Abstract Sorption of histidine in the cationic and zwitterionic forms on a framework aluminosilicate, clinoptilolite, has been investigated. The contributions of the exchange and nonexchange mechanisms of sorption to the sorption capacity have been determined. It has been shown that monolayer histidine sorption on clinoptilolite by the ion-exchange mechanism proceeds due to the electrostatic interaction

Abstract The peculiarities of the synthesis of silica-based mesoporous container particles with the use of sodium oleate as a templating agent have been discussed. Sodium oleate is an anionic surfactant and an efficient corrosion inhibitor. It has been shown that the container particles obtained as a result of combining the stages of their synthesis and loading contain a very large amount of the inhibitor

Abstract A review of the theoretical data accumulated for the last decade on the diffusion kinetics of the stage of homogeneous nucleation of liquid droplets and gas bubbles in multicomponent systems has been presented. In addition to the previously known results, the review contains new relations and discussions that represent the further development of own studies. Thermodynamic expressions that

Abstract A high-productivity method has been proposed for the synthesis of silver nanoparticles with sizes of 11.2 ± 0.3 nm in water-in-oil emulsions stabilized with sorbitan monooleate (Span 80). It has been shown that, in the course of the synthesis, initial reagents are transferred from emulsion droplets into Span 80 micelles. As a result, nanoparticles are formed due to the intermicellar exchange

Abstract The structural characteristics (structural resistance coefficient, volume porosity, tortuosity coefficient, average pore radius, specific surface area) and specific electrical conductivity of high-silica micro- and macroporous glasses with different compositions (basic magnetite-free and magnetite-containing glasses) have been studied in solutions of sodium, lanthanum, and iron(III) chlorides

Abstract Hydrogels have been prepared by mixing chitosan and pectin solutions, as well as solutions of their modified derivatives, in aqueous media at room temperature. The gels are obtained within a time period from several seconds to half an hour or more, depending on the process conditions. The hydrogels are formed due to both the covalent bonding between functional groups and the formation of

Abstract Convincing arguments have been presented testifying that that the surface tension of a small spherical droplet must decrease upon diminishing droplet radius in correspondence with a positive constant Tolman length. The solution of the Gibbs–Tolman–Koenig–Buff equation has been found in the most compact form. The surface tension of a small spherical droplet has been calculated within the framework

Abstract In this work we present a mathematical model for the flow of two fluids (micropolar and Newtonian ) through concentric cylinders having porous space of different permeability. The Poiseuille flow of micropolar fluid takes place in core region while Newtonian fluid in the annular region of concentric cylinders respectively. An analytical expression of velocity, flow rate, micro rotational velocity

Abstract Uniform silver nanoparticles with diameters smaller than 10 nm have been synthesized by the hydrothermal method on micro/nanofibrils of cellulose, which is used as a substrate, in a solution consisting of a water/ethylene glycol (reductant) mixture, a silver salt, poly(vinylpyrrolidone), and silver chloride used as a seed. Cellulose plays the role of an additional mild reductant, which prevents

Abstract It has been shown that the adsorption of inorganic phosphates, the molecules of which contain one to three phosphorus atoms, on the surface of nanocrystalline titanium dioxide may be interpreted as the formation of complexes of two types, i.e., outer-sphere electrostatic and inner-sphere covalent complexes. The stability constants of the adsorption complexes of both types have been calculated

Abstract Numerous experimental data are available on contact angles. However, the majority of them concern sessile droplets, although bubbles are more interesting from the point of view of colloid science, because a sessile bubble is distinguished by the existence of an equilibrium thin liquid film at a gas–solid interface. This paper presents the totality of modern thermodynamic equations necessary

Abstract Hydroxyapatite nanoparticles (NPs) have been synthesized by controlled precipitation in the presence of a surfactant, sodium dodecyl sulfate. The sizes, shapes, and structures of the NPs depend on the sequence of mixing the reagents . When the addition of sodium phosphate to a surfactant solution is followed by the addition of calcium nitrate, rodlike hydroxyapatite NPs are formed, the length

Abstract A magnetic fluid has been synthesized on the basis of magnetite particles stabilized with poly(dimethylsiloxane) (PDMS) having a molecular weight of 4670. PDMS-stabilized particles retain their mobility after the twofold dilution of this fluid with n-pentane and cooling to a temperature of –95°C. A concentrated sample of the magnetic fluid containing only particles with stabilizing shells

Abstract Flow around a Reiner–Rivlin non-Newtonian liquid particle, which is surrounded with a Newtonian liquid shell and placed into a permeable medium, is studied. This formulation of the problem is typical for, e.g., studying the motion of an oil droplet surrounded with an aqueous medium (oil-in-water emulsion) in a porous collector under the action of an external pressure drop. An analogous problem

Abstract Palladium nanoparticles catalyze the reduction of Ag+ ions with hydrogen on their surface, thereby leading to the formation of bimetallic particles with the “core–shell” structure. The catalytic reaction of methylviologen reduction with hydrogen at ratio [Ag] : [Pd] > 1 is suppressed by silver atoms located on the surface of palladium nanoparticles. At [Ag] : [Pd] ≤ 1, the reduction takes

Abstract The mechanism of montmorillonite modification with sodium metasilicate for inversing its ion-exchange characteristics has been studied. The blockage of the interlayer space in montmorillonite by amorphous silicon–oxygen clusters, which are formed as a result of sodium metasilicate hydrolysis, hinders the access of ions to the internal negatively charged surface of the mineral and increases

Abstract A methodological approach has been proposed for studying the effect of solvent nature on the adhesive properties of films of binary copolymers with different chain microstructures. The approach is based on a complex analysis of the thermodynamic work of adhesion in polymer–liquid model systems and the results of mechanical tests in combination with quantum-chemical calculations. The approach

