Imamura Koreyoshi, Ikeda Eiko, Nagayasu Takeshi, Sakiyama Takaharu, Nakanishi Kazuhiro
Department of Bioscience and Biotechnology, Faculty of Engineering, Okayama University, 3-1-1 Tsushima-naka, Okayama, 700-8530, Japan.
J Colloid Interface Sci. 2002 Jan 1;245(1):50-7. doi: 10.1006/jcis.2001.7967.
Methylene blue and its congeners as model dyes were adsorbed onto stainless steel particles at different ionic strengths, pH values, and ethanol contents, and the adsorption mechanism was investigated. A Fourier transform infrared spectroscopy (FTIR) analysis of the dyes adsorbed on the stainless steel plate was carried out to determine the orientations of the adsorbed dyes on stainless steel surface. The adsorption isotherms for all the dyes tested were approximated by a Langmuir equation (Q=Kq(m)C/(1+KC)) in most cases except under strongly basic conditions. From the ionic strength and ethanol content dependencies of the K value in the Langmuir equations, both the electrostatic and hydrophobic interactions were indicated to contribute to the adsorption of the dyes at neutral pH. By comparing the K and q(m) values for the methylene blue congeners and with the aid of the FTIR analyses, it was found that the kind of substituent groups at most positions of the polyheterocycles of methylene blue strongly affects the adsorption behavior, particularly the area occupied by an adsorbed dye molecule, the affinity for the stainless steel surface, and the orientation of the adsorbed dye molecule on the stainless steel surface.
以亚甲蓝及其同系物作为模型染料，在不同离子强度、pH值和乙醇含量条件下将其吸附到不锈钢颗粒上，并对吸附机理进行了研究。对吸附在不锈钢板上的染料进行了傅里叶变换红外光谱（FTIR）分析，以确定吸附染料在不锈钢表面的取向。除在强碱性条件下外，大多数情况下，所有测试染料的吸附等温线都可用朗缪尔方程（Q = Kq(m)C/(1 + KC)）近似。根据朗缪尔方程中K值对离子强度和乙醇含量的依赖性，表明静电相互作用和疏水相互作用都有助于染料在中性pH下的吸附。通过比较亚甲蓝同系物的K值和q(m)值，并借助FTIR分析，发现亚甲蓝多杂环大多数位置上的取代基种类强烈影响吸附行为，特别是吸附染料分子占据的面积、对不锈钢表面的亲和力以及吸附染料分子在不锈钢表面的取向。
