L Besra, M. Liu/ Progress in Materials Science 52(2007)1-61 3.1. Parameters related to the suspension 3.1.1. Particle size 3.1.2. Dielectric constant of liquid 667 3.1.3. Conductivity of suspension 3.1. 4. Viscosity of suspension. 3.1.5. Zeta potential 3.1.6. Stability of suspension 3. 2. Parameters related to the process 3.2.1. Effect of deposition time 0001 3.2.2. Applied voltage 3.2.3. Concentration of solid in suspension 13 3.2. 4. Conductivity of substrate 13 4. Kinetics of electrophoretic deposition 5. Role of polymer binders in EPD 6. Importance of powder washing before EPD 7. Practical considerations 17 8. Water-based EPD 9. Non-aqueous EPD 10. Charge development on powder surface in suspension 10. 1. Aqueous suspension I1. 1. The electrical double layer and electrophoretic mobility. 11. 2. DLvO theory and suspension stability. 4 12. Mechanism of EPD process 12. 1. Flocculation by particle accumulation 12. 2. Particle charge neutralization mechanism 12.3. Electrochemical particle coagulation mechanism 2. 4. Electrical double layer(EDL) distortion and thinning mechanism 13. Multi-component deposition Drying of deposits produced by EpD 15. Design of electrophoretic apparatus 16. Deposition on non-conducting substrates 17. Application of EPD 17. 1. Assembly of nanoscale particles into nanostructures and micropatterned thin films 17. 2. Near shape manufacturing of complex-shaped glasses and ceramics 17.3. Solid oxide fuel cell (SOFC) fabrication 174. Laminated materials 17.5. Functionally graded materials 48 17.6. Hybrid materials 17.7. Fibre reinforced ceramic matrix composites 18. Modeling of EPD process 19. Concluding remarks3.1. Parameters related to the suspension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.1.1. Particle size. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.1.2. Dielectric constant of liquid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1.3. Conductivity of suspension. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.1.4. Viscosity of suspension. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.1.5. Zeta potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.1.6. Stability of suspension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.2. Parameters related to the process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.2.1. Effect of deposition time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.2.2. Applied voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2.3. Concentration of solid in suspension . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.2.4. Conductivity of substrate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4. Kinetics of electrophoretic deposition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 5. Role of polymer binders in EPD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 6. Importance of powder washing before EPD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 7. Practical considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 8. Water-based EPD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 9. Non-aqueous EPD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 10. Charge development on powder surface in suspension . . . . . . . . . . . . . . . . . . . . . . . . . . 19 10.1. Aqueous suspension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 10.2. Non-aqueous suspension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 11. Properties of suspension for EPD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 11.1. The electrical double layer and electrophoretic mobility. . . . . . . . . . . . . . . . . . . 21 11.2. DLVO theory and suspension stability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 12. Mechanism of EPD process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 12.1. Flocculation by particle accumulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 12.2. Particle charge neutralization mechanism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 12.3. Electrochemical particle coagulation mechanism. . . . . . . . . . . . . . . . . . . . . . . . 28 12.4. Electrical double layer (EDL) distortion and thinning mechanism . . . . . . . . . . . 29 13. Multi-component deposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 14. Drying of deposits produced by EPD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 15. Design of electrophoretic apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 16. Deposition on non-conducting substrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 17. Application of EPD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 17.1. Assembly of nanoscale particles into nanostructures and micropatterned thin films. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 17.2. Near shape manufacturing of complex-shaped glasses and ceramics . . . . . . . . . . 41 17.3. Solid oxide fuel cell (SOFC) fabrication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 17.4. Laminated materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 17.5. Functionally graded materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 17.6. Hybrid materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 17.7. Fibre reinforced ceramic matrix composites . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 18. Modeling of EPD process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 19. Concluding remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 2 L. Besra, M. Liu / Progress in Materials Science 52 (2007) 1–61