Seite - 137 - in Advanced Chemical Kinetics

were omitted from the factorial trial for simplicity sake. Furthermore, butanol was used as solvent to synthesiseβ-FeOOHparticles tovalidate the relationsbetweenparticlegrowthand solvent surface tension.Table 1presents the real amount of each parameters that have been used at low and high levels, which is assigned by a positive (+) and negative ( ) sign, respectively. 3.3.Evaluationof theeffectsof factorsandthe interactionbetweenthefactorsonparticle growth Table 2 presents the obtained equivalent diameter at different experimental conditions according to the twolevel three factor factorialdesign.AParetochart ispresented inFigure2 to assess the interactionbetweenprocessparameters andobtainedequivalentdiameter of the particles. The factorial design can cover the main and interaction effects of the parameters within the whole range of selected parameters. Evaluation of the effect of principal factors revealed that these parameters have positive effects on the obtained equivalent diameters of theparticles. Basedonthesignificanceofeffects fromFigure2, ageneralisedempiricalcorrelationthat takes solvent surface tension,precursorconcentrationandtime intoaccount isproposed: Factors Lowlevel ( ) Highlevel (+) A:FeCl3 concentration [M] 0.05 0.5 B:%solvent towater ratio 30 90 C:Time(h) 2 12 Table 1. Real amount of each factor used in the factorial trial experiments. Samples FeCl3 concentration [M] %alcohol towater ratiousedassolvent Time(h) De 1 0.5 90 2 17 2 0.05 30 12 17 3 0.5 30 12 90 4 0.05 30 2 16 5 0.5 90 12 43 6 0.05 90 12 16 7 0.05 90 2 15 8 0.50 90 2 7 Table 2. Results obtained for a two level factorial design. Hydrothermal Precipitation of β-FeOOH Nanoparticles in Mixed Water/Alcohol Solvent http://dx.doi.org/10.5772/intechopen.70503 137