Department of Chemical Engineering, University of Washington , Seattle, Washington 98195, United States.
J Phys Chem B. 2012 May 17;116(19):5766-70. doi: 10.1021/jp300205m. Epub 2012 Apr 26.
Molecular dynamics simulations were performed to examine the mechanical properties of poly(carboxybetaine methacrylate) (pCBMA) hydrogels. pCBMA hydrogels with additional hydroxyl groups as physical cross-linkers (OH-pCBMA hydrogels) were studied for comparison. Results show that OH-pCBMA hydrogels have higher elastic modulus than pCBMA hydrogels. This improvement can be explained by hydrogen bond formation between hydroxyl groups and carboxylate groups in the OH-pCBMA hydrogel, which result in an enhanced polymer network within the hydrogel. The enhancement of the polymer work is also suggested by a smaller value of root-mean-square deviation of zwitterionic side chain pairs in the OH-pCBMA hydrogel than that in the pCBMA hydrogel. Additionally, the presence of hydrogen bonds leads to a lower equilibrium water content for the OH-pCBMA hydrogel compared to the pCBMA hydrogel, which is another reason for the greater mechanical modulus of the OH-pCBMA hydrogel.
通过分子动力学模拟研究了聚（羧基甜菜碱甲基丙烯酸酯）（pCBMA）水凝胶的力学性能。为了进行比较，研究了具有额外羟基作为物理交联剂的 pCBMA 水凝胶（OH-pCBMA 水凝胶）。结果表明，OH-pCBMA 水凝胶的弹性模量高于 pCBMA 水凝胶。这种改善可以通过 OH-pCBMA 水凝胶中羟基和羧酸盐基团之间形成氢键来解释，这导致水凝胶内聚合物网络的增强。通过 OH-pCBMA 水凝胶中两性离子侧链对 RMSD 的较小值也可以看出聚合物功的增强，而 pCBMA 水凝胶中两性离子侧链对 RMSD 的较小值则可以看出聚合物功的增强。此外，氢键的存在导致 OH-pCBMA 水凝胶的平衡含水量低于 pCBMA 水凝胶，这也是 OH-pCBMA 水凝胶具有更大机械模量的另一个原因。
