Colloid Journal最新文献

{"title":"Influence of Homogeneous Nucleation on the Intensity of Evaporation/Condensation Processes","authors":"V. Yu. Levashov, A. P. Kryukov, I. N. Shishkova","doi":"10.1134/s1061933x23601361","DOIUrl":"https://doi.org/10.1134/s1061933x23601361","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>An approach based on the direct numerical solution of the Boltzmann kinetic equation is proposed to take into account the influence of homogeneous nucleation on the mass transfer intensity in the evaporation/condensation (recondensation) problem. On the basis of the comparison between the scales of the formation time of a critical-size droplet and the time of supersaturation propagation, it is shown that it is possible to describe the considered problem in two stages, i.e., without taking into account the influence of droplets at the first stage and with taking into account their influence at the second stage. The calculation results show that, in the case of immobile droplets, there is a strong influence of bulk condensation on the intensity of the evaporation/condensation process.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140600948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and Study of Superhigh-Concentrated Organosols of Silver Nanoparticles","authors":"S. A. Vorobyev, M. Yu. Flerko, S. A. Novikova, E. V. Mazurova, Ye. V. Tomashevich, M. N. Likhatski, S. V. Saikova, A. S. Samoilo, N. A. Zolotovsky, M. N. Volochaev","doi":"10.1134/s1061933x23601294","DOIUrl":"https://doi.org/10.1134/s1061933x23601294","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Due to their unique properties, organosols of silver nanoparticles are widely used in optical and semiconductor devices, to produce electrically and thermally conductive films, as catalysts, antibacterial materials, etc. This work proposes a simple and highly productive method for the preparation of silver organosols, which have a metal concentration as high as 1800 g/L and contain spherical nanoparticles with low polydispersity and a median size of 9.1 nm. The method consists in the initial preparation of silver nanoparticle hydrosols with a concentration of higher than 30 g/L followed by the transfer of the NPs into an organic phase of <i>o</i>-xylene. A set of physical research methods has been employed to study the regularities of the extraction of silver nanoparticles with <i>o</i>-xylene in the presence of cetyltrimethylammonium bromide (CTAB) and ethanol and to determine the optimal process conditions, under which the extraction degree is as high as 62.5%. It has been found that bromine anions contained in CTAB molecules cause the aggregation of some amount of silver nanoparticles with the formation of silver metal sediment in the aqueous phase. According to X-ray photoelectron spectroscopy data, the sediment contains bromide ions (up to 4 at %) on the particle surface. Organosols synthesized under optimal conditions are stable for more than 7 months and withstand repeated cycles of drying and redispersing. Silver organosols have been used to obtain metal films with an electrical conductivity of about 68 500 S/cm, which increases to 412 000 and 509 500 S/cm (87.8% of the electrical conductivity of bulk silver) after thermal treatment at 150 and 250°C, respectively.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140600983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanochemical Synthesis of Nanocomposites with Specified Composition in the Presence of a Solvent for Precursors","authors":"F. Kh. Urakaev","doi":"10.1134/s1061933x23601245","DOIUrl":"https://doi.org/10.1134/s1061933x23601245","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The objective of this work is an attempt to introduce into scientific practice the method of “mechanochemical recrystallization” in solid-phase systems with small additives of a liquid solvent. Dimethyl sulfoxide (DMSO), a universal bipolar aprotic solvent, has been used as the additive. As an example, the mechanical activation of reaction AgNO₃ + NH₄I + <i>z</i> NH₄NO₃ (diluent) + <i>y</i>S + <i>x</i>DMSO = AgI + <i>y</i>S* + (<i>z</i>+1)NH₄NO₃ + <i>x</i>DMSO has been studied, where <i>z</i> ≈ 5, <i>y</i> ≈ 1, and <i>x</i> <span>( ll )</span> 1 are molar fractions. The formation of sulfur (S<b>*</b>) and silver iodide (AgI) nanoparticles has been revealed, and/or S*/AgI nanocomposites with controlled contents of the components have been synthesized. The use of NH₄NO₃, which is a non-target product of the mechanosynthesis, as a diluent leads to the stabilization of nanoparticle sizes. The nanoparticles are formed in the medium of DMSO due to the conventional recrystallization (continuous process of dissolution–crystallization of sulfur) or the reactional recrystallization (process of dissolution of AgNO₃ and NH₄I followed by their interaction with the AgI crystallization) rather than the direct mechanical activation. The former and latter mechanisms are realized when obtaining S* and AgI, respectively. The target products (S*, AgI, and S*/AgI) are purified from water-soluble components (NH₄NO₃, DMSO) by washing in an ultrasonic bath. The proposed technical solution of the problem has been realized in planetary ball mills with different milling tools.