The University of Osaka · Materials Science
Professor Yuji Ohkubo's research lab specializes in surface modification of polymers, particularly polytetrafluoroethylene (PTFE), using advanced plasma treatments to enhance adhesion properties without adhesives. The lab focuses on heat-assisted plasma (HAP) treatment, investigating how controlled heating during plasma exposure improves surface reactivity, radical formation, and interfacial bonding with various rubbers and metals. A key direction is developing adhesive-free bonding technologies for industrial applications, especially in sealing and packaging materials, by optimizing plasma parameters and rubber compounding agents like SiO₂. The lab also explores the role of different plasma gases (e.g., He, Ar) and their impact on surface chemistry and adhesion strength.
Figures are computed from collected data and may differ slightly.
Conventional low-temperature plasma treatment was reported to minimally improve the adhesion property of polytetrafluoroethylene (PTFE), whereas heat-assisted plasma (HAP) treatment significantly improved the same. An unvulcanized rubber was previously used as an adherent for PTFE. This study aimed to achieve strong adhesive-free adhesion between PTFE and vulcanized polydimethylsiloxane (PDMS) rubber. As-received vulcanized PDMS rubber did not adhere to HAP-treated PTFE, and as-received PTFE did
The heating effect on the adhesion property of plasma-treated polytetrafluoroethylene (PTFE) was examined. For this purpose, a PTFE sheet was plasma-treated at atmospheric pressure while heating using a halogen heater. When plasma-treated at 8.3 W/cm<sup>2</sup> without using the heater (Low-P), the surface temperature of Low-P was about 95 °C. In contrast, when plasma-treated at 8.3 W/cm<sup>2</sup> while using the heater (Low-P+Heater), the surface temperature of Low-P+Heater was controlled to
Heating during plasma treatment, known as heat-assisted plasma treatment, has recently reported to positively affect the adhesion properties of polytetrafluoroethylene (PTFE). In the present study, the adhesion properties of adhesive bonding and adhesive-free adhesion were compared for plasma-treated PTFE with different plasma treatment times and with or without heating during the plasma treatment. The relations among adhesion strength, plasma treatment time, radical density ratio, surface morph
A polytetrafluoroethylene (PTFE) surface was modified using atmospheric pressure plasma treatment under heating (heat-assisted plasma treatment) to promote its direct adhesion to isobutylene–isoprene rubber (IIR) without any adhesives.
Although heat-assisted plasma treatment enables drastic improvement of the adhesion property of polytetrafluoroethylene (PTFE), plasma-treated PTFE does not strongly adhere to any adherend. To clarify which rubber compounding agents positively affect the adhesion strength of a plasma-treated PTFE/rubber assembly, six types of unvulcanised rubbers were prepared and thermally compressed to a plasma-treated PTFE sheet. Thus, it was found that SiO2 addition to rubber drastically increased the adhesi
Heat-assisted plasma (HAP) treatment using He gas is known to improve the adhesive-bonding and adhesive-free adhesion properties of polytetrafluoroethylene (PTFE). In this study, we investigated the effects of He and Ar gaseous species on the HAP-treated PTFE surface. Epoxy (EP) adhesive-coated stainless steel (SUS304) and isobutylene-isoprene rubber (IIR) were used as adherents for the evaluation of the adhesive-bonding and adhesive-free adhesion properties of PTFE. In the case of adhesive bond
In this study, the effect of plasma treatment on glass-cloth-containing polytetrafluoroethylene (GC-PTFE) was investigated. Previous plasma studies investigated pure PTFE (which does not contain glass cloth) but not GC-PTFE. The effect of Ar + H<sub>2</sub>O plasma treatment on GC-PTFE was investigated. The Ar + H<sub>2</sub>O plasma-treated GC-PTFE sheets were thermally compressed to stainless steel (SUS304) foils without using adhesive, and the GC-PTFE/SUS304 adhesion strengths were measured u
Synchrotron X-ray-induced reduction of Au ions in an aqueous solution with or without support materials is reported. To clarify the process of radiation-induced reduction of metal ions in aqueous solutions in the presence of carbon particles as support materials, in situ time-resolved XANES measurements of Au ions were performed under synchrotron X-ray irradiation. XANES spectra were obtained only when hydrophobic carbon particles were added to the precursor solution containing Au ions. Changes
X-ray photoelectron spectroscopy (XPS) measurements and ab-initio calculations of the XPS chemical shift were performed to identify chemical species of the plasma-treated polytetrafluoroethylene (PTFE) surfaces. The obtained C1s-XPS and O1s-XPS spectra confirmed the generation of oxygen-containing functional groups on plasma-treated PTFE surfaces. We investigated the effect of the substitution of F atoms in a CF2– chain by H atoms on the C1s core level binding energy in PTFE; our calculations sh
Plasma surface treatment is typically not effective on fluoropolymers containing polytetrafluoroethylene (PTFE). It is reported that heat-assisted plasma (HAP) treatment at high temperatures (above 200 °C) under atmospheric pressure helium (He) plasma improves the adhesion properties of PTFE. In this study, we investigated the influence of the air concentration during HAP treatment on the adhesion properties of PTFE. Air concentration was controlled <i>via</i> ambient air inflow amount, in other
Abstract We performed an open-air-type plasma treatment of polytetrafluoroethylene (PTFE) at atmospheric pressure to increase the adhesion strength between PTFE and an Ag metal film obtained from Ag ink. When PTFE was Ar plasma-treated without H 2 O addition for 600 s, the coloration of the PTFE surface occurred, and the Ag/PTFE adhesion strength was 0.06 N mm −1 . This adhesion strength was the same as that of the as-received PTFE (0.04 N mm −1 ). When the PTFE was Ar plasma-treated with the H
Atmospheric pressure plasma treatment and surface graft polymerization were applied to a polytetrafluoroethylene(PTFE)sheet to improve adhesion strength between the PTFE sheet and electroless-plated Cu film. The surface temperature of the PTFE sheet during plasma treatment was adjusted via applied radio-frequency(RF)power for plasma treatment. For applied RF power at 25 W, the maximum surface temperature was ca. 100 ℃. For applied RF power at 65 W, the maximum surface temperature was ca. 280 ℃,
Open papers in the app to read, cite, and organize with AI.