为获得更多空间而受限：纳米孔中2-乙基-1-己醇更大的自由体积和增强的玻璃态动力学

Confinement for More Space: A Larger Free Volume and Enhanced Glassy Dynamics of 2-Ethyl-1-hexanol in Nanopores.

作者信息

Kipnusu Wycliffe K, Elsayed Mohamed, Kossack Wilhelm, Pawlus Sebastian, Adrjanowicz Karolina, Tress Martin, Mapesa Emmanuel U, Krause-Rehberg Reinhard, Kaminski Kamil, Kremer Friedrich

机构信息

Institute of Experimental Physics I, University of Leipzig , Linnéstrasse 5, 04103 Leipzig, Germany.

Department of Physics, Martin Luther University Halle , 06099 Halle, Germany.

出版信息

J Phys Chem Lett. 2015 Sep 17;6(18):3708-12. doi: 10.1021/acs.jpclett.5b01533. Epub 2015 Sep 4.

DOI:10.1021/acs.jpclett.5b01533

PMID:26722745

Abstract

Broadband dielectric spectroscopy and positron annihilation lifetime spectroscopy are employed to study the molecular dynamics and effective free volume of 2-ethyl-1-hexanol (2E1H) in the bulk state and when confined in unidirectional nanopores with average diameters of 4, 6, and 8 nm. Enhanced α-relaxations with decreasing pore diameters closer to the calorimetric glass-transition temperature (T(g)) correlate with the increase in the effective free volume. This indicates that the glassy dynamics of 2D constrained 2E1H is mainly controlled by density variation.

摘要

采用宽带介电谱和正电子湮没寿命谱来研究本体状态下以及受限在平均直径为4、6和8纳米的单向纳米孔中的2-乙基-1-己醇（2E1H）的分子动力学和有效自由体积。随着孔径减小且更接近量热玻璃化转变温度（T(g)），α弛豫增强，这与有效自由体积的增加相关。这表明二维受限2E1H的玻璃态动力学主要受密度变化控制。