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The solubility in dimethyl sulfoxide and disaggregation in water under the action of tetradecyltrimethylammonium bromide (С14TAB) have been studied for metal-free phthalocyanine modified with four alkylphosphoryl groups (I). Electronic absorption and luminescence spectroscopies have been employed to show that, in dimethyl sulfoxide, compound I exists not only in the associated state (as it was believed previously), but also as monomers, the amount which provides high-intensity radiation. In aqueous media at pH 7–9, aggregates of I prevail; however, they are disintegrated into individual molecules under the action of С14TAB. According to electronic absorption and luminescence spectroscopy data, compound I is stable with respect to aggregation in a С14TAB micellar solution with pH 7.4 not only at 298 K, but also upon rapid freezing to 77 K.

Protomicelle is a new term in colloid science that refers to micelle-like surfactant aggregates in solutions. Unlike conventional micelles, protomicelles have no critical micelle concentration (CMC) and are formed gradually via adsorption of surfactant molecules or ions on solubilization cores at concentrations significantly lower than the CMC. A completely formed protomicelle looks like an ordinary solubilisate-containing micelle. In this work, the process of monomerization of a given amount of crown-substituted magnesium phthalocyaninate (I) in a premicellar aqueous solution of tetradecyltriphenylphosphonium bromide (II) has been studied by spectrophotometry. It has been shown that compound I monomers are absent in a solution in pure water, while the content of dimers increases as surfactant II is added to the solution. This phenomenon strictly proves the existence of higher-order molecular aggregates of I in aqueous solutions. A new physicochemical parameter of phthalocyanine monomerization has been defined, namely, the monomerization concentration, i.e., compound II concentration that corresponds to the beginning of this process. It has been shown that phthalocyanine monomerization, which has begun long before the CMC of II, continues above the CMC, although at a lower rate. At this stage, monomerization of I proceeds exclusively at the expense of dimers.

Protomicelles represent a new concept of colloid science relevant to micelle-like aggregates of surfactants in solutions. In contrast to ordinary micelles, their formation requires no critical micelle concentration (CMC) and proceeds gradually through the adsorption of surfactant molecules or ions on a solubilization core at concentrations much lower than the CMC. A completely formed protomicelle looks like an ordinary solubilisate-containing micelle. Protomicelles can be formed on phthalocyanine monomers and dimers. In this work, the role of protomicelles in monomerization of crown-substituted magnesium phthalocyaninate (I) in aqueous sodium dodecyl sulfate (II) solutions has been studied spectrophotometrically at compound I concentrations of 0.38 and 1.2 μМ. Empirical methods have been developed for determining a new parameter, monomerization concentration (concentration of II required to initiate the monomerization of I), and it has been shown that the monomerization concentration decreases with an increase in the concentration of I. Another new parameter defined as the concentration of II corresponding to nearly complete monomerization of I has been studied in comparison with the CMC of II. For this purpose, the CMC has, for the first time, being measured (by conductometry) in the presence of protomicelles. The latter circumstance has been shown to decrease the CMC. At the same time, it has been revealed that the concentration corresponding to the completion of monomerization in the studied system nearly coincides with the CMC.

Solubilization of crown-substituted magnesium phthalocyaninate(I) has been studied by spectrophotometry in aqueous solutions of tetradecyltrimethylammonium(II), hexadecyltrimethylammonium(III), and hexadecyltriphenylphosphonium bromides. The experiments have been carried out with saturated solutions of I occurring at the thermodynamic equilibrium with its precipitate. The experimental data have been used to determine the following thermodynamic characteristics of the solubilization: the solubilization capacity of micelles, the coefficient of solubilisate partition between micelles and an ambient solution, and the standard solubilization affinity of I. It has been shown that, in spite of different structures of the surfactants, the standard works of a I molecule transfer to micelles of all three surfactants are almost equal. The found values of the solubilization capacity, as calculated per one molecule of I, in micelles of II and III lead to abnormally large aggregation numbers. This fact may be explained by possible development of a bimodal distribution of micelles, at which solubilisate-containing micelles coexist with “empty” micelles; as a result, the average number of solubilisate molecules in a micelle may appear to be smaller than unity.

