The effect of sodium alginate on the crystal growth of calcium carbonate

The effect of sodium alginate in supersaturated solutions of calcium carbonate was investigated under plethostatic conditions. The rates of crystal growth measured in the presence of sodium alginate at concentrations as low as 0.83 × 10^-7mol dm^-3 were drastically reduced. Kinetic analysis according to a Langmuir-type adsorption isotherm led to the calculation of an affinity constant K_aff = 999.8 × 10^-4mol dm^-3. The apparent order found from kinetic data was 3.0±0.2 suggesting a surface nucleation mechanism.