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The competitive adsorption at the air-water interface of hen egg-white lysozyme with non-ionic surfactant is studied using tensiometry, ellipsometry and surface dilation rheology. The adsorption is found to depend on the surfactant concentration in the bulk solution and also on the ionic or non-ionic nature of the surfactant.

The thermodynamic characteristics of the cluster formation for fatty acids with the general formula of nondissociated n-carboxylic acids C(sub n)H(sub 2n+1)COOH with n = 5-15 are studied. The contributions of the CH2 groups to the thermodynamic characteristics of alcohols and acids are the same and the differences in the formation of clusters by these substances are attributed to the differences in the structure and interactions of relevant functional groups.

The study calculated the framework of PM3 molecular orbital approximation the thermodynamic function characteristics of the formation and geometrical structure of monomers, dimers, trimers, and tetramers of fluoroalkanols. It concluded that fluoroalkanol monomers posses a helical structure with an average backbone torsion angle equal to 162 degree, which implies optical activity of these molecules and the existence of two types of dimers, dimers with equal and opposite directions of helixes winding.

A thermodynamic model is derived for the description of the equilibrium behavior of mixtures of a protein with an ionic surfactant adsorbed at the liquid/fluid interface. The experimental data for the mixtures HSA/CTAB (human serum albumin/cetyl trimethylammonium bromide) and beta-LG/SDS (beta-lactoglobulin/sodium dodecyl sulfate) agree satisfactorily with the theoretical estimates.

The dynamics of a mixed monolayer consisting of a soluble tailored amphiphile N-decyl-gamma-hydroxybutyric acid amide and its insoluble condensing homologue N-tetradecyl-gamma-hydroxybutyric acid amide are experimentally and theoretically studied. The result reveals that the theoretical predictions are in satisfactory agreement with the experiments.

The thermodynamic and textural properties of dipalmitoyl-phosphatidylglycerol monolayers are described.

The use of bubbles makes it possible to obtain real equilibrium surface tension values of protein solutions. The establishment of equilibrium takes quite a long time.

A model is derived to analyze the cis-trans photoisomerization of a photochromic trifluoromethyl-substituted metacrylate copolymer monolayer. It is shown that the model accurately predicts the characteristics of the components of the cis and trans transformation processes. Among these are that the minimum area demand per repeating unit of the trans conformation is less than that of the cis conformer. Good agreement was also obtained between model and experimental results.

A theoretical and experimental study was conducted that related to research on the use of insoluble-soluble-amphiphile-consisting mixed monolayers to investigate the penetration of insoluble monolayers by a soluble surfactant or protein. The study investigated a simple system consisting of the mixed monolayer of an insoluble, C=20, and soluble, C=12 homologue of dimethylphosphide oxide. It was shown that both the effect of a soluble component on the attributes of the aggregated equilibrium and the effect of the surface pressure increase of the mixed monolayer can be analyzed.

Research was conducted to examine a new equation of state valid for Langmuir monolayers. The theoretical model takes into account the 2D aggregation of monolayer material and the compliance with the important case that the molar area of molecules within an aggregate can differ from that characteristic for free monomers. The Pi-A isotherms for Langmuir monolayers of different amphiphiles are in good agreement with the proposed model for physically reliable values of model parameters.

A study was conducted to analyze the dynamics of surfactant adsorption from solution considering aggregation within the adsorption layer. A multicomponent adsorption layer was assumed to be characterized by monomers and aggregates in equilibrium. Experimental results indicated that the formation of aggregates within the adsorption layer correlated with decreases in the deceleration of the surface tension.

Protein adsorption layers at liquid/fluid interfaces were described using thermodynamic equations derived as a generalization of a novel theory which takes into account the nonideality of enthalpy and entropy of mixing. The effect of the electric charge of the protein molecules on surface pressure was also considered in the proposed theory. Results showed that the derived isotherm is highly consistent with experimental data. The values of the isotherm parameters surface area per molecule, adsorption layer thickness and electric charge of the HSA molecule are approximate to values obtained by other methods in literature.

The monolayer features of two very similar amphiphiles, N-tridecyl-[beta]-hydroxypropionic acid amide (THPA) and N-([beta]-hydroxyethyl) tridecanoic acid amide (HETA) and their 1:1 mixture are analyzed. The thermodynamic analysis has provided results on the specific phase properties of the mixed HETA/THPA monolayers.

The generalization of the equation of state for the monolayer with a fluid/condensed phase transition derived in the framework of a quasichemical approach is reported. The calculated results from equations provide insight into entropy nonideality of mixing of the monomers and clusters of amphiphilic molecules.

A study results which give additional information on the recognition kinetics for the dissolved non-surface-active substrates and the stability of the formed interfacial supramolecular complexes performed on 2[C.sub.11][H.sub.23]-melamine monolayers and barbituric acid as the pyrimidine derivative dissolved in the aqueous subphase is presented.

