Quantifying Specific Ion Effects
Put the same material in two different salty water solutions and often you end up with significantly different materials properties. This phenomenon is called specific ion effects and its microscopic origins have eluded quantitative measure for more than a century.
Now a large international collaboration led by Dr. Matthew Brown in the Laboratory for Surface Science and Technology has quantified the origins of specific ion effects at the interface of silica nanoparticles. Using a combination of in situ X-ray photoelectron spectroscopy, and more common tools of colloid nanoscience, the team found a larger capacitance of the Stern layer as the ion size decreases, which results in substantially lower surface potentials and consequently decreased particle stability.