{"title":"The Influence of Polybutylene Terephthalate Cross-Linking on Infrared Spectra","authors":"A. Abdullin, D. Faizullin, Y. Zuev, I. Sedov","doi":"10.1134/S0036024424702741","DOIUrl":"10.1134/S0036024424702741","url":null,"abstract":"<p>The attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) spectra of the samples of polybutylene terephthalate (PBT) with varying spatial densities of cross-links are obtained. The changes are primarily observed in the fingerprint region. The ratios of the area of the absorption bands 810/794 and 917/935 cm<sup>–1</sup> bands are shown to decrease with increasing degree of cross-linking and can be used to assess it. The changes in infrared absorption are linked to the difference in the bending frequency between the crystalline and amorphous phases of PBT. The latter is more prevalent in the densely cross-linked samples.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":"98 14","pages":"3243 - 3249"},"PeriodicalIF":0.7,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388880","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}
P. O. Sorina, M. A. Zolenko, A. A. Vanin, A. I. Victorov
{"title":"Description of an n-Alkane/Water Phase Boundary in Presence of Polyethylene Glycol Ethers of Fatty Alcohols with the Aid of Coarse-Grained Multilayer Quasi-Chemical Model and Molecular Dynamics","authors":"P. O. Sorina, M. A. Zolenko, A. A. Vanin, A. I. Victorov","doi":"10.1134/S0036024424702959","DOIUrl":"10.1134/S0036024424702959","url":null,"abstract":"<p>Liquid interfaces are modeled for <i>n-</i>alkane + water systems with an without added non-ionic surfactants: polyethylene glycol ethers of fatty alcohols (C<sub><i>n</i></sub>E<sub><i>m</i></sub>). Coarse-grained molecular dynamic (MD) simulation with the MARTINI force field is combined with a coarse-grained version of a multilayer quasi-chemical model (MQM) of a non-uniform fluid mixture. The effect the choice of the monomer’s unit size has on predicting the interfacial tension and mutual solubility of <i>n-</i>alkanes and water is demonstrated using the MQM. The interfacial tension’s dependence on the length of the <i>n-</i>alkane chain and the structure of the added surfactant molecule are predicted satisfactorily. A predicted drop in the interfacial tension upon adsorption of the surfactant is consistent with the MD data. Liquid-liquid phase diagrams are calculated, and the non-uniform of the surfactant between the hydrocarbon and aqueous phases is described, depending on the ratio of the hydrophobic and hydrophilic parts of the C<sub><i>n</i></sub>E<sub><i>m</i></sub> molecule. The coarse-grained MQM is used to obtain normal and tangental pressure profiles and data on the local structure for flat and spherical phase boundaries. A conclusion is reached on the limited applicability of the coarse-grained approach within the MQM.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":"98 14","pages":"3394 - 3403"},"PeriodicalIF":0.7,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388808","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}
Yu. A. Sarmini, S. S. Sologubov, N. N. Smirnova, O. V. Stepanova, A.V. Markin
{"title":"Thermodynamic Properties of Betamethasone Dipropionate","authors":"Yu. A. Sarmini, S. S. Sologubov, N. N. Smirnova, O. V. Stepanova, A.V. Markin","doi":"10.1134/S0036024424702911","DOIUrl":"10.1134/S0036024424702911","url":null,"abstract":"<p>Precision adiabatic vacuum and high-precision differential scanning calorimetry (DSC) are used to study the temperature dependence of the heat capacity of betamethasone dipropionate in the range of 6–520 K for the first time. A phase transition of betamethasone dipropionate (melting) is detected in the above range of temperatures, and its thermodynamic characteristics are calculated. The low temperature heat capacity (20 ≤ <i>T</i> ≤ 50 K) is processed on the basis of a multifractal model, and the chain-layered topology of the structure is established. The thermal stability of the steroid hormone is studied via thermogravimetric analysis (TGA). It is found that the temperature at which the substance begins to decompose is 480 K. The experimental data are used to calculate standard thermodynamic functions in the region <i>T</i> → 0 to 480 K for the crystalline and liquid states of betamethasone dipropionate.