Pub Date : 2024-09-05DOI: 10.1134/s1061933x24600489
N. B. Shestopalova, Yu. A. Fomina
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.
{"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":"https://doi.org/10.1134/s1061933x24600489","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><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":null,"pages":null},"PeriodicalIF":1.1,"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}
Pub Date : 2024-09-05DOI: 10.1134/s1061933x24600374
A. I. Nikiforov, E. O. Lazareva, E. V. Edemskaya, V. G. Semenov, K. G. Gareev, D. V. Korolev
Abstract
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.
{"title":"Microfluidic Synthesis of Magnetite Nanoparticles and its Comparison with Synthesis in a Batch Reactor","authors":"A. I. Nikiforov, E. O. Lazareva, E. V. Edemskaya, V. G. Semenov, K. G. Gareev, D. V. Korolev","doi":"10.1134/s1061933x24600374","DOIUrl":"https://doi.org/10.1134/s1061933x24600374","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><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":null,"pages":null},"PeriodicalIF":1.1,"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}
Pub Date : 2024-07-15DOI: 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
Abstract
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.
摘要 研究了用达夫法合成的超小金纳米粒子（GNPs）对 DNA 液晶分散体（LCDs）颗粒内部结构的破坏作用和稳定作用之间的相互联系，这取决于它们的有序化程度。结果表明，颗粒有序结构的 "稳定 "实际上是其 "破坏 "的结果。一种或另一种效应的主导地位取决于液晶分散体颗粒内相邻 DNA 分子之间的距离（由渗透条件决定），以及 GNPs 进入这些颗粒的效率。
{"title":"Interaction of Ultrasmall Gold Nanoparticles with Liquid-Crystalline DNA Microparticles: Destruction vs Stabilization","authors":"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","doi":"10.1134/s1061933x24600234","DOIUrl":"https://doi.org/10.1134/s1061933x24600234","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><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":null,"pages":null},"PeriodicalIF":1.1,"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}
Pub Date : 2024-07-15DOI: 10.1134/s1061933x24600179
I. S. Stepanov, L. I. Budaeva, S. V. Stepanov
Abstract
Ice melting front thickness has been estimated by studying the kinetics of thawed water accumulation during melting of ice balls with different sizes at room temperature (≈22°C) taking into account the temperature measured both on the surface and inside of the balls. The supplied heat flux is absorbed as the latent heat of fusion by an ice layer, which we define as the melting front. A model of this process has been formulated to describe the kinetics of ice ball melting. It has been assumed that the heat is supplied through the entire ice ball surface, the area of which decreases in the course of melting. The temperatures measured on the surface and inside of the balls have turned out to be ~0.4 and 0°С, respectively. Corrections associated with water evaporation have been taken into account. The fit of the experimental data according to the proposed model has made it possible to estimate the thickness of the ice melting front at room temperature. It has appeared to be approximately 3.2–3.6 mm.
{"title":"Estimation of the Thickness of Ice Melting Front by Studying the Kinetics of Ice Ball Melting in Air","authors":"I. S. Stepanov, L. I. Budaeva, S. V. Stepanov","doi":"10.1134/s1061933x24600179","DOIUrl":"https://doi.org/10.1134/s1061933x24600179","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Ice melting front thickness has been estimated by studying the kinetics of thawed water accumulation during melting of ice balls with different sizes at room temperature (≈22°C) taking into account the temperature measured both on the surface and inside of the balls. The supplied heat flux is absorbed as the latent heat of fusion by an ice layer, which we define as the melting front. A model of this process has been formulated to describe the kinetics of ice ball melting. It has been assumed that the heat is supplied through the entire ice ball surface, the area of which decreases in the course of melting. The temperatures measured on the surface and inside of the balls have turned out to be ~0.4 and 0°С, respectively. Corrections associated with water evaporation have been taken into account. The fit of the experimental data according to the proposed model has made it possible to estimate the thickness of the ice melting front at room temperature. It has appeared to be approximately 3.2–3.6 mm.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141718622","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}
Pub Date : 2024-07-15DOI: 10.1134/s1061933x24600076
V. A. Lomovskoy, S. A. Shatokhina, I. D. Simonov-Emel’yanov
Abstract
A theoretical analysis has been performed for experimental data on internal friction spectra and temperature–frequency dependences obtained by the method of free damped torsional oscillations for diverse liquid hardeners (TETA, PEPA, and MTHPA) of epoxy oligomers. The main phenomenological model representations have been considered and employed to analyze various physicomechanical and physicochemical characteristics of local dissipative processes, which may have different mechanisms of internal friction (hysteresis-, phase-, and relaxation-type).
