Surface Hydrophilicity Improvement of RGP Contact Lens Material by Oxygen Plasma Treatment

2009 ◽  
Vol 610-613 ◽  
pp. 1268-1272 ◽  
Author(s):  
Shi Heng Yin ◽  
Ying Jun Wang ◽  
Li Ren ◽  
Lian Na Zhao ◽  
Hao Chen ◽  
...  

Oxygen plasma was employed to treat a fluorosilicone acrylate RGP contact lens material (Boston EO) in order to improve surface hydrophilicity. X-ray photoelectron spectroscopy (XPS) was applied to characterize the surface chemical state. The surface morphology and hydrophilicity were investigated by scanning electron microscope (SEM) and contact angle measurement respectively. The surface contact angle measurement indicated an evident improvement of surface hydrophilicity after plasma treatment. XPS results indicated that the incorporation of oxygen and the transform of -Si-CH3 into hydrophilic -Si-O after plasma treatment were the main reasons for surface hydrophilicity improvement. SEM showed some decrease of surface roughness under moderate plasma condition. But plasma with higher power would etch the material surface.

Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 394
Author(s):  
Hsin-Yi Tsai ◽  
Yu-Chen Hsieh ◽  
Yu-Hsuan Lin ◽  
Han-Chao Chang ◽  
Yu-Hsiang Tang ◽  
...  

The widely used rigid gas permeable (RGP) contact lenses provide higher oxygen permeability and tear exchange rate than do soft contact lenses. However, their wettability warrants improvement to enhance the wearing comfort. This study used UV laser (wavelength = 355 nm) to modify the surface properties of RGP contact lenses with materials of Boston XO® (Bausch & Lomb Incorporated). Briefly, the mesh pattern was fabricated on the RGP contact lens surface by using the laser and smoothed by using oxygen plasma; the enhanced hydrophilic efficiency was analyzed using contact angle measurement. The experiment results indicated that the contact angle of the lens material decreased by approximately 10°–20° when the pitch of mesh pattern was <50 μm under a 500-mm/s scanning speed. The oxygen plasma enhanced surface wettability with a decreased contact angle (40°). The hydrophilic characteristic of the UV laser and oxygen plasma–treated surface was twice that of oxygen plasma–treated and untreated surfaces. In the future, RGP contact lens edges could be treated with UV laser and oxygen plasma to enhance the tear wettability and wearing comfort.


2012 ◽  
Vol 1395 ◽  
Author(s):  
Jason H. C. Yang ◽  
Kungen Teii

ABSTRACTNanocrystalline diamond (NCD) films are prepared from Ar-rich/N2/CH4 and Ar-rich/H2/CH4 mixtures by microwave plasma-enhanced chemical vapor deposition, and further treated by microwave hydrogen and oxygen plasma exposures separately to enhance the wetting property. The hydrogen plasma treatment has small effect on the surface roughness, while the oxygen plasma treatment forms fine protrusions on the film surface. Results show that the wettability of the hydrogen plasma treated NCD film is nearly constant or little improvement as the polar component of the apparent surface free energy is close to the as-deposit NCD film. In contrast, the wettability of the oxygen plasma treated NCD film is improved dramatically such that the contact angle is reduced from 92º and 4.7º to almost 0º for water and 1-bromonaphthalene, respectively, and the polar component increases significantly to 34 mJ/m2. The low contact angle suggests that the film is considerably a cell adhesive friendly surface, which is essential in maintaining multicellular structure, and thus making it a favorable wetting surface for biological and biomedical applications.


Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1326
Author(s):  
Ting-Yi Chiang ◽  
Chun-Chuan Yang ◽  
Yi-Hsuan Chen ◽  
Min Yan ◽  
Shinn-Jyh Ding

