Nature of organic fluid-montmorillonite interactions: An FTIR spectroscopic study
Nature of organic fluid-montmorillonite interactions: An FTIR spectroscopic study
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DOI：
10.1016/j.jcis.2009.05.011
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发表时间：
2009-09-01
影响因子：
9.9
通讯作者：
Katti, Dinesh R.
中科院分区：
文献类型：
--
作者：
Amarasinghe, Priyanthi M.;Katti, Kalpana S.;Katti, Dinesh R.
层间水中H-O-H伸缩振动和钠基蒙脱石(MMT)结构在MR(傅立叶变换红外光谱)中的Si-O伸缩振动的变化揭示了不同介电常数的流体对粘土结构的影响。采用介电常数为110~2.4的6种不同流体，在分子水平上研究了不同极性的流体进入粘土夹层的机理，以及这些分子与粘土结构和层间水相互作用的速率。与溶剂混合后，层间水的H-O-H弯曲振动几乎立即发生移动，蒙脱土的Si-O振动带几乎立即发生变化，与溶剂的极性无关。然而，H-O-H弯曲和Si-O伸缩的变化幅度和速率取决于溶剂的极性。结果表明，溶剂的极性与层间水的H-O-H弯曲位移、流体的极性与蒙脱土-溶剂样品的d(001)间距之间有很好的相关性。低极性流体，如甲醇，往往与粘土表面的氧和层间水分子产生微弱的静电相互作用，从而导致层间间距增加。虽然甲酰胺等高极性分子引起的Si-O结构的变化是一个连续的过程，但TCE(三氯乙烯)等非极性流体对Si-O结构的影响几乎是瞬时的，这可能导致粘土的高水力传导性。(C)2009 Elsevier Inc.保留所有权利。
The changes in the H-O-H stretching vibration in the interlayer water and Si-O stretching vibration of a Na-montmorillonite (MMT) structure in the MR (Fourier transform infrared) spectra provide insight into the effect of fluids of different dielectric Constants on the clay structure. Mechanisms by which the different fluids of varying polarities enter into the clay interlayer and the rates at which these molecules interact with the clay structure and the interlayer water are Studied at the molecular level using six different fluids with dielectric constants ranging from 110 to 2.4. The shift in H-O-H bending vibrations of interlayer water and changes in the Si-O vibration bands of MMT occur almost immediately after mixing with the solvent regardless of the polarity of the solvent. However, the extent and the rate of changes in H-O-H bending and Si-O stretching are dependent on the polarity of the solvent. Results show a very good correlation between the polarity of the solvent and the shift in H-O-H bending of interlayer water, and also between the polarity of the fluids and the d((001)) spacing of the MMT-solvent samples. Low polar fluids such as methanol tend to make weak electrostatic interactions with clay surface oxygen and interlayer-water molecules, which result in an increase in interlayer spacing. Although, the alteration of the Si-O structure due to high polar molecules such as formamide is a continuous process, the influence of nonpolar fluids such as TCE (trichloroethylene) on the Si-O structure is almost instantaneous, which may result in high hydraulic conductivity in the clay. (C) 2009 Elsevier Inc. All rights reserved.