Effective Diffusion Coefficients in Calcium Alginate Gel

The effective diffusion coefficient of glucose , D e in calcium alginate gel determined at 35°C by two different methods gave values which, on average, were at least 24% less than in water. Assessment of the effect of glucose concentration on D e seems to indicate that D e increased with decreasing glucose concentration at very low concentrations (i.e., < =100 mM) and increased with increasing glucose concentrations at high concentrations (i.e., > =200 mM). Increasing the concentration of either the calcium chloride or sodium alginate component used in calcium alginate formation substantially decreased D e , but the effect of sodium alginate was the greater of the two.