Colloid Journal最新文献

{"title":"On the Relation between Spontaneous Segregation of Components in Ternary Pt–Pd–Ni Nanoparticles and Stability of Core–Shell Nanostructures: Molecular Dynamics Study","authors":"V. M. Samsonov,&nbsp;I. V. Talyzin,&nbsp;A. A. Romanov,&nbsp;V. V. Puytov,&nbsp;D. V. Zhigunov,&nbsp;A. V. Lutsai,&nbsp;S. A. Vasiliev,&nbsp;N. I. Nepsha,&nbsp;N. Yu. Sdobnyakov","doi":"10.1134/S1061933X25600605","DOIUrl":"10.1134/S1061933X25600605","url":null,"abstract":"<p>The isothermal molecular dynamics method and the LAMMPS software package have been employed to perform a comparative study of the stability of Pd₅₀₀₀Ni₅₀₀₀@Pt₅₀₀₀, Pt₅₀₀₀Ni₅₀₀₀@Pd_5000, and Pt₅₀₀₀Pd₅₀₀₀@Ni₅₀₀₀ core-shell nanostructures during gradual heating from 300 to 2200 K. It has been revealed that all three homotopes retain their core–shell morphology up to the onset of melting. However, the ternary Pt₅₀₀₀Ni₅₀₀₀@Pd₅₀₀₀ nanoparticles have been found to be most stable: their melting begins at a higher temperature, and they partly inherit the core–shell morphology even after the completion of melting. A conclusion has been inferred about the relation between the higher stability of PtNi@Pd nanostructures and the effect of Pd surface segregation in ternary Pt–Pd–Ni nanoparticles. In turn, the pronounced surface segregation of Pd is explained by the fact that it is this component that has the lowest specific surface energy.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"87 4","pages":"547 - 559"},"PeriodicalIF":1.1,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853626","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":"Numerical Simulation of Stationary Nucleation in a Wide Range of Supersaturations Taking into Account Thermal Effects","authors":"E. E. Perevoshchikov,&nbsp;D. I. Zhukhovitskii","doi":"10.1134/S1061933X25600496","DOIUrl":"10.1134/S1061933X25600496","url":null,"abstract":"<p>The molecular dynamics method is employed to solve the problem of stationary vapor–liquid nucleation at a constant number of particles interacting via the Lennard-Jones potential for the cases of both isothermal and nonisothermal nucleation in a wide range of vapor supersaturations. A special simulation approach is used, in which clusters that have reached a certain size are removed from the system, while particles composing them are returned as monomers. The temperature distribution over cluster sizes is determined. It is found that the temperature somewhat decreases beginning from its value corresponding to monomers; however, as the cluster size approaches a critical value, it returns to its initial level and, then, rapidly increases. The temperature distribution over cluster sizes governs the distribution of their number densities and controls vapor nonideality, thus significantly affecting the nucleation rate. It is shown that the knowledge of the cluster temperature is of critical importance for analytical models, as it enables one to accurately determine the vapor supersaturation and the actual nonisothermal nucleation rate. The nucleation rates and critical cluster sizes determined for the isothermal and nonisothermal cases have shown satisfactory agreement with a theoretical model predicting a decrease in the nucleation rate under the nonisothermal conditions.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"87 4","pages":"537 - 546"},"PeriodicalIF":1.1,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853625","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":"A Study of Electroconvection during Uniform Flow of an Electrolyte Solution through an Ion-Selective Region","authors":"G. S. Ganchenko,&nbsp;V. S. Shelistov,&nbsp;I. I. Olberg,&nbsp;I. V. Morshneva,&nbsp;E. A. Demekhin","doi":"10.1134/S1061933X25600551","DOIUrl":"10.1134/S1061933X25600551","url":null,"abstract":"<p>This paper presents the results of theoretical studying electroconvection emergence and development near an ion-selective region during uniform flow of an electrolyte solution through this region. The analysis of the linear stability of the stationary solution of the problem has made it possible to determine the critical electric potential difference that causes the electrokinetic instability as a function of the external flow velocity. The two-dimensional numerical simulation has revealed the peculiarities of the nonlinear electroconvection regimes. The research has shown the stabilizing effect of the external flow: the electroconvection begins at higher potential differences, whereas its regimes change each other faster with increasing potential difference. Understanding of these effects is useful for practical applications, such as the development of systems for analyte preconcentration in microlaboratories before the chemical analysis of biological liquids.