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140601325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the Mechanical and Chemical Stability of Superhydrophobic Coatings Based on Reactive Copolymers of Glycidyl Methacrylate and Fluoroalkyl Methacrylates","authors":"V. V. Klimov, O. V. Kolyaganova, E. V. Bryuzgin, A. V. Navrotskiy, I. A. Novakov","doi":"10.1134/s1061933x23601208","DOIUrl":"https://doi.org/10.1134/s1061933x23601208","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">\u0000<b>Abstract</b>—</h3><p>This work is devoted to studying the stability of polymer coatings formed from reactive copolymers of glycidyl methacrylate and fluoroalkyl methacrylates and applied onto textured aluminum and cotton textile surfaces. The stability is determined with respect to the action of aggressive media and mechanical stress. The resulting coatings provide the achievement of long-term stable heterogeneous wetting with initial contact angles as large as 170°, thus preventing the penetration of corrosive agents into the hierarchical structure. The study has shown the influence of the composition of the reactive copolymers containing 3–7 fluorine atoms in a monomer unit on the stability of the polymer coatings with respect to the prolonged exposure to media with different acidities, as well as to cavitation, and abrasive wear.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Materials Based on Poly(lactic acid) and Copper(II) Sulfate Impregnated by the Crazing Method","authors":"S. D. Brovina, E. E. Mastalygina, E. S. Trofimchuk, A. A. Popov","doi":"10.1134/s1061933x23601178","DOIUrl":"https://doi.org/10.1134/s1061933x23601178","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The common approach to creating antimicrobial polymer materials is the distribution of a bactericidal additive in a material by mixing the additive with a solution or a melt of the polymer. This work proposes the method introducing of copper(II) sulfate, which has antimicrobial properties, into a poly(lactic acid) film by forced impregnation of a salt solution via the crazing mechanism. CuSO₄ has been found to be uniformly distributed in the bulk of the polymer in the form of particles with sizes of about 100 nm. In the course of the structural modification, the surface of the polymer film becomes rougher and more hydrophobic. The water contact angle increases from 40° to 60°–65°. The incorporation of CuSO₄ does not affect the surface properties but has a reinforcing effect on the polymer matrix as is evident from tensile tests (strength and elongation at break increase by 2.5 and 1.4 times, respectively).</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of the Structure of Water-in-Oil Microemulsions of Sodium Di-(2-ethylhexyl)phosphate and Sodium Dodecyl Sulfate on the Efficiency of Microemulsion Leaching of Copper","authors":"N. M. Murashova, A. S. Polyakova","doi":"10.1134/s1061933x2360104x","DOIUrl":"https://doi.org/10.1134/s1061933x2360104x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>A relationship has been found between the structure of microemulsions based on sodium dodecyl sulfate (SDS) and sodium di-(2-ethylhexyl)phosphate (D2EHPNa) and the efficiency of microemulsion leaching of copper. The dependences of electrical conductivity on the volume fraction of water have been studied for microemulsions containing D2EHPNa or a mixture of SDS and butanol, decane, water, and di-(2-ethylhexyl)phosphoric acid as an extractant for copper extraction. A gradual passage from water-in-oil microemulsions with the predominance of isolated droplets to microemulsions with the predominance of dynamic clusters of droplets (percolated structure) takes place with the increase in the volume fraction of water. The conductivity percolation thresholds are approximately 0.18 and 0.20 for the microemulsions based on D2EHPNa and SDS, respectively. The temperature dependence of the logarithmic electrical conductivity is linear in a range of 20–80°C for the microemulsions with water volume fractions below (0.13 and 0.07, respectively) and above (0.30 and 0.23) the percolation threshold; in this temperature range the structure of the considered microemulsions remains unchanged. The experiments on microemulsion leaching performed with the use of a CuO-based model system at <i>T</i> = 80°C have shown that, for the microemulsions with the percolated structure (having water volume fractions of 0.30 for D2EHPNa microemulsions and 0.23 for SDS microemulsions), copper extraction is higher than that for the microemulsions with the predominance of isolated droplets (water volume fraction of 0.13 and 0.07, respectively).</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Finite Element Model for the Interaction of Liquid Metals with Reactor Steel","authors":"O. A. Chikova, V. S. Wang, S. L. Li","doi":"10.1134/s1061933x23601154","DOIUrl":"https://doi.org/10.1134/s1061933x23601154","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract—</h3><p>The article discusses a model of the interaction between a liquid−metal coolant (Pb, Pb55Bi(e)) and a heat exchanger material (316L steel) in an SVBR-type nuclear reactor cooling device for the case in which the effect of liquid-metal embrittlement cannot be ignored. It is assumed that a crack propagates due to the penetration of the liquid-metal coolant into intergrain boundaries. The free energy of a wetted surface is calculated using the mean-field theory within the formalism of finite element analysis. Tensile stress <i>S</i> (MPa) is determined for the propagation of a crack 50 µm long from a defect in the form of a 0.15-mm scratch on the surface of the heat exchanger. The calculation is carried out for an operation temperature range of 900–1100 K, when the melt wets the steel. The values of <span>(S = 253{kern 1pt} -{kern 1pt} 358)</span> and <span>(210{kern 1pt} -{kern 1pt} 369,,~{text{MPa}})</span> have been obtained for the interaction of Pb55Bi melts and Pb with 316L steel, respectively. The calculation results mean that a heat exchanger with surface defects can be damaged due to the effect of liquid-metal embrittlement.