Determining coefficients for mass-transfer models for volatile organic compound emissions from architectural coatings

This research is to develop a mass-transfer model for describing the emission of volatileorganic compounds (VOCs) from architectural coatings, which accounts for both surfaceevaporation and internal diffusion during the drying period. To apply this model, it isnecessary to know the evaporation and diffusion coefficients of VOC emitted from thecoating materials. An experimental method was, therefore, developed to determine boththe evaporation and diffusion coefficients for six aliphatic hydrocarbons and six aromatichydrocarbons from oil-based paint. It was shown that diffusion coefficients are inverselyproportional to molecular weight, while evaporation coefficients are proportional tovapour pressure of the VOCs.