High-temperature Mass Spectrometry Research Articles

On the Possibility of Measuring the Electronic Work Function of Nonvolatile Materials by High-Temperature Mass Spectrometry

On the Possibility of Measuring the Electronic Work Function of Nonvolatile Materials by High-Temperature Mass Spectrometry

High-temperature liquid chromatography-isotope ratio mass spectrometry methodology for carbon isotope ratio determination of anabolic steroids in urine

BackgroundGas Chromatography Isotope Ratio Mass Spectrometry (GC-C-IRMS) has long been used in routine laboratories to determine the δ13C values of anabolic steroids in urine, differentiating between, e.g., endogenous and synthetic testosterone (T) in sports doping control. Until now, liquid chromatography (LC-IRMS) has not been used. The LC-IRMS setup doesn't allow organic solvents or modifiers in the mobile phase for δ13C determinations. Mid-to non-polar analytes such as steroids can be analysed in water heated to High Temperatures (HT, up to 200 °C) because at 200 °C has a similar polarity as 80/20 methanol/water at ambient temperature. In this work, we developed a method for steroids in urine, extending the application of the LC-IRMS to non-polar analytes in complex matrices. ResultAn HT-LC-IRMS method capable of determining the δ13C values of four steroids (i.e., testosterone (T), 5α-androstane-3α,17β-diol (ααβ), 5β-androstane-3α,17β-diol (βαβ) and pregnanetriol (PT)) in urine was developed and validated. Accuracy ranged from 0.23 ‰ (ααβ and βαβ) to 0.49 ‰ (T), and the detection limit was set at 10 ng mL−1 (T, ααβ+βαβ). The validation data and a comparison of authentic urine samples analysed with HT-LC-IRMS and GC-C-IRMS indicated a comparable performance between HT-LC-IRMS and GC-C-IRMS. SignificanceHT-LC-IRMS can be used to determine δ13C values of anabolic steroids, extending the applicability of both HT-LC and LC-IRMS to non-polar substances determined in a complex matrix in routine laboratory practice.

Thermal Runaway Mechanism in Ni-Rich Cathode Full Cells of Lithium-Ion Batteries: The Role of Multidirectional Crosstalk.

Crosstalk, the exchange of chemical species between battery electrodes, significantly accelerates thermal runaway (TR) of lithium-ion batteries. To date, the understanding of their main mechanisms has centered on single-directional crosstalk of oxygen (O2) gas from the cathode to the anode, underestimating the exothermic reactions during TR. However, the role of multidirectional crosstalk in steering additional exothermic reactions is yet to be elucidated due to the difficulties of correlative in situ analyses of full cells. Herein, the way in which such crosstalk triggers self-amplifying feedback is elucidated that dramatically exacerbates TR within enclosed full cells, by employing synchrotron-based high-temperature X-ray diffraction, mass spectrometry, and calorimetry. These findings reveal that ethylene (C2H4) gas generated at the anode promotes O2 evolution at the cathode. This O2 then returns to the anode, further promoting additional C2H4 formation and creating a self-amplifying loop, thereby intensifying TR. Furthermore, CO2, traditionally viewed as an extinguishing gas, engages in the crosstalk by interacting with lithium at the anode to form Li2CO3, thereby accelerating TR beyond prior expectations. These insights have led to develop an anode coating that impedes the formation of C2H4 and O2, to effectively mitigate TR.

Vaporization processes and thermodynamic properties of the SrO-ZrO<sub>2 </sub> system at high temperatures

Vaporization processes and thermodynamic properties of the SrO-ZrO2 system in the concentration range from 10 to 90 mol% SrO were studied by high-temperature differential mass spectrometry. Evaporation of the studied samples were carried out from tungsten Knudsen effusion cell. Partial pressures of vapor species in the temperature range of 1975-2800 K were determined. The values of SrO and ZrO2 activities, as well as Gibbs energies and excess Gibbs energies in the composition range from 90 to 45 mol% SrO were obtained at the temperature of 1940 K and from 45 to 10 mol% SrO at the temperature of 2123 K. It is established that in the SrO-ZrO2 system minor negative deviations from ideal behavior are observed.

