Differential Scanning Calorimetry Methods Research Articles

Thermally induced phase separation of UHMWPE mixture with dioctyl adipate: Competition of liquid–liquid phase separation and polymer crystallization

The thermal behavior of ultra-high molecular weight polyethylene (UHMWPE) with dioctyl adipate (DOA) was investigated by the differential scanning calorimetry (DSC) method. Capillary-porous bodies were obtained via thermally induced phase separation of DOA mixtures with polyethylenes of different molecular weight at different cooling rates. Analysis of the morphology of the prepared porous bodies together with DSC data and results of cloud point estimation revealed an unexpected effect of a cooling rate on the type of phase separation occurring in the mixture during its cooling from homogeneous state. Particularly it was shown that increase in the cooling rate reduces the probability of realization of liquid – liquid phase separation in the mixture. It was argued that such behavior, different from the standard semicrystalline polymers, is a result of kinetic hindrance of liquid – liquid phase separation in mixtures containing a polymer with such a high molecular weight.

Investigation of the Degree of Monomer Conversion in Dental Composites through Various Methods: An In Vitro Study

The degree of monomer conversion (DC) values of three different dental composites were examined using three different methods: surface microhardness (ratio of bottom/top), Fourier-transform infrared (FT-IR), and differential scanning calorimetry (DSC). Two of the dental composites included in the study were nanohybrid (Dentsply Neo Spectra ST HV and Omnichroma), and one was a microhybrid-labeled newly marketed composite containing nanoparticles (Dentac Myra). Composite discs were prepared according to the methodology for all methods and analyzed (2 mm thickness × 5 mm diameter). Surface microhardness values were measured in Vickers Hardness Number (VHN), while FT-IR and DSC values were obtained in percentage (%). Significant differences were observed in both bottom/top surface microhardness values and DC values obtained from FT-IR. However, there was no statistical difference in the ratio of bottom/top microhardness values. Neo Spectra ST HV exhibited superior performance in both microhardness and monomer conversion compared to the other two composites. Newly marketed Myra showed values close to Omnichroma. It was found that the values obtained by the DSC method were parallel to those obtained by FT-IR. In conclusion, the structure of dental composites leads to different mechanical properties. Additionally, DSC measurements and FTIR spectra were found to be complementary techniques for characterizing monomer conversion values.

Plasmonic photothermal therapy based synergistic drug release application through gold nanoparticles coated and embedded PLGA nanoparticles

Drug carrier structures based on the biocompatible polymer Poly(D-lactic-co-glycolic acid) (PLGA) are considered traditional delivery systems. To increase the potential of PLGA nanoparticle (NP)-based carriers for use in near infrared radiation (NIR)-based photothermal drug release applications, two important approaches are the combined use of gold nanoparticles with PLGA NPs structures. In this study, AuNPs were prepared both decorated on PLGA NPs and embedded in PLGA NPs structures. The particles were prepared and characterized for their structural and thermal properties using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Differential Scanning Calorimetry (DSC) methods. Morphological features and size distributions were also determined using Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), and Dynamic Light Scattering (DLS). Thermal changes caused by plasmonic particles under 808 nm NIR laser were examined using a thermal camera for spherical gold nanoparticle (AuNP) and star-shaped gold nanoparticle (AuNS). The most suitable increase in temperature has been obtained in the AuNS structures. Epirubicin (EPI) release studies were conducted using PLGA NPs embedded with AuNS, employing NIR and an ON/OFF based approach. Basic toxicological evaluations of these particles were performed on mouse fibroblast (L929) cells to assess biocompability properties. The study also investigated the impact of prepared EPI-loaded particles and laser-controlled drug release on cytotoxicity, ROS production, and genotoxicity, in human neuroblastoma (SH-SY5Y) cells. The results indicated that the activity of EPI-loaded AuNP@PDOP@PLGA NPs increases synergistically with the ON/OFF-based approach, as shown by the calculated combination index (CI) value. The developed combination approach shows promise for further evaluation before clinical use.

Analyzing Sustainable 3D Printing Processes: Mechanical, Thermal, and Crystallographic Insights.

