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化学学报
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化学学报 ›› 2006, Vol. 64 ›› Issue (6): 579-583. 上一篇    下一篇

研究简报

298.15和308.15 K温度条件下甘氨酰甘氨酸在电解质溶液中的热力学性质的研究: 体积性质

林贵梅，边平凤，林瑞森*   

  1. (浙江大学化学系 杭州 310027)
  • 投稿日期:2005-07-07 修回日期:2005-11-14 发布日期:2006-03-28
  • 通讯作者: 林瑞森

Study on Thermodynamic Properties of Glycylglycine in Aqueous Electrolyte Solutions at 298.15 and 308.15 K: Volume Properties

LIN Gui-Mei, BIAN Ping-Feng, LIN Rui-Sen*   

  1. (Department of Chemistry, Zhejiang University, Hangzhou 310027)
  • Received:2005-07-07 Revised:2005-11-14 Published:2006-03-28
  • Contact: LIN Rui-Sen

PDF

1273

被引次数

17

利用精密数字密度计测定了298.15和308.15 K甘氨酰甘氨酸在KCl-水和NaCl-水混合溶剂中的密度, 计算了甘氨酰甘氨酸的表观摩尔体积VΦ和极限偏摩尔体积VΦ?, 得到了其由纯水溶剂转移至混合溶剂中的迁移偏摩尔体积ΔtrsVΦ?和理论水化数Nh. 正的迁移偏摩尔体积说明在本文所研究的浓度范围内盐溶液可以提高球形蛋白的结构稳定性. 结果表明, 温度对迁移偏摩尔体积的影响很小; 溶液中离子与甘氨酰甘氨酸带电中心间的相互作用占主导地位. 利用共球交盖模型对结果进行了讨论.

关键词: 极限偏摩尔体积, 甘氨酰甘氨酸, 电解质

Apparent molar volumes VΦ of glycylglycine in aqueous KCl and NaCl solutions have been obtained from densities at 298.15 and 308.15 K measured with a vibrating-tube densimeter. These data have been used to deduce partial molar volumes of transfer ΔtrsVΦ? from water to different salt water mixtures. ΔtrsVΦ? values are positive. This result arises from the interaction of KCl and NaCl with the charged centers of glycylglycine. The positive ΔtrsVΦ? of glycylglycine shows that salts in the concentration range studied will stabilize the globular protein. The results show that ΔtrsVΦ? depends less on temperature. The interaction between the charged centers of glycylglycine and ions dominates other forms interactions. The results have been explained using the cosphere overlap model.

Key words: limiting partial molar volume, glycylglycine, electrolyte