Electrodeposition of Microfabricated Rhenium-Filaments

Metallic filaments comprised of refractory materials are a necessary part of mass spectrometers used to measure isotopes. The current state-of-the-art material, rhenium, is formed into filaments using a mechanical crimper, limiting the accuracy, speed, and quantity of filaments that can be fabricated. The current work describes the development of wafer-scale, microfabricated Re filaments using silicon molds followed by electrodeposition of Re. The goal is to develop filaments with tight dimensional tolerances, high purity, and mechanical rigidity for the desired application and offer the ability to create 100’s-1000’s of filaments on a single silicon wafer.Electrodeposition of Re is notoriously difficult as the reduction potential of rhenium is close to the hydrogen evolution reaction in aqueous solutions.1 While rhenium has been successfully deposited from alkaline, acid, and concentrated lithium chemistries,2 the films are often thin, porous, and contain many impurities such as hydrogen and oxygen. Rhenium oxide is susceptible to reaction with moisture in the air, resulting in poor quality films with short functional lifetimes. To electroform precise, pure rhenium structures, hardier chemistries must be developed.The current work seeks to address this challenge using a water-in-salt chemistry (WISE) comprised of up to 4M lithium salts, complexing agents, reducing agents, and oxygen scavengers. Numerous physical agitation techniques were utilized to improve the quality of the film. Solutions were analyzed using various electrochemical techniques, UV-VIS, and Raman spectroscopy. The optimized chemistry was used to electrodeposit bulk batches of microfabricated 2mm x 300 um x 300 um filaments. The filaments were analyzed using microscopy, XRF, XRD, SEM, and EDS with a goal of use in high temperature mass spectrometry experiments. References (1) Naor, A.; Eliaz, N.; Burstein, L.; Gileadi, E. Direct Experimental Support for the Catalytic Effect of Iron-Group Metals on Electrodeposition of Rhenium. Electrochemical and Solid-State Letters 2010, 13 (12), D91. DOI: 10.1149/1.3489532.(2) Pappas, D. P.; David, D. E.; Lake, R. E.; Bal, M.; Goldfarb, R. B.; Hite, D. A.; Kim, E.; Ku, H.-S.; Long, J.; McRae, C. Enhanced superconducting transition temperature in electroplated rhenium. Applied Physics Letters 2018, 112 (18), 182601. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. SAND2022-*****

OBTAINING, PROPERTIES, AND PROSPECTS FOR USE OF Al30-PILLARED MONTMORILLONITE

Over the past decade, the Department of Technology of Ceramics and Electrochemical Production has been conducting research related to the obtaining of new types of refractory non-metallic and silicate materials. One of the promising directions is focused on the modification of natural clay minerals in order to enhance their sorption, catalytic, electrolytic, optical and other properties. This article presents the results on the functionalization of pillared clays. Using the "giant" aluminum polycations [Al30O8(OH)56(H2O)24]18+, Al30-pillared montmorillonite (Al30-PMM) was obtained for the first time by the intercalation method, its structural and textural properties were characterized, and its functionality was studied. When identifying Al30 polycations and studying the physicochemical properties of Al30-PMM in comparison with the previously known Al13-PMM and the original natural montmorillonite (Dash-Salakhly deposit, Azerbaijan), the following methods were used: photometry, infrared and fluorescence spectroscopy, electron microscopy, static light scattering, NMR spectroscopy, porosimetry, dynamic laser beam scattering, X-ray diffractometry, thermogravimetric and differential thermal analysis, impedancemetry and high-temperature mass spectrometry. The effect of preliminary mechanical activation of the aluminosilicate matrix on the efficiency of intercalation of aluminum polycations has been studied. An anomaly in the temperature dependence of the current density of the thermal emission of alkali metal ions from the Al30-PMM surface was found, interpreted from the point of view of the phase transformation of pillars. The patterns of adsorption on Al30-PMM of organic dyes of cationic and anionic types in aqueous solutions, carotenoids and fatty acids in vegetable oil, as well as humic acids, for which, in combination with Al30-PMM, the detoxifying ability with respect to oil in water was examined. A new method of electrolytic modification of montmorillonite is proposed, which consists in doping with lithium and sodium ions of nanocavities of pillared montmorillonite. It has been shown that hydrothermal cohydrolysis of aluminum and cerium salts makes it possible to synthesize large-sized polyhydroxocomplexes that improve the textural properties of pillared montmorillonite compared to Al30-PMM. In general, the fundamental principles of the formation of a layered-columnar structure identified in the work can be used to design innovative materials based on layered systems by varying the sizes and chemical composition of intercalated ions. For citation: Butman M.F., Ovchinnikov N.L., Kosenko N.F., Filatova N.V., Pogonin A.E. Obtaining, properties, and prospects for use of Al30-pillared montmorillonite. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 7. P. 159-172. DOI: 10.6060/ivkkt.20236607. 6833j.

