SYNTHESIS OF HEMATITE PARTICLES

Hematite particles were synthesised following the method of Matijevic and Scheiner (1978), also described by Amal (1991), by forced hydrolysis of a homogeneous iron (III) chloride solution. The hematite particles produced with this method are monodispersed and spherical. Four different sizes of hematite were produced and the recipes are shown in Table A3.1. For larger particles, the hematite I 

Cooling Let Sol cool to room temperature Let Sol cool to room temperature Let Sol cool to room temperature Let Sol cool to room temperature 

All glassware used was cleaned with concentrated HCl (36%) to avoid nucleation at the glass surface. It is essential to use clean vials and wash bottles to avoid contamination of the hematite surface and thus variation of the surface characteristics. 

Vigorous stirring was applied during the addition of ferric chloride to the solution. For the small colloids (hematite IV, 40 nm), the solution needs to be excessively saturated to ensure very high 

For the larger particles. Hematite I is used as a seed sol, providing the nuclei for further growth on their surface. Seed sol and ferric chloride are added in this case to boiling perchloric acid. 

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