Does a porous medium have to be charged in order for the fluid to establish the streaming potential?

In [Wikipedia](https://en.wikipedia.org/wiki/Streaming_current), I read:



> 
> Adjacent to the channel walls, the charge-neutrality of the liquid is
> violated due to the presence of the electrical double layer: a thin
> layer of counterions attracted by the charged surface. The transport of counterions along with the pressure-driven fluid flow gives rise to a net charge transport: the streaming current.
> 
> 
> 


But when I asked the chat.openai, it said



> 
> No, a porous medium does not necessarily have to be charged to
> establish streaming potential. Streaming potential can arise in a
> porous medium when a fluid flows through it, and there is a pressure
> gradient across the medium. This can create a charge separation in the
> pore fluid due to the movement of ions, resulting in an electric
> potential difference across the medium. The zeta potential, which is
> the potential difference between the surface of the porous medium and
> the bulk fluid, can influence the magnitude and direction of the
> streaming potential. However, even in the absence of a zeta potential,
> a pressure-driven flow can induce a streaming potential in the pore
> fluid.
> 
> 
> 


So, now I'm a bit confused.


