Seite - 136 - in Advanced Chemical Kinetics

statistical purpose. The equivalent diameter of the rod-shapedparticleswas calculatedusing Huebscher formula toevaluate the roleof surface tensiononparticle size [14]: De¼1:30� a�bð Þ 0:625 aþbð Þ0:25 " # (4) where a and b are themeasured diameter and length of the particles in this study. It can be seen from Figure 1 that there is a linear relationship that holds approximately independent of the nature of the alcohol used to synthesise the particles. This illustration proves the point that the surface tension of themixed solvent can also be used to relate nucleation and growth. 3.2.Ageneric correlation topredictparticlegrowth Statistically designed experiments are effective optimising toolswhere theprocess is influen- ced by various external factors. In this chapter, a two level three factor factorial designwas used to evaluate the effect of interaction of various parameters that have beenmanipulated during the synthesis of β-FeOOHparticles. Previouswork [9, 10] has shown that the particle phase isvery sensitive to reaction temperatures andpH.Hence, reaction temperatureandpH Figure1. Correlationbetweenparticle sizeandsolvent surface tension. Advanced Chemical Kinetics136