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modification of Synthetic Valleriite Surface with Gold Nanoparticles: The Roles of Specific Adsorption and Zeta Potential","authors":"A. A. Karacharov, M. N. Likhatski, R. V. Borisov, E. V. Tomashevich, S. A. Vorobyev, S. M. Zharkov","doi":"10.1134/s1061933x23601075","DOIUrl":"https://doi.org/10.1134/s1061933x23601075","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Layered two-dimensional materials, whose properties dramatically differ from their bulk precursors, are of great theoretical and applied importance. Recently, a layered 2D material, an analog of a natural mineral, valleriite, in which quasi-monoatomic Cu−Fe−S sheets alternate with brucite-like ones, has been prepared using a simple hydrothermal synthesis procedure. The features of the electronic structure of these materials make it possible to propose them as new materials for a wide field of applications such as (electro)photocatalysis, high-capacity batteries, etc. In this work, nanocomposite materials have been prepared via immobilization of gold nanoparticles (AuNPs) from citrate hydrosols on the surface of the synthesized valleriites having different compositions of hydroxide layers, which control the surface charge density. According to X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive X-ray microanalysis (EDX), and selected area electron diffraction (SAED) data, AuNPs are immobilized on valleriite nanoflakes, which have lateral sizes of 150–200 nm and thicknesses of several tens of nanometers, as isolated metal nanoparticles with an average diameter of 11 nm. A small amount of aggregates indicates a high affinity of AuNPs for the valleriite surface. The amounts of immobilized gold are the same on all studied valleriites (~0.2%). This finding may be related to the simultaneous sorption of free citrate ions from the AuNP hydrosols, with these ions, according to zeta potential measurements, charging the surfaces of all studied valleriite samples to nearly the same negative value of –40 mV. According to the XPS data, the AuNPs immobilization markedly decreases the magnesium and oxygen contents on the surfaces of the synthesized valleriites due to the partial degradation/dissolution of the brucite layer. In addition, the amount of Fe³⁺ ions bound to OH groups decreases with a simultaneous increase in the fraction of Fe³⁺–O species. The TEM data have confirmed the preservation of the layered structure of valleriites after the immobilization of AuNPs.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Problem of Stability of Small Objects by the Example of Molecular Dynamics Models of Metal Nanoparticles and Nanosystems","authors":"V. M. Samsonov, N. Yu. Sdobnyakov, A. Yu. Kolosov, S. S. Bogdanov, I. V. Talyzin, S. A. Vasilyev, K. G. Savina, V. V. Puytov, A. N. Bazulev","doi":"10.1134/s1061933x23601191","DOIUrl":"https://doi.org/10.1134/s1061933x23601191","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>After briefly discussing the problem of stability/instability of dispersed systems in colloid chemistry, including ideas and concepts dating back to P.A. Rehbinder, the following classification has been proposed for instabilities of individual (free) nanoparticles: (1) instability with respect to the spontaneous disintegration into individual molecules (atoms) or smaller nanoclusters; (2) instability of shape; (3) instability of the integral structure of nanoparticles; (4) instability of the mesoscopic structure; (5) instability of physicochemical characteristics of nanoparticles; and (6) instability with respect to an external environment, including chemical instability, e.g., instability to oxidation. The problems concerning the stability of isomers of metal nanoclusters and of bimetallic core-shell nanostructures are considered as examples. The theoretical concepts of stability and instability have been illustrated by our molecular dynamics data on isomers of Au nanoclusters and mutually inverse (alternative) bimetallic Co@Au and Au@Co core-shell nanostructures, where the first element (before symbol @) corresponds to the central region (core) of a particle, while the second one refers to its shell.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of the Structure of Sulfonic Polyelectrolyte Matrices on the Adsorption of Cu2+ Ions","authors":"S. G. Laishevkina, O. D. Iakobson, E. M. Ivan’kova, B. M. Shabsel’s, N. N. Shevchenko","doi":"10.1134/s1061933x23600999","DOIUrl":"https://doi.org/10.1134/s1061933x23600999","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Porous hydrophilic polyelectrolyte matrices have been obtained by reverse suspension copolymerization of <i>p</i>-styrenesulfonate with <i>N</i>,<i>N</i>'-methylenebisacrylamide, as well as by cryotropic gelation of sulfonic acrylates (3-sulfopropyl methacrylate and sulfobetaine methacrylate). It has been shown that the concentration of sulfonate groups in the obtained polyelectrolytes is 2–3 mmol/g. The morphology and structure of the surface layer of the polyelectrolyte matrices have been studied by scanning electron microscopy and FTIR spectroscopy, while the specific surface area and pore size distribution have been investigated by the BET method. Adsorption of Cu²⁺ ions has been studied spectrophotometrically. It has been found that polyelectrolyte matrices containing aromatic sulfonate groups have the maximum sorption capacity.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}