Ceramic suspensions interaction energy

In Chapter 12 of this book, the mechanical properties of ceramic suspensions, pastes, and diy ceramic powders are discussed. Ceramic suspension rheology is dependent on the viscosity of the solvent with polymeric additives, particle volume fraction, particle size distribution, particle morphology, and interparticle interaction energy. The interparticle forces play a veiy important role in determining the colloidal stability of the suspension. If a suspension... 

Fig. 6.22. Volume fraction versus compressive yield stress of a flocculated polydisperse alumina suspension in decalin with various magnitudes of the attractive particle interaction energy. (From Bergstrom et al., /. Am. Ceram. Soc., 75 (1992) 3305.)...

Lu, K. Theoretical analysis of colloidal interaction energy in nanoparticle suspensions. Ceram. 7 i., 2008, 34, 1353-1360. 

If we want to create a colloidally stable system, some type of interparticle repulsion needs to be introduced to overcome the van der Waals attraction. In a stable system, the maximum attractive interparticle energy should be less than 1 -2 kT to allow thermal motion to readily break all particle-particle bonds. Since the magnitude and range of the attractive van der Waals interaction scales with the effective Hamaker constant, a relatively long-range repulsion is needed to stabilize suspensions of ceramic powders such as alumina and silicon carbide silica, however, is stabilized by a very short-range repulsion. 

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