Cristian Schulthess, University of Connecticut, Storrs, CT, Daniel Ferreira, Department of Biology, Chemistry, and Physics, Southern Polytechnic State University, Marietta, GA, Nadine Kabengi, Geosciences Department, Georgia State University, Atlanta, GA, James E. Amonette, Chemical and Material Sciences, Pacific Northwest National Laboratory, Richland, WA and Eric D. Walter, Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA
The retention of monovalent and divalent cations increases in constrained environments. It is particularly important to note that in medium-sized pores (~0.5 nm) the retention of monovalent ions greatly exceeds the retention of divalent ions. This phenomenon is explained by the Nanopore Inner-Sphere Enhancement (NISE) Theory. An explanation of the NISE theory is presented along with proof of the theory based on data from flow calorimetry and electron paramagnetic resonance (EPR) spectroscopy.