In this study, the objective was to optimize energy consumption in the fused deposition modeling (FDM) 3D printing process via a detailed analysis of printing parameters. By utilizing thermal analysis techniques, this research aimed to identify lower printing temperatures that could lead to reduced energy usage. Experimental analysis was conducted using a three-level L9 Taguchi orthogonal array, which involved a systematic combination of different extruder temperatures and cooling fan capacities. Furthermore, the research incorporated differential scanning calorimetry (DSC) and X-ray diffraction (XRD) methods to analyze the thermal properties and crystallinity of the 3D-printed specimens. The results indicated that temperature was a key factor affecting crystallinity, with samples printed at 190 °C and 60% fan capacity showing the highest mean values. By conducting a multi-objective desirability analysis, the optimal conditions for maximizing ultimate tensile strength (UTS), tensile modulus, and elongation at break while minimizing energy consumption for PLA 3D-printed samples were determined to be a temperature of 180 °C and a fan speed of 80%.

Effects of Adding Sorghum Procyanidins on the Structure, Molecular Interactions, and Thermal Properties of Agar-Glycerol-Gelatin Films

Films made with blends of agar and gelatin are usually unstable in aqueous environments and susceptible to temperature, so modifying these films with the addition of compatible compounds is necessary to improve their structural stability, properties, and potential uses. This work determined the effects of adding sorghum procyanidins on the structure, molecular interactions and thermal properties of agar-glycerol-gelatin films. Films were prepared by solution cast method and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and computational methods. Adding sorghum procyanidins to agar-gelatin films plasticized with glycerol produced significant modifications compared to control films. They contributed to the amorphous character and roughness of these films and the film’s microstructure, reducing weight loss and enhancing thermal stability. The predominant interactions among the film components were hydrogen bonds, van der Waals, and [Formula: see text]–[Formula: see text] interactions.

Synthesis and upconversion luminescence properties of Ho3+-Yb3+ co-doped glass ceramics containing LiGd(WO4)2

Ho3+-Yb3+ co-doped glass ceramics containing LiGd(WO4)2 were prepared by melt crystallization method. By using the methods of differential scanning calorimetry (DSC), X-ray diffraction (XRD), transmittance, and scanning electron microscopy (SEM), the optimal heat treatment condition for the samples was identified to be 580 °C/140 min. In these conditions, the transmittance of glass ceramic is about 75 % in the 380–780 nm range. In the upconversion emission spectra, strong green emission (543 nm) and red emission (650 nm) due to 5F4/5S2, 5F5→5I8 transitions are observed at 980 nm excitation. Additionally, the optimum doping concentrations of Ho3+ and Yb3+ were 0.12 % and 0.4 %. The crystal field changes around dopant ions were analyzed using J-O theory and Eu3+ probe to explain the up-conversion luminescence enhancement of glass ceramics containing LiGd(WO4)2. The chrominance coordinates of 0.12 % Ho3+-0.4 % Yb3+ co-doped glass ceramics are located in the green light region, and the color purity is 95.6 %. In summary, Ho3+-Yb3+ co-doped transparent glass ceramics containing LiGd(WO4)2 have potential applications in infrared detection and green solid-state lasers.

Theoretical and experimental study of molecular interactions between constituents of deep eutectic solvents

In this study, we aimed to elucidate the molecular interactions in deep eutectic solvents (DESs) and acquire additional experimental evidence to increase our understanding of the molecular mechanisms responsible for the preparation of DES. We investigated three N-methylthiourea (NMTU)-based DESs with choline chloride (ChCl), allyltrimethylammonium chloride (ATMAC), and benzyltriethylammonium chloride (BTEAC) as hydrogen bond acceptors (HBA). To accomplish this, we used both experimental techniques including isopiestic, differential scanning calorimetry (DSC), and FTIR measurements as well as molecular dynamics (MD) simulations. The thermal behaviors of the prepared DESs were investigated by DSC method. In order to study the interaction and hydrogen bonding between the DESs constituents, FT-IR analysis and isopiestic measurements were carried out. Constant solvent activity lines of ternary HBA + HBD + solvent mixtures were determined by the isopiestic technique. The large positive deviation of the isosolvent activity lines from the semi-ideal behavior indicates a strong interaction between HBA and HBD, which is much stronger than HBA-HBA and HBD-HBD interactions. Classical MD simulations were performed at 298.15 K to analyze the nanoscopic properties and structure of the DESs. To investigate the interaction between the components and visualize the three-dimensional structure of the DESs, radial distribution functions (RDFs), coordination numbers (CNs), and combined (CDFs), and spatial (SDFs) distribution functions were determined by MD simulations. The obtained theoretical results confirmed the importance of hydrogen bonds in the preparation of DESs and also showed that these systems exhibit different structural arrangements. MD simulations were also used to determine the density of the DESs and the results showed good agreement with the experimental density.

