Blood Compatibility of Metal Oxide Layers on Stainless-steel

2002 ◽  
Vol 734 ◽  
Author(s):  
Kanji Tsuru ◽  
Shinji Takemoto ◽  
Tatsuhiro Yamamoto ◽  
Satoshi Hayakawa ◽  
Akiyoshi Osaka ◽  
...  

ABSTRACTWe examined blood compatibility of titanium oxide layer on stainless-steel (SUS316L). The oxide layers with varied thickness were yielded on SUS316L plates by dip-coating of sol-gel solution starting from tetraethyltitanate. The blood compatibility was evaluated in term of platelet adhesion using platelet rich plasma. With increase in the thickness of the oxide layer, the number of adherent platelets decreased rapidly, reached minimum around 150nm. This indicated that the thickness of titanium oxide layer affected platelet adhesion.

2007 ◽  
Vol 280-283 ◽  
pp. 815-818 ◽  
Author(s):  
Xin Gang Yu ◽  
Yanbin Zuo ◽  
Hong Wen Ma ◽  
Hui Feng Zhao ◽  
Wu Wen Luo ◽  
...  

X-ray diffraction (XRD) method to measure the residual stress in the metal substrate surface layer and the medial oxide layer between thin film and metal substrate was introduced and the sol-gel TiO2-SiO2 thin film was successfully prepared on SUS304 stainless steel substrate by dip-coating process. The macro residual stress existing in metal substrate was analyzed by XRD. It turns out that the compressive stress existing in the metal substrate surface layer decreases with the raising of heat-treated temperature and that the compressive stress of metal substrate surface layer and the tensile stress of the medial oxide layer increase with the increase of the withdrawal speeds of the sol-gel dip-coating. Based on the above study, colored stainless steels of high quality were prepared by sol-gel process for the first time.


2008 ◽  
Vol 23 (6) ◽  
pp. 1682-1688 ◽  
Author(s):  
X.J. Wang ◽  
Y.C. Li ◽  
J.G. Lin ◽  
P.D. Hodgson ◽  
C.E. Wen

In the present study, pure titanium (Ti) plates were firstly treated to form various types of oxide layers on the surface and then were immersed into simulated body fluid (SBF) to evaluate the apatite-forming ability. The surface morphology and roughness of the different oxide layers were measured by atomic force microscopy (AFM), and the surface energies were determined based on the Owens–Wendt (OW) methods. It was found that Ti samples after alkali heat (AH) treatment achieved the best apatite formation after soaking in SBF for three weeks, compared with those without treatment, thermal or H2O2 oxidation. Furthermore, contact angle measurement revealed that the oxide layer on the alkali heat treated Ti samples possessed the highest surface energy. The results indicate that the apatite-inducing ability of a titanium oxide layer links to its surface energy. Apatite nucleation is easier on a surface with a higher surface energy.


2002 ◽  
Vol 12 (3) ◽  
pp. 260-265 ◽  
Author(s):  
Huafu Kong ◽  
James L. Wilkinson ◽  
James Y. Coe ◽  
Xiaoping Gu ◽  
Myra Urness ◽  
...  

