疏水缔合聚丙烯酸与蠕虫状胶束的协同作用

从宏观流变性和介观尺度方面, 研究了疏水缔合聚丙烯酸(HMPA)与油酸钠(NaOA)构筑的蠕虫状胶束的协同作用. 考察HMPA对蠕虫状胶束溶液流变性和表观粘度的影响, 结果表明, 极少量HMPA的引入导致蠕虫状胶束溶液体系动态模量明显增加; 其表观粘度随HMPA浓度的增加先增强后减弱. 另一方面, 通过耗散颗粒动力学(DPD)分子模拟方法研究了混合体系中溶液组成对HMPA分子链的均方根末端距的影响. 结果表明,随着NaOA浓度增加, HMPA的均方根末端距会出现峰值; HMPA的伸展程度受其自身浓度变化制约, 相对于纯HMPA体系, NaOA胶束的存在对高浓度区的HMPA伸展程度影响更明显. 结合流变实验和分子模拟结果,初步解释了聚合物与蠕虫状胶束的协同作用机制.

Synergism between Hydrophobically Modified Polyacrylic Acid and Wormlike Micelles

The synergism between wormlike micelles formed from sodium oleate (NaOA) and hydrophobically modified polyacrylic acid (HMPA) was investigated according to their macroscopic performances and mesoscopic scales, using a combination of viscosity/rheology measurements and dissipative particle dynamics (DPD) molecular simulations. The rheology of NaOA wormlike micelles changed significantly following the addition of a small amount of HMPA, which verified the synergistic effect between them. A peak in the apparent viscosity was observed following an increase in the concentration of HMPA, suggesting that the synergistic effect was restricted by the composition of the mixture. A DPD simulation also confirmed that the solution composition had an influence on the root mean square (RMS) end-to-end distances of HMPA, with the observed value fluctuating according to NaOA and HMPA concentrations. The micellar morphology affected the RMS end-to-end distances of HMPA and the presence of NaOA micelles exerted a significant impact on the extension of HMPA at high HMPA concentrations. A proposed synergistic mechanism has been presented according to the experimental and simulation results.