scholarly journals Catalysis of the Thermal Decomposition of Transition Metal Nitrate Hydrates by Poly(vinylidene difluoride)

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3112
Author(s):  
Lasanthi Sumathirathne ◽  
William B. Euler

Poly(vinylidene difluoride) (PVDF) doped with transition metal nitrate hydrates are cast into thin films giving a high β-phase content. Analysis of the thermal behavior of the doped PVDF shows that the decomposition of the metal (II) nitrate hydrates to metal (II) oxides is catalyzed by the PVDF, as evidenced by reduction in the decomposition temperature by as much as 170 °C compared to the pure metal salts. In contrast, there is little to no apparent catalysis for the decomposition of the metal (III) nitrate hydrates. The FTIR spectra of the gas phase decomposition products show H2O and NO2 are the major components for both PVDF-doped material and the pure metal nitrate hydrates. A mechanism for the role of PVDF is proposed that uses the internal electric field of the ferroelectric phase to orient the nitrate ions and polarize the N-O bonds.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Nur Athirah Abdullah ◽  
Sharizal Hasan ◽  
Nafisah Osman

The role of a combination between citric acid (CA) and ethylenediaminetetra acetic acid (EDTA) as chelating agents in preparation of BaCe0.54Zr0.36Y0.1O2.95powder by a modified sol-gel method is reported. The precursor solutions were prepared from metal nitrate salts (M+), chelating agents (C), and ethylene glycol (EG) at molar ratio of M+ : C : EG = 3 : 2 : 3. Chemical and phase transformation of samples during thermal decomposition were analyzed by thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. TGA results show that the sample prepared by a combination of CA-EDTA exhibited the lowest thermal decomposition temperature,Ttdsince there was no significant weight loss after 750°C. After calcined at 1100°C, the carbonates residue remained in the samples as proven by FTIR results. It was found that the used combination of CA-EDTA acts as a better combustion reagent to increase the reaction rate and influence the thermal decomposition behaviour compared to a single citric acid and EDTA, respectively. Apparently, calcination temperatures above 1100°C are needed to produce a pure perovskitic BaCe0.54Zr0.36Y0.1O2.95.


Author(s):  
Lars Mohrhusen ◽  
Jessica Kräuter ◽  
Katharina Al-Shamery

The photochemical conversion of organic compounds on tailored transition metal oxide surfaces by (UV) irradiation has found wide applications ranging from the production of chemicals to the degradation of organic...


2021 ◽  
Author(s):  
Rabia Jamil ◽  
Rashad Ali ◽  
Suraj Loomba ◽  
Jian Xian ◽  
Muhammad Yousaf ◽  
...  

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 286
Author(s):  
Edward R.T. Tiekink

A search of the Cambridge Structural Database was conducted for pyridyl-substituted dithiocarbamate ligands. This entailed molecules containing both an NCS2− residue and pyridyl group(s), in order to study their complexation behavior in their transition metal and main group element crystals, i.e., d- and p-block elements. In all, 73 different structures were identified with 30 distinct dithiocarbamate ligands. As a general observation, the structures of the transition metal dithiocarbamates resembled those of their non-pyridyl derivatives, there being no role for the pyridyl-nitrogen atom in coordination. While the same is true for many main group element dithiocarbamates, a far greater role for coordination of the pyridyl-nitrogen atoms was evident, in particular, for the heavier elements. The participation of pyridyl-nitrogen in coordination often leads to the formation of dimeric aggregates but also one-dimensional chains and two-dimensional arrays. Capricious behaviour in closely related species that adopted very different architectures is noted. Sometimes different molecules comprising the asymmetric-unit of a crystal behave differently. The foregoing suggests this to be an area in early development and is a fertile avenue for systematic research for probing further crystallization outcomes and for the rational generation of supramolecular architectures.


2014 ◽  
Vol 76 ◽  
pp. S124
Author(s):  
Juan Du ◽  
Brett A Wagner ◽  
Garry R Buettner ◽  
Joseph J Cullen

1975 ◽  
Vol 25 (11) ◽  
pp. 1201-1207 ◽  
Author(s):  
J. Málek ◽  
R. A. Evarestov ◽  
A. N. Ermoshkin ◽  
B. Hejda ◽  
K. Polák

1989 ◽  
Vol 161 (5-6) ◽  
pp. 574-580 ◽  
Author(s):  
X.X. Tang ◽  
A. Manthiram ◽  
J.B. Goodenough

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