Thermodynamics and vapourization of Cs-, Sr-, Ba-containing oxide systems valid for nuclear safety problems

The review provides a systematic analysis of the studies carried out mainly in the last decade in which the thermodynamic properties and vapourization of the systems containing cesium, strontium, and barium were studied by high-temperature mass spectrometry. Such systems are of particular interest for considering the problems of environmental safety in the nuclear power industry. Particular attention is paid to the issues of reliable identification of the content of the gaseous phase over oxide systems, which are important in various high-temperature technologies, including the disposal of radioactive waste, reprocessing of nuclear fuel, as well as ensuring the safe operation of nuclear power plants. A discussion and comparison of thermodynamic data found in the literature for the systems under consideration in a wide temperature range were also carried out featuring the main advantages of the Knudsen mass spectrometric effusion method.<br> The bibliography includes 117 references.

СИНТЕЗ И ИССЛЕДОВАНИЕ ФИЗИКО-ХИМИЧЕСКИХ И ТЕРМОДИНАМИЧЕСКИХ СВОЙСТВ В СИСТЕМЕ Na2O-BaO-B2O3

38 samples were synthesized in the Na2O-BaO-B2O3 system, some of which were glasses, some crystallized. The degree of interaction of the initial reagents in the synthesis process was controlled by X–ray phase analysis on a DRON-3M diffractometer using CuKa radiation. Crystal phases were identified using X–ray phase analysis on a DRON-3M diffractometer using CuKa radiation and the PDF–2 powder diffractometry database. The following crystalline phases were identified in the crystallized samples: β-BaВ2O4, NaBO2, NaBaB9O15. Density, microhardness, refractive index were measured for glassy samples of the system under study and melting/liquidus temperatures were determined. It is established that the nature of the dependence of the above properties on the content of sodium oxide with a constant content of boron oxide is linear. The study of vaporization processes and thermodynamic properties of the Na2O-BaO-B2O3 system was carried out by differential high-temperature mass spectrometry on the MS–1301 mass spectrometer. The studied samples were evaporated from a twin Knudsen molybdenum effusion cell. The heating of the cell was carried out by electronic bombardment, the temperature was measured with an optical pyrometer EOP–66. It was shown that as a result of the interaction of Na2O, BaO and B2O3 oxides, sodium and barium borates are formed in the condensed phase. It is established that the studied system is characterized by selective evaporation of NaBO2 in the temperature range of 1290–1350 K. The activity values of NaBO2 and B2O3 were determined depending on the composition of the condensed phase at a temperature of 1330 K. The activity of BaB2O4 was calculated using the Gibbs-Dugem equation. The obtained values of the Gibbs mixing energies and excess Gibbs energies indicate significant deviations of the Na2O-BaO-B2O3 system from the ideal behavior.

Высокотемпературные термодинамические свойства керамики на основе оксидов гафния и редкоземельных элементов

In the review results of thermodynamic properties and vaporization processes of ceramics based on hafnium and rare earth oxides studied during recent years using high temperature mass spectrometry up to the temperature 3000 K were classified. Advantages of semi-empirical and statistical thermodynamic approaches for the prediction of thermodynamic properties of multicomponent systems based on oxides considered were illustrated.

