含酯基Gemini表面活性剂在有机醇-水体系中的胶束热力学及聚集行为

发布时间：2018-05-13 07:05

本文选题：Gemini表面活性剂 + 电导法　；参考：《物理化学学报》2017年04期

【摘要】：采用电导法研究了不同温度下含酯基Gemini表面活性剂在纯水和在质量分数为10%的甲醇-水(MAWR),乙二醇-水(EG-WR),丙三醇-水(GL-WR)四种体系中的集聚行为和胶束热力学;聚集行为参数包括临界胶束浓度(cmc)和抗衡离子的解离程度(α)以及胶束的热力学参数,包括标准吉布斯自由能(ΔG_m~o)、吉布斯迁移自由能(ΔG_(trans)~o)、吉布斯烷基链胶束化自由能(ΔG_(tail)~o)、标准焓变(ΔH_m~o)和标准熵变(ΔS_m~o),均被计算和讨论。研究表明在所有的研究体系中,cmc值随着疏水链的增加而减小,随着加入的醇结构中羟基数目的增加而增大,随温度的升高先变小,后变大呈U字形;胶束化过程都是自发进行的,并且在293.15 K下,胶束化过程是吸热的,在293.15 K上,胶束化过程是放热的;通过稳态荧光光谱法研究了表面活性剂在纯水、有机醇-水混合溶液中的微极性,结果表明,在相同溶剂中,随着烷基链长度的增加,溶液微环境的疏水性越强;对于相同的Gemini表面活性剂,随着加入含羟基数目越多的醇,其微环境的疏水性越强。并研究了Gemini表面活性剂在混合体系中形成胶束过程的焓-熵补偿曲线。
[Abstract]:The agglomeration behavior and micellar thermodynamics of Gemini surfactants containing ester at different temperatures in pure water and methanol-water (10%) MAWRN, ethylene glycol (EG-WRN), glycerol / water (GL-WR) systems were studied. The aggregation behavior parameters include the critical micelle concentration (CMC), the degree of dissociation of counterions (伪) and the thermodynamic parameters of micelles. The standard Gibbs free energy (螖 G), the Gibbs free energy (螖 G / T), the Gibbs' free energy of alkyl chain micellization (螖 G), the standard enthalpy change (螖 Hmtio) and the standard entropy change (螖 S) are calculated and discussed. The results show that the CMC value decreases with the increase of hydrophobic chain, increases with the increase of hydroxyl group in the alcohol structure, and decreases firstly with the increase of temperature, and then becomes U shaped with the increase of temperature. The micellization process is spontaneous, and the micellization process is endothermic at 293.15 K and exothermic at 293.15 K. The micropolarity of organic alcohol-water mixed solution shows that the hydrophobicity of the solution is stronger with the increase of alkyl chain length in the same solvent, and the hydrophobicity of the same Gemini surfactant increases with the addition of alcohol with more hydroxyl groups. The hydrophobicity of the microenvironment is stronger. The enthalpy entropy compensation curves of micelle formation of Gemini surfactants in mixed systems were studied.
【作者单位】：安徽科技学院化学与材料工程学院;
【基金】：安徽省教育厅自然科学基金重点项目(KJ2016A184) 安徽科技学院重点学科项目(AKZDXK2015A01)资助~~
【分类号】：O647.2

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