Measurement of effective thermal conductivity of composite powders of 2D materials and metals for additive manufacturing

Laser Powder Bed Fusion (LPBF), a promising additive manufacturing technique for composites of 2D materials and metals, requires knowledge of thermophysical properties, such as the thermal conductivity of powder, for process optimization. In this study, we measured the effective thermal conductivity of the most representative Cu-graphene composite powder in the field of heat transfer applications. To measure thermal conductivity, we propose a differential scanning calorimetry (DSC) method to measure the thermal resistances of a powder bed under steady-state heat flow conditions. We observe that the thermal conductivity of a composite powder is 1,000 times lower than that of the bulk metal without 2D material addition; e.g., exhibiting ~ 0.30 W/mK in Cu-1wt.% graphene powder. Furthermore, we discuss powder size and morphology impact on thermal conductivity influencing the number of contact points and thermal contact resistance. Our findings contribute to understanding the thermal conductivity of composite powders in a powder bed and aid in optimizing LPBF processes.

Green synthesis and characterization of binary, ternary, and quaternary Ti/MMO anodes for chlorine and oxygen evolution reactions

Dimensionally stable anodes of titanium (Ti) metal coated with mixed metal oxides (MMO) are widely used in several electrochemical applications, especially chloro-alkali electrolysis. Herein, we deposited MMO coatings on Ti substrates in different compositions, namely, (60%RuO2-40%TiO2), (60%RuO2-30%TiO2-10%IrO2), and (60%RuO2-20%TiO2-15%IrO2-5%Ta2O5), where RuO2 has the same percentage ratio in all coatings. The aim was to use these electrodes for chlorine evolution reaction (CER) and oxygen evolution reaction (OER) applications. Electrochemical characterization of the coated samples was performed to identify the best Ti/MMO electrodes with the highest efficiencies among the various prepared combinations. The role of IrO2 and Ta2O5 in enhancing corrosion resistance and electrochemical efficacy was up for debate. Scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses were exploited to determine the surface morphology, chemical composition, crystallinity, surface composition, and chemical states of the acquired coatings. The differential scanning calorimetry (DSC) method was used to evaluate the apparent activation energy (Ea\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{\ ext{E}}}_{{\ ext{a}}}$$\\end{document}) of the deposited MMO. Additionally, the electrochemical performance of our designed coatings was scrutinized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), a current on–off test, a CV stability test (ST), and an accelerated stability test (AST). Furthermore, linear sweep voltammetry (LSV) was incorporated to assess the catalytic efficacy of the prepared anodes toward the CER in a brine solution of pH 2 and the OER in 1 M H2SO4. It became clear that the CER and OER incurred almost the same potential value (1.1 V) on both Ti/RuO2-TiO2 and Ti/RuO2-TiO2-IrO2 electrodes. However, on the Ti/RuO2-TiO2-IrO2-Ta2O5 anode, there was a 0.2 V potential difference between the CER occurring at 1.1 V and the OER happening at 1.3 V.

Evaluation of structural characteristics BaFe(12-x)InxO19 hexaferrite compounds at high temperatures

BaFeO-based hexaferrite compounds were synthesized by partially replacing Fe atoms with In atoms in barium hexaferrite, and their structural characteristics, thermal, and magnetic properties were studied. The crystal structure and lattice parameters of the hexaferrite were investigated using the X-ray diffraction method. Thermal property investigations were conducted at high temperatures. The results obtained by the Differential Scanning Calorimetry (DSC) method were analyzed, and the mechanisms of formation and decomposition of hydroxide groups in these crystals were explained. These effects were also determined by Thermogravimetric Analysis (TGA) studies. The vibrational magnetometry method studied the magnetic properties of BaFe11.4In0.6O19 and BaFe10.8In1.2O19 compounds. As the concentration of In atoms in the samples increases, the temperature of the ferrimagnetic-paramagnetic phase transition decreases. The observed effect in the temperature range of RT to 800 °C is attributed to weight loss due to the decomposition of structural water molecules through an endothermic reaction in hexaferrite compounds. The value of the Curie temperature for the BaFe11.4In0.6O19 compound was 383 °C, and for the BaFe10.8 In1.2O19 compound, it was 323 °C. Increasing In concentration from x = 0.6 to x = 1.2 increases the In3+ ionic radius in the structure, and due to the replacement of Fe3+ ions with more In3+ ions at x = 1.2, the magnetic hyperfine field area decreases.

