Nanoscale Inorganic Macroions in Solution

Many exciting new sciences emerge from the intermediate regions between different traditional areas. For complex fluid systems, a natural question is, what happens if we make hydrophilic, soluble ions larger and larger – reach the size of nanometer scale, or make hydrophobic colloidal particles smaller and smaller – down from the sub-micrometer level to only several nanometers? What would be the solution behaviors of such “macroions”? Do they behave more like soluble ions or colloids, or something else completely different?