Ion Specific Effects on the Stability of Halloysite Nanotube Colloids—Inorganic Salts versus Ionic Liquids
Bojana Katana, Dóra Takács, Edit Csapó, Tamás Szabó, Andrej Jamnik, István Szilágyi
Abstract
cations on the HNT surface was observed giving rise to charge neutralization and reversal of the oppositely charged outer surface of HNT. The direct Hofmeister series was extended with these IL cations. The main aggregation mechanism was rationalized within the classical theory developed by Derjaguin, Landau, Verwey, and Overbeek, while ion specific effects resulted in remarkable variation in the CCC values. The results unambiguously proved that the hydration level of the surface and the counterions plays a crucial role in the formation of the ionic composition at the solid-liquid interface and consequently, in the colloidal stability of the HNT particles in both inorganic salt and IL solutions.