Sol Methods
Sols are colloidal suspensions which are normally charge or sterically stabilized. Our sol particles are typically charge-stabilizied hydrous oxides suspended in aqueous media. However, polymeric organic sols as well as organic-inorganic sols are also possible. We utiiize a variety of “in-situ” techniques for characterizing these systems.
• ATR-FTIR
We use light scattering to characterize the size and state of aggregation of our particles. We can watch flocculation or aggregation of particles in real time. We are also utilizing electrophoretic mobility to measure the zeta potential of particles. We also utilize Attenuated Total Reflection FTIR methods to characterize the chemistry of the interface. This particular form of FTIR allows one to employ infrared spectroscopy in aqueous suspension as water would otherwise absorb too much irradiation in the IR part of the spectra. pH measurement is critical in these systems as the proton is one of the most important potential determining ions in these hydrous oxide suspensions. pH measurements should be made using high junction potential electrodes