title: Effective diffusivity in transient state.
abstract: The effective diffusivity in a polymer matrix modified with inclusions is usually calculated based on Kalnin-Kotomin's model [J. R. Kalnin, E. A. Kotomin, and J. Maier, J. Phys. Chem. Solids 63, 449-456 (2002)], which extends the well known Maxwell-Garnett formula. Kalnin-Kotomin's model correctly predicts effective diffusivity for stationary diffusion or for infinite media. In the present paper diffusion in composite media is studied for finite systems under transient conditions. The process of diffusion is modeled numerically and effective diffusion coefficient in the transient state is estimated, which, under certain conditions, is different from the predictions of the Kalnin-Kotomin's model. An analytical model is proposed to explain deviations of the transient effective coefficient of diffusion from the stationary case.
authors: Cracow University of Technology, Warszawska 24, 31-155 Krakow, Poland. tabor.zbislaw@gmail.com
authors: Zbisław
authors: Z
authors: Tabor
authors: Paweł
authors: P
authors: Nowak
authors: Małgorzata
authors: M
authors: Krzak
authors: Piotr
authors: P
authors: Warszyński