Enhanced CO2 Capture through SAPO-34 Impregnated with Ionic Liquid.

The concurrent utilization of an adsorbent and absorbent for carbon dioxide (CO2) adsorption with synergistic effects presents a promising technique for CO2 capture. Here, 1-butyl-3-methylimidazole acetate ([Bmim][Ac]), with a high affinity for CO2, and the molecular sieve SAPO-34 were selected. The impregnation method was used to composite the hybrid samples of [Bmim][Ac]/SAPO-34, and the pore structure and surface property of prepared samples were characterized. The quantity and kinetics of the sorbed CO2 for loaded samples were measured using thermogravimetric analysis. The study revealed that SAPO-34 could retain its pristine structure after [Bmim][Ac] loading. The CO2 uptake of the loaded sample was 1.879 mmol g-1 at 303 K and 1 bar, exhibiting a 20.6% rise compared to that of the pristine SAPO-34 recording 1.558 mmol g-1. The CO2 uptake kinetics of the loaded samples were also accelerated, and the apparent mass transfer resistance for CO2 sorption was significantly reduced by 11.2% compared with that of the pure [Bmim][Ac]. The differential scanning calorimetry method revealed that the loaded sample had a lower CO2 desorption heat than that of the pure [Bmim][Ac], and the CO2 desorption heat of the loaded samples was between 30.6 and 40.8 kJ mol-1. The samples exhibited good cyclic stability. This material displays great potential for CO2 capture applications, facilitating the reduction of greenhouse gas emissions.

Catalytic effect of N-phenylaminopropyl polyheadral oligomeric silsesquioxane in the synthesis of hybrid nanocomposites based on polycyanurate

Organic-inorganic nanocomposites based on heat-resistant crosslinked polycyanurate (PCN) and N-phenylaminopropyl polyhedral oligomeric silsesquioxane (NPAP-POSS), containing eight reactive secondary amino groups, were synthesized using the in situ reactive formation method. Fourier transmission infrared (FTIR) spectroscopy and dynamic differential scanning calorimetry (DSC) methods were used to study the effect of NPAP-POSS on the kinetics of bisphenol E dicyanate ester (DCBE) polycyclotrimerization during the formation of PCN in PCN/NPAP-POSS nanocomposites. The content of the nanofiller was varied from 0.05 to 1.00 wt.%. Based on the results of FTIR spectral studies, the main kinetic peculiarities of PCN formation were found and their changes under the action of NPAP-POSS nanofiller were determined. A significant catalytic effect of NPAP-POSS on the polycyclotrimerization of DCBE was found, which is confirmed by a decrease in the time of the onset of auto-acceleration, an acceleration of the conversion of cyanate groups of DCBE and the formation of triazine cycles of PCN, an increase in the values of the maximum reaction rate, a decrease in the duration of the reaction, etc. The dynamic DSC method also confirmed the catalytic effect of NPAP-POSS on the formation of PCN in the nanocomposites and established the main kinetic characteristics depending on the content of the nanofiller: a significant decrease in the temperature of the exothermic maximum, an increase in the reaction enthalpy, non-monotonic changes in the induction period and reaction rate, etc. From the analysis of the experimental data, it was concluded that the detected changes in the kinetics of the in situ reaction formation of PCN/NPAP-POSS nanocomposites and the recorded catalytic effect of the nanofiller are due to the fact that two chemical processes occur during the synthesis of the nanocomposites: chemical interaction of –O–C≡N groups of DCBE with secondary –NH groups of NPAP-POSS, which led to further embedding of nanoparticles into the resulting polymer matrix and the direct polycyclotrimerization of DCBE with formation of hybrid polycyanurate network. Schemes of the sequential reactions explaining the catalytic effect of the nanofiller in the synthesis of hybrid PCN/NPAP-POSS nanocomposites are proposed. It was concluded that under the selected conditions of the synthesis, the greatest catalytic effect of the nanofiller is manifested at its content of 0.10 wt.%, since for this sample the maximum shift of the reaction exothermic peak towards lower temperatures, the maximum reaction rate, and the minimum induction period and reaction start temperature were recorded. The results of the research make it possible to optimize the synthesis of heat-resistant materials promising for use in special-purpose structures.

Preparation and Characterization of Polyvinyl Alcohol (PVA)/Carbonized Waste Rubber Biocomposite Films.

