Journal of Thermal Analysis and Calorimetry

http://link.springer.com/journal/10973

List of Papers (Total 575)

Buffer contribution to formation enthalpy of copper(II)–bicine complex determined by isothermal titration calorimetry method

The isothermal titration calorimetry (ITC) technique supported by potentiometric titration data was used to study a buffer contribution to the formation enthalpy of copper(II)–bicine complex obtained directly from the ITC experiments. The calorimetric measurements were carried out at 298.15 K in 100 mM buffer solutions with a pH of 6. In experiments two biologically relevant pH ...

Size-controllable synthesis of lithium niobate nanocrystals using modified Pechini polymeric precursor method

Nanopowders of lithium niobate (LiNbO3, LN) were synthesized by a water-based modified Pechini method, in which Li2CO3 and ammonium niobate (v) oxalate hydrate (C4H4NNbO9·xH2O) are used as the Li and Nb source materials, respectively. The kinetics of formation of the intermediate gelatinous precursor was studied by thermal gravimetry and differential scanning calorimetry. The LN ...

Application of thermal analysis methods for damage assessment of leather in an old military coat belonging to the History Museum of Braşov—Romania

The aim of this work has been the assessment of the thermo-oxidative, hydrothermal and crystalline zone stabilities of several leather samples taken by the conservators from a military coat dated sixteenth–seventeenth centuries, belonging to the History Museum of Braşov—Romania. For this purpose, the thermo-gravimetry/derivative thermo-gravimetry (TG/DTG), differential scanning ...

Starch-g-poly(benzyl methacrylate) copolymers

The physicochemical properties such as swelling in polar and non-polar solvents, moisture resistance, chemical resistance, ability for gelatinization and the thermal properties along with the evolution of volatile decomposition products of some starch-g-copolymers obtained through the grafting of benzyl methacrylate monomer onto potato starch have been studied. The chemical ...

Application of hot-stage microscopy to evaluating sample morphology changes on heating

Investigations of the thermal properties of a raw material or a ceramic product under a hot-stage microscope allow, among others, determining the characteristic temperatures corresponding to the changes of the shape and the cross-section area of samples being heated. They are based on observing and analysing images of the sample recorded with the growth of its temperature. The ...

Supermolecular structure and nucleation ability of polylactide-based composites with silica/lignin hybrid fillers

In this paper, amorphous silica Syloid 244 and kraft lignin were mechanically coupled. Four hybrid materials containing silica and lignin in ratios 1:1, 2:1, 5:1 and 20:1 were prepared. As reference samples for hybrid fillers pristine silica and lignin were used. Particle size determination and microscopic observations were applied to determine dispersive and morphological ...

Effect of heat treatment on the physicochemical properties of nitrogen-enriched activated carbons

A series of functionalized carbonaceous adsorbents were prepared by means of reaction with urea and chemical activation of Polish brown coal. In order to obtain nitrogen groups bonded in different ways to the carbon structure, the reaction with urea was performed at two different stages of processing, with precursor or char. Additionally, the influence of annealing under nitrogen ...

Thermal analysis of the products of alkali activation of fly ash from CFB boilers

Currently, in the energy sector circulating fluidized bed boilers are popularly used, resulting in the production of large amounts of fly ash. Due to the limited possibilities of utilization, the development of technology for their processing is crucial. One of the most promising and intensively studied ways to exploit fly ash (including those derived from fluidized bed boilers) is ...

Effect of side substituents on thermal stability of the modified chitosan and its nanocomposites with magnetite

Three different novel chitosan derivatives for medical or biotechnological applications have been successfully obtained by chemical modification of reactive amino and hydroxyl groups in chitosan chain. The modification has led to incorporation of different amount (one to three) of long-distanced amino and imine groups into each repeating unit. These highly functionalized chitosan ...

Thermal, spectroscopic and dissolution studies of lovastatin solid dispersions with acetylsalicylic acid

Lovastatin (LOV) is widely used for the treatment of hypercholesterolemia. The poor water solubility of LOV leads to its poor gastrointestinal absorption and results in poor bioavailability. In this study, a preparation of solid dispersions with acetylsalicylic acid (ASA) was studied to improve the dissolution rate of LOV. Solid dispersions were prepared using various mass ratios ...

