Biomedical subjects

GL Aranovich

Publications and source records attributed to GL Aranovich.

6 recordsLinked to original sources

PubMed2000

Adsorption of Amphiphilic Dimers at Surfaces.

Adsorption of amphiphilic dimers is analyzed in the framework of density functional Ono-Kondo theory. There are three configurations for dimers absorbed at a surface: one parallel to the surface and two perpendicular to the surface (AB and BA, with A or B touching the surface, respectively). Densities of molecules in each configuration are calculated from density functional theory and compared to Monte Carlo simulation data. There is good agreement between theory and simulations. It is shown that the parallel configuration is preferred over the perpendicular configuration, except when there are very strong asymmetries in intermolecular forces. In most cases, the parallel configuration is even preferred over the combination of the two perpendicular configurations. Copyright 2000 Academic Press.

Journal Article↗

PubMed2000

Intermolecular Repulsions in Adsorbed Layers.

Adsorbate-adsorbate interactions are analyzed in the framework of the Ono-Kondo model. The results show that, at large amounts of adsorption, intermolecular interactions in the adsorbed phase are repulsive. In the range of small adsorption, microporous systems also can show repulsions due to limitations of the adsorption space. This effect also is possible in macroporous adsorbents with active site spacing that is less than that of the adsorbate bulk liquid. Copyright 2000 Academic Press.

Journal Article↗

PubMed1999

Adsorption of Chain Molecules.

We analyze the influence of chain length on the adsorption isotherm using the framework of lattice theory. Each molecule is represented as a chain of segments occupying separate sites in the lattice. Adsorption equilibria (particularly adsorption isotherms) are analyzed for one-component and two-component mixtures of chain molecules. Copyright 1999 Academic Press.

Journal Article↗

PubMed1999

Adsorption of Dimers at Surfaces.

A model for the adsorption of dimers at a surface is presented. The model is based on a generalization of the Ono-Kondo lattice theory. The densities of dimer molecules that are parallel to the surface, x parallel, and perpendicular to the surface, x perpendicular, are calculated. It is shown that symmetric dimer molecules adsorb preferentially parallel to the surface at all densities. The model also predicts that the Gibbs adsorption is negative for small interaction energies between dimers and the surface. Copyright 1999 Academic Press.

Journal Article↗

PubMed1999

Monolayer Adsorption for the Subcritical Lattice Gas and Partially Miscible Binary Mixtures.

Lattice theories have been used extensively to predict and correlate liquid-liquid equilibria in mixtures. Lattice theories also have been used to predict the behavior of gases adsorbing onto solid surfaces. Here, we use a lattice model based on the ideas of Ono and Kondo to predict the phase behavior in adsorbed monolayers for systems that are below their bulk-phase critical points. For such an analysis, it is important that molecular behavior in the bulk and the adsorbed layer is based on consistent assumptions. Here, this is accomplished by treating the fluid in the bulk as well as in the adsorbed layer as a strictly regular solution. Interesting new adsorption isotherms and phase diagrams are generated that provide useful insights into adsorption of both lattice gases (i.e., "mixtures" of molecules and holes) and dense lattice liquids (i.e., "mixtures" of molecules without holes), illustrating the similarities between adsorption of gases and liquids. Copyright 1999 Academic Press.

Journal Article↗

PubMed1998

Adsorption Hysteresis in Porous Solids.

Hysteresis has been observed in adsorption isotherms for a number of gas-solid systems and, generally, is attributed to adsorption in mesoporous materials with capillary condensation. This behavior is classified as Type IV or Type V in the IUPAC classification scheme. Here, lattice theory is used to predict adsorption behavior in pores. The Ono-Kondo theory is used with appropriate boundary conditions for fluid adsorption in infinite and semi-finite slit-like pores. It is shown that there can be phase transitions in the adsorbed phase which lead to hysteresis in kinetically controlled experiments. However, hysteresis in equilibrium behavior is exhibited only in pores of finite length. For finite-length pores, the interface geometry is predicted to be different during the processes of adsorption and desorption and this difference in interface shape leads to hysteresis. This simple molecular model is able to predict the change in the interface geometry without invoking the Kelvin equation or the macroscopic concept of surface tension. Copyright 1998 Academic Press.

Journal Article↗