Effect of particle concentration in a dispersion

Two equal-sized spherical particles at close distances H R) and low potential. kR 5. Debye-Hiickel approximation must hold 2keT Vr = 2)ueeofVo  

Equal-sized spheres (general) and x/ 10 Two cases Case 1. Constant surface potential (chaige controlled by the concentration of potential-determining ions in solution). Works well for all separations, H. Case 2. Constant surface chaige (e.g. isomorphous substitution in a lattice). Should be used with caution, especially at close approach (Goodwin, 2009). V/R = 2)ueeofVol ( +e Vr = 2)ueeoRv ln(l e 

Unequal-sized spheres with different (or same) surface potential in a single electrolyte and H / i, R2 (Reerink-Overbeek expression). /64)ueeoRi Rikg J 2  

Reduces to the first equation in this table for equal-sized spheres and when the Debye-HQckel approximation holds. zey/Qi q2I bT — 1 fi- zeyo, / glCT + 1 

Two similar flat surfaces (low potential, i.e. Debye-Hiickel approximation). For high potentials see Goodwin (2009). VR = 2eeoK gle-  

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