My physics background is shakey at best after many years. If I am doing an electrocapillary experiment, I have:
a negative zeta potential (ex. -50 mV)
a dilute salt solution as electrolyte in a small thin glass capillary
apply a positive potential (i.e. +5V)
the electric field is running parallel to the surface of the glass, but obviously so does the electrolyte. So *technically* speaking, is the salty fluid moving with the applied electric field or against it?