Purpose: Nitinol, a nickel-titanium alloy, is a valuable material in the construction of interventional endoluminal devices because of its biocompatibility, super elasticity, high resiliency and shape memory. The possibility of nickel toxicity has been raised with devices constructed of Nitinol. Our investigation examines the long-term corrosive behavior of this alloy in experimental and biological environments. Methods: We performed three levels of study. Microscopic examination was made of 64 devices of various sizes, randomly selected from 240 Amplatzer® Septal Occluders that had been exposed to saline solution at 37°C for fourteen months. All samples were studied by electron microscopy ranging from 50 to 5000 times magnification. We also studied microscopically 3 Amplatzer® devices explanted 18–36 months after implantation in dogs, and 2 Amplatzer Septal Occluders removed from patients 18 months (cardiac transplant) and 19 months (died of causes unrelated to device placement) after implantation, which were examined grossly and by electron microscopy up to 5000 times magnification. We then measured the levels of nickel in the blood using inductive plasma mass spectroscopy in 19 patients with implanted Amplatzer® devices, making measurements before and 6 months after implantation. Results: Electron microscopy showed an intact titanium oxide layer with no evidence of corrosion in vitro and in vivo. One explanted device in direct contact with the platinum leads of a pacemaker for eighteen months showed minor pitting of the titanium oxide layer believed to be galvanic in nature. No wire fractures were found in vitro after cycle testing with 400 million cycles, nor in devices taken from the animals and humans. Biochemical studies showed no significant elevation of levels of nickel levels after implantation. Conclusion: Nitinol wire of Amplatzer® septal occlusion devices is resistant to corrosion when exposed to physiologic saline solution, and in experimental animals as well as humans. A device in contact with a platinum pacemaker electrode developed minimal pitting of the titanium oxide layer, believed to be galvanic in nature and of no structural or clinical significance. There is no increase of concentrations of nickel in the blood of patients who have received Amplatzer® nitinol devices. These favorable testing results reveal that nickel-titanium is an inert, corrosion resistant alloy.


Coatings ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 368 ◽  
Author(s):  
Sara Lopez de Armentia ◽  
Mariola Pantoja ◽  
Juana Abenojar ◽  
Miguel Martinez

Silane-based coatings with nanoparticles have been widely used in applications related to surface protection. Between them, the improvement of corrosion resistance by increasing the hydrophobicity is one of the main research goals. However, most coatings present problems of low wear resistance and poor aesthetic appearance. Therefore, the overall goal of this research is to manufacture hydrophobic sol-gel coatings based on silanes which comply with good tribological and aesthetical properties. In the present study, stainless steel plates were coated with a silane-based solution containing zirconia nanoparticles by dip coating. Water–ethanol solutions with silanes (methyltrimethoxysilane (MTS) and tetrathoxysilane (TEOS)) and different percentages of ZrO2 nanoparticles were prepared. Gloss, color, contact angle, surface energy, wear resistance, and thickness of coating were analyzed to elucidate the effect of zirconium oxide on the performance of the coatings. Results demonstrate that the ZrO2–silane coatings on stainless steel offer a balanced combination of properties: low wettability, high wear resistance, and similar color and brightness compared to pristine stainless steel.


2009 ◽  
Vol 255 (20) ◽  
pp. 8328-8333 ◽  
Author(s):  
N. Barati ◽  
M.A. Faghihi Sani ◽  
H. Ghasemi ◽  
Z. Sadeghian ◽  
S.M.M. Mirhoseini

2007 ◽  
Vol 342-343 ◽  
pp. 605-608 ◽  
Author(s):  
Yi Bin Ren ◽  
Hua Juan Yang ◽  
Ke Yang ◽  
Bing Chun Zhang

The in vitro blood compatibility of a new nickel free high nitrogen austenitic stainless steel Fe-Cr-Mn-Mo-N (BIOSSN4) was studied by the kinetic clotting time test and the platelet rich plasma adhesion test in this paper. In comparison with 316L stainless steel, the kinetic clotting time of BIOSSN4 steel are longer, and only causes less activation of platelets in platelet adhesion test, which was indicated by their morphology and low spreading. The experimental results reveals that the BIOSSN4 stainless steel has better blood compatibility, the blood compatibility mechanism of steels was analyzed based on surface tension and interfacial tension between the steels and blood.


2007 ◽  
Vol 336-338 ◽  
pp. 2649-2651 ◽  
Author(s):  
Xin Gang Yu ◽  
Lan Yun Liu ◽  
Yan Bin Zuo ◽  
Lin Jiang Wang ◽  
Hong Wen Ma ◽  
...  

