Dielectric Spectra of Aerosol OT/Water Systems at Different Concentrations and Temperatures  

作　　者：ZHAO Kong-shuang JIA Zhan-jie YANG Li-kun XIAO Jin-xin 

机构地区：[1]College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China [2]Beijing FLUOBON Surfactant Institute, Beijing 100080, P. R. China

出　　处：《Chemical Research in Chinese Universities》2011年第6期1065-1071,共7页高等学校化学研究（英文版）

基　　金：Supported by the National Natural Science Foundation of China(Nos.20976015,21173025)

摘　　要：The dielectric spectra of aerosol OT[AOT, sodium（bis-2-ethylhexyl）sulfosuccinate]/water systems at different concentrations and temperatures were investigated by the dielectric relaxation spectroscopy（DRS）. Through the dielectric spectra of different concentrations, two dielectric relaxations were observed over a frequency range from 40 Hz to 110 MHz and the mechanisms of the relaxations were also interpreted based on the Grosse’s model. The low-frequency relaxation（around 105 Hz） was attributed to the radial diffusion of counterions along the long-half axis of the rod-like micelle, and the high-frequency relaxation（around 106 Hz） was ascribed to the radial diffusion of counterions along the short-half axis. Furthermore, specific emphasis was placed on studying the effects of temperature on system’s conductivity. It was observed that the low-frequency limit of conductivity（κl） decreased and then increased with the increment of temperature under the measured concentration. On the other hand, the conductivity（κm and κh） in meso- and high-frequency ranges always increased as temperature increased. Both the tendencies of alteration which mentioned above should be related to the phase transition of AOT/water system.The dielectric spectra of aerosol OT[AOT, sodium（bis-2-ethylhexyl）sulfosuccinate]/water systems at different concentrations and temperatures were investigated by the dielectric relaxation spectroscopy（DRS）. Through the dielectric spectra of different concentrations, two dielectric relaxations were observed over a frequency range from 40 Hz to 110 MHz and the mechanisms of the relaxations were also interpreted based on the Grosse’s model. The low-frequency relaxation（around 105 Hz） was attributed to the radial diffusion of counterions along the long-half axis of the rod-like micelle, and the high-frequency relaxation（around 106 Hz） was ascribed to the radial diffusion of counterions along the short-half axis. Furthermore, specific emphasis was placed on studying the effects of temperature on system’s conductivity. It was observed that the low-frequency limit of conductivity（κl） decreased and then increased with the increment of temperature under the measured concentration. On the other hand, the conductivity（κm and κh） in meso- and high-frequency ranges always increased as temperature increased. Both the tendencies of alteration which mentioned above should be related to the phase transition of AOT/water system.

关 键 词：Aerosol OT Rod-like micelle Dielectric relaxation spectroscopy 

分 类 号：O482.4[理学—固体物理] TQ460.72[理学—物理]