اصلاح سطح الاستومر سيليكون به منظور افزايش آبگريزي آن

Surface Modification of Silicone Elastomer to Increase Hydrophobicity

For surface modification of silicone coatings two methods have been adopted. In the first method the surface of the polymer was exposed to CO2 pulse laser in air at ambient condition. In the second method chemical agents were used to make porous polymer. The chemical changes of the modified surface were studied by attenuated total reflectance fourier transform infrared spectroscopy. The morphology of the samplesʹ surface were examined hy SEM and the degree of their hydrophobicity were determined by water drop contact angle and the obtained results were compared with the control samples. SEM pictures show interesting morphology in the way that the polymer surface modification is the same with both methods employed. The changes in water drop contact angle confirms the super hydrophobicity nature of silicone surface for irradiated surface. But, the modified sample by foaming method does not exhibit such results. Scanning electron microsecopy and FTIR studies indicated that porosity formed onto the surface of irradiated PDMS and a composite layer comprising air pocket and fragmented chains induced hydrophobicity. However, irradiation caused variations on molecular configuration of PDMS chains. These two important parameters might affect hydrophobicity greater for irradiated samples in comparison with control (unmodified) and/or modified samples by foaming method.