Variations in f(κ·a) and zeta potential with changing particle size and ionic strength according to the Ohshima correction[7, 35] using values for Ag NPs in NaCl (Fig 3) compared with the Smoluschowski (κ·a>>1, f(κ·a) = 1.5) and the Hückel (κ·a<<1, f(κ·a) = 1) models.

[35].