Effective Diffusion Coefficients in Calcium Alginate Gel

The effective diffusion coefficient of glucose, De 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 De seems to indicate that De 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 De, but the effect of sodium alginate was the greater of the two.