Biomedical subjects

S Harinipriya

Publications and source records attributed to S Harinipriya.

4 recordsLinked to original sources

PubMed2006

Analysis of electron transfer processes across liquid/liquid interfaces: estimation of free energy of activation using diffuse boundary model.

The evaluation of the free energy of activation pertaining to the electron-transfer reactions occurring at liquid/liquid interfaces is carried out employing a diffuse boundary model. The interfacial solvation numbers are estimated using a lattice gas model under the quasichemical approximation. The standard reduction potentials of the redox couples, appropriate inner potential differences, dielectric permittivities, as well as the width of the interface are included in the analysis. The methodology is applied to the reaction between [Fe(CN)6](3-/4-) and [Lu(biphthalocyanine)](3+/4+) at water/1,2-dichloroethane interface. The rate-determining step is inferred from the estimated free energy of activation for the constituent processes. The results indicate that the solvent shielding effect and the desolvation of the reactants at the interface play a central role in dictating the free energy of activation. The heterogeneous electron-transfer rate constant is evaluated from the molar reaction volume and the frequency factor.

Journal Article↗

PubMed2004

A simple simulation methodology for estimation of dehydration energies and surface potentials of concentrated NaCl solutions.

A novel simulation procedure for estimating the dehydration energies of NaCl solutions spanning a wide range of concentrations, which incorporates ionic and molecular sizes, ion-pair formation, etc., is proposed on geometric and phenomenological considerations. The extent of dehydration during each movement of the hydrated molecule is evaluated using the expected and actual displacement of the species and mean nearest-neighbor distances. The interdependence between the size of the simulation box, number of molecules, and electrolyte concentration is pointed out.

Journal Article↗

PubMed2004

Estimation of exchange current density for ferric/ferrous reaction at electrode surfaces--influence of ionic desolvation and dipolar adsorption.

The dependence of the exchange current density of the ferric/ferrous reaction on electrode surfaces has been investigated using the work functions of metals, surface potentials of the reactants, adsorption characteristics of water dipoles, hydration numbers, etc. The extent of dehydration of the reactant species at the reaction zone, as well as the influence of desorption of water dipoles from the electrode surface on the magnitude of exchange current density, is demonstrated.

Journal Article↗

PubMed2002

Condensation of nucleobases at mercury/aqueous solution interface--a structural perspective using hydrogen bonding considerations.

The two-dimensional condensation behavior exhibited by nucleobases at a mercury/aqueous solution interface is analyzed on the basis of their hydrogen-bonded quadruplex structures, and the experimentally observed critical temperatures are rationalized incorporating different types of hydrogen bonding, surface coordination effects, and stacking considerations. The proposed methodology provides a structural basis for the interpretation of critical temperatures and enables the calculation of the same pertaining to different modified nucleobases. The applicability of the procedure to order-disorder transitions of water dipoles at Hg electrodes is also indicated.

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