Colloid Journal最新文献

{"title":"Changes in the Physicochemical and Sorption Properties of Bleaching Clay in the Course of Thermal Treatment","authors":"S. V. Sverguzova,&nbsp;R. R. Gafarov,&nbsp;O. S. Zubkova,&nbsp;Zh. A. Sapronova,&nbsp;I. G. Shaikhiev","doi":"10.1134/S1061933X24600490","DOIUrl":"10.1134/S1061933X24600490","url":null,"abstract":"<p>The work is devoted to studying changes in the physicochemical and colloid–sorption properties of bleaching clay thermotreated after its use in the process of refining vegetable oil. Bleaching clay thermotreated at different temperatures has been used for comparison. The colloid–sorption properties have been studied by measuring adsorption of methylene blue dye from aqueous solutions. It has been shown that clay annealed at 350°C adsorbs methylene blue most efficiently. In the saturation region, the adsorption by clay thermotreated at 350°C has amounted to 0.28 mmol/g or 89.6 mg/g, while the adsorption by clay annealed at 250°C has appeared to be 0.24 mmol/g or 76.8 mg/g. When the annealing temperature is elevated above 500°C, the adsorption properties of the bleaching clay waste decrease, probably, due to the combustion of the carbon layer. Using bleaching clay waste from the Alekseevsky oil extraction plant as an example, it has been revealed that, during the thermal treatment of the material, various types of water (free, interpackage, and chemically bound one) are removed, thus leading to changes in the colloid–sorption properties, such as particle surface relief, specific surface area, sorption capacity, and ζ potential.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"86 4","pages":"571 - 579"},"PeriodicalIF":1.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210296","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":"Structuring of Nonionic Pluronic P123 Block Copolymer at Different Temperatures","authors":"A. S. Zavalyueva,&nbsp;S. I. Karpov,&nbsp;A. N. Dubovitskaya,&nbsp;M. G. Holyavka,&nbsp;V. F. Selemenev","doi":"10.1134/S1061933X24700212","DOIUrl":"10.1134/S1061933X24700212","url":null,"abstract":"<p>Dynamic light scattering has been employed to investigate aqueous Pluronic P123 solutions at different temperatures and in the presence of different solvents and quercetin additives. Significant changes have been revealed in the average particle size and polydispersity index depending on the conditions. The effect of temperature on micellization of the block copolymer in aqueous solutions has been studied in a range <i>T</i> = 15–45°C, which is most often considered when using P123 in the sol–gel synthesis of silica. The most pronounced effect of temperature on the micellization of the studied surfactant has been observed at <i>T</i> = 15–20°C. In this temperature range, the scattered light intensity distribution over particle sizes has a polymodal character, which indicates the presence of macromolecules, micelles, and their aggregates in the system. A further increase in temperature up to 45°C causes no significant changes in the particle size. In aqueous solutions, micelles with a narrow size distribution (minimum polydispersity index) are formed within temperature ranges of 21–25 and 35–40°C. Substantial effects have been found when adding alkanols and polyphenolic substances as solubilizers capable of influencing the structure of micelles both in their bulk and on the surface of polar moieties of the surfactant. It has been shown that, in the presence of butanol-1, micelles are stabilized at temperatures of 15–20°C. At <i>T</i> &gt; 30°C, the structure of micelles is transformed. As the fraction of butanol-1 in the solution increases, its influence is manifested at lower temperatures. It has been noted that ethanol has a destructive effect on micelles. Additives of quercetin exhibit an opposite effect of micelle stabilization, which leads to the formation of a homogeneous surfactant structure. It has been shown that, by varying solvent composition, the flavonoid–micelle binding can be controlled due to changes in the solvation. The greatest influence of quercetin on the structure formation of P123 has been observed at a solvent composition corresponding to ethanol-to-block copolymer molar ratio of n(EtOH) : n(P123) = 80 : 1.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"86 4","pages":"528 - 537"},"PeriodicalIF":1.