A spectrophotometric study of the solubilization of crown-substituted magnesium phthalocyaninate (I) has been carried out in an aqueous solution of sodium dodecyl sulfate (II). The experiments have been performed with saturated solutions of I at a thermodynamic equilibrium of a solution with a precipitate of I. The known transition from dimers of I to monomers upon solubilization has been studied in detail. It has been found that monomerization of I begins at concentrations much lower than the critical micelle concentration (CMC) of II, while specific micelles of II are formed with involvement of I dimers at still lower surfactant concentrations. The presence of dimers is also observed when I is dissolved in pure water; the solubility of I has appeared to be 7.38 μM (chemists usually suppose I to be insoluble in water). Extinction coefficients of monomers and dimers of I have been determined in the methodological part of the work. The following thermodynamic characteristics of solubilization have been found on the basis of experimental data: solubilization capacity of micelles, coefficient of solubilizate partition between micelles and an ambient solution, and the standard solubilization affinity of I. The found value of the solubilization capacity as calculated per one molecule of I in a micelle leads to an abnormally large aggregation number (309). One explanation of this fact is the possible development of a bimodal distribution of micelles, at which solubilisate-containing micelles coexist with “empty” micelles; as a result, the average number of solubilizate molecules in a micelle can appear to be smaller than unity.

The existence of a special type of surfactant micelles formed on the solubilization core of phthalocyanine at concentrations significantly below the critical micelle concentration (CMC) has been established. This discovery overturns the traditional concepts of colloidal chemistry, which imply that the surfactant micelles are first formed, and then solubilization occurs in them above the CMC. In the process of solubilization, phthalocyanines (usually existing in an aqueous solution in the form of dimers) undergo monomerization, which is crucial for the manifestation of the functional properties of their molecules. Here, the spectrophotometric study of crown-substituted magnesium phthalocyaninate (I) in an aqueous solution of sodium dodecyl sulfate (II) is reported. It has been found that specific micelles of II (they can be called proto-micelles) involving dimers of I are formed significantly below the CMC. The solubilization capacity of micelles determined from experimental data leads, as calculated per molecule of I in a micelle, to an abnormally large aggregation number (309). This phenomenon can be explained by the formation of a bimodal distribution of micelles, in which micelles with solubilizate coexist with “empty” micelles, so that the average number of solubilizate molecules in a micelle can be less than unity.

Electronic absorption spectroscopy and fluorescence spectroscopy have been employed to analyze the aggregation of zinc phosphoryl-substituted phthalocyaninate by the example of zinc 2,(3),9,(10),16,(17),23,(24)-tetra(2-phosphoryl)phenoxyphthalocyaninate ([ZnPc(PO(OH)2)4]) in dimethyl sulfoxide and water at different pH values. It has been found that, in aqueous systems with pH 4–9, this compound exists in an aggregated state, while it forms a molecular solution in dimethyl sulfoxide. Moreover, ZnPc(PO(OH)2)4 is in fact insoluble in water at pH < 5.7. The addition of tetradecyltrimethylammonium bromide as a cationic surfactant to an aqueous ZnPc(PO(OH)2)4 solution leads to the complete disaggregation of the dye into individual molecules within a wide pH range (from 4 to 9.18) and a marked increase in the solubility of ZnPc(PO(OH)2)4 in strongly acidic media. Analysis of the fluorescent properties of surfactant micellar solutions containing ZnPc(PO(OH)2)4 has shown that such systems can generate singlet molecular oxygen. At the same time, the high intensity of ZnPc(PO(OH)2)4 fluorescence in micellar solutions makes it possible to visually observe the distribution of micelles that carry nonaggregated dye molecules in living tissues.

The aggregation of zinc tetra(4-carboxyphenoxy) phthalocyaninate, ZnPc(COOH)4, in organic solvents and water at different pH values has been analyzed using electronic absorption and luminescence spectroscopies. It has been found that, in aqueous systems at pH 6–9, ZnPc(COOH)4 exists in an aggregated state, while it forms molecular solutions in dimethylformamide and dimethyl sulfoxide. The use of cationic surfactants (dodecyl-, tetradecyl-, and hexadecyltrimethylammonium bromides) causes the disaggregation of ZnPc(COOH)4 into individual molecules in aqueous solutions at pH ≥ 6. This opens up possibilities of applying ZnPc(COOH)4 as a preparation for photodynamic therapy in physiological solutions, because each molecule of this compound may participate in the generation of singlet molecular oxygen.

