Kimya BölümüKimya Bölümüne ait yayınlar içerir.https://hdl.handle.net/11630/65022024-03-29T15:42:59Z2024-03-29T15:42:59ZHydroxyapatite (HAP) coating with biomimetic method abstractBüyüksağiş, Ayselhttps://hdl.handle.net/11630/76052020-04-01T07:04:43Z2009-01-01T00:00:00ZHydroxyapatite (HAP) coating with biomimetic method abstract
Büyüksağiş, Aysel
Biomimetik yöntemle hidroksiapatit (HAP) kaplama en gelecek vaat eden tekniklerden birisidir. Bu çalışmada, üç farklı ön yüzey işlemi (HNO3, anodik polarizasyon, 5 N NaOH-1 N HCl (BA)) altlıkların (Ti ve Ti6Al4V) yüzey pürüzlülüğünü arttırmak için kullanılmıştır. Biomimetik apatit katmanlarının morfoloji, bileşim ve yapısı SEM, EDX ve FT-IR teknikleri ile incelenmiştir. 3xSBF’de 35 günlük daldırma sonrası yüzeyin tamamı apatit kaplama ile kaplanmıştır. SEM-EDX sonuçları kemikte bulunan tercihli yönlenme ve benzer bileşimin iyon bileşimi ve çözeltinin derişimine bağlı olarak biomimetik olarak sentezlendiğini göstermiştir. Kemik benzeri apatit katmanı sentezi, implantların biyoaktif yüzeylerini geliştirmek için bu biomimetik yöntemin etkin bir yol olduğunu göstermiştir. FT-IR analizi karakteristik HA absorpsiyon bantlarının sinterlenmiş yüzeyde oluştuğunu göstermiştir.; One of the most promising techniques to deposit hydroxyapatite (HAP) coating is the biomimetic method. In this
paper, different pretreatments (HNO3, anodic polarization, 5 N NaOH-1 N HCl (BA)) were used to increase
surface roughness of the substrates (Ti ve Ti6Al4V). The morphology, composition and structure of the
biomimetic apatite layers were investigated with SEM,EDX and FT-IR techniques. The entire surface after
immersed for 35 days in 3xSBF was covered by an apatite coating. The SEM-EDX results show that apatite
layers with preferred orientation and composition similar to that found in bone can be biomimetically synthesized
depending on the ion composition and concentration of the solution. It was shown that this biomimetic synthesis of
a bone-like apatite layer may be an effective way to produce bioactive surfaces of implants. FT-IR analysis shows
that characteristic HA absorption bands have occurred the sintered surface.
2009-01-01T00:00:00ZElectrochemical determination of bisphenol a with pencil graphite electrodes modified with Co(II), Ni(II), Cu(II) and Fe(II) phthalocyaninetetrasulfonatesBüyüksağiş, AyselÖzcan, LeventAltuntaş, M.Türk, H.Yurdakal, S.https://hdl.handle.net/11630/76042020-04-01T07:29:19Z2016-01-01T00:00:00ZElectrochemical determination of bisphenol a with pencil graphite electrodes modified with Co(II), Ni(II), Cu(II) and Fe(II) phthalocyaninetetrasulfonates
Büyüksağiş, Aysel; Özcan, Levent; Altuntaş, M.; Türk, H.; Yurdakal, S.
Pencil graphite electrodes modified with Co(II), Ni(II), Cu(II) and Fe(II) metallophthalocyaninetetrasulfonates (MePcTSs) were investigated for electrochemical determination of bisphenol A (BPA). Electrochemical performances of the modified electrodes for different pH values in phosphate and the Britton-Robinson buffers were determined by cyclic voltammetry and the electrode performances were better in the Britton-Robinson buffer. NiPcTS and CoPcTS modifications of the electrodes had remarkable enhancement on their performances. The differential pulse voltammetry parameters for the electrodes were optimised and found that the electrochemical response versus the concentration of BPA is linear from 5.0×10-7 to 1.0×10-5 M for the NiPcTS and CoPcTS modified electrodes. The detection limits of these modified electrodes are 2.9×10-7 M and 4.3×10-7 M, respectively and the effects of interfering species are less than 5%. The results show that NiPcTS and CoPcTS modified pencil graphite electrodes could be used for electrochemical determination of BPA for analytical purposes.
2016-01-01T00:00:00ZElectrochemical corrosion behavior of high strength carbon steel in H2S-Containing alkaline brinesFeng, R.Beck, JustinBüyüksağiş, AyselCianni, R.Ziomek-Moroz, M.Lvov, S.N.Wolfe, I.https://hdl.handle.net/11630/76032021-11-24T06:31:45Z2015-01-01T00:00:00ZElectrochemical corrosion behavior of high strength carbon steel in H2S-Containing alkaline brines
Feng, R.; Beck, Justin; Büyüksağiş, Aysel; Cianni, R.; Ziomek-Moroz, M.; Lvov, S.N.; Wolfe, I.
The electrochemical corrosion behavior of high strength low alloy carbon steel API S-135 was investigated using in-situ electrochemical measurements, ex situ surface analyses, and software modeling in the alkaline brines at pH of 7.9, 10.7, and 12.4 and at four different PH2S equal to 0 kPa, 0.83 kPa, 8.3 kPa, and 69 kPa at 85 oC. Linear polarization resistance (Rpol) at steady state increased as pH increased from 7.9 to 12.4 at lower PH2S whereas Rpol decreased and then increased at higher PH2S. The fastest corrosion rate (CR) was 0.26 mm yr-1 at pH 10.7 with PH2S 69 kPa, and the slowest CR was 0.0053 mm yr-1 at pH 12.4 with PH2S 0.83 kPa. The correlation between the primary species, corrosion products, localized corrosion and Rpol were discussed. The experimental CR and corrosion products were compared with the modeling CR and Pourbaix diagram.
2015-01-01T00:00:00ZThe effect of alcohol on the passivation of Al alloys in 1 N H 2 SO 4 solutionBüyüksağiş, Ayselhttps://hdl.handle.net/11630/76022020-04-01T07:51:20Z2010-01-01T00:00:00ZThe effect of alcohol on the passivation of Al alloys in 1 N H 2 SO 4 solution
Büyüksağiş, Aysel
In this study, the influence of different alcohol on the passivation of aluminium alloys have been investigated by using current potential curves. Experimental results show that the addition of alcohol in H2SO4 solution have been changed passivation potential distance of the alloys. Elemental compositions of alloys have also directly affected passivation of alloys. This influence is more effective especially in alloys con tent higher Si also and less Cu.
2010-01-01T00:00:00Z