Vaporization and the Thermodynamic Properties of the SrO–Al2O3–SiO2 System

Vaporization and thermodynamic properties of the SrO–Al2O3–SiO2 system are studied by high-temperature differential mass spectrometry in the concentration range from 90 to 10 mol % of SrO and the molar ratio of x(Al2O3)/x(SiO2) = 1.5. The samples are evaporated from Knudsen effusion cell made of tungsten. The partial pressures of the molecular forms of the vapor, the activities of the condensed phase components, the Gibbs energies, and the excess Gibbs energies are determined. It is established that the studied system is characterized by a slight negative deviation from the ideal behavior. For mullite (Al6Si2O13) the value of the standard enthalpy of formation is determined. The melting points of the synthesized samples are established by high-temperature microscopy.

Gas Chromatography—High-Temperature Proton-Transfer Reaction Mass Spectrometry as a Novel Tool for Forensic Drug Testing

Proton-transfer reaction mass spectrometry (PTR-MS) is a versatile tool for the mass spectrometric analysis of organic molecules in gaseous samples. Due to its operation principle, PTR-MS is a soft ionization technique generating spectral data typically rich in protonated molecule information. Most of the currently reported PTR-MS applications are designed to determine volatile compounds. Herein, we present a redesigned instrumental setup termed “high-temperature (HT)-PTR-MS” with improved capabilities for the analysis of low-volatile compounds. The developed HT-PTR-MS prototype was successfully hyphenated with gas chromatography (GC) to enable qualitative and quantitative analysis of licit and illicit drugs in human blood/plasma samples. Different kinds of spiked and authentic samples were used to evaluate the performance of the GC-HT-PTR-MS in forensic drug testing. Benchmarking against GC-MS with electron ionization demonstrated the improved detection capabilities of GC-HT-PTR-MS in screening applications. On average, one order of magnitude lower limits of detection/identification were reached. Clearly, GC-HT-PTR-MS has the vast potential to complement or even replace established mass spectrometric techniques in forensic drug analysis.

Thermodynamic properties over two phase region of U-Al system: Knudsen Effusion Mass Spectrometric study

High temperature vaporisation thermodynamic studies over <UAl2(cr)+U(cr)> two-phase region of U-Al system were carried out by employing Knudsen Effusion Mass Spectrometry (also known as High Temperature Mass Spectrometry) in the temperature range of 1146-1327 K. The vaporisation reaction occurs incongruently and Al(g) was the neutral vapour species observed in the equilibrium vapour. Partial pressure-temperature relation of Al(g) was derived as log(pAl/Pa) = (−19809 ± 209)/T + (12.58 ± 0.17). Using the p˗T relation, ΔrH298.15∘ of the following reaction: UAl2(cr) = 2Al(g) + U(cr) was evaluated by second and third law methods. Subsequently, enthalpy and Gibbs energy of formation of UAl2(cr) were deduced as ΔfH298.15∘ = −89.9 ± 24.1 kJ mol−1 and ΔfG298.15∘= −89.9 + 24.1 kJ mol−1, respectively. The vaporisation studies on this two phase region are being reported for the first time.

Vaporization Thermodynamics of GeO2 by High-Temperature Mass Spectrometry

Vaporization Thermodynamics of GeO2 by High-Temperature Mass Spectrometry

Thermodynamic Characteristics of Lithium Pivalate according to High-Temperature Mass Spectrometry Data

Thermodynamic Characteristics of Lithium Pivalate according to High-Temperature Mass Spectrometry Data

Ti3O5 and V2O3 Vaporization

The vaporization of Ti3O5 and V2O3 is studied by high-temperature mass spectrometry. Evaporation is carried out from Knudsen effusion cell made of tungsten. It is found that these oxides pass into vapor congruently with dissociation. Equations are obtained for the dependence of the partial pressures of molecular forms of the vapor on temperature in the form log p = –A/T + B.

