Intermolecular Interactions in Self-Assembly Process of Sodium Dodecyl Sulfate by Vertically Polarized Raman Spectra  

十二烷基硫酸钠自组装过程中分子间相互作用力的垂直偏振拉曼光谱研究

作　　者：王钰熙 林珂[2] 陈琳[1] 周晓国[1] 刘世林[1] 

机构地区：[1]中国科学技术大学化学物理系,合肥微尺度物质科学国家实验室(筹),合肥230026 [2]西安电子科技大学物理与光电工程学院,西安710071

出　　处：《Chinese Journal of Chemical Physics》2017年第4期365-371,I0001,共8页化学物理学报（英文）

基　　金：This work is supported by the National Natural Science Foundation of China （No.21473171 and No.21573208）, the Pundamental Research Funds for the Central Universities （No.JB160508）, and the Huashan Mountain Scholar Program.

摘　　要：Molecular self-assembly is extremely important in many fields, but the characterization of their corresponding intermolecular interactions is still lacking. The C-H stretching Raman band can reflect the hydrophobic interactions during the self-assembly process of sodium dodecyl sulfate （SDS） in aqueous solutions. However, the Raman spectra in this region are seriously overlapped by the OH stretching band of water. In this work, vertically polarized Raman spectra were used to improve the detection sensitivity of spectra of C-H region for the first time. The spectral results showed that the first critical micelle concentration and the second critical micelle concentration of SDS in water were 8.5 and 69 mmol/L, respectively, which were consistent with the results given by surface tension measurements. Because of the high sensitivity of vertically polarized Raman spectra, the critical micelle concentration of SDS in a relatively high concentration of salt solution could be obtained in our experiment. The two critical concentrations of SDS in 100 mmol/L NaCl solution were recorded to be 1.8 and 16.5 mmol/L, respectively. Through comparing the spectra and surface tension of SDS in water and in NaCl solution, the self-assembly process in bulk phase and at interface were discussed. The interactions among salt ions, SDS and water molecules were also analyzed. These results demonstrated the vertically polarized Raman spectra could be employed to study the self-assembly process of SDS in water.

关 键 词：Vertically polarized Raman spectroscopy Sodium dodecyl sulfate SELF-ASSEMBLY Critical micelle concentration Intermolecular interactions 

分 类 号：O[理学]