| AVS 65th International Symposium & Exhibition | |
| Thin Films Division | Thursday Sessions |
| Session TF-ThP |
| Session: | Thin Film Poster Session |
| Presenter: | Koki Iesaka, Kogakuin University, Japan |
| Authors: | K. Iesaka, Kogakuin University, Japan I. Takano, Kogakuin University, Japan |
| Correspondent: | Click to Email |
Polytetrafluoroethylene (PTFE) has excellent characteristics such as low friction coefficient, flame retardancy, electrical insulation, chemical resistance, etc. By utilizing these characteristics, PTFE is applied in various fields such as semiconductors, chemical plants, automobiles, etc. Furthermore, improvement of water repellency or hydrophilicity for PTFE leads to development of a new material with high-performance characteristics or a wider application.
In this study, two types of PTFE were used as samples. Those were a fluororesin adhesive tape (NITTO ) referred as T-PTFE in this paper and a NAFLON sheet (NICHIAS) referred as N-PTFE. The experimental conditions were 120 - 1200 s in an irradiation time and 50 - 200 W in an RF input power of Ar plasma under an ultimate pressure of < 6.0x10-6 Pa. The observation of the surface morphology was carried out by a laser microscope (OLS 4500; OLYMPUS Co. Ltd.) and a field emission Auger micro probe (JAMP-9500F; JEOL Ltd.). The determination of the surface characteristics was carried out using a contact angle meter (DM-300; Kyowa Kaimen Kagaku Co. Ltd.) about a contact angle of water and X-ray photoelectron spectroscopy (ESCA-K1S; SHIMADZU Co. Ltd.) about a surface chemical state.
In the case ofN-PTFE, the surface C and O atomic concentration measured by X-ray photoelectron spectroscopy gradually increased until 120 s in an Ar plasma treatment time. Over 120 s those concentration gradually decreased and approached those of the untreated N-PTFE at 600 s. On the other hand, from the contact angle measurement of water, the surface characteristic gradually changed to hydrophilicity until 120 s as compared to the untreated N-PTFE. It was considered that the CF2 bonds of PTFE which induced water repellency decreased by preferential sputtering of F and the free bonds of C absorbed O2 of the air or H2O.
The large treatment energy such as ion beams caused the formation of the needle-like morphology, while the low energy of Ar plasma changed only a chemical state regardless of a treatment time. It became clear that the treatment energy for the stable polymer like PTFE influenced the chemical state or the morphology.