Optimization of the Thermodynamic Properties of the Sm2O3–Y2O3–HfO2 System at High Temperatures by the Barker Method

The thermodynamic properties of the Sm2O3–Y2O3–HfO2 system at 2500 K were modeled based on the generalized lattice theory of associated solutions using experimental data obtained by high-temperature mass spectrometry. A comparison was made between the results of the calculations of the thermodynamic properties of the Sm2O3–Y2O3–HfO2 system using two independent approaches to modeling based on this theory: from the experimental data on the properties of the ternary system and from the data on its boundary binary systems Sm2O3–Y2O3, Sm2O3–HfO2, and Y2O3–HfO2. It was shown that the chemical potentials of the components that were calculated in the studied ternary system using the above approaches much better fit the experimental data in the former case.

Thermodynamic properties of the Gd2O3-Y2O3-HfO2 system studied by high temperature Knudsen effusion mass spectrometry and optimized using the Barker lattice theory

The vaporization processes and thermodynamic properties of twenty samples in the Gd2O3-Y2O3-HfO2 system in a wide concentration range were studied by high-temperature Knudsen effusion mass spectrometry. At the temperature 2500 K the main vapor species were GdO, YO, and O. From the measured values of their partial pressures activities of the Gd2O3 and Y2O3 as functions of concentration were determined. The HfO2 activity was calculated by the Gibbs-Duhem integration. The resulting excess Gibbs energy function exhibited negative deviations from ideal behavior. For the optimization of the obtained thermodynamic functions of the ternary Gd2O3-Y2O3-HfO2 system the generalized Barker-Guggenheim theory of associated solutions was applied. In an alternative computing procedure the same model was used, but the optimization was based on the available literature data for the corresponding binary Gd2O3-Y2O3, Gd2O3-HfO2, and Y2O3-HfO2 systems. Thus, the Barker lattice model may be used for estimation of the thermodynamic functions of a ternary system on the basis of the data for the corresponding binary sub-systems.

Thermodynamic Properties of NaNO3-KNO3 Melts

Thermodynamic properties of NaNO3-KNO3 melts have been studied by high-temperature mass spectrometry. The activities of the components of the condensed phase have been determined and the changes in the chemical potentials and Gibbs energies of the binary system have been calculated.

Features of Thermodynamic Description of Properties of Gd2O3-Y2O3-HfO2 Based Ceramics

Data on the thermodynamic description of Gd2O3-Y2O3-HfO2 system determined by high-temperature mass spectrometry at 2500 K were discussed using the Barker-Guggenheim statistical thermodynamic theory and the Redlich-Kister empirical approach to consider the accuracy and the possibility of further interpretation of the values found. A comparison was made of the results obtained on the basis of the indicated approaches with the aim of the most reliable optimization of the values of the excess Gibbs energy found in the system under consideration.

Functionalization of multi-walled carbon nanotubes with indazole

In this work, the functionalization of carbon nanotubes (CNTs) with indazole groups covalently bound to the CNTs’ surface is reported. The novel material was structurally characterized via near edge X-ray absorption fine structure (NEXAFS) spectroscopy and X-ray photoelectron spectroscopy (XPS) and successful functionalization was proven. As the novel material is a potential candidate for catalyst support application in high-temperature proton-exchange membrane fuel cells (HT-PEMFCs), thermal and electrochemical stability of the novel material was investigated. Measurements via thermogravimetric analysis coupled to a mass spectrometer (TGA-MS) showed that the indazole-functionalized CNTs are thermally stable until a temperature of approx. 300 °C is reached. The thermal degradation of the functional group was tracked by monitoring the evolution of NOX gases. Furthermore, electrochemical stability of the novel material was evaluated using high-temperature differential electrochemical mass spectrometry (HT-DEMS) under gas-phase conditions. Compared to unmodified CNTs, it was shown that the functionalization leads to a slightly increased electrochemical carbon corrosion. However, the indazole-functionalized CNTs show a higher electrochemical stability than carbon black (Vulcan XC72R) typically used as catalyst support in HT-PEMFCs. In comparison to unmodified CNTs, functionality tests of the indazole-functionalized CNTs showed a better dispersibility in water and a lower contact angle with concentrated H3PO4, which is the electrolyte in HT-PEMFCs. Ultimately, ion exchange capacity measurements showed that the indazole-functionalized CNTs are able to bind protons in the catalyst layer and, therefore, potentially improve the catalyst-electrolyte interface as well as the proton conductivity in the catalyst layer.