Synthesis and Characterization of Zinc Phosphates in Aqueous and Non-Aqueous Media with (2-Hydroxyethyl) Trimethyl Ammonium Hydroxide as Template

2010 ◽  
Vol 305-306 ◽  
pp. 89-94
Author(s):  
A. Samadi Maybodi ◽  
S.K. Hassani Nejad-Darzi

Zinc phosphate molecular sieve were synthesized using zinc chloride, phosphoric acid as a zinc and phosphor source, respectively. Different types of zinc phosphates zeolites were synthesized by conventional hydrothermal (using (2-hydroxyethyl) trimethylammonium hydroxide (2-HETMAOH) as new template. Also, ethylene glycol (EG) was utilized as co-solvent and ultrasonic tool was applied as mixer. The influence of the chemical composition of the starting sol-gel and the other parameters such as, Zn/P mole ratio, time of microwave irradiation were studied.

2009 ◽  
Vol 3 (1-2) ◽  
pp. 88-95 ◽  
Author(s):  
Nikolina Pavlovic ◽  
Dejan Kancko ◽  
Mészáros Szécsényi ◽  
Vladimir Srdic

Bismuth titanate based nanopowders with the different content of La or Ce were synthesized by the modified sol-gel method. After calcination at 600?C, in addition to Aurivillius layered structure, a small quantity of cubic pyrochlore phase was detected in the La modified powders, while this second phase was much more pronounced in the Ce substituted powders. In fact, as the powder with the highest amount of Ce (Bi3CeTi3O12) has the pure pyrochlore phase it seems that the presence of Ce stabilizes the formation of this phase. This different influence of cerium and lanthanum could be explained by the incorporation of their ions on the different sites in the titanate structure. Bismuth titanate based ceramics, sintered at 1050?C/2h, had densities above 93% of theoretical density and characteristic plate-like grain morphology. Small quantity of cubic pyrochlore phase was detected only in the Ce modified bismuth titanate ceramics. On the other hand, lanthanum addition caused formation of smaller grain size with pronounced plate-like morphology. .


2002 ◽  
Vol 37 (2-3) ◽  
pp. 169-175 ◽  
Author(s):  
K. Yanxiong ◽  
L. Jianmin ◽  
Z. Yugen ◽  
H. Gaofei ◽  
J. Zheng ◽  
...  

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 721 ◽  
Author(s):  
Jorge A. Ramírez-Gómez ◽  
Javier Illescas ◽  
María del Carmen Díaz-Nava ◽  
Claudia Muro-Urista ◽  
Sonia Martínez-Gallegos ◽  
...  

Atrazine (ATZ) is an herbicide which is applied to the soil, and its mechanism of action involves the inhibition of photosynthesis. One of its main functions is to control the appearance of weeds in crops, primarily in corn, sorghum, sugar cane, and wheat; however, it is very toxic for numerous species, including humans. Therefore, this work deals with the adsorption of ATZ from aqueous solutions using nanocomposite materials, synthesized with two different types of organo-modified clays. Those were obtained by the free radical polymerization of 4-vinylpyridine (4VP) and acrylamide (AAm) in different stoichiometric ratios, using tetrabutylphosphonium persulfate (TBPPS) as a radical initiator and N,N′-methylenebisacrylamide (BIS) as cross-linking agent. The structural, morphological, and textural characteristics of clays, copolymers, and nanocomposites were determined through different analytical and instrumental techniques, i.e., X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Adsorption kinetics experiments of ATZ were determined with the modified and synthesized materials, and the effect of the ratio between 4VP and AAm moieties on the removal capacities of the obtained nanocomposites was evaluated. Finally, from these sets of experiments, it was demonstrated that the synthesized nanocomposites with higher molar fractions of 4VP obtained the highest removal percentages of ATZ.


2002 ◽  
Vol 126 (2) ◽  
pp. 161-165 ◽  
Author(s):  
Junying Zhang ◽  
Zhongtai Zhang ◽  
Zilong Tang ◽  
Zishan Zheng ◽  
Yuanhua Lin

2014 ◽  
Vol 121 ◽  
pp. 20-29 ◽  
Author(s):  
Tim Van Gestel ◽  
Felix Hauler ◽  
Martin Bram ◽  
Wilhelm A. Meulenberg ◽  
Hans Peter Buchkremer

2003 ◽  
Vol 800 ◽  
Author(s):  
Brady J. Clapsaddle ◽  
Lihua Zhao ◽  
Alex E. Gash ◽  
Joe H. Satcher ◽  
Kenneth J. Shea ◽  
...  

ABSTRACTIn the field of composite energetic materials, properties such as ingredient distribution, particle size, and morphology, affect both sensitivity and performance. Since the reaction kinetics of composite energetic materials are typically controlled by the mass transport rates between reactants, one would anticipate new and potentially exceptional performance from energetic nanocomposites. We have developed a new method of making nanostructured energetic materials, specifically explosives, propellants, and pyrotechnics, using sol-gel chemistry. A novel sol-gel approach has proven successful in preparing metal oxide/silicon oxide nanocomposites in which the metal oxide is the major component. Two of the metal oxides are tungsten trioxide and iron(III) oxide, both of which are of interest in the field of energetic materials. Furthermore, due to the large availability of organically functionalized silanes, the silicon oxide phase can be used as a unique way of introducing organic additives into the bulk metal oxide materials. As a result, the desired organic functionality is well dispersed throughout the composite material on the nanoscale. By introducing a fuel metal into the metal oxide/silicon oxide matrix, energetic materials based on thermite reactions can be fabricated. The resulting nanoscale distribution of all the ingredients displays energetic properties not seen in its microscale counterparts due to the expected increase of mass transport rates between the reactants. The synthesis and characterization of these metal oxide/silicon oxide nanocomposites and their performance as energetic materials will be discussed.


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