| AVS 64th International Symposium & Exhibition | |
| Thin Films Division | Thursday Sessions |
| Session TF-ThP |
| Session: | Thin Films Poster Session |
| Presenter: | Yuki Yamashita, Kogakuin University, Japan |
| Authors: | Y. Yamashita, Kogakuin University, Japan I. Takano, Kogakuin University, Japan |
| Correspondent: | Click to Email |
Recently, the application of polytetrafluoroethylene (PTFE) has spread to various fields. PTFE is a macromolecular material that has repetition of two fluorine atoms combined to a carbon atom. Because these atoms are strongly combined, PTFE has various excellent characteristics such as heat-resistant, chemical stability, low friction, etc. The significant characteristic among them is the high water-repellency which is well known as the coating of a cookware. The improvement of the water-repellency or hydrophilicity has been carried out by using the ion beam or the plasma treatment. In the case of the ion beam, the both properties of PTFE are able to be controlled by suitable ion beam energy.
Higher water-repellency of PTFE is required in a field such as a medical equipment, while higher hydrophilicity is anticipated to adhere between PTFE and the different material. Improvement of water-repellency and hydrophilicity are caused by the physical change of the surface morphology and by the chemical change of the molecular structure respectively.
In this study, the PTFE substrates of two types were used. Those are the adhesive tape type with 0.1mm in a thickness (T-PTFE: Chukoh Chemical Industries, Ltd.) and the sheet type with 1mm in a thickness (N-PTFE: NICHIAS Co.). Water-repellency or hydrophilicity of PTFE irradiated by an Ar+ ion beam was investigated by the θ/2 method. The irradiated ion species were Ar+ ions with 10kV in an acceleration voltage at 40 μA/cm2 in a current density. Dependence of the PTFE substrate temperature was investigated at a range from -50 to 50 degrees using the control system of the liquid nitrogen cooling and the heater heating. Dependence of the irradiation time was changed from 0 s to 30 s in a room temperature. The surface morphology was observed by the laser microscope (OLS4500: Shimadzu Co.) and the SEM (JSM5310: JEOL Ltd.). The surface chemical state was measured using an X-ray photoelectron spectrometer (ESCA-K1s: Shimadzu Co.) .
In the case of the T-PTFE temperature dependence, the surface morphology changed hardly at -50 degrees, while the needle-like structure was clearly observed in the substrate temperature of 50 degrees. It was considered that the surface morphology was strongly influenced by the substrate temperature than by sputtering of the ion beam. From the XPS measurement, it was confirmed that F atoms were selectively sputtered at -50 degrees as showing the low contact angle, while the low contact angle was showed in the lower irradiation time of T-PTFE. It was considered that water-repellency and hydrophilicity of PTFE were influenced by the PTFE substrate temperature during the ion beam irradiation.