학술논문

Effect of Nanoscopic Confinement on the Microscopic Dynamics of Glass-Forming Liquids and Polymers Studied by Inelastic Neutron Scattering.
Document Type
Article
Source
AIP Conference Proceedings. 2/21/2008, Vol. 982 Issue 1, p79-84. 6p. 7 Graphs.
Subject
*NANOCHEMISTRY
*MICROORGANISMS
*GLASS transition temperature
*POLYMERS
*NEUTRON scattering
Language
ISSN
0094-243X
Abstract
In this article we present inelastic neutron scattering (INS) experiments on different systems of confined glass-formers. The aim of these experiments is to study the influence of spatial restriction on the microscopic dynamics related to the glass transition. Such results could be helpful for the detection of a currently speculated cooperativity length of the glass transition. The glass-forming component is either a molecular liquid or a polymer. The confining matrices are ‘hard’ (silica glass, silicon) or ‘soft’ (microemulsion droplets). For some experiments the confining structure could be spatially oriented. Except for the soft confinement the naïvely expected acceleration effect could only be found at low temperatures where INS experiments are difficult because of the long relaxation times. A clear effect of confinement could be observed for the glass-typical low energy vibrations (boson peak). This effect seems to be completely different for soft and hard confinement. Surprisingly, the experiments on oriented nanopores did not show any signs of an anisotropy of the dynamics. [ABSTRACT FROM AUTHOR]