Spectroscopic and Solubility Characteristics of Oxidized Soots

Abstract
Spectroscopic and solubility 1 1A “solution” of soot and water refers to a system that passes through Whatman 934-AH glass filter, and does not imply complete solid-solvent interaction at the molecular level. View all notes studies of reaction products of soot (black carbon) with O3, NO2/N2O4, and SO2 have revealed a relationship between reactivity and product solubility and structure. A remarkably high solubility of ozonated n-hexane soot has its origin in the formation of anhydride and lactone surface structures and their subsequent hydrolysis to carboxylic acid species. Calculations indicate that the rate of surface carboxylation of 0.1-μm diameter spheroidal soot particles, in the presence of 50 ppbv ozone at ambient temperature, is such that solubilization may occur within a 30-minute time frame. Measurements on ambient air aerosol samples in metropolitan Denver are consistent with these observations and demonstrate the high reactivity of soot with ozone even at very low levels in natural systems.