Effects of Reaction Medium on the Phase Synthesis and Particle Size Evolution of BaTiO3

2010 ◽  
Vol 93 (10) ◽  
pp. 3443-3448 ◽  
Author(s):  
Tomasz M. Stawski ◽  
Sjoerd A. Veldhuis ◽  
Ole F. Göbel ◽  
Johan E. Ten Elshof ◽  
Dave H. A. Blank
2018 ◽  
Author(s):  
Ping Peng ◽  
Fang-Fang Li ◽  
Xinye Liu ◽  
Jiawen Ren ◽  
jessica stuart ◽  
...  

The rate of ammonia production by the <u>chemical </u>oxidation of iron, N<sub>2</sub>(from air or as pure nitrogen) and water is studied as a function of (1) iron particle size, (2) iron concentration, (3) temperature, (4) pressureand (5) concentration of the alkaline reaction medium. The reaction meduium consists of an aqueous solution of equal molal concentrations of NaOH and KOH (Na<sub>0.5</sub>K<sub>0.5</sub>OH). We had previously reported on the <u>chemical </u>reaction of iron and nitrogen in alkaline medium to ammonia as an intermediate step in the <u>electrochemical </u>synthesis of ammonia by a nano-sized iron oxide electrocatlyst. Here, the intermediate <u>chemical </u>reaction step is exclusively explored. The ammonia production rate increases with temperature (from 20 to 250°C), pressure (from 1 atm to 15 atm of air or N<sub>2</sub>), and exhibits a maximum rate at an electrolyte concentration of 8 molal Na<sub>0,5</sub>K<sub>0,5</sub>OH in a sealed N<sub>2</sub>reactor. 1-3 µm particle size Fe drive the highest observed ammonia production reaction rate. The Fe mass normalized rate of ammonia production increases with decreasing added mass of the Fe reactant reaching a maximum observed rate of 2.2x10<sup>-4</sup>mole of NH<sub>3</sub>h<sup>-1</sup>g<sup>-1</sup>for the reaction of 0.1 g of 1-3 µm Fe in 200°C 8 molal Na<sub>0.5</sub>K<sub>0.5</sub>OH at 15 atm. Under these conditions 5.1 wt% of the iron reacts to form NH<sub>3</sub>via the reaction N<sub>2</sub>+ 2Fe + 3H<sub>2</sub>O ®2NH<sub>3</sub>+ Fe<sub>2</sub>O<sub>3</sub>.


2001 ◽  
Vol 360-362 ◽  
pp. 317-322 ◽  
Author(s):  
Jamie Guerrero-Paz ◽  
F. Robles-Hernandez ◽  
Roberto Martínez-Sánchez ◽  
D. Hernández-Silva ◽  
D. Jaramillo-Vigueras

1993 ◽  
Vol 327 ◽  
Author(s):  
Aloysius F. Hepp ◽  
Maria T. Andras ◽  
Christopher C. Landry ◽  
Andrew R. Barron

AbstractWe have discovered a novel two-phase synthesis of CuInSe2 at 25° from Cu2Se and (C5H5)3In in 4-methylpyridine (4-MePy). An analogous reaction to produce CulnS2 must be run at 140°C in refluxing 4-MePy in the presence of 2-mercaptopyridine. Microscopy of CuInSe2 produced at 25°C shows it to be platelet-shaped crystallites with an approximate particle size of 10 microns, less than 2% C and H, with a small amount of unidentified crystalline impurity. Our results demonstrate that it is possible to produce from solution a material that is ordinarily synthesized in bulk or films at much higher temperatures or using extraneous reagents and/or electrons.


2020 ◽  
Vol 20 (3) ◽  
pp. 267-276
Author(s):  
Mariana Daniela Berechet ◽  
Demetra Simion ◽  
Maria Stanca ◽  
Cosmin-Andrei Alexe ◽  
Ciprian Chelaru ◽  
...  

Keratin hydrolysates were obtained from sheep wool by alkaline hydrolysis at different concentrations of KOH (3%, 5% and 8%) and temperatures (75°C, 85°C, 95°C and 99°C) of the reaction medium. The protein content of the keratin extracts was between 65.54% and 87.10%. Particle measurements showed a decrease in particle size with the increase of concentration and temperature of the reaction medium. The ATR-FTIR spectra revealed specific bands to proteins and sulfur originated from keratin amino acids. The keratin hydrolysate type KerK895 was further investigated as organic fertilizer for two types of wheat seeds. The results showed that the use of 5% KerK895 led to the increase of the wheat stems lengths by 10.7% for Mirastar wheat and 18.3% for Tamino wheat, respectively, compared to control sample. Keratin hydrolysates are promising biopolymers as organic fertilizers in agriculture applications.


2018 ◽  
Author(s):  
Ping Peng ◽  
Fang-Fang Li ◽  
Xinye Liu ◽  
Jiawen Ren ◽  
jessica stuart ◽  
...  

The rate of ammonia production by the <u>chemical </u>oxidation of iron, N<sub>2</sub>(from air or as pure nitrogen) and water is studied as a function of (1) iron particle size, (2) iron concentration, (3) temperature, (4) pressureand (5) concentration of the alkaline reaction medium. The reaction meduium consists of an aqueous solution of equal molal concentrations of NaOH and KOH (Na<sub>0.5</sub>K<sub>0.5</sub>OH). We had previously reported on the <u>chemical </u>reaction of iron and nitrogen in alkaline medium to ammonia as an intermediate step in the <u>electrochemical </u>synthesis of ammonia by a nano-sized iron oxide electrocatlyst. Here, the intermediate <u>chemical </u>reaction step is exclusively explored. The ammonia production rate increases with temperature (from 20 to 250°C), pressure (from 1 atm to 15 atm of air or N<sub>2</sub>), and exhibits a maximum rate at an electrolyte concentration of 8 molal Na<sub>0,5</sub>K<sub>0,5</sub>OH in a sealed N<sub>2</sub>reactor. 1-3 µm particle size Fe drive the highest observed ammonia production reaction rate. The Fe mass normalized rate of ammonia production increases with decreasing added mass of the Fe reactant reaching a maximum observed rate of 2.2x10<sup>-4</sup>mole of NH<sub>3</sub>h<sup>-1</sup>g<sup>-1</sup>for the reaction of 0.1 g of 1-3 µm Fe in 200°C 8 molal Na<sub>0.5</sub>K<sub>0.5</sub>OH at 15 atm. Under these conditions 5.1 wt% of the iron reacts to form NH<sub>3</sub>via the reaction N<sub>2</sub>+ 2Fe + 3H<sub>2</sub>O ®2NH<sub>3</sub>+ Fe<sub>2</sub>O<sub>3</sub>.


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