Colloid Journal最新文献_第6页

Preparation of Nanoabrasive for Magnetorheological Polishing of KDP Crystals 制备用于 KDP 晶体磁流变抛光的纳米研磨剂

IF 1.4 4区化学

Colloid Journal Pub Date : 2024-09-05 DOI: 10.1134/S1061933X24600477

D. V. Belov, S. N. Belyaev, O. A. Malshakova, N. A. Sorokoletova, E. I. Serebrov

{"title":"Preparation of Nanoabrasive for Magnetorheological Polishing of KDP Crystals","authors":"D. V. Belov, S. N. Belyaev, O. A. Malshakova, N. A. Sorokoletova, E. I. Serebrov","doi":"10.1134/S1061933X24600477","DOIUrl":"10.1134/S1061933X24600477","url":null,"abstract":"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.","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}

引用次数: 0

Adsorption Properties of Individual Gold, Nickel, and Platinum Nanoparticles Deposited onto Silicon Surface 沉积在硅表面的单个金、镍和铂纳米颗粒的吸附特性

IF 1.4 4区化学

Colloid Journal Pub Date : 2024-09-05 DOI: 10.1134/S1061933X24600507

A. K. Gatin, S. A. Ozerin, P. K. Ignat’eva, V. A. Kharitonov, S. Yu. Sarvadii, M. V. Grishin

{"title":"Adsorption Properties of Individual Gold, Nickel, and Platinum Nanoparticles Deposited onto Silicon Surface","authors":"A. K. Gatin, S. A. Ozerin, P. K. Ignat’eva, V. A. Kharitonov, S. Yu. Sarvadii, M. V. Grishin","doi":"10.1134/S1061933X24600507","DOIUrl":"10.1134/S1061933X24600507","url":null,"abstract":"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.","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}

引用次数: 0

Magnetic Fluids Stabilized with Double Layers of Surfactants in Water Reject the Known Models of Rheology and Dipole–Dipole Interaction 水中双层表面活性剂稳定的磁性流体拒绝流变学和偶极-偶极相互作用的已知模型

IF 1.4 4区化学

Colloid Journal Pub Date : 2024-09-05 DOI: 10.1134/S1061933X24600362

A. V. Lebedev

{"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":"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.","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}

引用次数: 0

Pd(Acac)2–Chiral Stabilizer–H2 Colloidal System in the Enantioselective Hydrogenation of N-Acetyl-α-Amidocinnamic Acid Pd(Acac)2 手性稳定剂-H2 胶体系统在 N-乙酰基-α-脒基肉桂酸对映体选择性加氢反应中的应用

IF 1.4 4区化学

Colloid Journal Pub Date : 2024-09-05 DOI: 10.1134/S1061933X24600532

L. O. Nindakova, V. O. Strakhov, N. M. Badyrova

{"title":"Pd(Acac)2–Chiral Stabilizer–H2 Colloidal System in the Enantioselective Hydrogenation of N-Acetyl-α-Amidocinnamic Acid","authors":"L. O. Nindakova, V. O. Strakhov, N. M. Badyrova","doi":"10.1134/S1061933X24600532","DOIUrl":"10.1134/S1061933X24600532","url":null,"abstract":"It has been shown that the Pd(Acac)2–mod–H2 colloidal system, where mod denotes chiral stabilizers of molecular (8S,9R)-cinhonidine, (–)-Сin, and ionic (–)-Cin*HCl and (–)-Cin*2HCl types, exhibits catalytic activity in the asymmetric hydrogenation of N-acetyl-α-amidocinnamic acid (AACA) at room temperature and an H2 pressure of 5 atm. The esterification reaction of the product, N-acetylphenylalanine (N-APhA), occurs in the presence of protonated forms of cinchonidine. The excess of the R-(–)-enantiomer of N-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.","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}

引用次数: 0

Spectrophotometric Determination of the Critical Micelle Concentrations of Polyoxyethylated Alkylphenols in Aqueous Solutions 分光光度法测定水溶液中聚氧乙基烷基酚的临界胶束浓度

IF 1.4 4区化学

Colloid Journal Pub Date : 2024-09-05 DOI: 10.1134/S1061933X24600489

N. B. Shestopalova, Yu. A. Fomina

{"title":"Spectrophotometric Determination of the Critical Micelle Concentrations of Polyoxyethylated Alkylphenols in Aqueous Solutions","authors":"N. B. Shestopalova, Yu. A. Fomina","doi":"10.1134/S1061933X24600489","DOIUrl":"10.1134/S1061933X24600489","url":null,"abstract":"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.","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}

引用次数: 0

Microfluidic Synthesis of Magnetite Nanoparticles and its Comparison with Synthesis in a Batch Reactor 磁铁矿纳米粒子的微流控合成及其与间歇反应器合成的比较

IF 1.4 4区化学

Colloid Journal Pub Date : 2024-09-05 DOI: 10.1134/S1061933X24600374

A. I. Nikiforov, E. O. Lazareva, E. V. Edemskaya, V. G. Semenov, K. G. Gareev, D. V. Korolev

引用次数: 0

Interaction of Ultrasmall Gold Nanoparticles with Liquid-Crystalline DNA Microparticles: Destruction vs Stabilization 超小型金纳米颗粒与液晶 DNA 微颗粒的相互作用：破坏与稳定

IF 1.4 4区化学

Colloid Journal Pub Date : 2024-07-15 DOI: 10.1134/S1061933X24600234

M. A. Kolyvanova, M. A. Klimovich, E. M. Shishmakova, A. A. Markova, O. V. Dement’eva, V. M. Rudoy, V. A. Kuz’min, V. N. Morozov

引用次数: 0

Estimation of the Thickness of Ice Melting Front by Studying the Kinetics of Ice Ball Melting in Air 通过研究冰球在空气中融化的动力学估计冰融化前沿的厚度