The properties of aqueous two-phase system (ATPS) of mixed solution containing gemini cationic surfactant trimethylene-1,3-bis(dodecyldimethyl ammonium) bromide (12-3-12, 2Br-) and traditional anionic surfactant sodiu...The properties of aqueous two-phase system (ATPS) of mixed solution containing gemini cationic surfactant trimethylene-1,3-bis(dodecyldimethyl ammonium) bromide (12-3-12, 2Br-) and traditional anionic surfactant sodium dodecyl sulfate (SDS) with or without added salt have been studied. An ATPS is formed in a narrow region of the ternary phase diagram different from that of traditional aqueous cationic-anionic surfactant systems. In ATPS region, the lowest total concentration of surfactants varies with the mixing ratio of geminis to SDS. Photographs obtained from freeze-etching, negative-staining and transmission electron microscopy show that the microstructures of two phases are different from each other. Micelles and vesicles can coexist in a single phase. The addition of salts can change the phase diagram of ATPS. Furthermore, the added salts promote the aggregation of rod-like micelles to form coarse network structure that increase the viscosity of solutions. The negative ions of the added salts are the determining factor.展开更多
Optical heterodyne magnetic rotation enhanced velocity modulation spectroscopy was employed to observe thevisible absorption spectra of the B2∑u+ -X2∑g^ + electronic transition of C2-. Four hot bands (0,1), (1,2), (...Optical heterodyne magnetic rotation enhanced velocity modulation spectroscopy was employed to observe thevisible absorption spectra of the B2∑u+ -X2∑g^ + electronic transition of C2-. Four hot bands (0,1), (1,2), (2,3) and (3,4)have been observed and the band (3,4) is measured directly for the first time, so far as we know, by absorption. Arotational analysis was carried out to obtain molecular constants. With the Franck-Condon principle and the vibrationalBoltzmann distribution, we have estimated the vibrational temperature of C2- to be about 3000K.展开更多
基金the National Natural Science Foundation of China (No. 20025618, No. 20236010) Shanghai Municipal Education Commission of China.
文摘The properties of aqueous two-phase system (ATPS) of mixed solution containing gemini cationic surfactant trimethylene-1,3-bis(dodecyldimethyl ammonium) bromide (12-3-12, 2Br-) and traditional anionic surfactant sodium dodecyl sulfate (SDS) with or without added salt have been studied. An ATPS is formed in a narrow region of the ternary phase diagram different from that of traditional aqueous cationic-anionic surfactant systems. In ATPS region, the lowest total concentration of surfactants varies with the mixing ratio of geminis to SDS. Photographs obtained from freeze-etching, negative-staining and transmission electron microscopy show that the microstructures of two phases are different from each other. Micelles and vesicles can coexist in a single phase. The addition of salts can change the phase diagram of ATPS. Furthermore, the added salts promote the aggregation of rod-like micelles to form coarse network structure that increase the viscosity of solutions. The negative ions of the added salts are the determining factor.
文摘Optical heterodyne magnetic rotation enhanced velocity modulation spectroscopy was employed to observe thevisible absorption spectra of the B2∑u+ -X2∑g^ + electronic transition of C2-. Four hot bands (0,1), (1,2), (2,3) and (3,4)have been observed and the band (3,4) is measured directly for the first time, so far as we know, by absorption. Arotational analysis was carried out to obtain molecular constants. With the Franck-Condon principle and the vibrationalBoltzmann distribution, we have estimated the vibrational temperature of C2- to be about 3000K.
