Effects of concentration and temperature on SDS monolayers at the air-solution interface studied by infrared external reflection spectroscopy
Effects of concentration and temperature on SDS monolayers at the air-solution interface studied by infrared external reflection spectroscopy
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DOI：
10.1021/jp046858i
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发表时间：
2005-03-17
影响因子：
3.3
通讯作者：
Kon-No, K
中科院分区：
文献类型：
--
作者：
Kawai, T;Kamio, H;Kon-No, K
在不同的 SDS 浓度和温度下测量了十二烷基硫酸钠 (SDS) 单层在空气-溶液界面处的红外外反射 (IER) 光谱和相应水溶液的红外透射光谱。吸附单层和本体溶液的光谱之间的比较表明，随着SDS浓度的增加，空气-溶液界面处SDS烷基链的构象有序度提高，直到饱和吸附，并且吸附的单层SDS的构象有序度高于单体和胶束的构象有序度。此外，在克拉夫特点温度以下，吸附的 SDS 保持液晶状态，而本体溶液中的 SDS 处于结晶状态。此外，基于具有与SDS相同的烷基链长度的不溶性单层十三烷酸的IER带强度来评估SDS吸附密度。
Infrared external reflection (IER) spectra of sodium dodecyl sulfate (SDS) monolayers at the air-solution interface and infrared transmission spectra of the corresponding aqueous solutions were measured at various SDS concentrations and temperatures. A comparison between the spectra of adsorbed monolayers and bulk solutions revealed that the conformational order of the SDS alkyl-chain at the air-solution interface improved with increasing the SDS concentrations, up until the saturation adsorption, and that the conformational order of the adsorbed SDS monolayer was higher than those of monomers and micelles. In addition, below the Krafft point temperature, the adsorbed SDS was maintained in the liquid crystal state, while SDS in the bulk solution was in the crystalline state. Furthermore, the SDS adsorption density was evaluated based on the IER band intensities of the insoluble monolayer of tridecanoic acid with an identical alkyl chain length to SDS.