A comparative study on the rheological behavior of N-carboxyethylchitosan by molecular dynamic simulation and viscosity measurement
In this work,the rheological behavior of N-carboxyethylchitosan was investigated by molecular dynamic simulation and viscosity measurement under different pH,salt concentration and temperature conditions.The conformation of N-carboxyethylchitosan in aqueous solutions,in particular the radiuses of gyration,were obtained from molecular dynamic simulations,and the data were analyzed and compared with experimental data derived from the viscosity measurement.The dynamic viscosity of N-carboxyethylchitosan solutions showed that a viscosity minimum was found at pH≈7 and the polymer exhibits an anti-electrolyte behavior at neutral pH with increasing salt concentration.MD simulation performed on this system revealed a conformation behavior in accordance with the experimental results of viscosity,in particular,a much more compact conformation was adopted by the polymer at neutral pH and a compact conformation in the high/low pH conditions.The values of radiuses of gyration polymer showed the decreasing tendency at the low/high pH conditions and the increasing tendency at neutral pH condition with the temperature rising.All of these clearly demonstrate that the influence of pH and salt on the conformation and viscosity of the polymer aqueous solution was a result of electrostatic interaction of the polymer with its surrounding molecules.
Qiang Yin Lin Zhang Du Kai Ge Zhou Qin-jian Yin Yah Li Jian-hui Luo Bo Jiang
Research Center of Laser Fusion, China Academy of Engineering Physics, P.O.Box 919-987 Sichuan 62190 Research Center of Laser Fusion, China Academy of Engineering Physics, P.O.Box 919-987 Sichuan 62190 College of Chemistry, Sichuan University, Sichuan 610064, China
国际会议
南京
英文
1-15
2012-05-13（万方平台首次上网日期，不代表论文的发表时间）