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"87 4","pages":"454 - 461"},"PeriodicalIF":1.1,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853624","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":"Simulating the Influence of Convective Flows through an Ion-Selective Region on Electric Current Regimes in Binary Electrolyte Solutions","authors":"G. S. Ganchenko,&nbsp;V. S. Shelistov,&nbsp;I. I. Olberg,&nbsp;I. V. Morshneva,&nbsp;E. A. Demekhin","doi":"10.1134/S1061933X2560040X","DOIUrl":"10.1134/S1061933X2560040X","url":null,"abstract":"<p>The paper presents the results of the numerical simulation performed in a unidimensional formulation for a cell containing an ion-selective region. The employed mathematical model takes into account the nonideal selectivity of the ion-exchange region and the presence of a convective electrolyte solution flow through it. The flow has been found to influence the selectivity of the ion-exchange region. The electric current through the system may be both enhanced and diminished depending on a realized current regime, namely, underlimiting or limiting. The understanding of this effect will be useful for practical applications, such as analyte preconcentration systems in microlaboratories for chemical analysis of biological liquids and electrobaromembrane separation systems.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"87 4","pages":"447 - 453"},"PeriodicalIF":1.1,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853621","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":"Electrophoresis of Conducting and Nonconducting Microparticles in a Polar Electrolyte under a Strong Electric Field","authors":"E. A. Frants,&nbsp;A. A. Krylov,&nbsp;E. A. Demekhin","doi":"10.1134/S1061933X25600162","DOIUrl":"10.1134/S1061933X25600162","url":null,"abstract":"<p>This work is devoted to studying electrophoresis of conducting and nonconducting particles in a polar electrolyte solution under the action of a strong electric field. Numerical simulation results are presented for both types of particles, including distributions of cation and anion concentrations, charge densities, and total concentrations and fluxes of ions near the particle surface. It is shown that an extended spatial charge region arises near a dielectric surface at a sufficiently high surface charge. This region is formed due to a high surface conductivity in the electrical double layer and intense tangential ion fluxes. Qualitative differences are revealed between the the mechanisms of extended spatial charge formation for ion-selective and dielectric particles. The results obtained facilitate understanding the nonlinear electrokinetic processes and can be useful for designing microliquidic systems and colloidal technologies.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"87 4","pages":"593 - 605"},"PeriodicalIF":1.1,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853623","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":"The Effect of a Permeable Membrane on the Crystallization of a Simple Liquid","authors":"Yu. D. Fomin,&nbsp;E. N. Tsiok,&nbsp;V. N. Ryzhov","doi":"10.1134/S1061933X25600538","DOIUrl":"10.1134/S1061933X25600538","url":null,"abstract":"<p>The article discusses the deposition of a gas onto a crystalline substrate in the presence of a permeable membrane between the substrate and the gas. The membrane repels gas particles; however, the repulsive potential has a finite maximum force, thus allowing gas particles to penetrate through this membrane when their velocity exceeds a certain value. It is shown that, depending on the maximum repulsive force of the membrane (repulsion intensity), the system acquires absolutely different final states: a single crystal, polycrystals with different degrees of porosity, or no crystallization occurs in the system at all.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"87 4","pages":"584 - 592"},"PeriodicalIF":1.1,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853586","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":"Extension of the Inverse “Dry” Micelle Model to Disc-Shaped Aggregates","authors":"Yu. A. Eroshkin,&nbsp;L. Ts. Adzhemyan,&nbsp;A. K. Shchekin","doi":"10.1134/S1061933X25600356","DOIUrl":"10.1134/S1061933X25600356","url":null,"abstract":"<p>A molecular thermodynamic model has been considered for the formation and growth of nonionic aggregates of surfactant molecules in a nonpolar solvent in the absence of water. The model implies fluctuating coexistence of micelles having different shapes without activation barriers between them. The work of micelle aggregation has been derived for a <span>({{{text{C}}}_{{{text{12}}}}}{{{text{E}}}_{{text{4}}}})</span> solution in heptane using molecular dynamics data. In the considered model, it is assumed that, for any aggregation numbers, the minimal aggregation work depends not only on the aggregation numbers and surfactant monomer concentration, but also on two independent shape parameters characterizing the deviation from the spherical shape of an aggregate. This approach provides a unified description for both disc-shaped and cylindrical micelles.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"87 4","pages":"492 - 504"},"PeriodicalIF":1.1,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853620","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":"Atomistic Simulation of Thermoinduced Structural Transformations in Four-Component Cu–Au–Pt–Pd Nanoalloys with Different Morphologies","authors":"N. Yu. Sdobnyakov,&nbsp;V. M. Samsonov,&nbsp;S. V. Serov,&nbsp;N. I. Nepsha,&nbsp;D. N. Sokolov,&nbsp;K. G. Savina,&nbsp;S. A. Veresov,&nbsp;A. Yu. Kolosov","doi":"10.1134/S1061933X25600526","DOIUrl":"10.1134/S1061933X25600526","url":null,"abstract":"<p>The article presents the results of the molecular dynamics simulation performed for thermoinduced structural transformations in four-component Cu–Au–Pt–Pd nanoalloys using the tight-binding