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210292","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":"Electroosmotic Flow Modulation through Soft Nanochannel Filled with Power-law Fluid under Impacts of Ion Steric and Ion Partitioning Effects","authors":"Amit Malick,&nbsp; Bhanuman Barman","doi":"10.1134/S1061933X24600222","DOIUrl":"10.1134/S1061933X24600222","url":null,"abstract":"<p>The present article deals with the modulation of electroosmotic flow (EOF) and transport of ionic species within soft nanochannels. The power-law model is adopted to consider the non-Newtonian nature of bulk electrolyte. The soft layer grafted along the rigid walls often bears ionizable functional groups, which in turn leads to the net volumetric charge. Besides, the dielectric permittivity of the soft layer is in general lower than that of the ambient electrolyte solution, which in turn leads to ion partitioning effect. The net volumetric charge within the soft polymeric layer coated along the channel walls may be moderate to large. For such a case, the ion steric effect may play a pivotal role on the modulation of electrostatic potential and thereby the flow field across the channel. In the present article, we aim to study the flow modulation across the soft nanochannels considering all such intrinsic effects. The mathematical model is based on modified Poisson−Boltzmann equations based on Carnahan−Striling model, Cauchy momentum equation for flow field. The governing equations are solved via a suitable numerical scheme based on finite difference method to calculate the electrostatic potential as well as flow velocity. We further analyze the impact of pertinent parameters on the flow modulation and ion selectivity parameter.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"86 4","pages":"610 - 626"},"PeriodicalIF":1.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210276","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":"Preparation of Nanoabrasive for Magnetorheological Polishing of KDP Crystals","authors":"D. V. Belov,&nbsp;S. N. Belyaev,&nbsp;O. A. Malshakova,&nbsp;N. A. Sorokoletova,&nbsp;E. I. Serebrov","doi":"10.1134/S1061933X24600477","DOIUrl":"10.1134/S1061933X24600477","url":null,"abstract":"<p>Magnetorheological polishing technology is widely used in the processing of high-precision optical elements. One of the determining factors in the magnetorheological polishing technology is the nature and quality of a nanoabrasive present in a magnetorheological suspension. In this study, a method has been developed for the sol–gel synthesis of amorphous silica nanospheres used as a nanoabrasive for magnetorheological polishing of water-soluble crystals used to manufacture nonlinear optical elements for laser technology. The practical success has been achieved by incorporating the synthesized silica nanoabrasive into a magnetorheological suspension. The physicochemical characteristics of the resulting nanoabrasive have been presented. Electron microscopy data have confirmed the spherical morphology of SiO₂ particles, and it has been found that the particle size distribution varies in a range of 40–60 nm, thus ensuring the uniformity and high quality of treating the surfaces of optical elements with the magnetorheological suspension. The structure-related properties of the SiO₂ nanoabrasive have been studied by X-ray powder diffraction. The incorporation of the SiO₂ nanoabrasive into the magnetorheological suspension has made it possible to achieve the high-quality processing and cleanliness of the surface, as well as to ensure the finishing polishing of the surface of KDP single crystals to roughness values of no more than 6 Å. The results of the work are of interest for optimizing the process and improving the technology of magnetorheological polishing.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"86 4","pages":"505 - 518"},"PeriodicalIF":1.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210291","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":"Adsorption Properties of Individual Gold, Nickel, and Platinum Nanoparticles Deposited onto Silicon Surface","authors":"A. K. Gatin,&nbsp;S. A. Ozerin,&nbsp;P. K. Ignat’eva,&nbsp;V. A. Kharitonov,&nbsp;S. Yu. Sarvadii,&nbsp;M. V. Grishin","doi":"10.1134/S1061933X24600507","DOIUrl":"10.1134/S1061933X24600507","url":null,"abstract":"<p>Gold, nickel and platinum nanoparticles (NPs) have been synthesized by impregnating single-crystalline silicon surface with precursors (aqueous solutions of corresponding salts). The morphologies of the formed nanostructured coatings have been studied, and the electronic structures of the synthesized NPs, as well as their adsorption properties with respect to H₂, O₂, and H₂O, have been determined. It has been