Synthesis and characterization of lead-free piezoelectric (K0.50Na0.50)NbO3 powder produced at lower calcination temperatures: A comparative study with a calcination temperature of 850 °C

2016 ◽  
Vol 36 (7) ◽  
pp. 1595-1603 ◽  
Author(s):  
Mahdi Feizpour ◽  
Touradj Ebadzadeh ◽  
Darja Jenko
2019 ◽  
Vol 56 ◽  
pp. 142-151
Author(s):  
Hassan Shokry ◽  
Marwa Elkady ◽  
Hesham Hamad

Nano sized ZrO2 nanopowder was synthesized by precipitation method. Phase transformation was investigated as a function of calcination temperature by XRD, SEM , and FT-IR. It is indicated that the thermal anneling from 400 to 800 °C resulted in increasing the average crystallite size from 12 to 20 nm. As the calcination temperature increased, the crystallite size and the agglomeration were increased. The increase in the monoclinic content and grain growth are caused by the calcination temperatures even calcination at 800 °C.


2010 ◽  
Author(s):  
M. Pattanaik ◽  
P. Kumar ◽  
Dinesh K. Aswal ◽  
Anil K. Debnath

Author(s):  
Rosane Macchiarulo Jorge ◽  
Acácio Antonio Mesquita Furtado Filho

This paper describes the synthesis and characterization of a copper-based ballistic modifier, copper subsalicylate (monobasic copper salicylate), and its performance in green-type propellants. New lead-free ballistic modifiers and phthalatefree plasticizers with reduced toxicity, less harmful to the environment, have been employed to replace their traditional additives in green-type double-base propellant preparations. The characterization of the chemical compound was performed by FTIR, TGA-DSC, and WAXS, indicating that copper subsalicylate was obtained. The results of the characterization of propellant compositions showed that copper subsalicylate, in combination with a bismuth salt, could be a substitute for the traditional lead-based ballistic modifier producing green-type propellants without reducing ballistic performance.


Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Ratnawulan Ratnawulan ◽  
Ramli Ramli ◽  
Ahmad Fauzi ◽  
Sukma Hayati AE

This study reports on the synthesis, characterization of polystyrene(PS)/CuO-Fe2O3 nanocomposites, and their application as hydrophobic coatings. CuO and Fe2O3 materials were synthesized from natural materials by the milling method. Meanwhile, the PS/CuO-Fe2O3 nanocomposites were synthesized by the sol-gel method. Furthermore, the hydrophobic coating on the glass substrate was made by the spin-coating. To obtain highest value of contact angle, the composition of both CuO and Fe2O3 in nanocomposite as well as calcination temperatures were varied. Sample characterization was conducted using X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet visible (Uv-Vis) spectrophotometry analysis. The Sessile drop method was used to determine the contact angle of the layer. The results showed that PS/CuO-Fe2O3 nanocomposite was successfully obtained with a crystal size between 40–52 nm and grain size of 92 nm. In addition to the basic material of composites, hematite and tenorite, the presence of copper ferrite phase was also identified. The CuO-Fe2O3 composition and its large calcination temperature also plays an effective role in the magnitude of the contact angle. The highest value of contact angle obtained was 125.46° at 3:1 composition and calcination temperature of 200 °C. We found that the PS/CuO-Fe2O3 composite was hydrophobic, but the photocatalyst activity was very small at 0.24%.


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