I am an electrical engineer and so i will answer this question from this stand point. If we  have for example Na Cl with a strong bond when it is dry. When we dissolve it in high dielectric material like water. the electrostatic bond becomes weak because of the dielectric screening of the water molecules. It is so that each Positive ion surrounds itself with polarized water molecules and so does the negative Clour  ion, They became separated from each other at a longer distance and hence their interatomic forces gets weaker. This may be the basic idea for the solution of your problem.

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Thank you very much for your valuable inputs! We tried out high NaCl and divalent metal ions. It seems NaCl works nicely at 500 mM, which is a regular conc. used in biochemical assays. Nice day to you!

Hello Sir A. Zekry,

I would like to take benefit from this discussion and also considering the fact that you are in the field of electrical engineering so I would like to know if by any chance you work with COMSOL Multiphysics because I use it in electrostatics but I get lost when it comes to calculating the electrostatic force between a two parallel plates of a capacity? I would really appreciate your assistance ...

Thank you for your time and consideration.

Sincerely,

I. Oualid.