The technological properties of composite materials (thermal, strength, rheology, electrical and morphology) are very important parameters for high-performance applications. In this study, we aimed to improve the properties of PVA by using carbon materials obtained by the pyrolysis of waste tires, with the aim of recycling them instead of disposing of them. For this purpose, PVA biocomposite films containing carbonized waste rubber at different rates were prepared. The thermal properties of the prepared biocomposite films were examined via thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) methods. While rheological measurements were carried out with a rheometer, bulk conductivities were measured with a pico-ammeter. In addition, the morphology of biocomposite films was determined via field emission scanning electron microscopy. The nanomechanical properties of biocomposite film was investigated via XPM analyses. According to the rheological measurements and nanoindentation hardness results, it is understood that as the amount of carbonized waste rubber increases, flexibility decreases and harder and brittle structures are observed in biocomposite films. The electrical measurement results showed that electrical conductivity increased as the amount of carbonized waste rubber increased. When all the results obtained were evaluated, it could be concluded that biocomposite films obtained by increasing the electrical conductivity and hardness of PVA can be used in the electronics industry.

Single ferroelectric liquid crystal compounds targeted for optical voltage sensing

Nine compounds containing fluorine or chlorine atoms in the lateral position in the rigid core with a chiral terminal octyloxy-chain were synthesized mainly using Suzuki-Miyaura coupling, Mitsunobu, hydrogenation, and esterification reactions. New compounds were investigated using polarized optical microscopy (POM), differential scanning calorimetry (DSC), spectrophotometry, and electro-optical methods. A computational analysis of the effect of lateral substitution by halogen atoms on the phenyl ring on the dipole moment of the compound was provided and discussed. The designed compounds exhibit a wide temperature range of the ferroelectric phase (>40.0 °C), a low melting point (in most cases below 50.0 °C), low melting enthalpy (around 10.0–20.0 kJ/mol), a short helical pitch (in most cases below 200 nm at room temperature) and high tilt angle that ensures a cone angle of up to 90°; all those properties make them of great potential for the deformed helix ferroelectric (DHF) mode. Revealed features allow synthesized compounds in fully integrated polarization-based photonic transducers to have excellent linearity and the highest sensitivity observed in ferroelectric liquid crystals for DHF mode. For the first time, the DHF effect was reached for the single molecule FLC material in a broad temperature range down to 38 °C. These findings pave the way for a new class of optical sensors for, among others, industrial monitoring networks and brain/machine interfaces with unprecedented performance.

The Influences of Agglomeration and Storage on the Thermal Properties and Stability of Fats in Infant Formulas

The Influences of Agglomeration and Storage on the Thermal Properties and Stability of Fats in Infant Formulas

The effect of graphene nanoparticleson the thermal conductivity enhancementof organic phase change material and its energystorage properties

Organic phase change materials (PCMs), which are typically used as the accumulating material in latent heat thermal energy storage, provide chemical and thermal stability, but have low thermal conductivity. This limits heat transfer rates and prolongs storage charging/discharging time. A method to improve the thermal conductivity of organic PCMs is to add nanomaterials with high thermal conductivity. The paper presents the research on the effect of the addition of graphene nanoparticles (GNPs) on the thermal conductivity of organic PCM (RT28 HC), and its energy storage properties. The transient hot wire and the pipe Poensgen apparatus methods were used to measure thermal conductivity, and the differential scanning calorimetry method was used to determine the heat capacity and phase change temperature. The achieved characteristics of thermal conductivity depending on the amount of added graphene nanoparticles (and stabilizer) indicate that GNPs allow to increase the thermal conductivity on average by 26–87% in the solid state and by 7–28% in the liquid, but this reduces the PCM heat capacity. Therefore, the paper indicates what mass fraction of dopants is optimal to achieve the greatest improvement in thermal conductivity of RT28 HC and its smallest reduction in heat capacity, to use this nano-enhanced PCM in practice.

