Adsorption and Solution of Weakly Polar Vapors with Thin Layers of Water as Studied by Gas-Liquid Chromatography.
NORTHEASTERN UNIV BOSTON MASS DEPT OF CHEMISTRY
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The paper continues a study on the adsorption and solution of weakly polar vapors with thin layers of water by means of gas-liquid chromatography. In particular 7 new solutes were examined CH2Cl2, CHCl3, CCl4, cis and trans-2-octene, isopropyl ether, and ethyl formate. Mixed mechanisms of retention were found for CH2Cl2, CHCl3, CCl4 and ethyl formate, the other solutes being retained solely by adsorption. In terms of partition, good agreement has been found between static partition coefficients and heats of solution and chromatographic data. In the case of the thermodynamic quantities of adsorption at zero coverage, it has been concluded that the adsorbed state can be considered as a gaseous or mobile film in most cases. No evidence for hydrogen bonding has been found between isopropyl ether and the surface of water, whereas significant hydrogen bonding was previously postulated for n-propyl ether. Finally, the free energy and enthalpy of adsorption per methylene group has been found to be positive when methyl formate is compared with ethyl formate. Author
- Physical Chemistry