Binary Diffusion Coefficients for Methane and Fluoromethanes in Nitrogen.

Binary gas-phase diffusion coefficients, of interest in physical models of atmospheric and combustion chemistry, have been measured in for the homologous series of refrigerant-related (fluoro)methanes: methane (), fluoromethane (), difluoromethane (), and trifluoromethane (). Values have been determined by reverse-flow gas chromatography, which has been previously demonstrated to provide accurate results over a wide range of temperatures. Coefficients were measured at temperatures of (300 to 550) K for all species and extending up to 650 K and 723 K for and , respectively, and down to 250 K for .