Rheology of Poly(N-isopropylacrylamide)鈥揅lay Nanocomposite Hydrogels

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• 作者：Di Xu ; Divya Bhatnagar ; Dilip Gersappe ; Jonathan C. Sokolov ; Miriam H. Rafailovich ; Jack Lombardi
• 刊名：Macromolecules
• 出版年：2015
• 出版时间：February 10, 2015
• 年：2015
• 卷：48
• 期：3
• 页码：840-846
• 全文大小：450K
• ISSN：1520-5835

文摘

We used molecular dynamics simulations and experiments to study the rheology of polymer鈥揷lay nanocomposite hydrogels. The molecular dynamics simulations studied the formation of physical cross-linked networks as a function of the clay concentration. Simulations showed that while the local structure changed from isolated polymer鈥揷lay clusters to a percolating network with increasing clay concentration the networks were only able to sustain stress at concentrations of roughly 1.5 times the percolation transition. Experiments using poly(N-isopropylacrylamide) (PNIPA)鈥揷lay nanocomposites at different clay concentrations were compared with simulation results. Experiments showed a transition from viscous to gel like behavior at a clay concentration of 15.24g/L, in good agreement with simulations. The modulus, G鈥?and G鈥? prior to yield was observed to increase exponentially with clay concentration and G鈥?at yield could be fitted to the modified Mooney鈥檚 equation.