pH响应型P(HEMA/MAA)纳米微凝胶分散液的凝胶化行为和流变性能  

Rheological Properties and Gelation of pH-Responsive P(HEMA/MAA) Nano-Microgel Dispersions

作　　者：申迎华[1] 刘慧敏[1] 李国卿[1] 翟志国[1] 树学峰[2] 台秀梅[3] 

机构地区：[1]太原理工大学化学化工学院,太原030024 [2]太原理工大学应用力学与生物医学工程研究所,太原030024 [3]中国日用化学工业研究院,太原030001

出　　处：《物理化学学报》2011年第8期1919-1925,共7页Acta Physico-Chimica Sinica

基　　金：山西省自然科学基金(2010011032-2);山西省研究生优秀创新项目(20103036)资助~~

摘　　要：制备了在修复受损组织方面有应用潜能的纳米级聚(甲基丙烯酸羟乙酯/甲基丙烯酸)(P(HEMA/MAA))微凝胶;采用试管倒转法对不同pH值和浓度的P(HEMA/MAA)微凝胶分散液的凝胶化相转变行为进行了研究;借助椎板流变仪考察了低浓度和高浓度微凝胶分散液的流变性能,并对pH触发物理凝胶化相转变机理进行了推测.结果表明:在生理pH值环境下,一定浓度的P(HEMA/MAA)微凝胶分散液可以发生凝胶化相转变形成凝胶态,pH=7时,HEMA/MAA进料摩尔比为8/2的微凝胶分散液凝胶化后得到的凝胶力学性能最佳,最大弹性模量(G')可达7.58×103Pa;P(HEMA/MAA)微凝胶颗粒在不同条件下具有不同的溶胀效果,导致低浓度分散液的表观粘度发生相应的变化,并由此推测出微凝胶颗粒的溶胀过程由外及内,分为三个阶段;高浓度微凝胶分散液发生凝胶化相转变主要是由颗粒间或颗粒与分散介质间形成的空间静电稳定作用和氢键共同作用引起的.Poly（（2-hydroxyethyl methacrylate）-co-（methacrylic acid）） （P（HEMA/MAA）） microgels with potential application in the restoration of damaged tissue were prepared. The phase transition behavior of P（HEMA/MAA） microgel dispersions at different pH values and concentrations as well as rheological properties of diluent and concentrated dispersions were investigated by tube inversion measurements and rheometry, respectively. The mechanism of the pH-induced physical gel phase transition was discussed. The results indicate that P（HEMA/MAA） microgel dispersions at a given concentration can be transformed into a macroscopic gel for gelation at a physiological pH. The mechanical strength of the P（HEMA-co-MAA） macroscopic gel （nHEMA/nMAA=812, pH=7.0） is the best and the elastic modulus （G＇） value can reach 7.58× 10^3 Pa. The swelling effects of the P（HEMA/MAA） microgel are different under different conditions, which results in a variety of apparent viscosities for the diluent dispersions. We deduce that the swelling behavior of the microgel particles can be divided into three stages from the outer parts of the particles to the inner parts. The gelation transitions of the concentrated dispersions are caused synergistically by space electrostatic interactions and hydrogen bonds of the neighboring microgel particles or between microgel particles and water molecules.

关 键 词：凝胶化 P(HEMA/MAA)微凝胶 PH响应性 分散液浓度 弹性模量 

分 类 号：O648.1[理学—物理化学]