The behavior of magnesium octa[(4'-benzo-15-crown-5)oxy]phthalocyaninate (Mgcr8Pc) in aqueous micellar solutions of alkyltriphenylphosphonium bromides (CnTPPBs), where n = 8, 12, 14, and 16, has been studied by means of electronic absorption spectroscopy and measurements of fluorescence photophysical characteristics. Intense bands of absorption (λmax = 683 nm) and fluorescence (λmax = 694 nm) of Mgcr8Pc in CnTPPB micellar solutions are characterized by monoexponential decay of intensity (lifetime of 5.98–6.29 ns) and indicate that magnesium phthalocyaninate has the monomeric form. The disaggregation of Mgcr8Pc in the presence of CnTPPBs provides an opportunity to use aqueous micellar solutions containing this metallophthalocyane in photodynamic therapy, because it is the monomeric form of Mgcr8Pc that generates singlet oxygen molecules, which kill tumor cells.

Electronic absorption spectroscopy and fluorimetry have been employed to study the behavior of magnesium octa[(4′-benzo-15-crown-5)oxy]phthalocyaninate (Mg[(B15C5O)8Pc]) in aqueous micellar solutions of sodium dodecyl sulfate and hexadecyltriphenylphosphonium bromide. Conditions have been found for the existence of monomeric Mg[(B15C5O)8Pc] complex in surfactant solutions to provide the possibility of using mixed solutions of the complex and cationic surfactants (alkyltriphenylphosphonium bromides) for photodynamic therapy. In surfactant solutions with different concentrations of micelles (cm) and the complex (cp), the maximum amount of monomeric Mg[(B15C5O)8Pc] is achieved at cm/cp ≥ 4.

Conductometry and viscometry have been employed to study the effect of a background electrolyte (KBr) taken in concentrations of 0.03 and 0.1 M on the critical micelle concentration of dodecyltrimethylammonium bromide (С12ТАB) and the dependence of relative viscosity η/η0 of С12ТАB micellar solutions on the overall surfactant concentration. It has been found that, as a first approximation, each of these dependences may be represented as the sum of two linear portions. Concentrations c* of С12ТАB micellar solutions, which correspond to the inflections between the two linear portions in the concentration curves of relative viscosity, have been determined. The Einstein equation η/η0 = 1 + 2.5p (p is the volume fraction of the dispersed phase and 2.5 is a theoretical parameter that takes into account the spherical shape of the particles) has been transformed into a form corresponding to the concentration dependence of the relative viscosity on the overall surfactant concentration to make it applicable to the consideration of low-concentration systems, which are uncomplicated by intermicellar interaction. In particular, the applicability of the above equation for estimating micelle radii has been studied. It has been shown that the (η/η0–1) = f(c/с01–1) concentration dependences represented in bilogarithmic coordinates (c is the overall С12ТАB concentration and c01 is the critical micelle concentration) are linear in the absence of a significant intermicellar interaction and have slopes equal to unity. This fact may be considered as a criterion for the applicability of the Einstein equation to micellar solutions.

The calculation of the diffusion coefficients of nonionic surfactants as functions of their concentrations in micellar solutions has been analyzed within the framework of the quasi-chemical version of the law of mass action. The methods of the introduction of initial calculation parameters, calculation scheme for an ideal mixture of monomeric molecules and micelles, and corrections for varying solution viscosity have been considered. Numerical estimations have been performed using aqueous tetraoxyethylene octyl ether, pentaoxyethylene hexyl ether, and octyl-β-D-glucopyranoside solutions as examples.

Specific conductivity K of aqueous solutions of alkyltrimethylammonium bromides has been studied in a wide range of concentrations c of surfactants containing 10, 12, 14, and 16 carbon atoms in alkyl chains. In general, three break points have been observed in the K(с) dependences. The first point observed upon increasing overall solution concentration corresponds to critical micelle concentration CMC1. The CMC1 values of alkyltrimethylammonium bromides decrease with an increase in the alkyl chain length. They are in satisfactory agreement with the published data. It has been supposed that the second break point in the K(с) dependences corresponds to the formation micellar structures as clusters and the appearance of channels with a higher specific conductivity, which is provided by the contribution from the overlap of electrical double layers existing in the vicinities of micelles. Surfactant concentrations corresponding to these break points have been called “critical percolation concentrations” (CPCs). The position of a CPC in the concentration scale strongly depends on alkyl radical length. All K(с) curves exhibit a third break, which corresponds to second critical micelle concentration CMC2, at which the properties of ionic-surfactant solutions may substantially change because of the appearance of supramicellar structures. The experimental data obtained have been used to evaluate the parameters of the model of electrical percolation for micellar solutions, i.e., effective conductivity $${\tilde K_m}$$ and effective micelle radius r 0.