Abstract Gas transfer through a composite has been studied. The main parameters affecting the membrane permeability have been determined. It has been shown that, in the presence of a viscous flow of a gas through a porous support, its flow rate through the composite membrane depends on the direction of transfer. The intensity of this effect increases with an increase in the support resistance to the

Abstract A method has been proposed for calculating linear dynamic magnetization of a viscoelastic ferrocolloid in a constant magnetic field (displacement field). The magnetic phase of the colloid consists of Brownian ferromagnetic nanoparticles placed into a Jeffry’s fluid. Therefore, each particle, upon its rotation induced by an alternating (probe) field, dissipates energy via two friction “channels”

Abstract The stability of spherical nanoclusters of methane and carbon dioxide hydrates in the environment of supercooled water has been studied by the molecular dynamics method under the isochoric and isobaric conditions. The process of system melting has been considered within a temperature range of 180–280 K and at pressures of 1, 50, and 100 atm (under isobaric conditions). It has been shown that

Abstract The nonexchange sorption of diverse electrolytes by an MK-40 sulfonic cation-exchange membrane has been studied by conductometry without separating solution and membrane phases. The data of sorption experiments performed within the framework of the two-phase microheterogeneous model of an ion-exchange material have been used to find the Donnan constant for the MK-40 membrane in solutions of

Abstract Stable silver nanoparticles have been obtained in reverse micelles of known and available nonionic surfactants, sorbitan monooleate (Span 80) and tetraethoxylated dodecanol and p-nonylphenol (Brij 30 and Tergitol NP-4, respectively), in n-decane. The obtained nanoparticles have been characterized using a number of physicochemical methods. The stability, hydrodynamic diameter, and electrokinetic

Abstract A comparative analysis has been performed for the structure of ring deposits resulting from the evaporation of droplets of aqueous dispersions of gold nanorods and composite nanoparticles with a gold core/organosilica shell structure based thereon. The nature of the particles has been shown to have a key effect on the character of their packing near a three-phase contact line. The study of

Abstract Cross-linked cationic particles 150–300 nm in diameter have been synthesized via single-stage emulsifier-free copolymerization of methyl methacrylate and 2-aminoethyl methacrylate hydrochloride in the presence of cross-linking agents (ethylene glycol dimethacrylate and N,N'-methylenebisacrylamide). Factors that enable one to control the morphology and polydispersity of the resulting particles

Abstract Molecular dynamics has been employed to study rearrangements in the conformational structure of polyampholytic macrochains with different distributions of charged units in the electric field of a polarized metal nanoparticle. The angular and radial distributions have been calculated for the average densities of polypeptide atoms. The radial distributions of the average density of polypeptide

Abstract A method has been developed for the synthesis of calcium carbonate particles with the use of mesoporous silica particles as a template. Hydrosols of the synthesized CaCO3 particles are unstable with respect to aggregation at neutral pH values and coagulate to yield aggregates with submicron sizes. A procedure of electrostatic stabilization by adding an aqueous FeCl3 solution has been proposed

Abstract A model approach is developed, which enables one, using the concentration dependences of the diffusion permeability for individual layers, to estimate the density of a diffusion flux through a bilayer membrane, determine the concentration of a virtual solution at the interface between the membrane layers, and find the thickness of each layer that has constant diffusion characteristics. The

Abstract The deposition of aerosol nanoparticles in a quartz fibrous filter has been studied at a temperature of 700°C. It has been found that nanoparticles with radii larger than 2 nm formed in air from vapors of heavy refractory metals do not rebound from submicron quarts fibers at nanoaerosol flow velocities through the filter below 100 cm/s. It has been shown that the nanoparticles collected on

Abstract AgCl/Ag composite nanoparticles have been synthesized by mechanical activation of reaction NH4Cl + AgNO3 + zNH4NO3 = (z + 1)NH4NO3 + AgCl using an untargeted reaction product (NH4NO3) as a diluent, where z = 7.22 is the dilution parameter, followed by partial photoreduction of AgCl to Ag (Ag+ to Ag0). Formation of Ag nanocrystals (about 7 nm in size) on the surface of 40-nm AgCl nanoparticles

Abstract Complex cryogels have been obtained by freezing mixed aqueous solutions of poly(vinyl alcohol) (PVA) and chitosan hydrochloride (ChHC) at –20°С followed by incubation of frozen samples for 12 h and defrosting by heating at a rate of 0.03°С/min. Treatment of the cryogels with ammonia vapor has transformed ChHC into chitosan base, which has the form of a dispersed filler incorporated into the

Abstract— Nanosized and submicron gold particles are of great interest for application in optics, biophotonics, and analytical chemistry. In spite of the great progress that has been made in the development of methods for liquid-phase chemical synthesis of such colloids, no reliable procedures have been proposed for obtaining monodisperse particles with sizes larger than 300 nm. In this work, a method

Abstract Diffusion permeability and electrical conductivity have been studied for bilayer perfluorinated MF-4SC membranes modified with halloysite nanotubes (HNTs) containing noble metal nanoparticles (NPs) deposited onto their surface. It has been found that the diffusion permeability of the bilayer membranes depends on their orientation with respect to an electrolyte flow: the diffusion flux is higher

Abstract This work acquaints readers with the contemporary apparatus of chemical thermodynamics in the surface and colloid science. The J potential is a new parameter, which represents a series of thermodynamic potentials and is determined for fluid systems as a grand thermodynamic potential in combination with the product of a system volume and some pressure \(p{\kern 1pt} '.\) A classification has