新一族疏水缔合聚丙烯酰胺NaAMC14S/AM与Gemini表面活性剂之间的相互作用

在水溶液中进行了表面活性单体丙烯酰胺基十四烷基磺酸钠(NaAMC14S)与丙烯酰胺(AM)的均相共聚合, 制备了具有微嵌段结构的疏水缔合聚丙烯酰胺NaAMC14S/AM, 合成了阳离子型Gemini表面活性剂二溴化-N,N′-二(二甲基十二烷基)己二铵(C12C6C12Br2), 采用表观粘度法和荧光探针法研究了共聚物NaAMC14S/AM与Gemini表面活性剂C12C6C12Br2的相互作用. 研究结果表明, 疏水缔合聚丙烯酰胺NaAMC14S/AM与Gemini表面活性剂C12C6C12Br2之间存在着很强的相互作用, 既存在静电相互作用, 又存在强烈的疏水相互作用, 表现在以下几方面: C12C6C12Br2的加入, 使共聚物NaAMC14S/AM在浓度小于其临界缔合浓度(cac)时即发生分子间的缔合; C12C6C12Br2在低于其临界胶束浓度时, 就与共聚物NaAMC14S/AM形成混合胶束; 当共聚物的浓度为0.30%(w)时, 随着C12C6C12Br2加入量的增多, 共聚物水溶液的粘度会发生大幅度的增加, 在最大值处粘度竟提高了3个数量级. 研究还发现, 共聚物NaAMC14S/AM与C12C6C12Br2之间的相互作用还与共聚物分子链中的疏水微嵌段含量有关, 疏水微嵌段含量越多, NaAMC14S/AM与C12C6C12Br2之间的相互作用越强, 溶液粘度增加的程度越大.

Interaction between Cationic Gemini Surfactant with Hydrophobically Associatied Polyacrylamide of a New Family

Hydrophobically modified polyacrylamide with hydrophobic microblocks was prepared by homo-copolymerization of sodium 2-acrylamido-tetradecane sulfonate(NaAMC14S)and acrylamide(AM)in water,and cationic Gemini surfactant hexylene-1,6-bis(dodeccyldimethylammonium bromide)(C12C6C12Br2)was synthesized.Apparent viscosity measurement and fluorescence probe methods were used to study the interaction between copolymer NaAMC14S/AM and Gemini surfactant C12C6C12Br2.The experiment results showed that the interaction was strong and exhibited in several aspects as follows:addition of C12C6C12Br2 enabled the copolymer NaAMC14S/AM to produce intermolecular association below its critical association concentration in the absence of C12C6C12Br2;the mixed micells of NaAMC14S/AM and C12C6C12Br2 formed below the critical micellar concentration of C12C6C12Br2;for the aqueous solution of 0.30%(w)copolymer NaAMC14S/AM,the apparent viscosity increased dramatically with the increase of C12C6C12Br2 concentration,and the maximum value of the viscosity was enhanced three orders of magnitude higher than the initial value without C12C6C12Br2.It was found that the interaction between copolymer NaAMC14S/AM and C12C6C12Br2 was dependent on the microstructure of copolymer NaAMC14S/AM,and the greater the content of hydrophobic microblocks,the stronger the interaction and the greater the enhanced magnitude of viscosity.