We have the particles with negative surface charge in a solution of pH 7, some counter ions (anions) caused to form stern layer and shear plane responsible for Zeta potential of -50mV.

I wish to know the effect of Zeta Rod (HVCB) on particles ionic balance.

After Zeta rod treatment,

Is the increases in strength of anions in diffused layer causes to shift the zeta potential of colloidal particle from -50mv to -20mV?

OR

Any other principle which will decrease the ionic potential for destabilizing the particle?