A molecule is diffusing from a bulk solution across gel-like membrane into another bulk solution. The membrane is 1 mm in thickness and the temperature of this system is at 37C. The radius of the molecule is estimated to be 3.90 nm, and the diffusion coefficient of the molecule in water at 25C is 3.14 107 cm2 /s. The polymer fibers in the gel-like membrane have a radius of 2.79 nm. And the length of the fibers per unit volume is 2.05 103 nm2. The value of is 0.57 nm1.

(1) Estimate the effective diffusion coefficient and the membrane permeability of the molecule in this gel-like membrane.

(2) The membrane has an area of 2 cm2. The concentration of the molecule at the two surfaces of the membrane is found to be 1 mM and 0.5 mM. Find the flux and molar transport rate of this molecule across the membrane.