Abstract

Herein, the aggregation manners of polyvinyl alcohol (PVA) with tetradecyltrimethylammonium bromide (TTAB) in alcohols/diols media containing various concentrations and at several temperatures were performed using the conductivity measurement technique. Different physico-chemical parameters, such as critical micelle concentration (CMC), fraction of bound counter ions (β) and thermodynamic properties (ΔG^o_m, ΔH^o_m, ΔS^o_m, and ΔC^o_m) for the TTAB + PVA mixture in aqueous solutions of EtOH (EtOH), 1-propanol (1-PrOH), ethylene glycol (EG), and propylene glycol (PrG), have been determined. The CMC values were found to undergo a decrease in 1-PrOH in comparison to the values obtained in aqueous media, but in EtOH, the CMC value firstly decreases, touches the lowest point, and then exhibits an upsurge with further increase of the percentage of EtOH. The observed greater CMC values in diols media disclose that the micelle formation of TTAB + PVA mixture is delayed in the manifestation of diols. The CMC values of TTAB + PVA mixture have also been observed to vary with the change of study temperature. The negative values of ΔG⁰_m were obtained for all circumstances suggesting a spontaneous aggregation phenomenon of TTAB + PVA system. The values of ΔH⁰_m and ΔS⁰_m dictate that the PVA molecule interacts exclusively with TTAB through the formation of hydrogen bonding, ion-dipole, and hydrophobic interaction. Furthermore, the standard molar heat capacity (ΔC⁰_m), compensation temperature (T_c), intrinsic enthalpy gain (ΔH^0,*_m), and the thermodynamic properties of transfer (ΔG⁰_m.tr, ΔH⁰_m.tr. and ΔS⁰_m.tr.) for the studied system were assessed and demonstrated with appropriate explanations.

摘要

在此，使用电导率测量技术进行了聚乙烯醇 (PVA) 与十四烷基三甲基溴化铵 (TTAB) 在不同浓度和不同温度的醇/二醇介质中的聚集方式。不同的物理化学参数，例如临界胶束浓度 ( CMC )、结合抗衡离子的分数 ( β ) 和热力学性质 ( ΔG ^o _m、ΔH ^o _m、ΔS ^o _m和ΔC ^o _m) 在乙醇 (EtOH)、1-丙醇 (1-PrOH)、乙二醇 (EG) 和丙二醇 (PrG) 的水溶液中的 TTAB + PVA 混合物，已经确定。与在水性介质中获得的值相比， CMC值在 1-PrOH 中被发现有所降低，但在 EtOH 中，CMC 值首先降低，触及最低点，然后随着乙醇。在二醇介质中观察到的较大CMC值表明 TTAB + PVA 混合物的胶束形成在二醇的表现中被延迟。还观察到 TTAB + PVA 混合物的CMC值随研究温度的变化而变化。ΔG的负值⁰ _m在所有情况下获得表明 TTAB + PVA 系统的自发聚集现象。Δ H ⁰ _m和 Δ S ⁰ _m的值决定了 PVA 分子通过形成氢键、离子偶极子和疏水相互作用专门与 TTAB 相互作用。此外，标准摩尔热容 (Δ C ⁰ _m )、补偿温度 ( T _c )、固有焓增益 (Δ H ^0,* _m ) 和传递的热力学性质 (Δ G ⁰ _m.tr , Δ H ⁰ _m.tr.和ΔS⁰_米 ) 对所研究的系统进行了评估和证明，并提供了适当的解释。