Surface modification of fluorocarbon polymers by synchrotron radiation

The surface modification of a poly(tetrafluoroethylene) sheet was carried out by synchrotron radiation in the soft X-ray region. The poly(tetrafluoroethylene) substrate was exposed to synchrotron radiation while varying the substrate temperature from room temperature to 200degreesC. The contact angle of the modified surfaces with a water drop decreased from 96degrees to 72degrees by the irradiation at room temperature, while the contact angle increased to 143degrees by the irradiation at the substrate temperature of 200degreesC. Scanning electron microscopy suggested that this repellence was ascribable to the microstructure of the poly (tetrafluoroethylene) surface. We succeeded in controlling the wettability of the poly (tetrafluoroethylene) surface from hydrophobic to hydrophilic by irradiation of the soft X-ray light.