ANALYSIS OF THE PRESSURE EFFECT ON THE LOCAL COMPOSITION IN A WATER–ALKANOL MIXTURE USING KIRKWOOD–BUFF INTEGRALS
D. M. Makarov, G. I. Egorov
Krestov Institute of Solution Chemistry, Russian Academy of Sciences, Ivanovo, Russia
dmm@isc-ras.ru
Keywords: water-alcohol mixtures, Kirkwood-Buff integrals, local composition, excess pressurе
Abstract
Kirkwood-Buff integrals are calculated from the thermodynamic data for binary mixtures of water with methanol, ethanol, 1-propanol, and 2-propanol at a temperature of 298.15 K in the pressure range from atmospheric to 100 MPa. The values of local compositions Δnij are calculated which characterize the excess (or deficit) of molecules i around the central molecule j. It is found that the pressure affects destructively the homoassociation in all mixtures studied. In a series MeOH < EtOH < 2-PrOH < 1-PrOH an excess of molecules around the similar type molecules increases in the local environment and the pressure effect on the local composition is enhanced.
|
