Investigation on surface wettability and surface structure of PTFE after remote oxygen plasma treatment

Improving the strength of the bonding of zirconia to composite resins remains a challenge in dental restorations. The purpose of this study was to evaluate the shear strength of the bonding of zirconia to composite resins, thereby verifying the hypothesis that as the power of the non-thermal oxygen plasma increases, the bonding strength of the plasma-treated zirconia is increased. The effects of the oxygen plasma power (100, 200, and 400 W) on the surface structure, chemical composition, and hydrophilicity of the zirconia and the strength of the bonding between zirconia and composite resin were investigated. As a result, after different plasma power treatments, the surface structure and phase composition of zirconia were not different from those of zirconia without treatment. However, the oxygen plasma treatment not only reduced carbon adsorption but also greatly increased the hydrophilicity of the zirconia surface. More importantly, the strength of the bonding between the plasma-treated zirconia and composite resin was significantly higher than that in the corresponding control group without plasma treatment. Regardless of whether the zirconia was pristine or sandblasted, the higher the plasma power, the greater the bond strength obtained. The conclusion is that the oxygen plasma treatment of zirconia can effectively improve the strength of the bonding between the zirconia and composite resin without damaging the microstructure and phase composition of the zirconia.

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High Breakdown Voltage GaN HEMT Device Fabricated on Self-Standing GaN Substrate

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.347-350.1535 ◽

2013 ◽

Vol 347-350 ◽

pp. 1535-1539

Author(s):

Jian Jun Zhou ◽

Liang Li ◽

Hai Yan Lu ◽

Ceng Kong ◽

Yue Chan Kong ◽

...

Keyword(s):

Plasma Treatment ◽

Breakdown Voltage ◽

Oxygen Plasma ◽

Cutoff Frequency ◽

Chemical Vapor ◽

Current Gain ◽

Organic Chemical ◽

Oxygen Plasma Treatment ◽

Gan Hemt ◽

High Breakdown Voltage

In this letter, a high breakdown voltage GaN HEMT device fabricated on semi-insulating self-standing GaN substrate is presented. High quality AlGaN/GaN epilayer was grown on self-standing GaN substrate by metal organic chemical vapor deposition. A 0.8μm gate length GaN HEMT device was fabricated with oxygen plasma treatment. By using oxygen plasma treatment, gate forward working voltage is increased, and a breakdown voltage of more than 170V is demonstrated. The measured maximum drain current of the device is larger than 700 mA/mm at 4V gate bias voltage. The maximum transconductance of the device is 162 mS/mm. In addition, high frequency performance of the GaN HEMT device is also obtained. The current gain cutoff frequency and power gain cutoff frequency are 19.7 GHz and 32.8 GHz, respectively. A high fT-LG product of 15.76 GHzμm indicating that homoepitaxy technology is helpful to improve the frequency performance of the device.

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LDI-MS examination of oxygen plasma modified polymer for designing tailored implant biointerfaces

RSC Advances ◽

10.1039/c4ra02656j ◽

2014 ◽

Vol 4 (50) ◽

pp. 26240-26243 ◽

Cited By ~ 10

Author(s):

M. Gołda-Cępa ◽

N. Aminlashgari ◽

M. Hakkarainen ◽

K. Engvall ◽

A. Kotarba

Keyword(s):

Plasma Treatment ◽

Oxygen Plasma ◽

Oxygen Plasma Treatment ◽

Parylene C ◽

Modified Polymer

A versatile parylene C coating for biomaterials was fabricated by the mild oxygen plasma treatment and examined by the use of LDI-MS..

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Improved Affinity to Metallization of Graphite/Polymer Composites by Oxygen Plasma Treatment

Materials Science Forum ◽

10.4028/www.scientific.net/msf.437-438.81 ◽

2003 ◽

Vol 437-438 ◽

pp. 81-84 ◽

Cited By ~ 5

Author(s):

Miran Mozetič ◽

Anton Zalar

Keyword(s):

Plasma Treatment ◽

Polymer Composites ◽

Oxygen Plasma ◽

Oxygen Plasma Treatment

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Tuning the Surface Wettability of Cyclic Olefin Copolymer by Plasma Treatment and Graphene Oxide Deposition and Reduction

Polymers ◽

10.3390/polym13142305 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2305

Author(s):

Fadi Dawaymeh ◽

Yawar Abbas ◽

Maryam Khaleel ◽

Anas Alazzam ◽

Nahla Alamoodi

Keyword(s):

Contact Angle ◽

Plasma Treatment ◽

Treatment Duration ◽

Chemical Reduction ◽

Surface Wettability ◽

Oxygen Plasma Treatment ◽

Microfluidic Channels ◽

Cyclic Olefin Copolymer ◽

Cyclic Olefin ◽

Reduction Methods

Selective altering of surface wettability in microfluidic channels provides a suitable platform for a large range of processes, such as the phase separation of multiphase systems, synthesis of reaction controlled, nanoliter sized droplet reactors, and catalyst impregnation. Herein we study the feasibility to tune the wettability of a flexible cyclic olefin copolymer (COC). Two methods were considered for enhancing the surface hydrophilicity. The first is argon/oxygen plasma treatment, where the effect of treatment duration on water contact angle and COC surface morphology and chemistry were investigated, and the second is coating COC with GO dispersions of different concentrations. For enhancing the hydrophobicity of GO-coated COC surfaces, three reduction methods were considered: chemical reduction by Hydroiodic acid (HI), thermal reduction, and photo reduction by exposure of GO-coated COC to UV light. The results show that as the GO concentration and plasma treatment duration increased, a significant decrease in contact angle was observed, which confirmed the ability to enhance the wettability of the COC surface. The increase in hydrophilicity during plasma treatment was associated with the increase in surface roughness on the treated surfaces, while the increase during GO coating was associated with introducing oxygen-containing groups on the GO-coated COC surfaces. The results also show that the different reduction methods considered can increase the contact angle and improve the hydrophobicity of a GO-coated COC surface. It was found that the significant improvement in hydrophobicity was related to the reduction of oxygen-containing groups on the GO-coated COC modified surface.

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