPM reveal the different morphology of the fibers with different coatings. The examination by the ESEM equipped with a full energy dispersive X-ray (EDX) analysis indicates the change in the chemical compositions of the fiber surfaces.

CHARACTERIZATION OF DYNAMIC WETTING OF PLASMA-TREATED PTFE FILM

Polytetrafluoroethylene (PTFE) has been increasingly used in many industries due to its low frictional coefficient and excellent chemical inertness. The surface properties of PTFE are of importance in various applications. The surface properties of PTFE can be modified by different techniques. In this study, PTFE film was treated in oxygen plasma for improving surface wettability. The effects of plasma treatment on dynamic wetting behavior were characterized using Scanning Probe Microscopy (SPM), Fourier transform infrared spectroscopy (FTIR), and dynamic contact angle (DCA) measurements. SPM observations revealed the etching effect of the plasma treatment on the film. The introduction of hydrophilic groups by plasma treatment was detected by FTIR. The roughened and functionalized surface resulted in the change in both advancing and receding contact angles. Advancing and receding contact angles were significantly reduced, but the contact angle hysteresis was obviously increased after plasma treatment.