A quantitative structure-property relationship (QSPR) study has been made for the prediction of the surface tension of nonionic surfactants in aqueous solution. The regressed model includes a topological descriptor, ...A quantitative structure-property relationship (QSPR) study has been made for the prediction of the surface tension of nonionic surfactants in aqueous solution. The regressed model includes a topological descriptor, the Kier & Hall index of zero order (KH0) of the hydrophobic segment of surfactant and a quantum chemical one, the heat of formation (fHD) of surfactant molecules. The established general QSPR between the surface tension and the descriptors produces a correlation coefficient of multiple determination, 2r=0.9877, for 30 studied nonionic surfactants.展开更多
A series of piperazine-based Gemini and Bola surfactants were synthesized. Gemini 1 and 5 have well surface activities. Their critical micelle concentrations （cmc） is 6.47×10^-4 mol/L and 1.17×10^-3mol/L, ...A series of piperazine-based Gemini and Bola surfactants were synthesized. Gemini 1 and 5 have well surface activities. Their critical micelle concentrations （cmc） is 6.47×10^-4 mol/L and 1.17×10^-3mol/L, respectively. Bola surfactants 2 and compound 3, possessing better water solubility, have lower surface activities. Calculation, carried out by MM2 energy minimization, showed that compound with more hydrophobic chains in a spacer of limited length is difficult to be synthesized.展开更多
Four gemini cationic surfactants {N,N′-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s=2,3,4,6} were synthesized by using four bis(α-chloroacetamide)s and N,N-dimethyllaurylamine, resp...Four gemini cationic surfactants {N,N′-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s=2,3,4,6} were synthesized by using four bis(α-chloroacetamide)s and N,N-dimethyllaurylamine, respectively. The molecular structures were characterized by means of IR, ~ 1H NMR, \{~ ~13 C NMR\} and MS, and the behavior of their aqueous solutions was studied. The critical micell concentrations(CMC) of LAA-s-LAA were one order of magnitude lower than that of dodecyltrimethyl ammonium chloride(DTAC). With the change of the length of spacer chain(s), their CMC values change, and CMC reaches the top value at s=4.展开更多
A cationic gemini surfactant 10-2-10, 1,2-ethane bis(decyl dimethyl ammonium bromide) was synthesized, and the interactions in a mixture of the cationic gemini surfactant with a water-soluble polymer polyvinyl alcohol...A cationic gemini surfactant 10-2-10, 1,2-ethane bis(decyl dimethyl ammonium bromide) was synthesized, and the interactions in a mixture of the cationic gemini surfactant with a water-soluble polymer polyvinyl alcohol(PVA) were investigated by means of viscosity, electric conductivity, surface tension and ultraviolet spectrum measurements. The results showed that PVA displays viscosity behavior of polyelectrolyte-electroviscous effect in an aqueous solution with gemini surfactant 10-2-10 due to the molecular interaction between the polymer and the surfactant. The maximum UV absorption wavelength of polymer-surfactant solution shifted to higher wavelength compared with that of the surfactant, and the conductivity of polymer-surfactant solution increased with increase in concentration of PVA in a certain surfactant concentration. In addition, surface tension of gemini surfactant 10-2-10 solution decreased in the presence of PVA and its critical micelle concentration decreased from 5.9 mmol/L to 4.8 mmol/L in the presence of 1.25×10^-3 g/mL PVA.展开更多
基金the National Natural Science Foundation of China(to grant No.29903006 and 29973023)the Visiting Scholar Foundation of Key Laboratory in University of China for their financial support
文摘A quantitative structure-property relationship (QSPR) study has been made for the prediction of the surface tension of nonionic surfactants in aqueous solution. The regressed model includes a topological descriptor, the Kier & Hall index of zero order (KH0) of the hydrophobic segment of surfactant and a quantum chemical one, the heat of formation (fHD) of surfactant molecules. The established general QSPR between the surface tension and the descriptors produces a correlation coefficient of multiple determination, 2r=0.9877, for 30 studied nonionic surfactants.
文摘A series of piperazine-based Gemini and Bola surfactants were synthesized. Gemini 1 and 5 have well surface activities. Their critical micelle concentrations （cmc） is 6.47×10^-4 mol/L and 1.17×10^-3mol/L, respectively. Bola surfactants 2 and compound 3, possessing better water solubility, have lower surface activities. Calculation, carried out by MM2 energy minimization, showed that compound with more hydrophobic chains in a spacer of limited length is difficult to be synthesized.
文摘Four gemini cationic surfactants {N,N′-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s=2,3,4,6} were synthesized by using four bis(α-chloroacetamide)s and N,N-dimethyllaurylamine, respectively. The molecular structures were characterized by means of IR, ~ 1H NMR, \{~ ~13 C NMR\} and MS, and the behavior of their aqueous solutions was studied. The critical micell concentrations(CMC) of LAA-s-LAA were one order of magnitude lower than that of dodecyltrimethyl ammonium chloride(DTAC). With the change of the length of spacer chain(s), their CMC values change, and CMC reaches the top value at s=4.
文摘A cationic gemini surfactant 10-2-10, 1,2-ethane bis(decyl dimethyl ammonium bromide) was synthesized, and the interactions in a mixture of the cationic gemini surfactant with a water-soluble polymer polyvinyl alcohol(PVA) were investigated by means of viscosity, electric conductivity, surface tension and ultraviolet spectrum measurements. The results showed that PVA displays viscosity behavior of polyelectrolyte-electroviscous effect in an aqueous solution with gemini surfactant 10-2-10 due to the molecular interaction between the polymer and the surfactant. The maximum UV absorption wavelength of polymer-surfactant solution shifted to higher wavelength compared with that of the surfactant, and the conductivity of polymer-surfactant solution increased with increase in concentration of PVA in a certain surfactant concentration. In addition, surface tension of gemini surfactant 10-2-10 solution decreased in the presence of PVA and its critical micelle concentration decreased from 5.9 mmol/L to 4.8 mmol/L in the presence of 1.25×10^-3 g/mL PVA.
