CATALYSIS IN CONCENTRATED SOLUTIONS.

Structure of Concentrated HCl Solutions

A pentagonal ring is suggested as the basic structural unit of HCl(H2O)6 and (HCl)2(H2O)6 in solution. Modeled after the X-ray structure of a caged H13O6 compound, it contains bridged H5O2 and Clions, each with a coordination number around four. In the most concentrated HCl solutions, one of the ligands solvating Clis HCl, giving rise to a bichloride moiety. The proposed structure explains qual...

Multicomponent Concentrated Aqueous Electrolyte Solutions

Component dynamics in polyvinylpyrrolidone concentrated aqueous solutions.

(2)H-nuclear magnetic resonance (NMR) and neutron scattering (NS) on isotopically labelled samples have been combined to investigate the structure and dynamics of polyvinylpyrrolidone (PVP) aqueous solutions (4 water molecules/monomeric unit). Neutron diffraction evidences the nanosegregation of polymer main-chains and water molecules leading to the presence of water clusters. NMR reveals the s...

Equilibrium clusters in concentrated lysozyme protein solutions.

We have studied the structure of salt-free lysozyme at 293 K and pH 7.8 using molecular simulations and experimental SAXS effective potentials between proteins at three volume fractions, ϕ=0.012, 0.033, and 0.12. We found that the structure of lysozyme near physiological conditions strongly depends on the volume fraction of proteins. The studied lysozyme solutions are dominated by monomers only...

Entropic Colloidal Interactions in Concentrated DNA Solutions

We explore the entropic interactions between a pair of micron-sized colloidal spheres in DNA solutions. By confining the particles in a line-scanned optical tweezer, we directly measured the functional form of the interaction potential with sub-kBT resolution in samples where the spheres and the polymer coils were of comparable size. The potential is well described by the Asakura-Oosawa depleti...