Search results for "thermogravimetric analysis"
showing 10 items of 212 documents
A tris-oxovanadium pyrogallate complex: synthesis, structure, and magnetic and electronic properties
2021
International audience; With the aim of identifying new cation-phenolate complexes, we herein investigated the reactivity of pyrogallol (H(3)pgal) with vanadium salts. A trimetallic anionic complex was identified, and found to be formed under a broad set of reaction conditions. This complex, with the formula V3O3(pgal)(3)(3-), consists of three oxovanadium(iv) units connected together by three pyrogallate ligands to afford a bowl-shaped species presenting a pseudo 3-fold symmetry axis. Its crystal structure is reported, as well as its characterisation by a broad set of techniques, including powder X-ray diffraction, thermogravimetric analysis, infrared and Raman spectroscopy, and solid stat…
Characterization of thermoelectric and thermogravimetric properties of conductive PEDOT:PSS films blended with SWCNTs and PVA
2019
Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was blended with polyvinyl alcohol (PVA) and single-walled carbon nanotube (SWCNT) filler to form composites with thermoelectric properties. Studied samples were obtained by drop coating and solution casting methods. Thermoelectric measurements of PEDOT:PSS demonstrated that the addition of 5 wt. % SWCNTs increased the Seebeck coefficient value from 8.0 μV/K to 23.6 μV/K, while in the case of PEDOT:PSS/PVA blended with 5 wt. % SWCNT Seebeck coefficient value of 20.3 μV/K was achieved. Thermogravimetric analysis showed slight SWCNT effect on thermal stability of the investigated systems.
A Maze of Solid Solutions of Pimobendan Enantiomers: An Extraordinary Case of Polymorph and Solvate Diversity
2017
Over 10 polymorphs and solvatomorphs of the chiral pharmaceutically active ingredient pimobendan were found to lack enantioselectivity in the solid state, accordingly, forming solid solutions of enantiomers, which is reported to be a rare phenomenon. Solid form screening was performed on different enantiomeric composition samples to analyze obtained phases with powder X-ray diffraction and thermogravimetric differential scanning calorimetry. For nonsolvated forms, a melt phase diagram has been constructed convincingly showing the existence of stable and metastable solid solutions near the pure enantiomer and around the racemic composition regions. A crystal structure study combined with sol…
Ecocompatible Halloysite/Cucurbit[8]uril Hybrid as Efficient Nanosponge for Pollutants Removal
2016
Hybrid materials based on halloysite nanotubes (HNT) and cucurbit[8]uril (CB[8]) were prepared with the aim to obtain efficient nanosponges towards hydrocarbons both in liquid and vapor phases. The loading on both HNT surfaces and the hybrid morphology were evidenced by FTIR spectroscopy, thermogravimetric analysis and scanning electron microscopy. In order to highlight the interactions in the hybrid 13C {1H} CP-MAS NMR experiments were performed. The aqueous colloidal stability of HNT/CB[8] was highlighted through ζ potential and dynamic light scattering measurements. The HNT/CB[8] composite was employed as nanosponge to capture aromatic oils in aqueous phase as evidenced by fluorescence e…
Nafion® and polyaniline composite modification with Li and Mg ions
2019
Funding from European Union`s Horizon 2020 Research and Innovation Program project under grant agreement No 768789 is greatly acknowledged.
Characterization and reactivity of charcoal from high temperature pyrolysis (800-1600°C)
2019
This study presents the effect of wood origin and heat treatment temperature on the CO2 reactivity, nanostructure and carbon chemistry of chars prepared at 800, 1200, and 1600 °C in slow pyrolysis reactors. The structure of charcoal was characterized by transmission electron microscopy, Raman spectroscopy, mercury intrusion porosimetry and N2 adsorption. The CO2 reactivity of char was investigated by thermogravimetric analysis. Results showed that spruce and oak chars have similar reactivity at all heat treatment temperatures. The oak char prepared at 1600 °C contained long and flat graphene layers and interplanar distance that is similar to graphite and thus, was more ordered t…
On the self-heating behavior of upgraded biochar pellets blended with pyrolysis oil: Effects of process parameters
2020
Abstract Biochar obtained from biomass pyrolysis is a promising carbon neutral material which can be used in substitution of fossil coal and coke in metallurgical applications. Biochar’s mechanical properties improve significantly without compromising reactivity, when upgraded by densification with pyrolysis oil and reheated. However, upgraded biochar pellets use in the industry is limited due to the risks associated with self-heating. This issue must be seriously considered for further industrial production of upgraded biochar pellets. Self-heating oven tests are generally time-consuming and limit the possibility of testing various potential solutions. The aim of this work was both to inve…
Simulation of abrasion–corrosion at high temperatures by in situ pulsed laser spallation of oxide films
1999
Abstract A pulsed Nd:YAG laser combined with a thermogravimetric cell has been used to spall in situ the oxide films grown on a Fe–2.25Cr–1Mo steel at high temperature in oxidizing media. This technique allows to define the oxidation rate of bare metal surfaces, which can be used to simulate the corrosion-dominated regime during slurry–erosion tests.
One step grafting of monomethoxy poly(ethylenglycol) during synthesis of maghemite nanoparticles in aqueous medium
2008
Abstract Grafting of silanated monomethoxy poly(ethylene glycol) (m-PEG) onto maghemite nanoparticles surface in aqueous medium through one step procedure was investigated. The major characteristic of this work is that the grafting of m-PEG was produced during the synthesis of maghemite nanoparticles. The maghemite nanoparticles were characterized by photon correlation spectroscopy (PCS), zeta potential measurement, X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS). The spinel structure of maghemite nanoparticles was verified and successful grafting of m-PEG was evid…
Effect of plasma treatment on the properties of Arundo Donax L. leaf fibres and its bio-based epoxy composites: A preliminary study
2016
Abstract A preliminary investigation about the effect of plasma treatment on the properties of natural fibres extracted from the leaf of the giant reed Arundo Donax L. and their compatibility with a bio-based epoxy resin is performed. To this aim, the influence of plasma treatment on the functional groups and on the thermal behaviour of fibre were investigated using Fourier transform infrared spectroscopy and thermogravimetric analysis. Moreover, the mechanical characterization of fibres was performed through fibre tensile tests. Short randomly oriented fibres/bio-based epoxy composites were manufactured by hand lay-up method followed by compression moulding, varying both fibres weight cont…