Determination of Solvation Layer Thickness by a Magnetophotonic Approach
Determination of Solvation Layer Thickness by a Magnetophotonic Approach
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DOI：
10.1021/nn3007288
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发表时间：
2012-05-01
期刊：
影响因子：
17.1
通讯作者：
Yin, Yadong
中科院分区：
文献类型：
--
作者：
He, Le;Hu, Yongxing;Yin, Yadong
Derjaguin-Landau-Verwey-Overbeek (DLVO) 理论未能解释在有效屏蔽静电力的高离子强度条件下，水悬浮液中胶体颗粒的优异稳定性。越来越多的证据表明，当颗粒间距离减小到几纳米时，在胶体颗粒表面附近形成一层薄薄的溶剂分子刚性层会产生额外的排斥相互作用。然而，有效确定溶剂化层的厚度仍然是一个挑战。在这里，我们展示了一种简单而强大的磁光子技术，可用于研究各种极性溶剂中胶体二氧化硅表面形成的溶剂化层的厚度。确定了溶剂的氢键能力与胶体二氧化硅表面溶剂化层厚度之间的关系；发现这一观察结果与先前提出的溶剂化力的氢键起源一致。
Derjaguin-Landau-Verwey-Overbeek (DLVO) theory fails in explaining the superior stability of colloid particles in aqueous suspensions under conditions of high ionic strengths where electrostatic forces are effectively screened. Accumulating evidence shows that the formation of a thin rigid layer of solvent molecules In the vicinity of a colloidal particle surface provides an additional repulsive interaction when the interparticle distance is reduced to several nanometers. The effective determination of the thickness of the solvation layer however remains a challenge. Here, we demonstrate a simple yet powerful magnetophotonic technique that can be used to study the thickness of the solvation layers formed on the colloidal silica surface in various polar solvents. A relationship between the hydrogen-bonding ability of the solvents and the thickness of solvation layer on colloidal silica surfaces has been Identified; this observation is found to be consistent with the previously proposed hydrogen-bonding origin of the solvation force.