Biomedical subjects

Anwar Ahniyaz

Publications and source records attributed to Anwar Ahniyaz.

3 recordsLinked to original sources

PubMed2005

Tetragonal nanocrystals from the Zr0.5Ce0.5O2 solid solution by hydrothermal method.

The formation of tetragonal Zr(0.5)Ce(0.5)O(2) solid solution nanocrystallites of 5 +/- 1 nm size by a hydrothermal method at 120 degrees C for 6 h was confirmed by careful Raman and XRD studies for the first time. It was characterized as the t' '-form with an axial ratio of c/a = 1 but with oxygen ion displacements. The as-prepared sample was hydrous in nature, which is responsible for the lattice expansion. However, most of the water held in the structure can be expelled by heating the sample above 600 degrees C. Above 1050 +/- 50 degrees C the t' '-form of tetragonal Zr(0.5)Ce(0.5)O(2) solid solution dissociates into two phases, cubic phase and the t-form of tetragonal phases.

Journal Article↗

PubMed2005

Direct fabrication of TiO2 nanoparticles deposited on hydroxyapatite crystals under mild hydrothermal conditions.

TiO2 nanoparticles-deposited on hydroxyapatite (HAp) have been successfully synthesized by direct (single step) hydrothermal treatments of a CaCO3 suspension in a H3PO4 solution with 10 vol% TAS-FINE (titanium amine complex) at 150 degrees C for 6 h or 120 degrees C for 12-24 h under nearly neutral pH conditions. The obtained products were characterized by XRD, SEM-EDX, visible, Raman, and TEM. The XRD and Raman results showed the formation of HAp and TiO2 anatase phases under these hydrothermal conditions. SEM and TEM observations revealed that anatase TiO2 nanoparticles with the size of about 10 nm were deposited on the surfaces of the HAp crystals.

Coated Materials, Biocompatible↗

PubMed2004

Low-temperature direct synthesis of CeO2-ZrO2 solid solution nanoparticles by a hydrothermal method.

Well-crystallized CeO2-ZrO2 solid solution nanoparticles were successfully prepared by a hydrothermal method in a single step at 120 degrees C, for 6 h without any post heat treatment. The particle sizes of 6 +/- 3 nm by surface area measurements are in good agreement with crystallite sizes of 6 +/- 3 nm by X-ray diffraction. Transmission microscopy also confirmed the formation of crystals of 5-8 nm in the products. In the formation of the homogeneous solid solutions the complete oxidation of Ce3+ to Ce4+ in the precipitated gels seems to be one of the important steps. The solid solutions contained several wt % water, but it was expelled by calcining > or = 600 degrees C. The heating of the samples brought about grain growths, but did not change the phases. The specific areas of 120-200 m2/g of as-prepared samples were decreased to 4-14 m2/g by heating at 900 degrees C for 4 h.

Cerium↗