{"title":"Phenomenological Description of the “Structure–Property” Relation for Epoxy Oligomer Hardeners on the Basis of Internal Friction Spectra","authors":"V. A. Lomovskoy, S. A. Shatokhina, I. D. Simonov-Emel’yanov","doi":"10.1134/s1061933x24600076","DOIUrl":"https://doi.org/10.1134/s1061933x24600076","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>A theoretical analysis has been performed for experimental data on internal friction spectra and temperature–frequency dependences obtained by the method of free damped torsional oscillations for diverse liquid hardeners (TETA, PEPA, and MTHPA) of epoxy oligomers. The main phenomenological model representations have been considered and employed to analyze various physicomechanical and physicochemical characteristics of local dissipative processes, which may have different mechanisms of internal friction (hysteresis-, phase-, and relaxation-type).</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141718620","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}
Pub Date : 2024-07-15DOI: 10.1134/s1061933x24600167
M. A. Kryuchkova, I. R. Ishmukhametov, Y. A. Frank, A. V. Simakova, V. V. Yartsev, D. A. Nadueva, A. A. Varenitsina, Y. V. Andreeva, R. F. Fakhrullin
Abstract
Using dark-field hyperspectral microscopy, we analyzed the distribution of fluorescently-labelled polystyrene microspheres with a size of 2 μm in mosquito larvae and observed the quenching of fluorescence and changes in spectral properties due to histological processing. We propose enhanced dark-field microscopy coupled with hyperspectral imaging as a versatile method for analysing polymer colloids (microplastics) biodistribution in complex tissues.
{"title":"Fluorescence-Free Tracking of Polystyrene Microplastics in Mosquito Larvae Using Dark-Field Hyperspectral Microscopy","authors":"M. A. Kryuchkova, I. R. Ishmukhametov, Y. A. Frank, A. V. Simakova, V. V. Yartsev, D. A. Nadueva, A. A. Varenitsina, Y. V. Andreeva, R. F. Fakhrullin","doi":"10.1134/s1061933x24600167","DOIUrl":"https://doi.org/10.1134/s1061933x24600167","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Using dark-field hyperspectral microscopy, we analyzed the distribution of fluorescently-labelled polystyrene microspheres with a size of 2 μm in mosquito larvae and observed the quenching of fluorescence and changes in spectral properties due to histological processing. We propose enhanced dark-field microscopy coupled with hyperspectral imaging as a versatile method for analysing polymer colloids (microplastics) biodistribution in complex tissues.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141718623","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}
Pub Date : 2024-07-15DOI: 10.1134/s1061933x24600246
A. Yu. Zubarev, L. Yu. Iskakova, A. Yu. Musikhin
Abstract
The magnetization reversal kinetics has been theoretically considered for a nanosized ferromagnetic particle in a soft viscoelastic medium. In contrast to well-known works, we have considered the simultaneous action of the Néel mechanism of magnetization reversal of a particle (overcoming the potential barrier of magnetic anisotropy by its magnetic moment), and rotation (turn) of the particle body as a result of a change in the external magnetic field. The case of a high magnetic anisotropy of the particle is considered, i.e., it has been assumed that its energy significantly exceeds the thermal energy of the system and the energy of the interaction between the particle and the magnetic field. No other limitations have been imposed on field strength. The case of low fields has been considered in greater detail in the linear approximation of the dependence of magnetization on the field. The components of the complex susceptibility of the composite are calculated within the framework of this approximation. It has been shown that the real component of the susceptibility decreases monotonically with the field frequency. If the stiffness of the composite is high or low, the imaginary component has one maximum, which corresponds to the Néel mechanism of magnetization reversal or particle rotation in a viscoelastic medium, respectively. At intermediate values of composite stiffness, the frequency dependence of the imaginary susceptibility has two maxima.
