Figure 7
Particle size measurement of P/12-NH-12/L and P/12-NGK-12/L at different pH. A second order polynomial curve (solid line) was found to be a best fit (R2 > 0.9) for P/12-NH-12/L while a third order polynomial (dashed line) curve (R2 > 0.9) described the effect of pH on P/12-NGK-12/L particle size. Stronger acidic conditions resulted in a significant increase in P/12-NGK-12/L particle size.