GeoDict Forum

Filtration => Air- and Liquid Filtration => Topic started by: Syuhei on August 17, 2022, 09:47:13 AM

Title: Regarding how to convert from measured zeta potential to GeoDict's surface charg
Post by: Syuhei on August 17, 2022, 09:47:13 AM
Dear GeoDict-Team,

How do they measure it in the laboratory that the amount of Filter Surface Charge at Movement subtab on Particles tab in  FilterDict-Media’s setting?
Title: Re: Regarding how to convert from measured zeta potential to GeoDict's surface charg
Post by: Liping Cheng on August 18, 2022, 04:08:32 PM

Surface charge:
  The electric charges are constrained on this 2-D surface, and surface charge density, measured in coulombs per square meter (C/m^2), is used to describe the charge distribution on the surface.

Zeta potential:
Zeta potential is the electrical potential at the slipping plane. The Grahame equation expresses the relation between surface charge and surface potential:
σ = Ɛ · Ɛ0 · Ψ0 / λ_d where Ɛ and Ɛ0 are the dielectric constants of two phases and λ_d is Debye distance up to which the ions get adsorbed on to the surface to meet the bulk liquid called the slipping plane where Ψ0 decreases to the value called Zeta potential so that above relation becomes:
σ = Ɛ · Ɛ0 · ζ / λ_d

Here are the links for your reference:
https://www.researchgate.net/post/Are-zeta-potential-and-surface-charge-density-the-same-And-whether-stability-of-colloids-depends-upon-of-point-of-zero-charge#:~:text=Firstly%2C%20Zeta%20potential%20is%20the,one%2C%20two%20or%20three%20dimensions.
https://www.researchgate.net/post/What_is_the_difference_between_surface_charge_and_zeta_potential
https://en.wikipedia.org/wiki/Surface_charge

Title: Re: Regarding how to convert from measured zeta potential to GeoDict's surface charg
Post by: Syuhei on August 19, 2022, 10:14:20 AM
Dear Liping,

Thank you for your reply!

Best regards,
Syuhei