{"title":"On the Theory of Dynamic Susceptibility of Soft Magnetic Colloids","authors":"A. Yu. Zubarev, L. Yu. Iskakova, A. Yu. Musikhin","doi":"10.1134/s1061933x24600246","DOIUrl":"https://doi.org/10.1134/s1061933x24600246","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The magnetization reversal kinetics has been theoretically considered for a nanosized ferromagnetic particle in a soft viscoelastic medium. In contrast to well-known works, we have considered the simultaneous action of the Néel mechanism of magnetization reversal of a particle (overcoming the potential barrier of magnetic anisotropy by its magnetic moment), and rotation (turn) of the particle body as a result of a change in the external magnetic field. The case of a high magnetic anisotropy of the particle is considered, i.e., it has been assumed that its energy significantly exceeds the thermal energy of the system and the energy of the interaction between the particle and the magnetic field. No other limitations have been imposed on field strength. The case of low fields has been considered in greater detail in the linear approximation of the dependence of magnetization on the field. The components of the complex susceptibility of the composite are calculated within the framework of this approximation. It has been shown that the real component of the susceptibility decreases monotonically with the field frequency. If the stiffness of the composite is high or low, the imaginary component has one maximum, which corresponds to the Néel mechanism of magnetization reversal or particle rotation in a viscoelastic medium, respectively. At intermediate values of composite stiffness, the frequency dependence of the imaginary susceptibility has two maxima.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141718675","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}
Pub Date : 2024-07-15DOI: 10.1134/s1061933x2460012x
Haoyu Li, Ruojun Ye, Xingping Zhou
Abstract
This paper reports on the successful preparation of a series of ZnO–Ag2O nanocomposite crystals with varying elemental contents by a novel oil−water interface method. The structures, compositions, microscopic morphologies, and optical properties of these crystals were characterized using HRTEM, SEM, XRD, EDX, XPS, UV-Vis, and PL measurements. The obtained well-dispersed hetero-structure nanocomposite crystals, with a particle size mainly ranged from 50 to 100 nm and a high purity, displayed a good absorption ability in the visible region. Virtually, the nanocomposite crystals exhibited a significant red-shift 5–15 nm in the UV diffuse absorption edge towards the visible range, accompanied by a substantial reduction in fluorescence absorption intensity. Importantly, the photocatalytic degradation of these nanocomposites was tested against Congo red (CR) dye under visible light excitation. The results revealed that the degradation efficiencies of ZnO–Ag2O nanocomposite crystals against CR under visible light were 9.4 and 2.7 times as high as those of pure ZnO and Ag2O nanoparticles, respectively. Also, the antimicrobial function of ZnO–Ag2O nanocomposite crystals was tested against harmful bacteria. The study results indicated that the diameters of inhibition zone of the nanocomposite crystals were respectively 13.5 mm for Gram-negative Escherichia coli and 12.9 mm for Gram-positive Bacillus subtilis, significantly larger than that of pure ZnO due to the synergistic effects of ZnO and Ag2O nanoparticles. The high photocatalytic efficiency and strong antimicrobial activity of ZnO–Ag2O nanocomposite crystals suggest their great significance in degrading pollutants and killing harmful bacteria.
{"title":"Novel Synthesis of ZnO–Ag2O Nanocomposite Crystals and Their Photocatalytic and Antibacterial Activity Evaluation","authors":"Haoyu Li, Ruojun Ye, Xingping Zhou","doi":"10.1134/s1061933x2460012x","DOIUrl":"https://doi.org/10.1134/s1061933x2460012x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper reports on the successful preparation of a series of ZnO–Ag<sub>2</sub>O nanocomposite crystals with varying elemental contents by a novel oil−water interface method. The structures, compositions, microscopic morphologies, and optical properties of these crystals were characterized using HRTEM, SEM, XRD, EDX, XPS, UV-Vis, and PL measurements. The obtained well-dispersed hetero-structure nanocomposite crystals, with a particle size mainly ranged from 50 to 100 nm and a high purity, displayed a good absorption ability in the visible region. Virtually, the nanocomposite crystals exhibited a significant red-shift 5–15 nm in the UV diffuse absorption edge towards the visible range, accompanied by a substantial reduction in fluorescence absorption intensity. Importantly, the photocatalytic degradation of these nanocomposites was tested against Congo red (CR) dye under visible light excitation. The results revealed that the degradation efficiencies of ZnO–Ag<sub>2</sub>O nanocomposite crystals against CR under visible light were 9.4 and 2.7 times as high as those of pure ZnO and Ag<sub>2</sub>O nanoparticles, respectively. Also, the antimicrobial function of ZnO–Ag<sub>2</sub>O nanocomposite crystals was tested against harmful bacteria. The study results indicated that the diameters of inhibition zone of the nanocomposite crystals were respectively 13.5 mm for Gram-negative <i>Escherichia coli</i> and 12.9 mm for Gram-positive <i>Bacillus subtilis</i>, significantly larger than that of pure ZnO due to the synergistic effects of ZnO and Ag<sub>2</sub>O nanoparticles. The high photocatalytic efficiency and strong antimicrobial activity of ZnO–Ag<sub>2</sub>O nanocomposite crystals suggest their great significance in degrading pollutants and killing harmful bacteria.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141718624","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}
Pub Date : 2024-07-15DOI: 10.1134/s1061933x24700200
G. M. Mirgaleev, S. V. Shilova
Abstract
Polyelectrolyte complexes of chitosan (ChTS) with κ-carrageenan (CARR) have been obtained and characterized as potential adsorbents of fluorescein (FLC) nanomarker in aqueous media at different pH values. The binding of FLC to ChTS and the κ-CARR–ChTS complex has been studied by spectroscopic methods. The efficiency and mechanism of fluorone dye adsorption on the synthesized complexes have been investigated by analyzing equilibrium adsorption isotherms. The isotherm of FLC adsorption on particles of the polyelectrolyte complex has been adequately described within the framework of the Freundlich model. Data on fluorescence quenching have been used to determine the effective Stern–Volmer constants of FLC with ChTS and the κ-CARR–ChTS complex and to show that the nanomarker is bound to biopolymers via different interaction mechanisms.
