scholarly journals Effect of Temperature and pH on Phase Transformations in Citric Acid Mediated Hydrothermal Growth of Tungsten Oxide

2018 ◽  
Vol 2018 (7) ◽  
pp. 917-923 ◽  
Author(s):  
Kasper Wenderich ◽  
Johannes Noack ◽  
Anne Kärgel ◽  
Annette Trunschke ◽  
Guido Mul
Author(s):  
Pramesti Prihutami ◽  
Wahyudi Budi Sediawan ◽  
Widi Astuti ◽  
Agus Prasetya

e-Polymers ◽  
2015 ◽  
Vol 15 (3) ◽  
pp. 179-183 ◽  
Author(s):  
B.S. Supriya ◽  
P. Nagaraja ◽  
K. Byrappa

AbstractThe synthesis of well-dispersed carbon spheres using starch as a carbon source, citric acid as a catalyst, and distilled water as a medium without involving any organic solvent at 120–150°C for 16 h under hydrothermal treatment is presented. The use of citric acid promoted starch dehydration and allowed the use of a lower hydrolysis temperature. Under similar conditions the formation of carbon spheres was not possible in the absence of citric acid. We noticed the significant effect of temperature on the particle size and shape. The particle size increased with the increase in temperature. The synthesized carbon spheres were characterized using field-emission scanning electron microscope (FE-SEM), scanning electron microscope (SEM), X-ray diffraction, Fourier-transform infrared (FTIR) and Raman spectroscopy.


1992 ◽  
Vol 7 (6) ◽  
pp. 1328-1335 ◽  
Author(s):  
Kunsong Ma ◽  
Alain C. Pierre

Superconducting materials in the Bi–(Pb)–Sr–Ca–Cu–O system have been synthesized by sol-gel processing from nitrates by complexation with citric acid. The gelation process and the microstructures of the gels obtained have been studied through titration and SEM observation. Their phase transformations and microstructure development, during heat treatment, have also been investigated. The critical temperature Tc of superconductors by this sol-gel processing can reach above 100 K.


Sign in / Sign up

Export Citation Format

Share Document