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":"98 14","pages":"3372 - 3378"},"PeriodicalIF":0.7,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388781","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":"Thermodynamic Barriers to the Formation of Critical-Sized Crystalline Embryos in Silicate Glasses","authors":"G. A. Sycheva","doi":"10.1134/S0036024424702960","DOIUrl":"10.1134/S0036024424702960","url":null,"abstract":"<p>The author proposes and describes a way of estimating the magnitude of the thermodynamic barrier to the formation of a critical-sized crystalline nucleus. The frequency of the formation of such nuclei that are stable and capable of further growth determines the rate of nucleation. For nucleation to occur, the nucleus must overcome the thermodynamic barrier. The measure of the magnitude of this barrier is the work needed to create the surface of a nucleus <i>W</i>*, determined from the values of surface energy σ and size <i>r</i>* of the critical nucleus for different temperatures of the preliminary heat treatment of glasses and their subsequent manifestation (crystal growth). The values of σ and <i>r*</i> are obtained from experimentally determined rates <i>I</i><sub>st</sub> of steady-state crystal nucleation; periods τ of non-stationary crystal nucleation, the measure of which is time <i>t</i><sub>ind</sub> of the induction period; and difference Δφ between the specific free energies of the glass and crystal. Values of <i>W</i>* are obtained for a series of silicate glass compositions for promoting crystal nucleation in these glasses.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":"98 14","pages":"3404 - 3410"},"PeriodicalIF":0.7,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388807","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}
A. I. Rusanova, L. D. Son, B. A. Rusanov, V. E. Sidorov, A. L. Beltyukov
{"title":"Non-Monotonic Relaxation Processes in Ga95Nd5 and Ga97Sm3 Melts","authors":"A. I. Rusanova, L. D. Son, B. A. Rusanov, V. E. Sidorov, A. L. Beltyukov","doi":"10.1134/S0036024424703023","DOIUrl":"10.1134/S0036024424703023","url":null,"abstract":"<p>Experimental studies of density and viscosity of gallium-rare-earth metal composition alloys with light lanthanides (neodymium and samarium) are investigated for the first time. It is established that these compositions are characterized by long-term non-monotonic changes of properties (relaxation processes) in liquid state. The coefficients of temperature expansion of Ga<sub>95</sub>Nd<sub>5</sub> and Ga<sub>97</sub>Sm<sub>3</sub> alloys and activation energy of viscous flows of their melts are calculated based on experimental data.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":"98 14","pages":"3449 - 3453"},"PeriodicalIF":0.7,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388924","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":"Using a Thermodynamic Model of Adsorption to Describe the Behavior of Salts of Modified Humic Acid in Surface Layers","authors":"M. I. Rogatko, S. L. Khil’ko","doi":"10.1134/S003602442470290X","DOIUrl":"10.1134/S003602442470290X","url":null,"abstract":"<p>A mathematical model of polymolecular adsorption developed for protein solutions at liquid–gas interfaces (V.B. Fainerman, R. Miller, et al.) is used to describe experimental concentration dependences of the change in the equilibrium surface tension and viscoelastic modulus of aqueous solutions of salts of modified humic acids and hymatomelanic acids. It is shown that experimental data are in satisfactory agreement with theoretical estimates. The polymolecular adsorption model of natural polyelectrolytes for solutions of salts of modified humic acids is used to identify correspondence between experimental data and theoretical calculations for bimolecular adsorption, and for the trimolecular adsorption of macromolecules from solutions of salts of hymatomelanic acids at interfaces with air.