A Multiscale Fractal Model for Predicting the VOC Diffusion Coefficient of Fabric

Fabric is widely distributed indoors. Its porous structure results strong adsorption capacity for volatile organic compound (VOC). The secondary source effect caused by desorption can exacerbate indoor air pollution and prolong the pollution period. Fabrics play a significant role in the VOC mass transfer process indoors. VOC emission is mainly characterized by three characteristic parameters: the initial emittable concentration (C0), the diffusion coefficient (D) and the partition coefficient (K). In this paper, a new model for predicting the diffusion coefficient (D) of fabric is proposed. The model analyzed the multilayer anisotropic interlacing fiber structures comprehensively. A series of environmental chamber experiments were carried out to verify the correctness of the model. Three different types of fabrics (silk, cotton, and polyester) were selected as experimental samples, and formaldehyde was selected as the representative VOC gas. This paper provides a theoretical basis for the accurate prediction of indoor air quality and the design of appropriate control strategies.