Diffusion coefficients of monoalkyl ethers of poly(ethylene glycols), С8Е4 and С12Е5, and octyl-β-D-glucopyranoside have been measured in aqueous micellar solutions within wide ranges of temperatures and concentrations by dynamic light scattering. The study of the С12Е5–water system containing cylindrical micelles has been supplemented with viscosity measurements, which make it possible to better monitor structural transformations and phase transformations.

Results of calculating diffusion coefficients of ionic surfactants as functions of their concentration in micellar solutions have been analyzed within the framework of the quasi-chemical variant of the law of mass action. Diffusion coefficients have been evaluated for an ideal mixture of monomeric molecules and micelles, as well as taking into account the correction for the variability of the aggregation number of a surfactant using aqueous solutions of hexadecyltrimethylammonium bromide, hexadecylpyridinium chloride and bromide, and alkyltriphenylphosphonium bromides as examples.

Effects of electrical percolation accompanying variations in overall surfactant concentration с have been studied by the example of micellar sodium dodecyl sulfate solutions. It has been found that, in the studied concentration range of 0.001–1.2 M, dependences of electrical conductivity K on c may exhibit at least three break points, with the dK/dc derivatives changing in the vicinities of these points. At two of these points, which are reliably identified and correspond to critical micelle concentrations (CMC1 and CMC2), they decrease. At the third concentration, lying between CMC1 and CMC2, the dK/dc derivative increases. A substantiated assumption has been put forward that this break point, at which the dK/dc derivative increases, results from the clustering of micelles and the appearance of channels with a higher specific conductivity, which is provided by the contribution from the electrical conductivity of the diffuse and dense parts of micelle electrical double layers, upon the formation of clusters. The ionic surfactant concentration that corresponds to the break point at which the dK/dc value increases has been denoted as the critical percolation concentration.

The possibility of development of electrical percolation upon variations in the contents of components in a disperse system has been studied in terms of Bruggeman’s ideas of an effective medium and the continual model of the electrical conductivity of composite materials. The case of a small difference between the specific conductivities of a dispersed phase Km and a dispersion medium Kd has been considered. It has been shown that the dependence of electrical conductivity K of a disperse system on volume fraction p of a wellconducting component may exhibit an inflection in the vicinity of the p* value, which depends on the Km/Kd ratio. Different methods for determining the p* value have been described. At low ratios between the conductivities of a dispersed phase and a dispersion medium, the inflection is very weakly pronounced. However, the representation of the K(p) dependences in semilog coordinated substantially facilitates its identification.

Theoretical relations are formulated to describe the effect of an activity coefficient reflecting interparticle interaction on the diffusion coefficient of a surfactant in a micellar system. The activity coefficient of hexadecyltrimethylammonium bromide in an aqueous micellar solution is measured with a bromide-selective electrode. Analysis of the data obtained shows that, above the critical micelle concentration, surfactant mobility and solution viscosity stronger affect an increase in the diffusion coefficient followed by its reduction than the interparticle interaction in a micellar system dose.

Aqueous micellar solutions of dodecyl- and hexadecyltrimethylammonium bromides, hexade- cylpyridinium bromide and chloride, domiphen bromide ((dodecyldimethyl-N-2-phenoxyethyl)ammonium bromide), hexadecyltriphenylphosphonium bromide, and sodium dodecyl sulfate have been investigated using dynamic light scattering. A local increase in the diffusion coefficient has been discovered for all ionic surfactants at concentrations higher than the first critical micelle concentration (CMC1). It has been shown that, at the same alkyl chain length and counterion nature, the increase in the diffusion coefficient with surfactant content becomes more pronounced with a reduction in CMC1. The concentration dependences of the diffusion coefficients have been explained in terms of a previously proposed theory formulated for ideal micellar systems. The existence of the local minimum in the diffusion coefficient near CMC1 has been shown to be a general regularity for binary surface-active electrolytes.

Dynamic light scattering and capillary viscometry have been employed to study aqueous micellar solutions of nonionic (pentaoxyethylene dodecyl ether) and ionic (decyl-, dodecyl-, and tetradecyltrimethyammonium bromides) surfactants in a wide concentration range covering the first and second critical micelle concentrations (CMC1 and CMC2, respectively). The concentration curve for the diffusion coefficient of the nonionic surfactant has been shown to correspond to a monotonically decreasing function. The diffusion coefficients of the ionic surfactants pass through maxima above CMC1. As the alkyl chain length increases, the slopes of the concentration curves rise in the range of the linear growth in the diffusion coefficient, while the values of the maxima increase, their positions shifting toward lower concentrations. The concentration dependences of the diffusion coefficients have been explained based on their relation to activity coefficients.

