Hi Mfon Rebecca, It depends on the kind of nanoparticles. But the higher the absolute value of zeta potential, the more stable the nanoparticle is.

Mfon Rebecca Nanoparticles with zeta potentials of greater than +30 mV or less than -30 mV are considered strongly cationic and strongly anionic, respectively. That will be stable and monodispersed. Electrostatic interactions between the anionic membrane and cationic nanoparticles facilitate the uptake. But it can be depend the modes of interaction site and delivery system for targeted point.

Mfon Rebecca Your statement 'Just like there is a range of zeta potentials that indicates whether Nanoparticles in solution are stable or not' is not true. Sterically stabilized particles with a calculated ZP of 0 mV can be perfectly stable.

Vinod Kumar A small amount of research on RG and the original literature (Riddick) will debunk the '30 mV' myth for charge/electrostatic stabilization. A good starting point is here:

https://www.researchgate.net/post/Why-the-zeta-potential-of-PEGylated-nanoparticles-eg-gold-nanoparticles-is-negative

https://www.researchgate.net/post/How_do_I_interpret_zeta_potential_values

As far as I'm concerned, the contributions of Alan F Rawle along with the bibliography links are more than enough to inform the discussion, however, I thought these two RG threads might be useful for enlarging the discussion and answer.

https://www.researchgate.net/post/What_it_means_by_the_negative_symbol_in_the_zeta_potential_magnitude

https://www.researchgate.net/post/What_is_the_significance_of_positive_and_negative_zeta_potential_values

thanks

My regards

I strongly agree with Alan F Rawle. Sterically stabilised nanofluids with negligible zeta potentials are more stable than electrostatically stabilized nanofluids of zeta potential 30mV.

https://asianjournalofchemistry.co.in/User/ViewFreeArticle.aspx?ArticleID=32_3_15

Zeta potential is most useful when looking at changes (rather than absolute values). Changing the pH, ionic strength, buffer type, additives may provide insight into what affects your nanoparticles.

As an example, specific or non-specific ion adsorption can show up in zeta potential versus pH in different buffers https://www.materials-talks.com/zeta-potential-in-salt-solution-or-any-other-ions/