Yuan Haiyang, Deng Wenjie, Zhu Xiaolong, Liu Guangming, Craig Vincent Stuart James
Department of Chemical Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei 230026, P. R. China.
State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei 230026, P. R. China.
Langmuir. 2022 May 17;38(19):6164-6173. doi: 10.1021/acs.langmuir.2c00519. Epub 2022 May 5.
Surface force measurements have revealed that at very high electrolyte concentrations as well as in neat and diluted ionic liquids and deep eutectic solvents, the range of electrostatic interactions is far greater than the Debye length. Here, we explore the consequences of this underscreening for soft-matter and colloidal systems by investigating the stability of nanoparticle dispersions, the self-assembly of ionic surfactants, and the thickness of soap films. In each case, we find clear evidence of re-entrant properties due to underscreening at high salt concentrations. Our results show that underscreening in concentrated electrolytes is a general phenomenon and is not dependent on confinement by macroscopic surfaces. The stability of systems at very high salinity due to underscreening may be beneficially applied to processes that currently use low-salinity water.
表面力测量结果表明，在非常高的电解质浓度下，以及在纯离子液体、稀释离子液体和深共熔溶剂中，静电相互作用的范围远大于德拜长度。在此，我们通过研究纳米颗粒分散体的稳定性、离子表面活性剂的自组装以及肥皂膜的厚度，探讨这种欠屏蔽对软物质和胶体系统的影响。在每种情况下，我们都发现了由于高盐浓度下的欠屏蔽而导致的折返特性的明确证据。我们的结果表明，浓电解质中的欠屏蔽是一种普遍现象，并不依赖于宏观表面的限制。由于欠屏蔽，系统在非常高盐度下的稳定性可能会有益地应用于目前使用低盐度水的过程中。
