Molecular mechanism of the viscosity of aqueous glucose solutions

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• 作者：L. A. Bulavin ; Yu. F. Zabashta ; A. M. Khlopov…
• 关键词：viscosity ; aqueous solution ; glucose ; network model
• 刊名：Russian Journal of Physical Chemistry A
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：91
• 期：1
• 页码：89-93
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Physical Chemistry;
• 出版者：Pleiades Publishing
• ISSN：1531-863X
• 卷排序：91

文摘

Experimental relations are obtained for the viscosity of aqueous glucose solutions in the temperature range of 10–80°C and concentration range 0.01–2.5%. It is found that the concentration dependence of fluidity is linear when the concentration is higher than a certain value and varies at different temperatures. The existence of such a dependence indicates that the mobilities of solvent and solute molecules are independent of the concentration of solutions. This assumption is used to construct a theoretical model, in which the structure of an aqueous glucose solution is presented as a combination of two weakly interacting networks formed by hydrogen bonds between water molecules and between glucose molecules. Theoretical relations are obtained using this model of network solution structure for the concentration and temperature dependence of solution viscosity. Experimental data are used to calculate the activation energies for water (U_w = 3.0 × 10–20 J) and glucose molecules (U_g = 2.8 × 10–20 J). It is shown that the viscosity of a solution in such a network structure is governed by the Brownian motion of solitons along the chains of hydrogen bonds. The weak interaction between networks results in the contributions to solution fluidity made by the motion of solitons in both of them being almost independent.