Effects of different solutes on the physical chemical properties of aqueous solutions via rearrangement of hydrogen bonds in water
Effects of different solutes on the physical chemical properties of aqueous solutions via rearrangement of hydrogen bonds in water
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DOI：
10.1016/j.molliq.2021.116288
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发表时间：
2021-05-04
影响因子：
6
通讯作者：
Zaslavsky, Boris Y.
中科院分区：
文献类型：
--
作者：
da Silva, Nuno;Ferreira, Luisa A.;Zaslavsky, Boris Y.
研究了无机盐和有机物水溶液中OH伸缩带的衰减全反射-傅里叶变换红外光谱（ATR-FTIR）; Na 2SO 4、NaCl、NaClO 4、NaSCN、N-氧化三甲胺、尿素、聚乙二醇、聚乙烯吡咯烷酮和乙二醇和丙二醇共聚物（Ucon）在不同浓度下的光谱。将谱带分解为峰值在3080、3230、3400和3550 cm（-1）的四个高斯分量，与这里检查的每种化合物都拟合，残差基本上是平坦的。这些成分被视为代表四个不同的亚群的水与不同的H-键的安排。这些组分的实验估计的相对贡献取决于溶质类型和浓度，并且与先前报道的实验测量的水的溶剂特征（例如溶剂偶极性/极化率，pi*，溶剂氢键供体酸度，α和溶剂氢键受体碱度，β）强烈相关。我们建议，水包括一个合奏的四个不同的亚群的分子与各种氢键强度，几何形状，和键缺陷取决于溶质。这种假设显然过于简化，但对于这里研究的各种溶质，我们发现给定的溶质改变了这些亚群的相对量，从而改变了水的上述溶剂特征。特别地，溶剂特征pi* 和alpha描述了各种化合物的水溶液的各种物理化学性质，例如水活度、渗透系数、相对粘度、介电常数和表面张力。因此，水溶液的所有这些物理化学性质都是由上述水分子亚群的相对量决定的。(C)2021爱思唯尔有限公司版权所有。
The Attenuated Total Reflection - Fourier Transform Infrared (ATR-FTIR) spectra of the OH-stretch band in aqueous solutions of inorganic salts and organic materials; Na2SO4, NaCl, NaClO4, NaSCN, trimethylamine N-oxide, urea, poly(ethylene glycol), polyvinylpyrrolidone, and copolymer of ethylene glycol and propylene glycol (Ucon) were studied at various concentrations. The decomposition of the band into four Gaussian components peaking at 3080, 3230, 3400, and 3550 cm(-1) fits every compound examined here with essentially flat residuals. These components were viewed as representing four different subpopulations of water with different H-bond arrangements. The experimentally estimated relative contributions of these components depend on solute type and concentration, and correlate strongly with previously reported experimentally measured solvent features of water such as solvent dipolarity/polarizability, pi*, solvent H-bond donor acidity, alpha, and solvent H-bond acceptor basicity, beta. We suggest that water includes an ensemble of four different subpopulations of molecules with various hydrogen bond strengths, geometry, and bond defects depending on the solute. This assumption is obviously oversimplified, but for the wide range of solutes examined here we find that a given solute changes the relative amounts of these subpopulations and hence the above solvent features of water. The solvent features, pi* and alpha, in particular, describe a variety of physicochemical properties, such as water activity, osmotic coefficient, relative viscosity, permittivity, and surface tension, of aqueous solutions of various compounds. It follows therefore that all these physicochemical properties of aqueous solutions are determined by the relative amounts of the above subpopulations of water molecules. (C) 2021 Elsevier B.V. All rights reserved.