化工学报 ›› 2015, Vol. 66 ›› Issue (S1): 54-59.DOI: 10.11949/j.issn.0438-1157.20150123

• 热力学 • 上一篇    下一篇

2,6-二甲氧基苯酚在1-丁基-3-甲基咪唑四氟硼酸盐水溶液中溶解行为的红外光谱分析

赵德扬, 魏立纲, 李坤兰, 王艳涛, 马英冲, 邵国林, 闫冰, 万文英, 刘畅   

  1. 大连工业大学轻工与化学工程学院, 辽宁 大连 116034
  • 收稿日期:2015-01-26 修回日期:2015-02-02 出版日期:2015-06-30 发布日期:2015-06-30
  • 通讯作者: 魏立纲
  • 基金资助:

    国家自然科学基金项目(21276034);辽宁省教育厅科学研究一般项目(L2013220)。

Understanding dissolution behavior of 2,6-dimethoxyphenol in 1-butyl-3-methylimidazolium tetrafluoroborate aqueous solutions by infrared spectroscopy

ZHAO Deyang, WEI Ligang, LI Kunlan, WANG Yantao, MA Yingchong, SHAO Guolin, YAN Bing, WAN Wenying, LIU Chang   

  1. School of Light Industry and Chemical Engineering, Dilian Polytechnic University, Dalian 116034, Liaoning, China
  • Received:2015-01-26 Revised:2015-02-02 Online:2015-06-30 Published:2015-06-30
  • Supported by:

    supported by the National Natural Science Foundation of China (21276034) and the Scientific Research Project of the Department of Education of Liaoning Province (L2013220).

摘要:

利用衰减全反射红外光谱(ATR-IR)和二维相关红外技术研究2, 6-二甲氧基苯酚(2, 6-DMP)在1-丁基-3-甲基咪唑四氟硼酸盐([C4mim]BF4)水溶液(离子液体摩尔分数xIL=1.0~0.02)中的溶解行为。随着水量增大, 2, 6-DMP溶解度先增大而后急剧减小, 对应的xIL阈值为0.1。2, 6-DMP与[C4mim]BF4之间存在强相互作用, 2, 6-DMP上的甲氧基是重要作用位点之一;当少量的水加入[C4mim]BF4(xIL=0.1~1.0), 致密的离子簇结构被解离, 2, 6-DMP容易与[C4mim]BF4作用, 溶解度增大;随着大量水加入(0.02<xIL<0.1), 离子簇完全解离为大分子水簇包围的离子对, 憎水的2, 6-DMP与[C4mim]BF4作用困难, 溶解度减小。这种由于水量改变引起的[C4mim]BF4水溶液微观结构变化影响2, 6-DMP溶解行为。

关键词: 离子液体, 水, 2,6-二甲氧基苯酚, 溶解性, 红外光谱

Abstract:

Dissolution behavior of 2, 6-dimethoxyphenol (2, 6-DMP) in 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim]BF4) aqueous solutions (ionic liquid mole fraction xIL=1.0—0.02) was investigated by attenuated total reflectance infrared (ATR-IR) spectroscopy and two-dimensional correlation IR spectroscopy. The results indicated that 2,6-DMP solubility increases and then dramatically decreases with increasing amount of water added into [C4mim]BF4. The corresponding threshold of xIL is 0.1. There is a strong interaction between 2, 6-DMP and [C4mim]BF4, and the methoxyl group of 2, 6-DMP is one of main active sites. In the case of adding small amount of water into [C4mim]BF4 (xIL=0.1—1.0), compact ionic clusters of [C4mim]BF4 could be dissociated. 2, 6-DMP is easy to interact with [C4mim]BF4, which results in the increase of its solubility. In the case of adding a large amount of water into [C4mim]BF4 (xIL=0.02—0.1), the ionic clusters are completely dissociated into ionic pairs surrounded by large molecular water clusters. The interactions between hydrophobic 2, 6-DMP and [C4mim]BF4 become difficult, and the 2, 6-DMP solubility decreases. This transformation of microstructure with water addition influences the 2, 6-DMP dissolution.

Key words: ionic liquid, water, 2,6-dimethoxyphenol, solubility, infrared spectroscopy

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