阴离子磺酸盐型Gemini表面活性剂与PEO-PPO-PEO嵌段共聚物相互作用的研究  

Interaction of Anionic Sulfonate Gemini Surfactant with PEO-PPO-PEO Triblock Copolymers

作　　者：王瑞娟[1] 王毅琳[1] 

机构地区：[1]中国科学院化学研究所,北京100190

出　　处：《化学学报》2014年第1期41-50,共10页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.21025313,21021003)资助~~

摘　　要：用差示扫描微量热、等温滴定微量量热、动态光散射和核磁共振(NOESY,弛豫时间)技术,研究了在pH=9时阴离子磺酸盐型Gemini表面活性剂12-3-12(SO3)2与PEO-PPO-PEO嵌段共聚物F127(EO97PO69EO97)和P123(EO20PO70EO20)之间的相互作用.研究发现,随着12-3-12(SO3)2浓度的增大,聚合物的临界胶束温度(CMT)降低.与传统的单链离子表面活性剂相比,12-3-12(SO3)2具有更强的降低共聚物CMT的能力.此外,在低于聚合物的CMT时,12-3-12(SO3)2与聚合物单体可以形成聚合物/表面活性剂胶束聚集体;在高于聚合物的CMT时,12-3-12(SO3)2的加入首先与聚合物单体和胶束的混合物或聚合物胶束形成聚合物/12-3-12(SO3)2混合胶束,然后随着12-3-12(SO3)2浓度的增大,混合胶束逐步解离为小的聚集体,但是,即使在很高的12-3-12(SO3)2浓度时,混合胶束也未完全解离.The interaction of anionic sulfonate gemini surfactant 1,3-bis（N-dodecyl-N-propylsulfonate sodium）-propane （12-3-12（SO3）2） with two triblock copolymers poly（ethylene oxide）-poly（propylene oxide）-poly（ethylene oxide）, F127 （EO97PO69EO97） and P123 （EO20POToEO20） having the similar hydrophobic PPO central block but with different hydrophilic PEO end block, has been studied in aqueous solution at pH 9 by using differential scanning calorimetry （DSC）, isothermal titration calorimetry （ITC）, dynamic light scattering （DLS） and NMR techniques. At pH 9, the sulfonate groups of 12-3-12（SO3）2 are completely deprotonated and each molecule carries two negative charges as an anionic gemini surfactaut. DSC measurements have shown that the critical micellar temperature （CMT） of the two copolymers decreases as the 12-3-12（SO3）2 concentration increases. Moreover, at intermediate 12-3-12（SO3）2 concentrations, there appear two overlap- ping endothermic peaks, which is related to the aggregate transition between micelles with different sizes and microstruc- tures, which has been substantiated by the DLS and NMR （spin-lattice （T0 and spin-spin （/＇2） relaxation times, and two-dimensional nuclear Overhauser effect spectroscopy （2D NOESY）） measurements. Compared with traditional sin- gle-chain ionic surfactants, the anionic gemini surfactant 12-3-12（SO3）2 has a much stronger ability of lowering the CMT of copolymers, which should be attributed to the stronger aggregation ability and the lower critical micellar concentration of 12-3-12（SO3）2. Furthermore, a combination of experiments involving ITC and DLS has shown that 12-3-12（SO3）2 binds to the two copolymers at temperatures below and above their CMT. At the temperature below their CMT, the 12-3-12（SO3）2 micelles form complex with monomeric copolymer, which is similar to that observed in the traditional single-chain ionic surfactant/copolymer systems, but the critical aggregation concentration fo

关 键 词：GEMINI表面活性剂 嵌段共聚物 相互作用 差示扫描微量热 等温滴定微量量热 

分 类 号：O647.2[理学—物理化学]