Effect of pH on the interaction between zwitterions and titanium oxide.
Effect of pH on the interaction between zwitterions and titanium oxide.
复制标题
pH 对两性离子和氧化钛之间相互作用的影响。
DOI：
10.1016/j.jcis.2008.10.042
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发表时间：
2009
影响因子：
9.9
通讯作者：
T. Hanawa
中科院分区：
文献类型：
--
作者：
Yuta Tanaka;Haruka Saito;Y. Tsutsumi;H. Doi;N. Nomura;H. Imai;T. Hanawa
根据滴定曲线测定了甘氨酸和两端端基聚乙二醇(NH2-PEGCOOH)两种两性离子的等电点(IEPs)，并用椭偏仪测定了不同pH值下钛表面浸渍和电沉积固定两性离子的厚度，以考察pH和固定化技术对两性离子与钛表面相互作用的影响。由滴定曲线测得甘氨酸的等电点pK1、pK2和等电点分别为2.8、8.9和5.9，NH2-PEGCOOH的等电点pK1、pK2和等电点分别为2.1、11.7和6.9。在一定的pH条件下，甘氨酸或氨基聚乙二醇单甲氧基乙二醇水解制得+H3N-CH2-COO-−或+H3N-PEGCOO-−。此外，在此pH值下，钛表面带负电荷。结果表明，在浸泡条件下，两性离子末端基团与钛表面羟基之间的静电反应活性最强，固定层厚度在pH为12时最大；在电沉积方面，甘氨酸的相对分子质量较低的甘氨酸比相对分子质量较高的NH_2-PEG-COOH更容易被吸附到钛表面，而在pH为12时，固定层的厚度最大。
The isoelectric points (IEPs) of two zwitterions, glycine and both-terminals-terminated poly(ethylene glycol) (NH2–PEG–COOH), were determined from the titration curves, and the thicknesses of zwitterion layers immobilized on titanium (Ti) with immersion and electrodeposition at various pH based on IEPs were evaluated with ellipsometry to investigate the effect of pH and the immobilization technique on the interactions between the zwitterions and the Ti surface. From the titration curves, pK1, pK2, and the IEP of glycine were determined as 2.8, 8.9, and 5.9, respectively, and pK1, pK2, and the IEP of NH2–PEG–COOH were determined as 2.1, 11.7, and 6.9, respectively. At a certain specific pH,+H3N–CH2–COO−or+H3N–PEG–COO−was formed by hydrolysis of glycine or NH2–PEG–COOH. In addition, the Ti surface was negatively charged at this pH. As a result, for immersion, the electrostatic reactivity between terminal groups of zwitterions and hydroxyl groups on the Ti surface was the highest and the thickness of the immobilized layer was significantly the largest at pH 12. For electrodeposition, glycine, with its lower molecular weight, was more easily attracted to the Ti surface than NH2–PEG–COOH, which has a higher molecular weight, while the thickness of the immobilized layer was the greatest at pH 12 in both zwitterions.
影响因子：
14
作者：
Kyomoto, Masayuki;Iwasaki, Yasuhiko;Ishihara, Kazuhiko
通讯作者：
Ishihara, Kazuhiko
XPS和CD-OES测定钛表面电沉积端胺聚乙二醇的固定方式
DOI：
--
发表时间：
2007
期刊：
Materials Transaction 48
影响因子：
--
作者：
Tanaka Y;Doi H;Kobayashi E;Yoneyama T;Hanawa T
通讯作者：
Hanawa T