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":"98 14","pages":"3365 - 3371"},"PeriodicalIF":0.7,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388805","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":"Electrochemical Characteristics of LiAsF6 Solutions in Mixed Solvents Based on Dimethyl Sulfoxide","authors":"E. Yu. Tyunina, M. D. Chekunova","doi":"10.1134/S0036024424702972","DOIUrl":"10.1134/S0036024424702972","url":null,"abstract":"<p>The electrochemical behaviors of lithium hexafluoroarsenate-based systems in the acetonitrile (AN)–dimethyl sulfoxide (DMSO) and propylene carbonate (PC)–DMSO binary mixtures were compared. The specific electric conductivity of LiAsF<sub>6</sub> solutions in the AN–DMSO mixed solvent with a molal concentration of ionophore of 0.2–1.8 mol/kg and DMSO contents of 0.24–0.68 mole fractions at temperatures of 253.15, 263.15, 273.15, 283.15, 293.15, 303.15, 313.15, 323.15, and 333.15 K was determined for the first time. The concentration dependence of the specific conductivity of the test solutions obeys the Castell–Amis equation. The solvent and ionophore contributions to the activation energy of ionic conductivity were determined based on the application of the transition state theory. In the PC–DMSO and AN–DMSO mixed solvents, LiAsF<sub>6</sub> solutions have a narrower electrochemical window compared to that in solutions of this ionophore in the individual solvents.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":"98 14","pages":"3411 - 3420"},"PeriodicalIF":0.7,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388915","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}
Ya. V. Nikolskiy, V. V. Emelyanov, E. L. Krasnykh, Yu. F. Ivanova, A. A. Ruslyakov
{"title":"Retention Characteristics and Enthalpy of Sorption of Esters of 2,2-Dimethylbutury Acid and Aliphatic Alcohols with Linear Structure C1–C10","authors":"Ya. V. Nikolskiy, V. V. Emelyanov, E. L. Krasnykh, Yu. F. Ivanova, A. A. Ruslyakov","doi":"10.1134/S0036024424703011","DOIUrl":"10.1134/S0036024424703011","url":null,"abstract":"<p>Gas–liquid chromatography on a non-polar phase is used in the 393.2–473.2 K range of temperatures to determine the retention characteristics and enthalpies of sorption for 10 esters of 2,2-dimethylbutyric acid and linear alcohols C<sub>1</sub>–C<sub>10</sub>. A linear dependence of the indices of retention on temperature and the number of carbon atoms in the alcohol molecule is shown for all studied ethers. Enthalpies of evaporation are calculated, and the excess enthalpies of the mixing of ethers are determined.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":"98 14","pages":"3444 - 3448"},"PeriodicalIF":0.7,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388787","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}
A. K. Gatiatulin, A. R. Italmasov, M. A. Ziganshin, V. V. Gorbatchuk
{"title":"Ambivalent Thermodynamic States of Water in Solid γ-Cyclodextrin Hydrates","authors":"A. K. Gatiatulin, A. R. Italmasov, M. A. Ziganshin, V. V. Gorbatchuk","doi":"10.1134/S0036024424702807","DOIUrl":"10.1134/S0036024424702807","url":null,"abstract":"<p>The thermodynamics of γ-cyclodextrin hydration was studied using methods of thermal analysis and solution calorimetry. The enthalpy and entropy changes are in a good agreement with two steps of γ‑cyclodextrin hydration isotherm and changes of unit cell volume. The first step of γ-cyclodextrin hydration is more exothermic and has more negative change of entropy while as the second step is less exothermic providing more disorder of water molecules in the hydrate crystal. The kinetic study of γ-cyclodextrin dehydration process revealed the activation energy of this process.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":"98 14","pages":"3297 - 3303"},"PeriodicalIF":0.7,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388794","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}
D. B. Borgekov, M. V. Zdorovets, A. L. Kozlovskiy, M. D. Kutuzau, E. E. Shumskaya, E. Yu. Kaniukov
{"title":"Retraction Note: Effect of Acidity on the Morphology, Structure, and Composition of Ni Nanotubes","authors":"D. B. Borgekov, M. V. Zdorovets, A. L. Kozlovskiy, M. D. Kutuzau, E. E. Shumskaya, E. Yu. Kaniukov","doi":"10.1134/S0036024424140012","DOIUrl":"10.1134/S0036024424140012","url":null,"abstract":"","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":"98 14","pages":"3547 - 3547"},"PeriodicalIF":0.7,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388929","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}