Anti-Sticking Properties of PVD CrWNx, CrOx and ZrOx Coatings on Medical Electrode Application

2010 ◽  
Vol 297-301 ◽  
pp. 656-663
Author(s):  
Y.L. Hsu ◽  
C.H. Lee ◽  
S.M. Chiu ◽  
Y.C. Sung ◽  
K.Y. Yang ◽  
...  

The side effect of electrosurgery includes tissue charring, smoke generation and the adhesion of tissue to electrodes. These effects prolong surgery and interfere with effective coagulation. In this paper, CrWNx, CrOx and ZrOx coating were prepared by an unbalanced magnetron sputtering. The microstructure of films was characterized using XRD, XPS, TEM and AFM. The hydrophobicity and surface energy of coatings were calculated by contact angle measurement and Wu harmonic mean approach. Anti-sticking in vitro test was performed by monopolar electrosurgery using pork liver tissue. The hardness of CrWNx , ZrOx and CrOx coatings were 44 GPa, 26.3 GPa and 20.7 GPa, respectively. The CrOx coating had the lowest surface energy 33.5 mN/m and the highest contact angle of water as high as 103°. The high surface O-H bonds density of CrOx coating and N-H bonds density of CrWNx coating could explain about their lower polar component of surface energy. All the three PVD coatings remarkably reduced the quantity of tissue adhesion on the electrode from about 2 times (ZrOx and CrWNx coatings) to 4.88 times (CrOx coating) than uncoated SUS304 electrode.

2002 ◽  
Vol 16 (06n07) ◽  
pp. 1031-1037 ◽  
Author(s):  
J. S. CHEN ◽  
S. P. LAU ◽  
Z. SUN ◽  
G. Y. CHEN ◽  
Y. J. LI ◽  
...  

Ta-C and iron containing amorphous carbon (a-C:Fe) films were deposited by filtered cathodic vacuum arc technique. The influences of Fe contents on the wettability of the films were investigated in terms of surface energy. The surface energy of a-C:Fe films was determined by the contact angle measurement. Atomic force microscopy (AFM), Raman spectroscopy and X-ray induced photoelectron spectroscopy (XPS) were employed to analyze the origin of the variation of surface energy with various Fe content. It is found that the contact angle for water increases significantly after incorporating Fe into the films and the films become hydrophobic. The roughness of these films has a little effect on the contact angle. The surface energy is reduced after incorporating Fe into the a-C film which is due to the reduction of both dispersive and polar component. The reduction in dispersive component is ascribed to the decrease of atomic density of the a-C:Fe films due to the increase in sp2 bonded carbon. The absorption of oxygen on the surface play an important role in the reduction of polar component for the a-C:Fe films. It is proposed that such network as (Ca-O-Fe)-O-(Fe-O-Ca) may be formed and responsible for the reduction of polar component.


2009 ◽  
Vol 16 (06) ◽  
pp. 801-806 ◽  
Author(s):  
Y. C. GUAN ◽  
W. ZHOU ◽  
H. Y. ZHENG

Laser surface melting is known to alter surface energy and wettability of a few engineering materials, but its effect on magnesium alloys has never been reported. Effort was made to study how Nd : YAG laser irradiation influenced surface energy of an AZ91D magnesium alloy. Contact angle measurement was carried out using three types of liquids to make it possible to calculate the surface energy quantitatively based upon the acid–base theory. The laser irradiation was found to enhance surface wettability significantly and lead to a drastic increase in surface energy from 25.82 to 40.78 mJ/m2. The change in surface property was attributed to the laser-induced refinement of α- Mg and β- Mg 17 Al 12 phases and enrichment of Al in the microstructure.


2011 ◽  
Vol 9 (6) ◽  
pp. 1039-1045 ◽  
Author(s):  
Beata Butruk ◽  
Paulina Ziętek ◽  
Tomasz Ciach

AbstractThe aim of this study was to develop a method of manufacturing versatile hydrophobic coatings for polymers. Authors present a simple technique of polyurethane (PU) surface modification with covalently attached silicones (PDMS) or fluorocarbons (PFC). Diisocyanates were applied as linker molecules. The obtained coatings were characterized using spectroscopic analysis (FTIR), scanning acoustic microscopy (SAM) and water contact angle measurements. FTIR analysis revealed high efficiency of grafting reaction. The results of contact angle measurement indicated significant increase of hydrophobicity — from 66° (unmodified PU) to 113° (PU grafted with PDMS) and 118° (PU grafted with PFC). Acoustic microscopy analysis confirmed satisfactory homogeneity and smoothness of the fabricated layers. In vitro cell tests revealed non-adherent properties of the surfaces. Both, MTT assay and fluorescence staining confirmed non-cytotoxicity of the coatings, which makes them potential candidates for use in biomedical applications.


Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 93
Author(s):  
Catrin Bannewitz ◽  
Tim Lenz-Habijan ◽  
Jonathan Lentz ◽  
Marcus Peters ◽  
Volker Trösken ◽  
...  

