Cationic Gemini surfactants, alkanediyl-α ,ω- bis(dimethyl dodecylammonium bromide) have been synthesized by the following method: firstly dodecyl bromide was prepared by the reaction of dodecanol with bromic acid i...Cationic Gemini surfactants, alkanediyl-α ,ω- bis(dimethyl dodecylammonium bromide) have been synthesized by the following method: firstly dodecyl bromide was prepared by the reaction of dodecanol with bromic acid in the presence of strong sulfuric acid. Dodecylbromide was then reacted with N,N- tetramethyl ethane diamine(or N,N- tetramethyl hexana diamine) to prepare the title- compounds. Micellization of these Gemini surfactants was investigated using conductivity measurement. The results showed that the critical micelle concentration(cmc) of the Gemini surfactants has a much lower value compared with that of the corresponding " monomer" . For a series of the Geminis with the same length(s) in the spacer chain, the cmc decreased with increasing the carbon number (m) in the alkyl chain. The aggregation number(N) of the micelle also drastically decreased with m. For the same value of m, the cmc varied slightly with s, which indicated that the electrostatic interaction between the ionic- groups of the " monomer" has been naturally changed duo to a link between the two ionic- groups of the " monomer" through a spacer. However, N was strongly decreased with s,which may be a reason of steric inhibition coming from the ionic- groups due to a link of spacer. With increasing temperature, micellization of the Gemini surfactants was slightly enhanced.展开更多
报道了一种含多酯基不对称阳离子Gem in i表面活性剂(Ⅰ)的合成。在甲醇钠催化下,N,N-二甲基乙醇胺与邻苯二甲酸二甲酯酯交换制得二(N,N-二甲基氨基乙基)邻苯二甲酸酯(Ⅱ),收率92%(以邻苯二甲酸二甲酯计);氯乙酸分别与十二醇、十六醇反...报道了一种含多酯基不对称阳离子Gem in i表面活性剂(Ⅰ)的合成。在甲醇钠催化下,N,N-二甲基乙醇胺与邻苯二甲酸二甲酯酯交换制得二(N,N-二甲基氨基乙基)邻苯二甲酸酯(Ⅱ),收率92%(以邻苯二甲酸二甲酯计);氯乙酸分别与十二醇、十六醇反应合成氯乙酸十二醇酯(Ⅲ)和十六醇酯(Ⅳ),产率分别为93%(以十二醇计)、91%(以十六醇计);(Ⅱ)与(Ⅲ)反应,经石油醚洗涤除去杂质后,再与(Ⅳ)季铵盐化,经乙腈重结晶,得白色晶体(I),采用两相滴定法测定其质量分数为99.5%,收率59%(以氯乙酸十二醇酯计)。用IR1、HNMR、元素分析表征了其结构,测定了其CMC和γCMC,研究了其乳化性和泡沫性质。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
文摘Cationic Gemini surfactants, alkanediyl-α ,ω- bis(dimethyl dodecylammonium bromide) have been synthesized by the following method: firstly dodecyl bromide was prepared by the reaction of dodecanol with bromic acid in the presence of strong sulfuric acid. Dodecylbromide was then reacted with N,N- tetramethyl ethane diamine(or N,N- tetramethyl hexana diamine) to prepare the title- compounds. Micellization of these Gemini surfactants was investigated using conductivity measurement. The results showed that the critical micelle concentration(cmc) of the Gemini surfactants has a much lower value compared with that of the corresponding " monomer" . For a series of the Geminis with the same length(s) in the spacer chain, the cmc decreased with increasing the carbon number (m) in the alkyl chain. The aggregation number(N) of the micelle also drastically decreased with m. For the same value of m, the cmc varied slightly with s, which indicated that the electrostatic interaction between the ionic- groups of the " monomer" has been naturally changed duo to a link between the two ionic- groups of the " monomer" through a spacer. However, N was strongly decreased with s,which may be a reason of steric inhibition coming from the ionic- groups due to a link of spacer. With increasing temperature, micellization of the Gemini surfactants was slightly enhanced.
文摘报道了一种含多酯基不对称阳离子Gem in i表面活性剂(Ⅰ)的合成。在甲醇钠催化下,N,N-二甲基乙醇胺与邻苯二甲酸二甲酯酯交换制得二(N,N-二甲基氨基乙基)邻苯二甲酸酯(Ⅱ),收率92%(以邻苯二甲酸二甲酯计);氯乙酸分别与十二醇、十六醇反应合成氯乙酸十二醇酯(Ⅲ)和十六醇酯(Ⅳ),产率分别为93%(以十二醇计)、91%(以十六醇计);(Ⅱ)与(Ⅲ)反应,经石油醚洗涤除去杂质后,再与(Ⅳ)季铵盐化,经乙腈重结晶,得白色晶体(I),采用两相滴定法测定其质量分数为99.5%,收率59%(以氯乙酸十二醇酯计)。用IR1、HNMR、元素分析表征了其结构,测定了其CMC和γCMC,研究了其乳化性和泡沫性质。
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.
