hydroxyapatite (ha) nano-rods with uniform morphology and controllable size have been successfully synthesized in the presence of cationic and non-ionic surfactants by a hydrothermal method. (nh4) 2hpo4 and ca(no 3)2.4h2o were used as the phosphorus and calcium sources, respectively. the composition of synthesized powders was characterized using x-ray diffraction, and fourier transform infrared...

zeolite fau type-y is one of the most studied framework of all zeolites, and has been used as catalysts for number of reactions in the refinery and petrochemical industry. in this research, nanocrystalline zeolite y was synthesized by hydrothermal method. the crystal size of zeolite y is influenced by temperature, aging time, alkalinity, and water content. the synthesized zeolite nay is identif...

lta zeolite nanoparticles was successfully synthesized from clear solution under controlled conditions using hydrothermal method using tetramethyl ammonium hydroxide as a structural directing agent. the as-synthesized lta zeolite particles were characterized by powder x-ray diffraction (xrd) analysis, scanning electron microscopy (sem), fourier transform infrared (ft-ir) spectroscopy, energy di...

the synthesis of nb doped batio3 has been investigated under microwave-hydrothermal (mh) conditions in the temperature of 150°c for only 2 h using c16h36o4ti, bah2o2.8h2o and nbcl5 as ba, ti and  nb sources, respectively.  typical experiments performed on mh processing have not yet reported for nb doped batio3.  in the mh process, the formation of high purity nano tetragonal nb-batio3 was stron...

nano-sized batio3 powders with particular nb concentrations were prepared by rotary- hydrothermal (rh) method. hydrothermal method was used at 180 °c for 5 hours with new ti pressure and the teflon vessel was rotated at a speed of 160 rpm during the hydrothermal reaction. new hydrothermal method was used instead of previous solid state reaction for the system batio3±nb2o3 in high temperature to...

Thermodynamic calculations showed that the autotrophic synthesis of all 20 protein-forming amino acids was energetically favored in hot (100 degrees C), moderately reduced, submarine hydrothermal solutions relative to the synthesis in cold (18 degrees C), oxidized, surface seawater. The net synthesis reactions of 11 amino acids were exergonic in the hydrothermal solution, but all were endergoni...

in our current study, supercritical water impregnation (scwi) was introduced as a unique catalyst preparation method by employing the high diffusivity property of supercritical water. the method allows nano-particles to place on support surfaces in extremely dispersed conditions. the silica-based nanocatalyst granules for this purpose were prepared by initial impregnation of highly porous silic...

a hydrothermal method for preparation of nano-size zirconia has been studied to optimize the effective parameters (precursor concentration, temperature and time) using response surface methodology (rsm). the synthesized zirconia samples were characterized through x-ray diffraction (xrd), scanning electron microscope (sem) and transmission electron microscopy (tem) analyses to identify mean nano...

This study presents experimental results dealing with the possibility of transforming F-class fly ash into a zeolitic material. Two types of synthesis methods were used in the research: hydrothermal and low-temperature synthesis. As a result of alkaline reaction of fly ash with NaOH, all experimental cases yielded zeolitic material that are rich in a Na-X phase. The mineralogical composition (d...

in the present work, the effect of ca(no3)2.4h2o and (nh4)2hpo4 primary solutions as the beginning materials in synthesis of a calcium phosphate phase, was examined. so, we investigated the wet chemical reactions in solution at different temperatures by a hydrothermal condition aimed at hydroxyapatite (ca10(po4)6(oh)2); (hap) synthesis. the powders were investigated by xrd,sem, fe-tem, hrtem, e...