| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2016) | |
| Nanomaterials | Wednesday Sessions |
| Session NM-WeP |
| Session: | Nanomaterials 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) spreads to various fields. PTFE is a macromolecular material that has the repetition of two fluorine atoms combined to a carbon atom. Because these atoms are strongly combined, PTFE has variously excellent characteristics such as a heat-resistant, an electrical insulation, a chemical stability, a 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 by modifying the PTFE surface morphology has been carried out by using the ion beam or the plasma treatment. In this case, the morphological change of the PTFE surface is caused by the heat and sputtering.
In the present study, the temperature dependence of the PTFE surface morphology irradiated by an Ar+ ion beam was investigated. Two kinds of PTFE were used. They are the adhesive tape type (T-PTFE; Nitto Denko Corporation.) and the sheet type (N-PTFE; NICHIAS Corporation). The irradiated ion species were Ar+ ions with 10 kV in an acceleration voltage at 40 μA/cm2 in a current density. The temperature of PTFE substrates was controlled by the both of liquid nitrogen cooling and the heater heating, and was kept with -50, -25, 0, 25 and 50 degrees. The surface morphology was observed by the laser microscope (OLS4500 OLYMPUS) and the SEM (JSM-5310LV JEOL). The modified surface was evaluated about the water-repellency which was measured by the water-contact-angle meter (Kyowa Interface Science Co, Ltd.) using the θ/2 method. The surface chemical state was investigated using X-ray photoelectron spectroscopy (SHIMADZU Co.Ltd.).
In the same condition of the ion beam irradiation, the T-PTFE surface morphology changed by the T-PTFE substrate temperature. In the case of -50 degrees the surface change was hardly observed, 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. In addition, the atomic concentration measured by the X-ray photoelectron spectroscopy showed that fluorine atoms decreased and carbon atoms increased with a lower temperature, because the preferential sputtering was caused. On the other hand, oxygen atoms increased with a lower temperature because free bonds generated by the removed fluorine atoms from T-PTFE absorbed oxygen atoms in the atmosphere.
It was confirmed that the change of the PTFE substrate temperature in ion irradiation influenced the surface morphology and the atomic content.