A prediction model of VOC partition coefficient in porous building materials based on adsorption potential theory

The partition coefficient (K) of the interface between air and building materials has a significant effect on the emission characteristics of volatile organic compounds (VOCs). Existing research on determining the partition coefficient is mostly performed experimentally. However, the experimental data only apply to a particular condition and are unable to reveal the functional mechanism of the primary controlling factors of K, such as temperature, VOC properties and building material parameters. This study deduced a dual-scale calculation model of K respectively for micropores and macro-mesopores in porous materials based on the adsorption potential theory. The model considers a number of factors that affect the partition coefficient, such as pore scale, porosity, temperature, VOC properties and other parameters. Three types of medium density fiberboard (MDF) and one type of particleboard (PB) which were commonly used in interior decoration were chosen as the experimental objects in the mercury intrusion porosimetry (MIP) tests and the continuous temperature rising - variable volume loading (CTR-VVL) method. By fitting and comparing the experimental data and theoretical calculation values, the obtained equations of K exhibited high consistency with the experimental results, which provides a reliable approach to predict K.