Improving the bond strength of veneering ceramics to ZrO2-based cores remains a challenge. The purpose of this study was to evaluate the shear bond strength of different ZrO2 cores containing calcium silicate (CaSi) to veneering ceramics. Five types of ZrO2-based cores (n = 230) were divided into two groups: with or without oxygen plasma treatment. These were bound to two veneering ceramics (IPS e.max Ceram or VITA VM9). Shear bond strength of veneering ceramics to various cores was measured (n = 10), in addition to phase composition, surface morphology and contact angle of the cores. The results indicated that the plasma treatment had a significant effect on the water contact angle of the ZrO2-based cores, but had little effect on the bond strength. Regardless of plasma treatment, the highest strength value was recorded in the ZrO2 core specimen containing 20 wt % CaSi, when all cores were adhered to VITA VM 9 veneer. When using IPS e.max Ceram veneer, the shear bond strength of the plasma-treated 20 wt % CaSi-containing ZrO2 core was 16.6 ± 0.9 MPa higher than that of VITA In-Ceram YZ core control (13.4 ± 1.0 MPa) (p < 0.05). We conclude that the presence of 20 wt % CaSi in ZrO2 can improve the shear bond strength of zirconia-based cores to veneering ceramic.


2013 ◽  
Vol 747 ◽  
pp. 210-213 ◽  
Author(s):  
Mintra Meemusaw ◽  
Rathanawan Magaraphan

We demonstrated the environmentally friendly method, Cold Plasma treatment with oxygen plasma gas, in order to introduce the polar groups into non-polar polymer. HDPE pellets were treated with cold plasma under the mixture of plasma gas and air at atmospheric pressure. After that, the treated samples were immediately subjected into the twin-screw extruder. Plasma treatment time, 30 seconds, 1 and 2 minutes, was studied. From the contact angle measurement, all treated samples showed lower contact angle value than the neat HDPE from 96.83° to 80.84° - 84.53° suggesting that the hydrophilicity of all treated samples were improved. The polar part of surface free energy (γsp) of all treated samples increased from the neat HDPE from almost zero to 13.34-21.88 mN/m. ATR-FTIR results confirmed the increasing of γsp value. It was due to the new oxygenated functional groups which were introduced into the non-polar polymer. Lastly, from SEM images, the roughness of cross-sectional area increased after plasma treatment which attributed to the incompatible between the polar component and the non-polar component.


2009 ◽  
Vol 610-613 ◽  
pp. 1259-1262 ◽  
Author(s):  
Na Ru Zhao ◽  
Ying Jun Wang ◽  
Li Ren ◽  
Xiao Feng Chen

Chitosan membranes were prepared by solvent cast method. In order to increase cell adhesion of the chitosan membranes, oxygen plasma treatment was applied to improve the hydrophilicity of the surface of chitosan membranes. The surface properties were characterized by scanning electron microscopy (SEM), contact angle analyzer, X-ray photoelectron spectroscopy (XPS). The effects of exposure time, plasma generating power, and chamber pressure on water contact angle of the chitosan membranes were investigated. The water contact angle of chitosan membranes decreased from 94.1° to 49.2° after plasma treatment. Which suggested the surfaces became more hydrophilic. XPS analysis showed that the oxygen content and the ratio of O/C increased markedly after oxygen plasma treatment. Furthermore, it was found that C-H bonds were broken with oxygen plasma treatment. C-OH group had been increased after plasma irradiation.


2012 ◽  
Vol 9 (3) ◽  
pp. 1581-1586 ◽  
Author(s):  
Xiwen Wang ◽  
Jian Hu ◽  
Yun Liang

A new surface modification method fibrillation combined with oxygen plasma treatment to improve the wettability and hydrophily of PBO fiber was studied in this paper. The surface chemical structure and morphology of PBO fiber were characterized by the methods of FTIR, XPS and SEM. The wettability and hydrophlic characters changes on the surface were evaluated by the dynamic contact angle system and image analysis. The results show that the increase surface roughness by fibrillation could improve the wettability. Fibrillation combined oxygen plasma treatment has a better effect than oxygen plasma treatment to improve the wettability and hdyrophlization of PBO fiber. The specific area of PBO fiber increased to 10.7 m2/g from 0.7 m2/g, contact angle decreased to 43.2° from 84.4° and WRV increased to 208.4% from 13.7%. The modified fibers have a good dispersion in water for hydrophilization improvement.


