Modification of the Transmittance of Bulk Polytetrafluoroethylene via Synchrotron Radiation Irradiation

We demonstrate the modification of transmittance of bulk polytetrafluoroethylene (PTFE) via synchrotron X-ray irradiation. X-ray irradiation of the PTFE substrate is conducted to mechanically suppress the photoevaporation of PTFE molecules. This method drastically increases the ultraviolet and visible transmittance of the irradiated areas of the substrates, with greater than 80% transmittance observed at the 350-nm wavelength. We observed the irradiated area via scanning electron microscopy and determined that this optical property modification is due to the homogenization of the bulk PTFE texture with nanometer to micron-sized pores. We expect that this modified PTFE will be employed as a construction material for various micro system devices such as Lab-on-a-chip and micro total analysis systems.