Enhanced uptake of water by oxidatively processed oleic acid

[摘要] A quartz crystal microbalance apparatus has been used to measure the roomtemperature uptake of water vapour by thin films of oleic acid as a functionof relative humidity, both before and following exposure of the films tovarious partial pressures of gas phase ozone. A rapid increase in thewater-sorbing ability of the film is observed as its exposure to ozone isincreased, followed by a plateau region in which additional water is takenup more gradually. In this fully-processed region the mass of water taken upby the film is about 4 times that of the unprocessed film. Infrared spectraof the films, measured after variable exposures to ozone, show dramaticincreases in both the "free" and hydrogen-bonded O-H stretching regions,and a decrease in the intensity of olefinic features. These results areconsistent with the formation of an oxygenated polymeric product orproducts, as well as the gas phase products previously identified.

[学科分类] 大气科学