Bare metal endovascular implants pose a significant risk of causing thrombogenic complications. Antithrombogenic surface modifications, such as phenox’s “Hydrophilic Polymer Coating” (pHPC), which was originally developed for NiTi implants, decrease the thrombogenicity of metal surfaces. In this study, the transferability of pHPC onto biomedical CoCr-based alloys is examined. Coated surfaces were characterized via contact-angle measurement and atomic force microscopy. The equivalence of the antithrombogenic effect in contact with whole human blood was demonstrated in vitro for CoCr plates compared to NiTi plates on a platform shaker and for braided devices in a Chandler loop. Platelet adhesion was assessed via scanning electron microscopy and fluorescence microscopy. The coating efficiency of pHPC on CoCr plates was confirmed by a reduction of the contact angle from 84.4° ± 5.1° to 36.2° ± 5.2°. The surface roughness was not affected by the application of pHPC. Platelet adhesion was significantly reduced on pHPC-coated specimens. The platelet covered area was reduced by 85% for coated CoCr plates compared to uncoated samples. Uncoated braided devices were completely covered by platelets, while on the pHPC-coated samples, very few platelets were visible. In conclusion, the antithrombogenic effect of pHPC coating can be successfully applied on CoCr plates as well as stent-like CoCr braids.


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.


2020 ◽  
Vol 847 ◽  
pp. 28-33
Author(s):  
Evana Yuanita ◽  
Yuli Amalia Husnil ◽  
Myrna Ariati Mochtar ◽  
Rahma Lailani ◽  
Mochamad Chalid

This work was aimed to investigate the effect of alkalization treatment on the fiber-matrix interfacial interaction and hence their compatibility. Kenaf fiber was treated using a 6% NaOH solution for 8 hours. The composites were produced by mixing the treated fiber with PP at various temperatures, duration, and fiber composition. Alteration on the surface chemistry of the fiber was identified by performing FTIR analysis. The surface energy of the treated fiber was mathematically derived from the contact angle measurement results. The compatibility level between treated fiber and PP matrix was visualized through FESEM analysis. Tensile strength tests were also conducted to obtain data necessary for exploring the relationship between the thermodynamic aspects of the fiber-matrix interfacial interaction and the mechanical properties of the composites. The FTIR spectra show that there was significant increase in the %transmittance at wavelength range of 3100-3600 cm-1 indicating that O-H groups were degraded during treatment. However, the polar component of the surface energy for treated fiber was instead higher compared to the untreated one. The SEM images show that there are no noticeable reduction in the size of the treated fibers as expected. On the other hand, the tensile strength of the PP-treated fibers composites reached its highest value when the matrix were loaded with fibers at the lowest percentage i.e. 5%.


1993 ◽  
Vol 20 (4) ◽  
pp. 297-305 ◽  
Author(s):  
C. O'Kane ◽  
R. G. Oliver ◽  
R. E. Blunden

Surface characteristics that are considered important for bacterial attachment to thirteen orthodontic bonding composite cements and one glass ionomer cement were examined in vitro before and after toothbrush abrasion. The surface roughness and contact angle measurements were found to be statistically significantly different between the materials, both before and after brushing, and there were also statistically significant changes within materials after brushing. There were low correlation coefficients between surface roughness and contact angle for both pre-and post-brushed materials.


2019 ◽  
Vol 31 (06) ◽  
pp. 1950047
Author(s):  
Ika Maria Ulfah ◽  
Khalil Gibran ◽  
Boy M. Bachtiar ◽  
Muhammad Ibadurrohman ◽  
Slamet

Modification of Ti–6Al–4V alloys with silver-loaded TiO2 nanotubes was investigated. In this study, TiO2 nanotube (TiNT) was grown on the surface of Ti–6Al–4V plates by means of anodization in an electrolyte solution containing glycerol, water and 0.5[Formula: see text]wt.% of NH4F. Silver particles were deposited on TiNT using a Photo-Assisted Deposition (PAD) method. Formation of crystalline phase of TiO2 on the surface was confirmed by means of XRD while its superficial morphology was observed using FESEM/EDS. Hydrophilicity was assessed by means of contact angle measurement. As-synthesized silver-loaded TiNT on osteoblast ATCC growth in vitro was also investigated in terms of its capacity in supporting osseointegration. The cell viability was determined by MTT (3-[4,5-dimethylthiazol-2yl]-2,5diphenyl-2H-tetrazolium bromide) assay and its differentiation activity was measured by alkaline phosphatase (ALP) assay. The results showed that desposition of silver on TiNT increased cell viability after 14 days culture while improving the hydrophilicity feature. Silver-loaded TiNT on Ti–6Al–4V alloy with Ag precursor concentration of 0.10[Formula: see text]M showed the optimum viability of osteoblast growth, with 14% improvement in comparison to its unmodified counterpart. The MTT assay showed that no cytotoxicity in vitro was observed on this material. This study provides corroborating evidences that the modification of Ti–6Al–4V alloy may enhance the cell viability and its prominence as dental implant materials.


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