Absorption of monochromatic light in solutions of cetyltrimethylammonium (CTAB) and cetylpyridinium (CPB) bromides has been studied in the wavelength λrange of 190–1000 nm. The investigation has been performed at 30°C and surfactant concentrations ranging from 5 × 10−5 to 3.5 × 10−3 M. Spectra of solutions of LiBr, KBr, and CTAB in the premicellar concentration region have been shown to coincide with each other. They are unimodal, and the heights of their maxima at λmax ≈ 193 nm depend on Br− concentration alone. In contrast to CTAB solutions, the UV spectra of CPB solutions are characterized by the presence of two absorption maxima near λmax1 = 191 nm and λmax2 = 259 nm, as well as a shoulder at 210–218 nm. Their existence is caused by the presence of both Br− anions and CP+ cations in the solutions. The dependences of the integral absorption in the examined wavelength range on CPB concentration exhibit inflections both in the premicellar region and upon the transition to micellar solutions, with these inflections characterizing the critical dimerization and micellization concentrations, respectively. For CTAB, this regularity has only been observed at the critical micellization concentration. The data on the concentration dependence of the light absorption have resulted in the proposal of a method for determining the degree β of counterion binding by micelles of ionic surfactants. The β values calculated for CTAB and CPB are equal to 0.89 ±0 0.1.

Cetyltrimethylammonium bromide (CTAB) aqueous solutions are studied by dynamic light scattering method in a wide concentration range covering the first and second critical micelle concentrations (CMC1 and CMC2, respectively). Nonmonotonic and ambiguous behavior of diffusion coefficients D with an increase in concentrations above CMC1 is revealed. An increase in the D values in the first decade of CTAB concentration above CMC1 agrees with known published data for aqueous solutions of ionic surfactants. It is shown that an increase in the ionic strength of solution with the addition of KBr leads to a decrease in the positive slope of the dependence of diffusion coefficients on CTAB concentration up to zero at 0.05 M KBr. Two relaxation processes corresponding to large and small D values are simultaneously observed in micellar solutions, beginning with 0.03 M CTAB concentration. The data obtained are compared with published data, as well as with the results of viscosity measurements. The performed analysis indicates that the observed relaxation processes are explained by the coexistence of spherical and nonspherical micelles. It is established that micelles acquire a cylindrical shape at CTAB concentrations ranging from 0.2 to 0.25 M. Hydrodynamic radii and lengths of micelles are calculated.

The organic-inorganic materials with fluorescence properties are synthesized in the form of gels and xerogels from tetraethoxysilane and glycidoxypropyltrimethoxysilane by the sol-gel method. The concentration of the introduced Nile Red dye is 2.2 × 10−6 M. The fluorescence spectra of the prepared materials are measured and analyzed as a function of the ratio between the initial components forming the sol-gel epoxy siloxane matrices. The assumption regarding the structure of the synthesized hybrids is made invoking the data obtained by Fourier-transform IR spectroscopy and atomic-force microscopy.

The hybrid organic-inorganic materials with fluorescence properties are synthesized in the form of gels and xerogels from tetraethoxysilane and a mixture of epoxy resins by the sol-gel method. The concentration of the introduced Nile Red dye is 1.6 × 10−6M. The fluorescence spectra of the prepared materials are measured and analyzed as a function of the ratio between the initial components forming the sol-gel epoxy siloxane matrices. The assumption regarding the structure of the synthesized hybrids is made invoking the data obtained by Fourier-transform IR spectroscopy and atomic-force microscopy.

The hybrid organic-inorganic materials with optical properties are synthesized in the form of gels and thin-layer coatings by the sol-gel method. The fluorescence of the materials synthesized is investigated as a function of the Nile Red concentration and the composition of the precursors forming the hybrid sol-gel matrices. It is demonstrated that the materials synthesized hold much promise for use in the fabrication of optical gas sensors.

The corrosion resistance of the convex and concave sides of bent plates from a high-nitrogen non-magnetic steel has been studied in aqueous solutions of sulfuric and hydrochloric acids. Weighing and hydrogen methods are used to control the corrosion rate of bent-sample sides and to find a number of effects that complement the picture of the stress corrosion of iron alloys and support the existence of the mechanochemical deformation sign effect.

