Abstract
When a penetrant is desorbed from the sheet having initial concentration distribution which is obtained by absorption controlled by a constant diffusion coefficient D, the concentration C at distance x is given by
where h is the half-thickness of the sheet, C0 the surface concentration for absorption, D and t are the diffusion coefficient and time for absorption, D′ and t′ those for desorption, respectively. The total desorption amount at time t′ is derived from integrating eq (1).
P-aminoazobenzene was desorbed by means of sublimation from the nylon 6 film roll dyed with it. It was confirmed that the concentration distributions remaining and the desorption amounts in this system obey eq (1) and its derivative.
A method for estimation of diffusion coefficient D′ by the desorption amounts is proposed.