Improving the technology of oxidative stabilization of rapeseed oil

The object of the research is the oxidation process of rapeseed oil. Rapeseed oil is used for technical purposes, in the chemical and food industries, in particular, in the production of ecological fuel. Vegetable oils are subjected to oxidative deterioration processes, which are intensified under the conditions of access to oxygen, elevated temperatures, etc. Oxidation products worsen the technological properties and complicate the use of oils in chemical reactions. An important task is to improve the technology of oxidative stabilization of rapeseed oil, which is of great industrial importance. The oxidation process of refined deodorized rapeseed oil according to DSTU 8175 (CAS Number 120962-03-0) at a temperature of 110 °C was studied by the method of differential scanning calorimetry. The influence of different ratios of antioxidants (tocopherol, butylhydroxyanisole and butylhydroxytoluene) in the mixture on the oil induction period was determined. The total concentration of the antioxidant mixture in each experiment was 0.02 %. The induction period of the initial oil is 408.48 min. The rational ratios of the components of the antioxidant mixture were determined: tocopherol: butylhydroxyanisole (75:25) %; tocopherol: butylhydroxyanisole: butylhydroxytoluene (66.67:16.67:16.67) %. The corresponding oil induction periods were 579.75 min. and 561.55 min. The physico-chemical indicators of rapeseed oil after 12 months of storage at a temperature of (20±2) °C in its original form and with the addition of the developed antioxidant mixtures were determined. The peroxide value of the oil was 12.5, 4.59, 6.45 ½ O mmol/kg, respectively. The research results allow improving the technology of oxidative stabilization of rapeseed oil at elevated and standard temperatures. This will help to extend the oil shelf life, more efficiently and rationally use the oil in various areas

Synthesis and characterization of a di-methacrylated polymerizable ionic liquid through two-step esterification and ion exchange process

An effective two-step synthesis for the di- methacrylation of 2-hydroxylethylammonium chloride ionic liquid was developed in the presence of methacrylic anhydride. The esterification process was performed through the hydroxyl moiety and the side product methacrylic acid was effectively captured through an ion exchange process via sodium bicarbonate to yield a polymerizable di- methacrylate monomer. The esterification and ion exchange processes were monitored via titrations and spectroscopy. This low viscosity (62 cP) di- functional modified ionomer is thermally homo-polymerized and co-polymerized with 55 wt% bis-GMA as a nonvolatile reactive diluent yielding impressive glass transition temperature (Tg) values up to 157 °C and 170 °C for homo- and co- polymer respectively as determined via differential scanning calorimetry method.

High-temperature interaction of water vapor with lithium ceramics Li2TiO3

Selection of materials for fusion reactors and, in particular, for blanket systems is one of the most important tasks that determine the development of fusion energy. Lithium ceramics Li2TiO3 is considered as prospective candidate for solid breeders of future fusion reactors' blankets. The paper presents the results of high-temperature tests of Li2TiO3 + 5 mol% TiO2 ceramics, performed under conditions of blowing with argon containing impurities of water vapor of different isotopic compositions (H2O, HDO, D2O) in the range of temperature from 100 °C to 1400 °C. The vapor–gas mixture for the experiment was prepared in a special mixing tank. The interaction of Li2TiO3 + 5 mol% TiO2 ceramics with chemically active gases and water vapors was investigated by thermogravimetry (TG), differential scanning calorimetry (DSC) and mass spectrometry (MS) methods. As a result of experiment, the dependences of the sample mass change during heating under single purge gas composition was obtained. Mass spectra that characterize the changes in the qualitative composition of the gas mixture in the reaction chamber with the investigated sample were recorded and subsequently analyzed. An isotope effect is observed during the experiment: the release of D2 gas begins significantly earlier than the release of HD gas. The observed effect appears only in the high-temperature region (above 1050 °C), which characterizes the investigated material as almost completely chemically neutral towards water vapor.

Interfacial Phenomena in Nanostructured Systems with Various Materials.

Interfacial phenomena linked to the behavior of bound water, organic solvents (co-sorbates, dispersion media), hydrogen, methane, acids/bases, and salts bound to various silicas, polymers, and carbon materials were analyzed vs. temperature and concentrations using 1 H NMR spectroscopy, differential scanning calorimetry (DSC) and other methods. The material characteristics were studied using microscopy, infrared spectroscopy (IR), small angle X-ray scattering (SAXS), and nitrogen adsorption. Confined space effects (CSE) result in enhanced freezing point depression (FPD) and stronger diminution of solvent activity and colligative properties of liquid mixtures in narrower pores. Short hydrophobic functionalities (≡Si-CH3 , =Si(CH3 )2 ) at a silica surface and the presence of nanopores result in differentiation of bound water into weakly (WAW, δH =0.2-2.0 ppm) and strongly (SAW, δH =4-6 ppm) associated waters of smaller solvent activity in smaller clusters located in narrower pores and unfrozen below a bulk freezing point. These effects are enhanced in hydrophobic dispersion media. Hydrophobic liquids could displace bound water into narrower pores inaccessible for their molecules larger than water and/or into broader pores to reduce contact area between immiscible liquids. The observed phenomena depend on sorbent/sorbate kinds and play an important role on practical applications of various sorbents.