The electric charge of mineral surfaces changes in flowing
water – a finding that is also important for understanding geological processes
When water flows over glass or rock, the chemical changes
that occur are more profound than had been previously assumed. Using a
sophisticated spectroscopic method, a team from the Mainz-based Max Planck
Institute for Polymer Research and the University of Namur in Belgium has
discovered that the electric charge of mineral surfaces changes radically under
a flow of water, as many ions are preferentially dissolved from the material.
The type of mineral involved and the acidity or alkalinity of the flowing water
determine whether and how strongly the surface is positively or negatively
charged.