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）. Throug...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.展开更多
Different structures are proposed for the complexes formed from the interaction between the cationic cyanine dye 1, 1’-diethyl-2, 2’-carbocyanine chloride (Pinacyanol chloride) and the anionic surfactant sodium bis ...Different structures are proposed for the complexes formed from the interaction between the cationic cyanine dye 1, 1’-diethyl-2, 2’-carbocyanine chloride (Pinacyanol chloride) and the anionic surfactant sodium bis (2-ethylhexyl) sul- fosuccinate (Aerosol-OT) in ethanol-water solutions. UV/vis and electronic circular dichroism (CD) spectra provide tools to study the concentration and solvent dependence of this interaction. The aggregation spectra of the dye are dominated by a strongly blue-shifted, sharp and single visible band, which appears at concentrations much below the critical micelle concentration (cmc) of Aerosol-OT. Above the cmc, the spectra in pure aqueous solution indicate disso- ciation into monomer and dimer species, and the system becomes completely empty of chirality. Two different CD spectra with a distinct isosbestic point are observed for complexes with different surfactant to dye ratios. Both the addi- tion of ethanol (more than 7.5%) and increasing the temperature retards the metachromatic process between the dye and Aerosol-OT. By using the peakFit program, the two overlapping excitonic absorption bands together with the optically inactive absorption band for one spectrum (the most optimal one) at a specific Aerosol-OT concentration were sepa- rated.展开更多
对Mark V Deluxe1140测定喷气燃料水分离指数仪进行了校验评价。结果表明:使用标注ASTMD3948的聚结器及配件仪器性能不能符合要求,测定结果不可靠;采用国产和进口气溶胶OT对校验结果无影响;测定仪转速不恒定,相关标准中未对高速乳化装...对Mark V Deluxe1140测定喷气燃料水分离指数仪进行了校验评价。结果表明:使用标注ASTMD3948的聚结器及配件仪器性能不能符合要求,测定结果不可靠;采用国产和进口气溶胶OT对校验结果无影响;测定仪转速不恒定,相关标准中未对高速乳化装置进行规范。展开更多
基金Supported by the National Natural Science Foundation of China(Nos.20976015,21173025)
文摘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.
文摘Different structures are proposed for the complexes formed from the interaction between the cationic cyanine dye 1, 1’-diethyl-2, 2’-carbocyanine chloride (Pinacyanol chloride) and the anionic surfactant sodium bis (2-ethylhexyl) sul- fosuccinate (Aerosol-OT) in ethanol-water solutions. UV/vis and electronic circular dichroism (CD) spectra provide tools to study the concentration and solvent dependence of this interaction. The aggregation spectra of the dye are dominated by a strongly blue-shifted, sharp and single visible band, which appears at concentrations much below the critical micelle concentration (cmc) of Aerosol-OT. Above the cmc, the spectra in pure aqueous solution indicate disso- ciation into monomer and dimer species, and the system becomes completely empty of chirality. Two different CD spectra with a distinct isosbestic point are observed for complexes with different surfactant to dye ratios. Both the addi- tion of ethanol (more than 7.5%) and increasing the temperature retards the metachromatic process between the dye and Aerosol-OT. By using the peakFit program, the two overlapping excitonic absorption bands together with the optically inactive absorption band for one spectrum (the most optimal one) at a specific Aerosol-OT concentration were sepa- rated.
