疏水缔合和静电作用调控P(DTAB-co-AM)与蠕虫状胶束自组装网络

SELF-ASSEMBLY NETWORKS OF P(DTAB-co-AM) AND WORMLIKE MICELLES MEDIATED BY HYDROPHOBIC ASSOCIATION AND ELECTROSTATIC INTERACTIONS

由新型的阳离子疏水单体二甲基十四烷基(3-丙烯酰胺基丙基)溴化铵(DTAB)与丙烯酰胺(AM)共聚合成了阳离子型疏水缔合共聚物P(DTAB-co-AM),研究了该共聚物与蠕虫状胶束自组装后的协同增黏效应,及改变疏水单体含量对自组装体系黏度的调控作用.制备了十八烷基三甲基氯化铵(CTAC)/水杨酸钠和芥酸钾/三羟乙基苄基氯化铵两类稳定的黏度较大的蠕虫状胶束体系.共聚物P(DTAB-co-AM)与芥酸钾/三羟乙基苄基氯化铵蠕虫状胶束在疏水缔合和静电吸引双重作用下自组装可形成协同增黏的缔合体系,而与CTAC/水杨酸钠阳离子蠕虫状胶束进行自组装由于只有疏水缔合作用,增黏效果不及前者.表观黏度研究表明,随着疏水单体含量的增加,P(DTAB-co-AM)与芥酸钾/三羟乙基苄基氯化铵缔合体系的黏度先增加后降低,当疏水单体含量为0.15 mol%时,缔合体系黏度达到极大值;当疏水单体含量为0.3 mol%时,缔合体系黏度反而低于与阳离子蠕虫状胶束缔合后的黏度.对于共聚物与CTAC/水杨酸钠蠕虫状胶束缔合体系,随着疏水单体含量增加,由于疏水缔合作用与静电排斥作用的相互抵消,致使体系黏度有所下降.由此说明改变疏水单体含量可以达到调控自组装体系黏度的目的.

The synergistic enhanced viscosity of self-assembly networks of wormlike micelles and cationic hydrophobically associative eopolymer P （DTAB-co-AM） synthesized by copolymerization of cationic hydrophobic monomer, dimethyltetradeeyl （3-acrylamidopropyl） ammoniumbromide （ DTAB）, with aerylamide （AM） was studied, and the effect of hydrophobie monomer content on the self-assembly systems was also probed. Two kinds of stable wormlike micelles with high viscosity, Octadecyhrimethyl ammonium chloride CTAC/sodium salieylate and potassium erucate/benzyhrihydroxyethylammonium chloride, were prepared. The eopolymer P （DTAB-co-AM） and anionic wormlike micelles, potassium erucate/benzyltrihydroxyethylammonium chloride, could form self-assembly system with synergistic enhanced viscosity because both of hydrophobic association and electrostatic interactions play an important role. But the viscosity enhancement of the associative system composed of the copolymer P （DTAB-co-AM） and cationic wormlike micelles, CTAC/sodium salieylate, was weaker than that of the former because of the single hydrophobic association interaction. The results of the viscosity experiments show the viscosity of the self-assembly system made up of P（DTAB-co-AM） and anionic wormlike micelles first increased, then decreased with the increase of feed content of hydrophobic monomer in copolymer. When the feed content of DTAB in P （ DTAB- co-AM） was 0.15 mol%, the viscosity of association system reached the maximum. When the feed content of DTAB was 0.3 mol% ,the viscosity of this self-assembly system was lower than that of the system formed by this eopolymer and cationic wormlike mieelles because of more strong electrostatic interaction leading to phase separation. In contrast, the viscosity of the system self-assembled by this copolymer and cationic wormlike micelles appear a slight decrease with the increase of the DTAB content because hydrophobie association and electrostatic repulsion offset each other. Based on the above discussions, the aim to mediate the viscosity of self-assembly system by the feed content of hydrophobie monomer can be realized.