2011 ◽  
Vol 213 ◽  
pp. 103-106
Author(s):  
A. Thongphud ◽  
P. Visal-athaphand ◽  
Pitt Supaphol ◽  
Boonchoat Paosawatyanyong

Electrospun polyacrylonitrile (PAN) fabrics were prepared by electrospinning with 7%w/v concentration to dissolve in dimethylformamide (DMF) and spinning time 12 h. Radio frequency inductively couple plasma (RF-ICP) at 13.56 MHz were used to improve PAN fabrics surface by O2 gas in plasma treatment that became to hydrophilic properties of PAN fabrics surface. Physical properties were determined by scanning electron microscopy (SEM) and contact angle measurement which found that characterized on PAN fabrics surface after plasma treatment with increased treated time had been damaged on these fabrics surface which measured contact angle measurement with water were range 29.3 to 74.7. Chemical properties were analysed by fourier transform infrared spectroscopy (FTIR) that had been found peak intensities of aliphatic C-H band at 1450 and 2930 cm-1 and peak intensities of cyclic C=O bands at 1732 cm-1 and peak intensities of saturated nitriles at 2243 cm-1 and peak intensities of hydroxyl O-H band at 3600-3650 cm-1.


2007 ◽  
Vol 1009 ◽  
Author(s):  
Stéphane Béfahy ◽  
Sami Yunus ◽  
Véronique Burguet ◽  
Jean-Sébastien Heine ◽  
Etienne Dague ◽  
...  

AbstractA process to fabricate stretchable and adherent gold tracks on flat silicone rubber substrates is studied by X-ray photoelectron spectroscopy (XPS), static water contact angle measurement, atomic force microscopy (AFM) and scanning electron microscopy (SEM). The process involves several steps: curing flat silicone substrate; removing uncured oligomers by hexane Soxhlet extraction; pre-stretching the substrate; activating the strained silicone surface by an oxygen plasma treatment; coating the strained substrate with 5nm titanium and 80nm gold layers by e-beam evaporation; and finally releasing the sample. The plasma treatment creates a thin brittle silica-like layer that temporarily increases the substrate's surface energy. Indeed the plasma treatment is followed by a hydrophobic recovery. As a consequence, the delay between plasma treatment and metal deposition has to be reduced as much as possible. The silica-like layer can be nicely observed after release. Its thickness is estimated to be around 20nm to 50nm. The entire process allows us to obtain stretchable metallized samples that remain conductive even after an excessive deformation leading to electrical failure.


2013 ◽  
Vol 747 ◽  
pp. 178-181 ◽  
Author(s):  
Wasana Kosorn ◽  
Boonlom Thavornyutikarn ◽  
Wanida Janvikul

Polycaprolactone (PCL) was surface modified with alkaline hydrolysis by NaOH and/or low pressure oxygen (O2) plasma treatment. The hydrolysis was conducted in two different stages: one was performed prior to PCL scaffold fabrication by a high pressure supercritical CO2 technique; the other was carried out after the fabrication. The resulting hydrolyzed PCL scaffolds, with pore sizes in the range of 150-250 μm, were denoted as pre-HPCL and post-HPCL, respectively. Both non-hydrolyzed and hydrolyzed PCL scaffolds were subsequently subjected to the plasma treatment, to further enhance the hydrophilicity of the scaffolds. The surface morphology, wettability and chemical composition of all PCL scaffolds were analyzed by scanning electron microscopy (SEM), water contact angle measurement, and X-ray photoelectron spectroscopy (XPS), respectively. It was found that the surface of the scaffolds turned from fairly smooth to highly rough after the hydrolysis and plasma treatment, particularly when both treatments were in use. The post-hydrolysis induced more surface roughness, compared to the pre-hydrolysis. In addition, the water contact angles on the scaffolds enormously reduced after the treatments; plasma treatment, however, showed a more prominent effect than the alkaline hydrolysis. Although expressing a zero-degree contact angle, the plasma-treated pre-HPCL scaffold was wetted more readily than the plasma-treated post-HPCL. These were in good agreement with the XPS results; interestingly, the plasma-treated pre-HPCL scaffold exhibited the greatest O/C atomic ratio among the PCL scaffolds. This indicated its highest extent of PCL chain oxidation, a degradation of ester groups into-COOH and-OH groups.


Sign in / Sign up

Export Citation Format

Share Document