found that oxidized nickel NPs are reduced by molecular hydrogen, while pure platinum NPs are oxidized by molecular oxygen already at room temperature. This phenomenon has not been observed for particles deposited in a similar way onto highly oriented pyrolytic graphite. In addition, it has been revealed that water molecules are formed on gold NPs as a result of the interaction between H₂ and O₂ in two stages, in contrast to the three-stage process (sequential exposure in H₂, O₂, and H₂), which is inherent in NPs deposited onto graphite. Differences in the adsorption properties of NPs of the same type deposited onto graphite and silicon are associated with the adsorption of a significant amount of the test gases on the latter.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"86 4","pages":"519 - 527"},"PeriodicalIF":1.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210293","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":"Magnetic Fluids Stabilized with Double Layers of Surfactants in Water Reject the Known Models of Rheology and Dipole–Dipole Interaction","authors":"A. V. Lebedev","doi":"10.1134/S1061933X24600362","DOIUrl":"10.1134/S1061933X24600362","url":null,"abstract":"<p>Three samples of aqueous magnetic fluids based on magnetite particles stabilized with double layers of surfactants have been synthesized. The samples have been stabilized with lauric and oleic acids, as well as their salts, taken in three different combinations. The viscosity of the synthesized samples has been measured as depending on the concentration, temperature, and shear rate. With increasing temperature, the viscosity of a sample of the fluid stabilized with a double layer of lauric acid does not decrease relative to the viscosity of water, as has been previously observed for classical magnetic fluids, but rather increases. For a sample stabilized with two layers of lauric and oleic acids, the temperature dependence of the relative viscosity is nonmonotonic. The relative viscosity of a sample stabilized with a double layer of oleic acid is actually independent of temperature. To determine the concentrations of the samples, measurements of magnetization curves were carried out followed by their granulometric analysis. It has been found that the dispersity of the samples remains unchanged upon dilution. The initial magnetic susceptibility of the fluid samples has been shown to increase with concentration more slowly than it has been predicted by the modified effective field model. In contrast to the effective field model (and other ones), the coefficient at the quadratic term in the expansion of the initial susceptibility in terms of the Langevin susceptibility has turned out to be significantly lower than 1/3. Thus, new theories of dipole–dipole interparticle interaction must be developed to describe the properties of magnetic fluids stabilized with double layers of surfactants.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"86 4","pages":"538 - 546"},"PeriodicalIF":1.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210294","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":"Pd(Acac)2–Chiral Stabilizer–H2 Colloidal System in the Enantioselective Hydrogenation of N-Acetyl-α-Amidocinnamic Acid","authors":"L. O. Nindakova,&nbsp;V. O. Strakhov,&nbsp;N. M. Badyrova","doi":"10.1134/S1061933X24600532","DOIUrl":"10.1134/S1061933X24600532","url":null,"abstract":"<p>It has been shown that the Pd(Acac)₂–mod–H₂ colloidal system, where mod denotes chiral stabilizers of molecular (8<i>S</i>,9<i>R</i>)-cinhonidine, (–)-Сin, and ionic (–)-Cin*HCl and (–)-Cin*2HCl types, exhibits catalytic activity in the asymmetric hydrogenation of <i>N</i>-acetyl-α-amidocinnamic acid (AACA) at room temperature and an H₂ pressure of 5 atm. The esterification reaction of the product, <i>N</i>-acetylphenylalanine (<i>N</i>-APhA), occurs in the presence of protonated forms of cinchonidine. The excess of the <i>R</i>-(–)-enantiomer of <i>N</i>-acetylphenylalanine is as large as 78% for the Pd(Acac)₂–(–)-Сin–H₂ system at (–)-Сin/Pd = 1.5, while the protonated forms of the quinine alkaloid show lower efficiency as modifiers of the catalytic system with respect to chiral induction. The X-ray diffraction analysis and high-resolution transmission electron microscopy have been employed to show the formation of palladium nanoparticles with average sizes of 5.3 ± 0.8 and 4.2 ± 0.5 nm for the Pd(Acac)₂–(–)-Cin–H₂ and Pd(Acac)₂–(–)-Сin *HCl–H₂ systems, respectively.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"86 4","pages":"559 - 570"},"PeriodicalIF":1.