Generation of Static Electricity

[eqm]

I was wondering if and/or how one would could calculate the the generation of static electricity between 2 materials.

For example material A is immersed in substance B and moves within it at a constant velocity. Knowing the velocity and volume / surface area of material A and the electron affinities of both material A and substance B, could you calculate the rate at which material A loses / gains electrons?

 

[CWatters]

I suspect you would need to know how the two surfaces interact at the molecular level. That would make it a difficult problem. Perhaps similar to trying to calculate the coefficient of friction from first principles.