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Abstract  

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.

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cotton fabrics treated with the hydrolyzed pure precursor sol (DEPTES or APTES) and MF. In addition, the FT-IR spectra of the hybrid thin films, obtained mixing DEPTES with MF or APTES, applied and annealed on the textile samples are shown in Figs. 2

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Abstract  

Hyperbranched epoxy resin (HTDE) has relatively low viscosity and high molecular mass and holds great promise as a functional additive for enhancing the strength and toughness of thermosetting resins. In this work, the curing and thermal degradation kinetics of HTDE/diglycidyl ether of bisphenol-A epoxy (DGEBA) hybrid resin were studied in detail using differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) techniques by Coats–Redfern model. The effect of molecular mass or generation and content of HTME on the activation energy, reaction order, and curing time were discussed; the results indicated that HTDE could accelerate the curing speed and reduce the activation energy and reaction order of the curing reaction.

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Abstract  

A new hybrid ion exchanger, Triton X-100 based tin(IV) phosphate (TX-100SnP) has been synthesized and characterized by ion exchange and physico-chemical methods such as ion exchange capacity, elution and concentration behaviour, IR, X-ray, TG/DTA and elemental analysis. Its adsorption behaviour has also been studied for some alkaline earths and heavy metal ions in different acidic media. It has been found generally more selective for metal ions as compared to tin(IV) phosphate prepared earlier. For Pb(II), Hg(II) and Fe(III) its selectivity has been found to be exceptionally good. On this basis, some binary separations have been performed involving these metal ions. Thermal studies show a high thermal stability of the material. It retains 54.54% of its i.e.c. at 200�C and 27.27% at 300�C.

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Abstract  

Abstract Passive air samplers (polyurethane foam disks) were deployed at 25 urban sites and 66 rural sites over the period of July to October 2005, partly between October 2005 and January 2006 for about 120 days across China, and analyzed for extractable organo-chlorine /-bromine /-iodine (EOCl/EOBr/EOI) and polychlorinated biphenyls (PCBs) using hybrid neutron activation analysis (NAA) combined with gas chromatographymass spectrometry (GC-MS). The average concentration of EOCl, EOBr, EOI and ΣPCBs among all the sites were 173.7, 3.5, 1.0 and 0.74 ng/d, respectively. Higher values of EOCl/Br/I and PCBs were detected in the areas of high usage and high emission, which were linked to relatively high-income areas in China, while lower in the west ill-developed region of China, which indicated that these pollutants mainly came from industrial pollution. Higher EOCl contents in traffic areas stated that the exhaust emission from vehicle was another main source of organochlorines in the air. The relative proportions of the known organochlorines (84 PCB congeners) to total EOCl were 0.02–3.0%, which implied that most of EOCl measured in air were unknown.

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Abstract  

Thermogravimetry (TG) and mass spectrometry (MS) combined techniques have been used to investigate the thermal degradation and catalytic decomposition of high-density polyethylene (HDPE) over solid acid catalysts as H-ZSM-5, Al-MCM-41 and a hybrid material with a bimodal pore size distribution (H-ZSM-5/Al-MCM-41). The silicon/aluminum ratio of all catalysts is 15. Both thermal and catalytic processes showed total conversion in a single mass loss step. Furthermore, the catalytic conversion presents average reduction of 27.4%, in the onset decomposition temperature. The kinetic parameters were calculated using non-isothermal method. These parameters do not indicate significant differences between the thermal and catalytic processes. Even though, the presence of the catalysts changes the reaction mechanism, from phase boundary controlled reaction to random nucleation mechanism. Important difference in distribution of evolved products was detected when several catalysts were used. However, in all cases the main products were alkanes (C2, C3 and C4), alkenes (C3 and C4), dienes (C4 and C5) and traces of aromatic compounds.

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Journal of Thermal Analysis and Calorimetry
Authors: A. Swiderski, A. Wojtal, P. Muras, A. Mikulko, S. Wrobel, and H. Koloczek

Abstract  

The DSC method was used to study phase transitions in Rhododendron L. leaf tissues caused by temperatures below the freezing point of water. The curves show several stages of water crystallisation, demonstrating that these processes do not occur simultaneously in various types of cell organelles. Temperatures and enthalpies of the phase transitions were determined and significant changes were found in the DSC curves when the sample was repeatedly subjected to sub-zero temperature cooling and heating. Also, frost resistance of the same rhododendron taxons was studied by conductometric analysis and the DSC results were compared with the data from other laboratory studies.

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Pyridine based thorium(IV) phosphate hybrid fibrous ion exchanger

Synthesis, characterization and thermal behaviour

Journal of Thermal Analysis and Calorimetry
Authors: K. Varshney, A. Agrawal, and S. Mojumdar

Abstract  

Pyridine based thorium(IV) phosphate (PyThP) has been synthesized by drop-wise addition of the thorium(IV) nitrate with constant stirring into a mixture of pyridine and phosphoric acid. This material has been characterized using X-ray, IR spectra, TG, DTG and SEM studies in addition to its ion exchange capacity, elution and pH titrations. The material has been found amorphous and fibrous in nature on the basis of X-ray diffraction and SEM studies. TG has revealed the changes incurred in the material on thermal treatment and IR spectral studies have shown the presence of various groups in its structure.

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Journal of Thermal Analysis and Calorimetry
Authors: Vincent Janssens, Christophe Block, Guy Van Assche, Bruno Van Mele, and Peter Van Puyvelde

Abstract  

A newly developed hyphenated technique is presented that combines an existing rheometer and differential scanning calorimeter (DSC) into a single experimental setup. Through the development of a fixation accessory inside the cell of the calorimeter and the introduction of an add-on unit for the rheometer, the simultaneous calorimetric and rheological measurement inside the well-controlled thermal environment of a Tzero™ DSC cell opens new experimental possibilities. The evolution of thermal and flow properties of a material can be simultaneously monitored during steady or oscillatory shear flow and regular or modulated temperature DSC measurements. The technique offers interesting opportunities for the investigation of flow-induced transitions, such as crystallization or phase separation, and provides a possibility for high-throughput screening of materials. The signal quality of the novel technique in comparison to the stand-alone techniques is demonstrated by the evaluation of the calibration factors and by measurements on standard materials. Finally, combined rheological and calorimetric melting and crystallization experiments on polycaprolacton are performed.

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Abstract  

Vermiculite was prepared to react with aliphatic diamines (ethylene-, trimethylene-, tetramethylene- and hexamethylene-) diamine. The products were characterized by elemental analysis, infrared spectroscopy and X-ray diffraction. The amounts of diamines adsorbed were 0.89, 0.86, 0.79 and 0.68 mmol g–1, respectively for NH2(CH2)⋅nNH2 where n=2, 3, 4, 6. The basal spacings of the intercalated vermiculites varied between 1300 and 1470 pm. Thermogravimetry and DSC data confirmed intercalation of diamines in gallery space of vermiculite.

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