Authors:M. Zaharescu, A. Jitianu, A. Braileanu, J. Madarász, and G. Pokol
It is well known that SiO2 -based inorganic-organic hybrid materials present significant differences due to the organic moieties bound to the inorganic
network and to the preparation conditions.
In the present work the ageing effect on the thermal stability of the SiO2 -based inorganic-organic hybrid materials prepared using tetraethoxysilan (TEOS), triethoxymethylsilan (MTEOS), triethoxyvinylsilan
(VTEOS), tetramethoxysilan (TMOS), trimethoxymethylsilan (MTMOS) and trimethoxyvinylsilan (VTMOS) was studied.
TG/DTA-MS was used to study the decomposition process of the materials. The structural modifications of the materials during
ageing were studied using spectral methods.
The gels obtained starting with more reactive alkoxides, of methoxy-type, present more complex structures and are less stable
Authors:Marcela Stoia, Mirela Barbu, Mircea Ştefănescu, Paul Barvinschi, and Lucian Barbu-Tudoran
, and CrPVA were characterized by FT-IRspectrometry and thermal analysis. All precursors were annealed at different temperatures (350, 500, and 1,000 °C), and the obtained products were characterized by FT-IRspectrometry, X-ray diffractometry, and SEM
Authors:Marcela Stoia, Paul Barvinschi, Lucian Barbu Tudoran, Mirela Barbu, and Mircea Stefanescu
controlled thermal decomposition of the precursors at 290 °C, a magnetic powder is obtained which was further annealed at different temperatures. The obtained powders have been characterized by X-ray diffractometry, FT-IRspectrometry, specific surface area
Authors:Mircea Stefanescu, Marcela Stoia, Oana Stefanescu, and Paul Barvinschi
The formation of the coordination compounds between metallic ions and the carboxylate ligands was evidenced by FT-IRspectrometry. Table 2 presents the bands of the characteristic FT-IR spectra and their assignment for D1, D2, D3
Authors:Marcela Stoia, Mircea Stefanescu, Mirela Barbu, Paul Barvinschi, and Lucian Barbu-Tudoran
gels and nanocomposites have been characterized by thermal analysis, infrared Fourier transform (FT-IR) spectrometry, X-ray diffraction (XRD), and transmission electron microscopy (TEM).
The progress of the redox reactions between mixtures of
Authors:Mirela Barbu, Mircea Stefanescu, Marcela Stoia, Gabriela Vlase, and Paul Barvinschi
°C min −1 , using as reference α-Al 2 O 3 .
The synthesized powders were characterized by FT-IRspectrometry with a Shimadzu Prestige FT-IR spectrometer, in KBr pellets, in the range 400–4,000 cm −1 . The phase composition of the powders was
The extraction of U(VI) with newly synthesized alkylamide, N,N-diethyloctadecanamide (DEODA), has been studied. The dependence of the extraction on nitric acid concentration, DEODA concentration and temperature from nitric acid solution has been considered. The extracted species has also been investigated using FT-IR spectrometry. The related themodynamic functions were calculated.
The aim of the study was to investigate the solubility properties of the phosphogypsum a sideproduct of phosphor industry. Phase diagrams of potassium, calcium, hydrogen phosphates, sulphates and water are presented in order to determine equilibrium of solubility. Solid phases were investigated by X-ray diffraction, IR spectrometry and thermal analysis (DTG-DTA).
Authors:P. Antonetti, A. Berrada, M. El Idrissi, Y. Claire, J. Kaloustian, and A. Périchaud
The oxidation of pure and recycled polyethylene samples was studied by thermal analysis (DTA-TG-DSC): presence of two exothermic
peaks and mass loss. The thermo-oxidation products, containing C-O and C=O links, were identified by IR spectrometry and GC-MS
spectrometry. The oxidation is easier from low to high density polyethylene.
Authors:Shao Hua, Han Jing-Tian, Sun Guo-Xin, Bao Bo-Rong, and Sun Si-Xiu
The extraction of uranium(VI) from nitric acid by N-octanoylpiperidine (OPPD) in toluene has been investigated at varying concentrations of nitric acid, extractant, salting-out agent LiNO3 and at different temperatures. The mechanism of extraction is discussed in the light of the results obtained. The extracted species have also been investigated using FT-IR spectrometry. The related thermodynamic functions were calculated.