2. High temperature aerosol processing Overview Example of TiO2 Vapor phase generators Spray pyrolysis Spray generation Jung Hyeun Kim’s presentation

3. Aerosol Reactors Vapor Phase Reactors - Titania, Fumed Silica, Nitrides, etc. - Hot Wall, Flame, Plasma, Laser Ablation, Laser Pyrolysis Spray Pyrolysis - Ferrites, Single and Multicomponent oxides, metals and alloys - Spray Nozzles - single and two fluid, Acoustic Sprayers and Nebulizers

4. Problem Particles Process Effluents - Power Plant Fly Ash, Smelter Emissions, Sintering Plants Contaminants - Contamination in Pharmaceutical, Semiconductor Industries (Mr. Doug Kremer on Thursday) Occupational Exposure

5. Process Players Solid/gas reactors - Reactant Feeding Size Classification - Powder Dispersion in Gases Coatings on Surfaces - Condensation

6. PRODUCTS Titania pigment, Carbon blacks, Fumed silica, Alumina etc. Metals and alloys - Ni, Ag, Au, Pd - electronics circuits Multicomponent Oxides - Ferrites, Superconductors,Dielectrics Nanoscale Materials

7. Vapor Phase Reactors Precursor is in vapor phase Chemical reaction to condensable species or condensation of vapor happens to make products (can have combination of both) Chemically reactive environment can be: flame, plasma, thermal with resistive heating, thermal via laser etc… Condensation induced by mixing, expansion (big pressure gradients!) or both

8. Titania Process TiCl 4 Oxygen Flame Agglomerates Molecular Clusters Product Thermophoresis - Wall Deposits Fuel Fabric Filter

9. Titania Process Nucleation - Particle Formation Coagulation and Aggregate Formation Thermophoresis and Wall Losses Solid/Gas Separation - Fabric Filter(Bag House Collectors)

10. Agglomeration and Aggregation

11. Spray Pyrolysis Very common method for making particles Here precursor starts as droplets or solid particles Thermal, plasma, flame also used as reaction environment but reaction is in liquid or solid phase (tiny microreactors!) Mr. JH Kim will discuss this…

12. Droplet Drying and Conversion Drying and conversion rates affect morphology of the particles Can have hollow particles or can shatter particles Mr. Kim will talk about effect of solvent on chemistry of particles How to make spray? Some examples…

13. Time: 0 sec Time: 71 secTime: 95 sec Time: 117 secTime: 145 secTime: 188 sec Video Images of Drying Droplet

14. Condensation Aerosol Generator Vaporizer Condenser Gas Heater

15. Nebulizer Impaction Target Aerosol

16. Nebulizer/Condensation Generator Nebulizer Evaporator Condenser Aerosol