Sierra-Martín B, Laporte Y, South A B, Lyon L A, Fernández-Nieves A
School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2011 Jul;84(1 Pt 1):011406. doi: 10.1103/PhysRevE.84.011406. Epub 2011 Jul 28.
We report measurements of the bulk modulus of individual poly(N-isopropylacrylamide) microgels along their swelling transition. The modulus is determined by measuring the volume deformation of the microgel as a function of osmotic pressure using dextran solutions. We find that the modulus softens through the transition, displaying a nonmonotonous behavior with temperature. This feature is correctly reproduced by the theory of Flory for polymer gels, once the concentration dependence of the solvency parameter is properly incorporated.
我们报告了单个聚（N-异丙基丙烯酰胺）微凝胶在其溶胀转变过程中的体积模量测量结果。通过使用葡聚糖溶液测量微凝胶的体积变形作为渗透压的函数来确定模量。我们发现模量在转变过程中变软，随温度呈现非单调行为。一旦适当考虑了溶剂化参数的浓度依赖性，聚合物凝胶的弗洛里理论就能正确再现这一特征。