{"title":"Fluorescein Binding with Chitosan and a Chitosan-Based Polyelectrolyte Complex in Aqueous Solutions","authors":"G. M. Mirgaleev, S. V. Shilova","doi":"10.1134/s1061933x24700200","DOIUrl":"https://doi.org/10.1134/s1061933x24700200","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Polyelectrolyte complexes of chitosan (ChTS) with κ-carrageenan (CARR) have been obtained and characterized as potential adsorbents of fluorescein (FLC) nanomarker in aqueous media at different pH values. The binding of FLC to ChTS and the κ-CARR–ChTS complex has been studied by spectroscopic methods. The efficiency and mechanism of fluorone dye adsorption on the synthesized complexes have been investigated by analyzing equilibrium adsorption isotherms. The isotherm of FLC adsorption on particles of the polyelectrolyte complex has been adequately described within the framework of the Freundlich model. Data on fluorescence quenching have been used to determine the effective Stern–Volmer constants of FLC with ChTS and the κ-CARR–ChTS complex and to show that the nanomarker is bound to biopolymers via different interaction mechanisms.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141718621","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}
Pub Date : 2024-05-30DOI: 10.1134/s1061933x24600180
K. A. Emelyanenko, A. M. Emelyanenko, L. B. Boinovich
Abstract
Despite the significant interest of researchers, icing of aircraft, vehicles, ships, and equipment of offshore oil structures remains to be an urgent problem. This paper considers the factors that promote a decrease in the strength of the contact between ice and surfaces under an applied shear load. The main attention is focused on studying the influence of the rate of shear loading on the fracture of the interfacial contact between ice and superhydrophobic coatings. The strength of the adhesive contact under the conditions of controlled variations in the applied load is measured using a technique based on the detachment of ice from a surface under the influence of centrifugal force. The study is carried out for large ensembles of samples in the temperature range from −5 to −20°C, thereby making it possible to evaluate the influence of the quasi-liquid layer and the Rehbinder effect on a decrease in the shear adhesive strength. The results obtained indicate that the contact between ice and a superhydrophobic coating is fractured through a mixed viscous–brittle mechanism. In this case, a decrease in temperature or an increase in the loading rate causes a transition from the viscous to the brittle fracture. These results indicate a potential acceleration of ice shedding with an increase in the growth rate of the shear stress.
{"title":"Effect of Shear Loading Conditions on the Measured Strength of Ice Adhesion to Superhydrophobic Surfaces","authors":"K. A. Emelyanenko, A. M. Emelyanenko, L. B. Boinovich","doi":"10.1134/s1061933x24600180","DOIUrl":"https://doi.org/10.1134/s1061933x24600180","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Despite the significant interest of researchers, icing of aircraft, vehicles, ships, and equipment of offshore oil structures remains to be an urgent problem. This paper considers the factors that promote a decrease in the strength of the contact between ice and surfaces under an applied shear load. The main attention is focused on studying the influence of the rate of shear loading on the fracture of the interfacial contact between ice and superhydrophobic coatings. The strength of the adhesive contact under the conditions of controlled variations in the applied load is measured using a technique based on the detachment of ice from a surface under the influence of centrifugal force. The study is carried out for large ensembles of samples in the temperature range from −5 to −20°C, thereby making it possible to evaluate the influence of the quasi-liquid layer and the Rehbinder effect on a decrease in the shear adhesive strength. The results obtained indicate that the contact between ice and a superhydrophobic coating is fractured through a mixed viscous–brittle mechanism. In this case, a decrease in temperature or an increase in the loading rate causes a transition from the viscous to the brittle fracture. These results indicate a potential acceleration of ice shedding with an increase in the growth rate of the shear stress.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141198006","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}
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