Epoxy resins, namely diglycidyl ether bisphenol-A (DGEBA) and carboxylated polyester (CPE), are versatile materials used in powder coatings. Such powder coatings are called hybrid coatings, where they are
Authors:M. Zaharescu, A. Jitianu, A. Brãileanu, V. Bãdescu, G. Pokol, J. Madarász, and Cs. Novák
The hydrolysis-polycondensation of organically modified Si-alkoxides leads to the obtaining of inorganic-organic hybrid materials
in which the organic moieties remain as permanent groups bonded to the inorganic network.
The molecular species previously determinated by GC-MS during the gelation process have been significantly different according
to the type of the alkoxide used.
In the present work, thermal stability of SiO2-based inorganic-organic hybrid materials starting with TEOS (tetraethoxysilan), MTEOS (triethoxymethylsilan), VTEOS (triethoxyvinylsilan)
and MTMOS (trimethoxymethylsilan) was studied.
The molecular structure of the gels obtained determines differences in their thermal behaviour. Gels obtained starting with
MTEOS show the highest thermal stability, while gels obtained using VTEOS the lowest, among the substituted alkoxides. A particular
behaviour presents the gel obtained with MTMOS that decomposes in four steps. This could be explained by the presence in the
gel of some prevalent types of molecular species with different thermal stability.
A new phase of the hybrid fibrous ion exchanger, pyridine based cerium(IV) phosphate (PyCeP), has been synthesized in the
form of a sheet like paper by mixing ceric sulphate, phosphoric acid and pyridine in a particular ratio to get the material
of the optimum ion exchange characteristics. This material has been characterized with the help of ion exchange capacity,
elution and concentration and pH titrations behaviour in addition to some physicochemical studies like X-ray diffraction,
IR, TG, DTG and SEM studies. The SEM study confirms the fibrous nature of the material while amorphous nature is revealed
by its X-ray spectrum.
Authors:Árpád Illés, Csaba Bojtor, Seyed Mohammad Nasir Mousavi, L. Csaba Marton, Péter Ragán, and János Nagy
) ( Gombos & Nagy, 2019 ). In the scope of the experiment, in 2019 three maize ( Zea mays L.) hybrids with different maturity groups like H1 = FAO 400, H2 = FAO 330, H3 = FAO 490 were studied in long-term experiment, where the environment promotes the large
Authors:A. Rekondo, L. Irusta, and M. Fernández-Berridi
The thermal behaviour of a new kind of hybrid system based on silanized poly(ether-urethanes) (SPURs) has been analyzed by
thermogravimetric analysis (TG). The influence of the chemical nature of employed alkoxysilanes, polyether diol molecular
weight and the physical state of the obtained hybrids (cured and non-cured) has been studied. The results show that in the
non-cured state, aminosilane-based systems present a higher stability compared with those based on isocyanatesilane. However,
in the cured state, both types of hybrids present a similar thermal stability, but much higher than their corresponding partners
before the curing process. The presence of the inorganic silica network improves the thermal stability of all the systems
Authors:M. Portela Marques, I. Miranda Salvado, F. Margaça, and L. Ferreira
Hybrid materials were prepared by sol–gel method using Tetraethylortosilicate and Polydimethylsiloxane silanol terminated
with the addition of small contents of Zirconium Propoxide ≤5 wt%. The thermal stability of the prepared samples was studied
by Infra-red spectroscopy, 29Si Nuclear Magnetic Resonance, Thermal Analysis and Scanning Electron Microscopy. All samples were monolithic after drying
at 120 °C. After heat treatment at 400 °C the samples prepared with 0 wt% in Zirconium Propoxide present high porosity. It
was found that the content in Zirconium Propoxide is directly related with the thermal stability of the hybrid materials prepared
in this study.
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:S. Musavi Nasab, A. Negarestani, and S. Mohammadi
A new model based on electric circuit theory has been introduced for modeling the radon exhalation from water to air in a
sample bottle. Comparing the differential equations for radon exhalation from water to air and a hybrid electrical circuit
shown that the volume of water or air, radon concentration, radon flux and solubility coefficient (dependent on temperature
of water) are equivalent with capacitance, voltage across of capacitor, current and voltage gain, respectively. Then by using
a hybrid electrical model total radon transfer velocity from water to air and time variation of water radon concentration
in our experimental setup has been obtained. Also the variations of air radon concentration with temperature, volume of water
and volume of air is obtained. The results show a good agreement with those in literatures.
Authors:Ana Alves, André Silva, Oberto da Silva, Maria da Fonseca, Luiza Arakaki, and J. Espínola
Silylation of vermiculite surface with organosilane (H3CO)3SiR,
being R is the corresponding organic moieties
were carried out to yield organofunctionalized nanomaterial, named as VCl.
The product reacted subsequently with three aliphatic diamines H2N
(n=2, 4 and 6). The new hybrids were characterized
by elemental analysis, infrared spectroscopy, X-ray diffraction and thermogravimetry.
The grafting chloro derivates onto surface amounted to 2.1 mmol g–1.
The incorporation of alkyl amines was more effective for butyl>ethylene>hexyldiamines.
The sequence is in agreement with thermogravimetry and elemental analysis
Authors:Jung-Hoon Song, Min-Chul Song, Kyeong-Ho Yeon, Jung-Bae Kim, Kun-Jai Lee, and Seung-Hyeon Moon
A magnetic filter — continuous electrodeionization (CEDI) hybrid separation system was investigated for the purification of the primary coolant in a nuclear power plant. A magnetic filter system with a 3000 Gauss magnetic field and a CEDI system with a cell consisting of 3 compartments were used for the removal of magnetite and nickel ions, respectively. The hybrid separation system achieved removal rates of 98% for magnetite and 99% for the nickel ions demonstrating its feasibility for the purification of primary coolant.