Effect of Yarn Density on Diffusion of p-Aminoazobenzene in Multiple Layers of Nylon Fabric

Abstract

Diffusion of p-aminoazobenzene into multiple layers of nylon fabric has been in vestigated using four kinds of plain weave nylon fabrics whose yam density ischanged by varying the pick spacing. The apparent diffusion coefficient and the diffusional boundary layer parameter are estimated in such a way that the experimental data fit with the theoretical curves of concentration distribution based on the diffusional boundary layer model. Since the apparent diffusion coefficient increases with the de creasing pick density of the fabric, the diffusion behavior is explained based on a combined transport mechanism of pore and intrafilament diffusion. The plots of the apparent diffusion coefficient versus the product of the porosity and the specific pore volume show a linear relationship in the limited porosity range of about 0.68 to 0.73 at various temperatures.