Dynamic—static Chamber Method for Simultaneous Measurement of the Diffusion and Partition Coefficients of VOCs in Barrier Layers of Building Materials

Abstract

Barrier layers on the surface of building materials play an important role in reducing the emission of volatile organic compounds (VOCs), but there is little data about their transport properties such as the solid-phase diffusion coefficient (D) and the solid/air partition coefficient (K). This paper develops a dynamic—static chamber (DSC) method for determining the D and K for VOCs in barrier layers. The developed method has the following advantages: (1) it can simultaneously but separately determine D and K for a VOC mixture with controllable concentration in a single test and (2) it requires a relatively shorter experimental time (e.g., less than 1 h for the testing of VOCs in the barrier layers). Using this method, the two key parameters for formaldehyde in three commonly used barrier layers were measured. The uncertainty and sensitivity of the measured parameters were analysed. The results indicated the feasibility of simultaneous estimation of the two parameters (D and K) by the present method. Finally, the impact of the tested barrier layers on VOC emissions from building materials was investigated based on a multilayer mass transfer model. It is found that barrier layers can greatly reduce the indoor VOC concentration. The measured D and K values of barrier layers are useful for predicting VOC emissions from building materials and in the design of low-emission building materials.