SIZE DEPENDENCE OF TRACER DIFFUSION IN SUPERCOOLED LIQUIDS

Citation
G. Heuberger et H. Sillescu, SIZE DEPENDENCE OF TRACER DIFFUSION IN SUPERCOOLED LIQUIDS, Journal of physical chemistry, 100(37), 1996, pp. 15255-15260
Citations number
36
Categorie Soggetti
Chemistry Physical
ISSN journal
00223654
Volume
100
Issue
37
Year of publication
1996
Pages
15255 - 15260
Database
ISI
SICI code
0022-3654(1996)100:37<15255:SDOTDI>2.0.ZU;2-Y
Abstract
We have determined by forced Rayleigh scattering the diffusion coeffic ients D of several photochromic tracers with van der Waals radii betwe en 0.38 and 8 nm (the largest ones being photolabeled polystyrene micr onetworks) in 10 glass-forming liquids at temperatures between the gla ss temperature T-g and similar to 1.2T(g) The results were analyzed in terms of power law plots, D(T) proportional to T/eta(T)(xi), where et a is the solvent shear viscosity, and temperature shifts, D(T) proport ional to T/eta(T + Delta T). The shift Delta T was related with the wi dth of the rotational correlation time distribution via the time-tempe rature superposition principle.