Liquid–crystal equilibrium application for 2,3-DNT initial thermal decomposition analysis

2,3-Dinitrotoluene (2,3-DNT) thermal decomposition and its products were studied. Main attention was paid on the initial stage of decomposition, because the degradation of even a few percent of high energetic compound may cause significant hazard. Partial decomposition of 2,3-DNT was performed conditioning at the temperature range of 457–568 K. Impurities production at the initial ...

Effect of carbonate minerals on the thermal stability of fertilisers containing ammonium nitrate

Fertilisers containing ammonium nitrate are the most efficient sources of nitrogen used in agriculture. The major hazard associated with production, storage and transport of materials containing this compound is its liability to rapid decomposition, or even detonation under certain conditions. Properly selected calcium and magnesium carbonates may increase the thermal stability of ...

An experimentally validated numerical model of interface advance of the lithium sulfate monohydrate dehydration reaction

Interface advance plays an essential role in understanding the kinetics and mechanisms of thermal decomposition reactions such as the dehydration reaction of lithium sulfate monocrystals. However, many fundamental processes including mass transfer during interface advance are still not clear. In this work, the dynamics of interface advance, involving interaction between interfacial ...

Thermodynamic study of competitive inhibitors’ binding to urease

Three competitive inhibitors of urease: boric acid, 2-mercaptoethanol and phosphate buffer pH 6.45, were subjected to the studies of temperature effects on their binding to the enzyme. The first of their kind for these systems, the studies were carried out at temperatures between 15 and 35 °C in HEPES buffers. The Michaelis K M and inhibition K i constants determined for the ...

The influence of polyoxymethylene molar mass on the oxidative thermal degradation of its nanocomposites with hydroxyapatite

In this paper, the influence of mass-average molar mass (M w) of polyoxymethylene (POM) copolymer on the thermooxidative degradation behavior of its nanocomposites with hydroxyapatite (HAp) is reported. POM copolymers’ thermal stability slightly decreases with a decrease in mass-average molar mass. Thermal stability of POM/HAp nanocomposites is lower in comparison with pure POM, ...

Synthesis and thermal behavior of triblock semifluorinated n-alkanes

A series of semifluorinated long-chain triblock alkanes of the general formula: H(CH2)n(CF2)6(CH2)nH, abbreviated as HnF6Hn, where n = 12, 14, 16, 18 and 20, have been synthesized in two steps, by radical addition of 1,6-diiodoperfluorohexane I(CF2)6I to two equivalents of an appropriate terminal alkene CH2 = CH(CH2)n−2H, followed by subsequent deiodination. This novel class of ...

Nanoparticle distribution in NR/BR blend

The distribution of carbon black (CB) nanoparticles in natural rubber/polybutadiene (NR/BR) blend was evaluated by DSC and AFM. The restriction of BR due to the interaction between BR and CB was smaller than that of NR from the glass transition behavior. The AFM phase images of NR/BR blend with and without CB were observed at various at 370 kHz. The phase-separated structures of ...

Effect of carbon fibers on thermal properties and mechanical strength of ceramizable composites based on silicone rubber

Ceramizable (ceramifiable) silicone composites are one of the most important elastic technical materials produced industrially. These composites are commonly used to increase flame retardancy of electrical cables and to ensure integrity of electricity network during fire by their ability to create a continuous ceramic structure. In this paper, ceramizable silicone composites filled ...

Synthesis, spectral and thermal study of La(III), Nd(III), Sm(III), Eu(III), Gd(III) and Tb(III) complexes with mefenamic acid

New binuclear complexes of La(III), Nd(III), Sm(III), Eu(III), Gd(III) and Tb(III) ions with mefenamic acid were obtained in solid phase. For all compounds considered, complexation occurs at pH 6–6.5. The analyzed complexes were characterized on the basis of chemical and elemental analyses, molar conductance, UV–Vis, IR and 1H NMR spectroscopies as well as thermoanalytical ...

Studies on the redox reaction kinetics of selected, naturally occurring oxygen carrier

This paper presents the results of a chemical-looping combustion (CLC) study. The CLC technology is believed to be one of the most promising combustion technologies. The production of a concentrated CO2 stream that is obtained after the water condensation without any loss of energy in its separation is one of the most crucial advantages of this technology. The objective of this ...

Thermal properties of hot-pressed aluminum nitride–graphene composites

This paper concerns the modification of thermal properties of aluminum nitride polycrystalline ceramic material with high thermal conductivity coefficient. The way to change these properties was to distribute graphene particles in the high-conductive matrix. The composite material was hot-pressed at 1900 °C under 25 MPa pressure. The applied pressure allowed to orient the graphene ...