Oxide surfaces develop a charge in H2O. Do we have any, even vague, handle on how long does an indivdual charge last on avg. before being neutralised? We often know, from e.g. titration experiments, what the average surface charge density of a surface is.

How do these charges vary over both time and space (i.e. dynamics)? I have been unable to find much (well, any really!) literature on this.

Example

Taking the example of oxide surfaces, you have the following processes going on:

$\ce{S-O- + H3O+&lt;=&gt;[\text{K1}]S-OH +H2O}$ #Protonation/Autoionisation 

$\ce{S-OH + OH- &lt;=&gt;[\text{K2}]S-O- +H2O}$ #Deprotonation/Protonation

$\ce{S-OH + H3O+ &lt;=&gt;[\text{K3}]S-OH2+ +H2O}$ #Protonation/Deprotonation

If you know (from experimental/theoetrical calculation of the Equilibrium Constants K1, K2, K3), that you have 100 negative charges per micrometer squared (i.e we are at high pH). Is it a more realistic picture on a picosecond/nanosecond timescale to consider it being something like 10,000 charges per micrometer squared which are being regularly neutralised over time or simply 100 charges per micrometer which are fixed?
Proton transfer reactions in water such as the ones you wrote down are diffusion controlled under ambient conditions (rate constant about 1e+12 per sec.) A snapshot in time will have a certain distribution of charges on the surface, but these are continually in flux, so any one charged site will have an exceedingly short lifetime. You could reasonably represent that system with a fixed set of charges on the surface, for some types of models (e.g., states at equilibrium).