Showing 3 results for Nanopowder
Ghobeiti Hasab M., Seyyed Ebrahimi S.a., Badaee A.,
Volume 2, Issue 2 (6-2005)
Abstract
In this research the sol-gel auto-combustion method was used to prepare strontium hexaferrite nanopowder. A solution of distilled water, ferric and strontium nitrates, citric acid, trimethylamine, and n-decyltrimethylammonium bromide cationic surfactant, was heated to form a viscous gel. The gel was heated and then ignited automatically. As-burnt powder was calcined at temperatures from 700 to 900?C in air to obtain SrO.6Fe2O3 phase. The influence of the calcination temperature on the phase composition of the products has been investigated. X-ray diffraction confirmed the formation of single-phase strontium hexaferrite nanopowder at temperature of 800?C.
A. Nemati, K. Pourazarang,
Volume 5, Issue 3 (9-2008)
Abstract
Abstract: The PZT-based ceramics with a composition of Pb1.1-xLax (Zr0.53Ti0.47)O3, were prepared
by conventional mixed oxide followed by mechanical alloying and sol-gel methods in which x was
chosen in the range of 0.02–0.06. The samples were calcined in the range of 450 °C - 750 °C for
4h. The physical and electrical properties of the samples were determined as a function of the
calcination temperature. The obtained data from two methods were compared with conventional
mixed oxide method. Microstructural and compositional analyses of the samples were carried out
using XRD and SEM. Dielectric properties of the samples were measured with an impedance
analyzer. The ferroelectric properties of the PZT and PLZT samples were measured using the
frequencies applying equipment and d33 tester. The results indicated a complete tetragonal phase
prepared from both methods. It was shown that the addition of La and reduction in calcination
temperature improved both the dielectric and piezoelectric properties. The dielectric constant
tended to increase with doping content, giving the maximum value of about 2000 at 3 mol% La3+.
In addition, the mechanical coupling factor (Qm) of the doped samples showed a significant
decrease. Finally, the value of planar coupling factor (kp) reached the maximum value of 0.47 at 1
mol% La3+.
S. M. Alduwaib, Muhannad M. Abd, Israa Mudher Hassan,
Volume 19, Issue 3 (9-2022)
Abstract
Background: Superhydrophobic materials which have contact angle higher than 150°, considering their widespread applications, are very important for researchers.
Method: In this research, silica nanopowder was synthesized successfully using inexpensive sodium silicate source and very simple and facile method. Synthesis of hydrophobic solution was carried out by sol-gel method. The surface modification of silica nanopowder was performed using different silane/siloxane polymers and was deposited on glass slides. For characterization of the samples XRD, FESEM, EDX, TEM, FTIR, and Raman analysis were used.
Results: The XRD result shows a very wide peak at 2q = 24.7° which indicates the amorphous nature of the silica particles. The results of the performed characteristics confirm the synthesis of silica nanopowder with the size of less than 25 nm. The EDX spectrum shows that only Si and O elements are present in the structure and no impurities are visible. The contact angle between water droplet and thin films was measured and the effect of different synthesis parameters on the contact angle was studied. Among the studied polymers and solvents, the most hydrophobicity was obtained using TMCS polymer and xylene solvent. The optimized sample has a maximum contact angle of 150.8°.
Conclusion: The synthesized thin films have superhydrophobic properties and the method used in this research can be developed for use in industrial applications.
