Effect of ionic strength (NaCl concentration) on the changes in average size with time for the 0.5 μm MDCP suspensions at 25 °C, as determined using PCS. (A) MDCP dispersed in solutions of different ionic strengths. The samples were dispersed in solutions with NaCl concentration of: ●, 0 mol·L−1; ○, 0.02 mol·L−1; ▼, 0.04 mol·L−1; ▽, 0.06 mol·L−1; ■, 0.08 mol·L−1. (B) Effect of ionic strength (NaCl concentration) on the rate of aggregation and ζ-potential of MDCP suspensions. ●, rate of aggregation; ○, ζ-potential.