Patent ID: 7744741
Filing Date: 2010-06-29
Classification: G01N

Abstract:
1. A method for determining an effective diffusivity of a known substance through porous materials, comprising the steps of: (a) obtaining a first compartment loaded with a permeable solution having a first concentration, and obtaining a second compartment loaded with said permeable solution having a second concentration lower than said first concentration, said permeable solution mixed with a conductive solution; (b) immersing said porous material in between said first compartment and said second compartment to obtain a concentration gradient of said permeable solution between two ends of each pore of said porous material to diffuse said permeable solution having said first concentration to said second compartment; (c) setting a probe in said second compartment, said probe connecting to an electrochemical impedance analyzer; and (d) detecting data signals from the electrochemical impedance analyzer to obtain resistivity at various temperatures and for various times; using an empirical formula based on a linear relationship of resistivity and concentration and Fick's law so as to obtain a value for an effective diffusivity coefficient of said porous material.