Electrostatic properties and stability of charged virus-like nano-shells are examined in ionic solutions with monovalent and multivalent ions. A theoretical model based on a thin charged spherical shell and multivalent ions within the "dressed multivalent ion" approximation, yielding their distribution across the shell and the corresponding electrostatic (osmotic) pressure acting on the shell, ...

Shifts of the critical coagulation concentration (CCC) in particle suspensions in salt solutions containing multivalent co-ions and monovalent counterions are rationalized. One observes that the CCC is inversely proportional to the valence, and this behavior is referred to as the inverse Schulze-Hardy rule. This dependence is established by means of measurements of the stability ratio for posit...

The structures of isolated alkaline earth metal cationized amino acids are investigated using infrared multiple photon dissociation (IRMPD) spectroscopy and theory. These results indicate that arginine, glutamine, proline, serine, and valine all adopt zwitterionic structures when complexed with divalent barium. The IRMPD spectra for these ions exhibit bands assigned to carboxylate stretching mo...

Proper balance of ions in intracellular and extracellular space is the key for normal cell functioning. Changes in the conductance of membranes for ions will lead to cell death. One of the main differences between normal and cancerous cells is the low extracellular pHe and the reverse pH gradient: intracellular pHi is higher than extracellular pHe. We report here pH-selective transfer of nano-p...

The binding of an anionic surfactant onto an anionic surface by addition of divalent ions is reported based on experimental data from specular neutron reflection (NR) and attenuated total internal reflection IR spectroscopy (ATR-IR). Similar measurements using monovalent ions (sodium) do not show any evidence of such adsorption, even though the amount of surfactant can be much higher. This data...

In this work we have investigated whether the asymmetrical properties of the Na/Ca exchange process found in intact preparations are intrinsic to the exchange protein(s) or the result of the asymmetric ionic environment normally prevailing in living cells. The activation of the Na/Ca exchanger by Ca2+ ions, monovalent cations, ATP gamma S and the effect of membrane potential on the different op...

Cobalt(II)-M-hexacyanoferrate(II), M = K, NH4, Cs, as synthetic sorbents have ion exchange properties selective for monovalent cations. They show a higher selectivity for the ions with larger crystal radius if the sorption takes place in dilute solutions, whereas in concentrated sulutions the selectivity sequence is reversed. The phenomenon is attributed to the differences in physico-chemical p...

Interactions of different anions with phospholipid membranes in aqueous salt solutions were investigated by molecular dynamics simulations and fluorescence solvent relaxation measurements. Both approaches indicate that the anion-membrane interaction increases with the size and softness of the anion. Calculations show that iodide exhibits a genuine affinity for the membrane, which is due to its ...