How does sensitivity to dynamical heterogeneity in supercooled colloidal liquids depend on tracer size?
文献类型:期刊论文
作者 | Sarangapani, Prasad1; Zhao, Jiang2; Zhu, Yingxi1 |
刊名 | JOURNAL OF CHEMICAL PHYSICS |
出版日期 | 2008-09-14 |
卷号 | 129期号:10 |
ISSN号 | 0021-9606 |
DOI | 10.1063/1.2976770 |
英文摘要 | Few experimental investigations have examined the dependence of probe length scale on the evolution of dynamical heterogeneity in supercooled liquids. In this study, we use fluorescent tracer probes, which are smaller than that of the constituent unlabeled particles in the matrix suspension, to investigate the tracer size sensitivity to the onset of dynamical heterogeneity in model hard-sphere colloidal suspensions close to the glass transition. The dynamics of poly(methyl methacrylate) (PMMA) tracer particles of radii a(S)= 137 nm embedded into constituent PMMA particles of a(L) = 212 and 637 nm with bulk volume fraction phi varied from 0.50 to 0.57 is examined using fluorescence correlation spectroscopy (FCS). Upon increasing phi for the largest tracer size ratio explored, f (= a(S)/a(L)) = 0.646, the onset of dynamic heterogeneity is observed from the broad distribution of characteristic decay times of the tracers, which is extracted from the measured FCS autocorrelation functions. The strong coupling between tracer size and its sensitivity to dynamical heterogeneity is reflected in the dynamic susceptibility, where dynamic correlation lengths are immeasurable for the smallest size ratio and show a marked increase to five tracer particle diameters for the largest size ratio. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2976770] |
语种 | 英语 |
出版者 | AMER INST PHYSICS |
WOS记录号 | WOS:000259883600034 |
源URL | [http://ir.iccas.ac.cn/handle/121111/64221] |
专题 | 中国科学院化学研究所 |
通讯作者 | Sarangapani, Prasad |
作者单位 | 1.Univ Notre Dame, Dept Chem & Biomol Engn, Notre Dame, IN 46556 USA 2.Chinese Acad Sci, Inst Chem, Beijing 100190, Peoples R China |
推荐引用方式 GB/T 7714 | Sarangapani, Prasad,Zhao, Jiang,Zhu, Yingxi. How does sensitivity to dynamical heterogeneity in supercooled colloidal liquids depend on tracer size?[J]. JOURNAL OF CHEMICAL PHYSICS,2008,129(10). |
APA | Sarangapani, Prasad,Zhao, Jiang,&Zhu, Yingxi.(2008).How does sensitivity to dynamical heterogeneity in supercooled colloidal liquids depend on tracer size?.JOURNAL OF CHEMICAL PHYSICS,129(10). |
MLA | Sarangapani, Prasad,et al."How does sensitivity to dynamical heterogeneity in supercooled colloidal liquids depend on tracer size?".JOURNAL OF CHEMICAL PHYSICS 129.10(2008). |
入库方式: OAI收割
来源:化学研究所
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