Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (04): 815-824.doi: 10.3866/PKU.WHXB20110341

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Molecular Dynamics Simulation of the Diffusion Behavior of Water Molecules in Oil and Cellulose Composite Media

LIAO Rui-Jin, ZHU Meng-Zhao, ZHOU Xin, YANG Li-Jun, YAN Jia-Ming, SUN Cai-Xin   

  1. State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing 400044, P. R. China
  • Received:2010-08-18 Revised:2011-01-05 Published:2011-03-29
  • Contact: LIAO Rui-Jin E-mail:rjliao@cqu.edu.cn
  • Supported by:

    The project was supported by the National Key Basic Research Project of China (973) (2009CB724505-1), National Natural Science Foundation of China (5107736), and Fundamental Research Funds for the Central Universities, China (CDJXS11152235).

Abstract:

The diffusion behaviors of water molecules in oil-cellulose composite media were studied at different temperatures using a molecular dynamics simulation. By analyzing the formation of hydrogen bonds between the water molecules and cellulose we found that the water molecules that were initially present in the oil gradually spread to the cellulose, and hydrogen bonds were formed between them. The water molecules that were present in the cellulose initially also formed hydrogen bonds and were bound to cellulose molecules. By analyzing the diffusion coefficients of the water molecules at different temperatures we found that the diffusion behaviors of the water molecules in the two single-media, namely oil and cellulose, were very different because of their different polarities. The diffusion coefficients of the water molecules in the composite media were influenced greatly by the ratio of water molecules present in the oil and cellulose and a strong correlation was apparent between them. The water molecule-oil interaction energy and the water molecule-cellulose interaction energy were also strongly related to the polarities of the oil and the cellulose. The interaction energies also exhibited a strong correlation to the distribution of water molecules at different temperatures. This was the reason for the weakened influence of temperature on the diffusion coefficient of the water molecules, which was due to the different distributions of water molecules at different temperatures.

Key words: Molecular dynamics, Composite medium, Hydrogen bond, Diffusion coefficient, Interaction energy, Correlation

MSC2000: 

  • O641