X-ray diffraction (XRD) method to measure the residual stress existing in the metal substrate surface layer was introduced and the sol-gel ZrO2-CeO2 thin film was successfully prepared on SUS304 stainless steel substrate by dip-coating process. The macro residual stress existing in metal substrate was analyzed by XRD. It turns out that the compressive stress existing in the metal substrate surface layer increases with the increase of heat-treated temperature. Based on the above study, colored stainless steels of high quality were prepared by sol-gel process.


2018 ◽  
Vol 9 (2) ◽  
pp. 69
Author(s):  
Widodo W Purwanto ◽  
Yuswan Muharam ◽  
Dwi Yulianti

Methane decomposition is an alternative way to produce high quality carbon nanotubes (CNTs) and hydrogen simultaneously. The use of gauze reactor for methane decomposition had proven in solving pressure drop problem in fixed bed reactor. This experiment was carried out to study the effects of operation conditions (space time, temperature, and feed ratio) to gauze rector performance. Ni-Cu-Al catalyst which is prepared by sol-gel method with atomic ratio 2:1:1, was coated to Stainless Steel gauze by dip coating method. The reaction was done by flowing methane into the reactor at atmospheric pressure and varying space time (0.0006; 0.0032; 0.006 g×kat×min/mL), temperature (700, 750, and 800°C), and feed ratio CH4:H2 (1:0, 4:1, 1:1). An online gas chromatograph is used to detect the gas products. Reactor performances were observed from methane conversion, hydrogen purity, carbon yield and quality of nanocarbon that have been produced. Experiment result showed that the highest reactor performance (except nanocarbon quality) occurred at space time 0.006 gr cat min/mL, temperature 700 °C, and with pure methane as feed which give methane conversion, hydrogen purity, and yield carbon results are 90.66%, 90.16%, and 37 g carbon/g catalyt, respectively. Based on SEM analysis indicated that the best nanocarbon morphology can be gained at CH4:H2 ratio of 1:1.Keyword : methane decompotition, gauze reactor, carbon nanotube Abstrak Dekomposisi katalitik metana adalah salah satu alternatif untuk memproduksi hidrogen dan nanokarbon bermutu tinggi secara simultan. Penggunaan reaktor gauze untuk dekomposisi metana terbukti dapat mengatasi permasalahan penyumbatan pada reaktor unggun diam. Penelitian ini dilakukan untuk mengetahui pengaruh kondisi operasi (space time, temperatur, dan rasio umpan) terhadap kinerja reaktor gauze. Katalis Ni-Cu-Al disiapkan dengan menggunakan metode sol-gel dengan perbandingan atomik 2:1:1 dilapiskan pada gauze Stainless Steel dengan metode dip-coating. Reaksi dilakukan dengan mengalirkan metana ke dalam reaktor pada tekanan atmosferik dan dengan memvariasikan space time (0,0006; 0,0032; 0,006 g×kat×min/mL), temperatur (700, 750, dan 800 °C), dan rasio umpan CH4:H2 (1:0, 4:1, 1:1). Produk gas dianalisis dengan menggunakan gas chromatography yang terpasang secara online. Kinerja reaktor pada penelitian ini ditinjau dari konversi metana, kemurnian hidrogen, perolehan dan kualitas nanokarbon yang dihasilkan. Berdasarkan hasil eksperimen diketahui bahwa kinerja reaktor paling tinggi (kecuali kualitas nanokarbon) terjadi pada space time 0,006 g×kat×min/mL, temperatur 700 °C, dan dengan menggunakan metana murni yang memberikan hasil konversi metana, kemurnian hidrogen, serta perolehan karbon secara berturut-turut 90,66%, 90,16%, dan 37 gram karbon/gram katalis. Hasil analisis menggunakan SEM menunjukkan bahwa morfologi nanokarbon paling baik didapat pada komposisi reaktan CH4: H2 = 1:1.Kata Kunci : dekomposisi metana, reaktor gauze, karbon nanotube


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