Modelling studies of the diffusivity and intersolubility of semi volatile organic compounds in water

Semi-volatile organic compounds (SVOCs) are hazardous contaminants found in several products – ranging from personal care products to plastic products and the environment. Their chemical migration into food substances, raising environmental and health concerns, has been well documented. The dispersion/diffusion and solubility of SVOCs in food simulants is an indicator of their migration from food packaging materials. Here, we employed molecular dynamics simulations to investigate molecular mass transfer/diffusivity and intersolubility of three (S)VOCs from various sources into water. The simulation results illustrated that the molecular weight of SVOCs affects their dispersion and solubility in water. SVOC molecules are also much easier to diffuse into water at higher temperatures and longer time periods. The intersolubility of SVOCs in water according to the Flory-Huggins parameter (χ) and Hildebrand solubility parameter (δ) occurs in the following order: methyl isocyanate > caprolactam > naphthalene. The solubility of SVOCs increases with temperature, as evident by the decreasing δSVOCs and χsvocs. These results will play a key role in expanding the knowledge base of chemical migration of small molecules into food simulants.