potential. The following configurations have been chosen as initial ones: a core–shell (Cu₂₀₀–Au₆₀₀–Pt₈₀₀)@Pd₂₄₀₀ system, in which the core is a multicomponent alloy with uniformly distributed components; an onion-like Cu₂₀₀@Au₆₀₀@Pt₈₀₀@Pd₂₄₀₀ structure, a Cu₂₀₀–Au₆₀₀–Pt₈₀₀–Pd₂₄₀₀ alloy with a uniform distribution of the components, and Janus structures with asymmetric (Cu₂₀₀/Au₆₀₀/Pt₈₀₀/Pd₂₄₀₀) and symmetric (Cu₁₀₀/Au₃₀₀/Pt₄₀₀/Pd₂₄₀₀/Pt₄₀₀/Au₃₀₀/Cu₁₀₀ and Pd₁₂₀₀/Pt₄₀₀/Au₃₀₀/Cu₂₀₀/Au₃₀₀/Pt₄₀₀/Pd₁₂₀₀) distributions of the components. The analysis of the temperature dependences of the potential component of the internal energy has been employed to determine the temperatures corresponding to the onset of the melting–crystallization phase transition and to estimate the value of the temperature hysteresis. The regularities have been found for variations in these values as depending on the thermal action rate. The regularities of the structure formation have been analyzed, the dominating role of the local fcc environment has been revealed, and the cases of the formation of other crystalline structures (hcp and bcc) have been observed. The regularities of chemical segregation have been described confirming that different scenarios of the segregation behavior of the components may take place. An original technique has been used to estimate the specific surface energy for multicomponent metal nanoparticles (final configurations resulting from a cycle of a thermal action including the melting–crystallization phase transitions). The values of the specific surface energy correlate with the stability of the final configurations corresponding to different initial configurations.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"87 4","pages":"560 - 571"},"PeriodicalIF":1.1,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853622","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":"Transformation of Aqueous Methyl Methacrylate Solution into Stable Monodisperse Latex via Polymerization Initiated by Hydroquinone–Potassium Persulfate System","authors":"A. A. Hovhannisyan,&nbsp;G. K. Grigoryan,&nbsp;A. G. Nadaryan,&nbsp;N. H. Grigoryan","doi":"10.1134/S1061933X25600332","DOIUrl":"10.1134/S1061933X25600332","url":null,"abstract":"<p>The goal of this work is to determine the possibilities to synthesize stable latex with a narrow particle size distribution by homogeneous polymerization of methyl methacrylate in an aqueous solution. For the first time, methyl methacrylate is polymerized under static conditions in an aqueous solution of a hydroquinone–potassium persulfate redox system. It is assumed that semiquinone radical anions formed at the intermediate stage of hydroquinone oxidation can participate in the termination of growing radicals and affect the process of formation of latex particles by changing parameters of polymer molecules. The article presents the results of studying the colloidal parameters of the obtained latex, which show that the selected polymerization conditions make it possible to reproducibly synthesize monodisperse stable latexes.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"87 3","pages":"379 - 383"},"PeriodicalIF":1.1,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145144939","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 Interfacial Processes between Oil and Well Stimulation Fluids under Different Contact Conditions","authors":"T. I. Yunusov,&nbsp;L. F. Davletshina","doi":"10.1134/S1061933X25600216","DOIUrl":"10.1134/S1061933X25600216","url":null,"abstract":"<p>One of the practical problems in the oil and gas industry is the formation of oil–acid emulsions and asphaltene sludge when well stimulation fluids come in contact with oil. The key to solving these problems lies in understanding the processes occurring at the interfaces between oil and these agents, with these processes being qualitatively studied in this work. This research investigates the processes occurring between sensitive oil and two types of well stimulation fluids based on hydrochloric acid and ethylenediaminetetraacetic acid (EDTA) in the presence and absence of a surfactant. Three following methods have been employed: simple mixing (“bottle-test”), simultaneous flow of fluids in a capillary, and simultaneous flow of fluids in a micromodel simulating a porous medium. Using the simple mixing method, it has been shown that the addition of the surfactant to a 15% hydrochloric acid solution can prevent sludge formation but does not hinder emulsion formation. Additionally, it has been found that EDTA-based fluids with neutral pH values are compatible even with sensitive oil. Experiments on the simultaneous flow have shown the role of capillary walls in creating sludge and the cleaning ability of the chelating agent. The simultaneous flow in the micromodel has revealed the distinctive features of hydrochloric acid as compared with the chelate, i.e., the discrete flow, emulsion formation in the near-wall layer, and precipitate formation on pore walls. The results of this study may be useful both for further fundamental studying interfacial processes in oil reservoirs and for practical applications.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"87 3","pages":"396 - 407"},"PeriodicalIF":1.1,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145144941","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}