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210354","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":"Spectrophotometric Determination of the Critical Micelle Concentrations of Polyoxyethylated Alkylphenols in Aqueous Solutions","authors":"N. B. Shestopalova,&nbsp;Yu. A. Fomina","doi":"10.1134/S1061933X24600489","DOIUrl":"10.1134/S1061933X24600489","url":null,"abstract":"<p>A spectrophotometric method has been employed to study micellization of nonionic surfactants (NSs), namely, polyoxyethylated alkylphenols, Triton X-100 (TX-100) and Triton X-114 (TX-114), in aqueous solutions. The spectral characteristics have been calculated for the curves of light absorption by surfactant solutions in concentration ranges of 0.02–0.80 and 0.02–0.40 mmol/L for TX-100 and TX-114, respectively. The influence of the steps of scanning along the wavelength scale (0.1, 0.2, 0.5, and 1.0 nm) on the positions of the maxima and the intensities of the absorption has been studied. The optical density has been found to increase monotonically throughout the concentration range. It has been revealed that, at all scanning steps, a bathochromic shift is observed for the absorption maximum of the long-wavelength band (275 nm) by 1.5 and 2.0 nm for TX-114 and TX-100, respectively, at certain NS concentrations. The curve for the dependence of absorption maximum position on NS concentration exhibits a characteristic inflection, whose position depends on the scanning step. A new method has been proposed for the spectrophotometric determination of the critical micelle concentrations (CMCs) of TX-100 and TX-114 from the dependence of the position of the absorption maximum of the long-wavelength band in the electronic absorption spectrum on the surfactant concentration in an aqueous solution. It has been found that a scanning step of 0.1 nm is optimal for the graphical determination of CMC. The CMC values have been determined for TX-100 and TX-114. The obtained values have appeared to be consistent with the literature data and equal to (0.24 ± 0.02) and (0.20 ± 0.01) mmol/L, respectively.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"86 4","pages":"580 - 587"},"PeriodicalIF":1.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210356","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":"Microfluidic Synthesis of Magnetite Nanoparticles and its Comparison with Synthesis in a Batch Reactor","authors":"A. I. Nikiforov,&nbsp;E. O. Lazareva,&nbsp;E. V. Edemskaya,&nbsp;V. G. Semenov,&nbsp;K. G. Gareev,&nbsp;D. V. Korolev","doi":"10.1134/S1061933X24600374","DOIUrl":"10.1134/S1061933X24600374","url":null,"abstract":"<p>This work discusses the synthesis of magnetite nanoparticles using microfluidic method. The main characteristics of the resulting nanoparticles were investigated, including chemical composition, size distribution, saturation mass magnetization, and coercive force. To assess the possibility of using nanoparticles for medical and biological purposes, the hemolytic activity of a suspension of magnetite nanoparticles was studied.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"86 4","pages":"547 - 558"},"PeriodicalIF":1.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210295","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":"Interaction of Ultrasmall Gold Nanoparticles with Liquid-Crystalline DNA Microparticles: Destruction vs Stabilization","authors":"M. A. Kolyvanova,&nbsp;M. A. Klimovich,&nbsp;E. M. Shishmakova,&nbsp;A. A. Markova,&nbsp;O. V. Dement’eva,&nbsp;V. M. Rudoy,&nbsp;V. A. Kuz’min,&nbsp;V. N. Morozov","doi":"10.1134/S1061933X24600234","DOIUrl":"10.1134/S1061933X24600234","url":null,"abstract":"<p>The interconnection between the destructive and stabilizing effects of ultrasmall gold nanoparticles (GNPs) synthesized by the Duff method in relation to the internal structure of the particles of DNA liquid-crystalline dispersions (LCDs), depending on the degree of their ordering, was studied. It is shown that “stabilization” of the particles’ ordered structure is, in fact, a consequence of its “destruction.” The dominance of one or another effect depends in a complex way on the distance between neighboring DNA molecules within the particles of its LCD, determined by osmotic conditions, and the efficiency of penetration of GNPs into these particles.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":"86 3","pages":"396 - 407"},"PeriodicalIF":1.4,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141718619","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}