Dynamic heterogeneity in aqueous ionic solutions

doi:10.1039/c8cp02787k

CORC > 理论物理研究所 > 中国科学院理论物理研究所 > 理论物理所科研产出 > 理论物理所1978-2010年知识产出

	Dynamic heterogeneity in aqueous ionic solutions
	Ren, G ; Chen, L 1; Wang, YT
刊名	PHYSICAL CHEMISTRY CHEMICAL PHYSICS
	2018
卷号	20 期号:33 页码:21313-21324
关键词	ALKALI-HALIDE SOLUTIONS STOKES-EINSTEIN RELATION MOLECULAR-DYNAMICS CONDUCTIVITY RELAXATION DIELECTRIC-SPECTROSCOPY HOMOGENEOUS NUCLEATION ELECTROLYTE-SOLUTIONS SUPERCOOLED WATER LIGHT-SCATTERING LENNARD-JONES
ISSN号	1463-9076
DOI	10.1039/c8cp02787k
英文摘要	It is well known that supercooled liquids have heterogeneous dynamics, but it is still unclear whether dynamic heterogeneity also exists in aqueous ionic solutions at room or even higher temperatures. In this work, taking KSCN aqueous solutions as an example, we identify by molecular dynamics simulation that dynamics of ionic solutions at a finite concentration are heterogeneous at room and even higher temperatures. Our results indicate that thermal movements of K+ and SCN- deviate from the Gaussian distribution in time and space, as demonstrated by a non-Gaussian parameter and the self-van Hove function. The dynamic susceptibility is nonzero at intermediate times for both K+ and SCN-. The self-intermediate scattering function of ions decays in a stretched exponential way with an exponent smaller than one. The dynamics of the solution are more homogeneous at a higher temperature. Since transient ion clusters of different sizes decay with different lifetimes and exponents, we propose that the dynamic heterogeneity is introduced by transient cluster formation and dissociation in ionic solutions, which leads to a mixed relaxation scenario. Variants of the Stokes-Einstein relation are found to break down into a fractional form analogous to supercooled liquids, but the original Stokes-Einstein relation is indeed valid if taking into account the temperature dependence of the effective hydrodynamic radius. Overall, despite some quantitative differences, the dynamic heterogeneity in aqueous ionic solutions at room or higher temperatures is qualitatively analogous to that in supercooled liquids at a much lower temperature.
学科主题	Chemistry ; Physics
语种	英语
内容类型	期刊论文
源URL	[http://ir.itp.ac.cn/handle/311006/22823]
专题	理论物理研究所_理论物理所1978-2010年知识产出
作者单位	1.Civil Aviat Flight Univ China, Dept Phys, Guanghan, Peoples R China 2.Southwest Univ Sci & Technol, State Key Lab Environm Friendly Energy Mat, Mianyang, Peoples R China 3.Chinese Acad Sci, CAS Key Lab Theoret Phys, Inst Theoret Phys, Beijing, Peoples R China 4.Univ Chinese Acad Sci, Sch Phys Sci, Beijing, Peoples R China
推荐引用方式 GB/T 7714	Ren, G,Chen, L,Wang, YT. Dynamic heterogeneity in aqueous ionic solutions[J]. PHYSICAL CHEMISTRY CHEMICAL PHYSICS,2018,20(33):21313-21324.
APA	Ren, G,Chen, L,&Wang, YT.(2018).Dynamic heterogeneity in aqueous ionic solutions.PHYSICAL CHEMISTRY CHEMICAL PHYSICS,20(33),21313-21324.
MLA	Ren, G,et al."Dynamic heterogeneity in aqueous ionic solutions".PHYSICAL CHEMISTRY CHEMICAL PHYSICS 20.33(2018):21313-21324.