Izlaganje sa skupa

Recent Thermodynamic Data on Vicinal Water and a Model for Their Interpretation

Frank M. Etzler ; Department of Chemistry, East Carolina University, Greenville, North Carolina 27834
Walter Drost-Hansen ; Laboratory for Water Research, Department of Chemistry, University of Miami, Coral Gables, Florida 33124, USA

Sažetak

Results of recent measurements on vicinal (i.e. surface modified)
water are reported, particularly data for the density, thermal
expansion coefficient, and viscosity. The results are discussed and
related to previous studies, suggesting that vicinal water extends
over large distances, probably in the range of 30 to 100 molecular
diameters. It is proposed also that vicinal water is induced not only
by proximity to a »solid« interface but may also occur as vicinal
hydration of macromolecules larger than a certain minimum size,
likely in the range of 1000 to 5000 Daltons. The temperatures (Tk)
at which the thermal anomalies in the properties of vicinal water
occur have been confirmed by an extensive DSC study. The critical
temperatures are found to be independent of the chemical nature
of the solid substrate, based on DSC measurements with porous
quartz, polystyrene suspensions and diamond powder, thus
lending credence to the reality of the »Paradoxical Effect«. Finally,
a percolation model of vicinal water, based on the work by Stanley
and Teixeira, is discussed. The model leads to a predicted value
for the density of vicinal water of 0.97 g/cm3 in good agreement
with the observed value. However the model does not predict the
occurence of the thermal anomalies.

Ključne riječi

Hrčak ID:

194183

URI

https://hrcak.srce.hr/194183

Datum izdavanja:

9.11.1983.

Posjeta: 993 *