Papers by Keyword: Thermogravimetry

Abstract: The use of biomass as an alternative fuel to reduce the use of fossil fuels continues to increase, one of which is palm kernel shell (PKS) waste. This study investigated the pyrolysis reactivity of biomass samples (PKS) through thermogravimetric analysis. In addition, the pyrolysis mechanism is approached through the activation energy determined from the model used. This study utilized palm kernel shells as biomass with the addition of iron ore as a catalyst. The TGA test was carried out with variations in the catalyst composition (0, 10, and 15% of total mass) and heating rates (5, 10, and 15 °C/min) of the pyrolysis process. The kinetic parameter, E, was estimated using the independent model method, namely FWO (Flynn Wall Ozawa) and KAS (Kissinger Akahira Sunose). The study showed that the concentration effect on the conversion rate was almost the same for all concentrations in heating rate of 10 °C/men. The heating rate of 15 °C/min provided the highest conversion rate compared to the other two heating rates. Furthermore, the activation energy values fluctuated in the kinetic analysis using the FWO and KAS methods. Besides, the best fit is obtained from the conversion of 0.2-04 and 0.8-0.9.

Abstract: Solution Spray Pyrolysis (SST) was successfully implemented to fabricate thin perovskite and fluorite films on dense Yttria Stabilized Zirconia (YSZ) and Lanthanum Strontium Ferrate (LSF70) substrates. These composite structures are ubiquitous in solid oxide fuel cells and electrolyzers, CO gas sensors and ceramic membranes. With this technique, successful in situ manipulation of the film’s functional characteristics such as porosity and thickness is easily achieved by adjusting its functional parameters.In the present contribution, we report on the optimization of the physicochemical parameters of this open atmosphere technique with respect to the substrate temperature and deposition time for the fabrication of films of suitable morphology. Sintered films were characterized by XRD and SEM while thermal analysis was performed on the precursor salts. In addition, AC Impedance analysis was performed on some CGO films in order to assess their electron blocking capability in contact with the LSF substrates.

Abstract: Innovative preparation strategies for nanomaterial functionalization were proposed to provide novel tool to be used as drug delivery vectors for biomedical applications. In particular, three different carbon nanotubes were considered in this study such as the very small CNTs, the carboxylated CNTs (CNT-COOH) and the buckypapers and two polymers were used to study the functionalization. Different preparation procedures were investigated by thermogravimetric analysis (TGA), including the selection of the most performing polymer to be linked to the nanomaterial between PEI and PAMAM, the percentage of the polymer and the time of suspension. To simultaneously evaluate all these variables, an experimental design was planned and the recorded data were processed by chemometrics to identify the preparing procedure providing new nanomaterials able to conjugate microRNAs and to transfect efficiently endothelial cells.

Abstract: The complex oxide BaLaIn_0.9Nb_0.1O_4.1 with Ruddlesden-Popper structure was obtained for the first time. It was found that the introduction of niobium into indium sublattice leads to the increase in the cell volume. Hydration processes and electrical properties have been investigated. For BaLaIn_0.9Nb_0.1O_4.1 it was proved the capability for water uptake and the appearance of proton current carriers. It was established that niobium doping leads to the increase of conductivity compared to undoped composition BaLaInO₄ at ~1 order of magnitude in whole temperature range.

Abstract: The processes of pyrolysis and burning of rubber based on synthetic rubbers are studied. It is determined that teflon (polytetrafluoroethylene) thereby reducing rubber burning rate doubled from 0.25 mm/s to 0.14 mm/s based on a mixture of isoprene and butadiene-styrene rubbers.

Abstract: Identified in work dependency allow to predict the flammability properties, rate of coke combustion and height butadiene-nitrile rubberswith BS-120 white carbon additives and novolac phenol-formaldehyde SF010A resins.

Abstract: The processes of pyrolysis and combustion of rubber-based synthetic rubbers were studied. Determined that Teflon (polytetrafluoroethylene) helps reduce the rate of burning rubber in half, from 0.25 mm/s to 0.14 m/s based on a mixture of isoprene and butadiene-styrene rubbers

Abstract: The temperature-time regimes of drying of polyetheretherketone were revealed, during which it is completely possible to get rid of sorption water. The upper limit of the drying temperature is established, above which the thermal stability of polymers deteriorates markedly.

Abstract: Ultrafine powders of β-Sialon were prepared by the combined sol-gel and microwave carbothermal reduction nitridation method, and their oxidation process was studied by a non-isothermal thermogravimetry method. The results indicated that two different mechanism functions respectively corresponded to the initial and final oxidation stages. The reverse Jander equation with activation energy of 240.5 kJ/mol and the Avrami-Erofeev equation with activation energy of 410.7 kJ/mol were respectively identified as the most probable mechanism function for the initial and final oxidation stages in the temperature range of 1423-1623 K.

Abstract: The oxyhalides Ba₂InO₃F, Ba₂InO₃Cl, and Ba₂InO₃Br were synthesized using the solid state method. It was found that the increasing of halide ion radius leads to the increase of lattice parameters and also caused to redistribution of indium-oxygen bond lengths. The possibility of water uptake was proved by thermogravimetry measurements. The presence of different forms of oxygen-hydrogen groups in the structure of hydrated oxyhalides was indicated by infrared spectroscopy.