The equation of state for the monolayer comprised of the molecules of different sizes is modified to describe the fluid state of the molecules monolayer. The values of molecular areas of amphiphilic molecules estimated from the fitting of experimental data to the proposed equation are found to be quiet similar to those measured in independent grazing incidence X-ray diffraction experiments.

A new derivation for an equation of fluid state of Langmuir monolayers was given by Anatoly I. Rusanov, which claimed that, the basic differential equation of state and all other equations derived on its basis are incorrect. Rusanov reveals that excluded area is not the defining factor but in his equations he has taken the factor of excluded area equal to unity as an approximation, which shows that his comments are erratic.

A drastic change of the characteristic features (Pi-A isotherms, morphology of the condensed phase domains) of the 2C11H23-melamine monolayers by molecular recognition of the pyrimidine derivatives uracil and thymine, large affected by the reaction kinetics of the recognition process is studied. The experimental data reveals that the main characteristics of the interfacial system are largely affected by the reaction kinetics of the recognition process.

Results are reported on experimental studies of the dilational rheology of a beta-lactoglobulin mixture with the nonionic surfactant decyl dimethyl phosphine oxide (C10DMPO) at the solution/air interface. The results indicated that the calculated limiting elasticities of the mixtures comply with the experiments.

The thermodynamic and structural properties of the Langmuir monolayers of a homologous series of a selected amphiphilic melamine-type are presented. The findings suggest that good candidates for the formation of supermolecular structures are monolayers of amphiphilic melamine derivatives.

The study shows that the DeSNa desorption kinetics is governed by a pure diffusion mechanism while the desorption of more surface-active surfactants such as C13 DMPO and Triton X-100 obeys a mixed mechanism. The analysis of the study indicates that the temperature dependence of the beta-lactoglobulin (BLG) desorption kinetics it is possible to calculate the activation energy of this process, which is quite close to the free energy of BLG adsorption.

The dynamic and equilibrium surface tensions of the cationic alkyl trimethylammonium bromides (C(sub n)TAB) solutions for n =12, 14 and 16 are studied using ring and bubble pressure tensiometry. A new theoretical model is used, which assumes intrinsic compressibility of the surfactant molecules in the adsorption layer and accounts for the nonideality of the surface layer enthalpy and entropy.

Experimental studies of the dynamics and equilibrium of the penetration of the soluble cationic surfactant cetyltrimethylammonium bromide (CTAB) into arachidic acid monolayers are reported. A new theoretical model is proposed involving the enthalpic nonideality of the mixed monolayer.

The thermodynamic behavior and the structure features of hydroxyctadecanoic acid monolayers, which are largely affected by the position of the hydroxyl group in the alkyl chain are discussed. In combination with the GIXD experimental data it is possible to draw conclusions on the orientation of the molecules in the different monolayer states and their changes at the main phase transition.

A model for the surface pressure isotherm and high frequency limit of dilational elasticity of a surfactant adsorption layers is proposed which assumes a two-dimensional compressibility of adsorbed molecules. It is observed that while this compressibility of absorbed molecules has no significant effect on the isotherm, the elasticity is enormously affected.

A comparative analysis of a theoretical model, which describes the displacement of the two-dimensional phase equilibrium in monolayers at the air/water interface, is performed. The thermodynamic characteristics for the first-order phase transition are calculated on the basis of various theoretical models.

Reasonable values of the thermodynamic characteristics for the cluster formation of odd alcohols at the air/water interface are obtained by the quantum chemical PM3 approximation. The calculated values of enthalpy deltaH(sub m)(super cl), entropy deltaS(sub m)(super cl) and Gibbs energy deltaG(sub m)(super cl) for the formation of clusters of a given structure depend linearly on the number of CH2 groups in the odd alcohol molecule.

The surface pressure adsorption kinetics pie(t) and Brewster angle microscopy (BAM) studies are combined for characterizing the two-dimensional phase transition. The standard thermodynamic characteristics calculated are used to compare the adsorption of dodecanol from the aqueous solution and the dodecanol aggregation in the adsorbed monolayer.

Data from literature, interpreted in terms of phase transitions in the adsorption later, are analyzed with a developed thermodynamic model that considers the formation of small aggregates or larger clysters at the interface. It is shown that an interfacial phase would require a change in the interfacial tensions isotherm opposite to that observed experimentally.

The thermodynamic model of Fainerman and Miller for the description of ideal adsorption layers of surfactants forming small surface aggregates is generalized for the case of very large aggregates in the surface layer, for nonideal surface layers and ionic surfactants.

The phase behaviour of the dipalmitoylphosphatidylcholine (DPPC) monolayer affected by the penetration of bovine beta-lactoglobulin has been investigated. Penetration of beta-lactoglobulin into fluidlike DPPC monolayers induces a first-order main phase transition of DPPC.