Mechanochemical effects have been investigated in the processes of corrosion of bent plates of unalloyed and high-alloy steel in aqueous solutions of sulfuric and hydrochloric acids. Special attention was paid to the strain sign effect discovered recently and caused by the existence of a surface stress in solids. The use of the weight method and the hydrogen method of corrosion control has yield well consistent results confirming the existence of the mechanochemical effect of the strain sign even under condition of the starting corrosion cracking. The domination of corrosion on the concave side gives evidence of the negative sign of surface stress at the steel/solution boundary, which can be explained by the formation of the electrical double layer.

Based on data on the colloid chemical properties and conductivity of disperse systems prepared by mixing latexes of the copolymer of 2-perfluoropentoxytetrafluoropropyl acrylate and N-methylolmethacrylamide (LFM-N) and the copolymer of butadiene, acrylonitrile, and methacrylic acid (BNK-40/4), a conclusion was drawn concerning the formation of particles of composite structure in these systems. The possibility of attaining a high level of hydro- and oleophobic properties in textiles modified with LFM-N:BNK-40/4 composite in the ratio of 80:20 was demonstrated.

This paper reports on the results of rheological investigations into the kinetics of gelation of the sol-gel systems based on a water-alcohol solution of tetraethoxysilane (TEOS) modified by a number of metal salts and organic polyhydroxyl compounds, such as glycerol, poly(ethylene glycol) (PEG-300), and hyperbranched aliphatic complex polyol polyethers (HBP-49, HBP-64). It is demonstrated that, at a dispersed phase concentration of approximately 10 wt %, water-ethanol sol-gel systems containing 2–4 g/l of high-molecular additives possess a shear strength and are characterized by anomalous properties in their flow. The gelation time of sols in the presence of organic additives is affected by the ratio between the numbers of OH− hydrophilic and CH3 hydrophobic groups in the polymer molecule, the concentration of the introduced additive, and the electrolyte multivalence. The presence of metal salts enhances the structuring effect of polymers.

The stability of latexes of poly(1,1-dihydroperfluoroheptyl acrylate) (LFM-3), poly(vinyl chloride-co-vinylidene chloride) (SVKh), poly(butadiene-co-methacrylic acid) (SKD-1), and their mixtures, as well as the wettability of the films produced on their basis are studied. It is revealed that, in some cases, the stability of binary systems exceeds that of individual dispersions. A correlation is established between the stability of latexes (varying in the film-formation process) and the critical concentration of their coagulation, on the one hand, and the water contact angles, on the other hand. It is shown that the aggregation of latex particles considerably affects the texture of hydrophobic films.

Organic–inorganic composites are synthesized by introducing a number of low- and high-molecular water-soluble polyhydroxyl compounds (with different molecular weights and different molecular structures) into sols based on tetraethoxysilane. The coatings on nickel substrates are prepared by adding chromium dioxide as a finely disperse filler to the soles. The rheological properties of the sol–gel systems synthesized are investigated, and the surface condition and the microstructure of the coatings formed are examined. The xerogels and the coatings are studied by differential thermal and X-ray powder diffraction analyses.

The effect of four 1:1 electrolytes (KCl, KBr, NH4Cl, and CH3COONa) on optical (stimulated by laser pulse) cavitation in thin layers bounded by hydrophobic and hydrophilic surfaces has been explored. For water and all salts (up to 1 M) in the case of hydrophobic surfaces, the cavitation probability is enhanced as compared with the case of hydrophilic walls. The increased cavitation probability observed with hydrophobic surfaces can be linked to an enhanced concentration of gas-filled submicrocavities close to them. The phenomenon seems to depend strongly on dissolved gas. Variations in the probability of cavitation that occur with electrolyte are significant and depend on its concentration and type. The specific effect of electrolytes on optical cavitation in a thin layer likely makes sense only in terms of the previously neglected ionic dispersion interactions. The results obtained may have implications for the mechanisms of the long-range hydrophobic interactions between surfaces and hydrophobic slippage.

A method for modifying polyester fibres by incorporating a fluorine-containing polymer in the surface layer of the fibres was developed to give the fibres nonstick properties with respect to liquids of different chemical nature. It is best to use polyfluoroalkyl acrylate latex stabilized with a cationic or nonionogenic SF for modification, since it gives the fibre antistatic as well as nonstick properties.

A difference in corrosion rates on the concave and convex sides of a bent carbon steel plate exhibits the mechanochemical effect of the strain sign as a new discovery in the field of corrosion under stress.