TBP extraction of lanthanides from molten calcium nitrate hydrate

2002 ◽  
Vol 90 (2) ◽  
Author(s):  
Hajimu Yamana ◽  
Hideki Asano ◽  
Toshiyuki Fujii ◽  
Ryuta Goto ◽  
Hirotake Moriyama
Keyword(s):  
Water Content ◽  
Calcium Nitrate ◽  
Phosphate Solution ◽  
Extraction Equilibrium ◽  
Nitrate Hydrate

SummaryExtraction equilibrium of lanthanides between tri-butyl phosphate solution and molten calcium nitrate hydrate, which is generally called a hydrate melt, was studied radiochemically. The dependence of the extractions on the water content of the melt was studied at 70 °C in the range of

scholarly journals Synthesis of Hydroxyapatite by Interfacial Reaction in a Multiple Emulsion

2007 ◽  
Vol 2007 ◽  
pp. 1-4 ◽  
Author(s):  
Isao Kimura
Keyword(s):  
Interfacial Reaction ◽  
Aqueous Phase ◽  
Single Phase ◽  
Nitrate Solution ◽  
Calcium Nitrate ◽  
Phosphate Solution ◽  
Multiple Emulsion ◽  
Hydrogen Phosphate ◽  
Dipotassium Hydrogen Phosphate ◽  
Initial Ph

Interfacial reaction in a multiple emulsion, which is one of methods for producing inorganic microspheres, was applied to synthesize hydroxyapatite. The multiple emulsion was a W/O/W emulsion, made of dipotassium hydrogen phosphate solution as an inner aqueous phase, benzene as an oil phase, and calcium nitrate solution as an outer aqueous phase. The reaction was carried out in the multiple emulsion for 24 hours at 323 K. The crystalline phase was varied with an initial pH of the inner aqueous phase, and single phase hydroxyapatite was synthesized at an initial pH of 12. The products were composed of porous microspheres of less than 3 μm in size. The microspheres were composed of nanospheres of less than 120 nm in size. By considering the mass balance, it was suggested that each nanosphere was formed in an inner aqueous phase droplet.

scholarly journals Unique extraction behavior of americium and curium in a system of TBP and calcium nitrate hydrate melt

2010 ◽  
Vol 9 ◽  
pp. 012067 ◽  
Author(s):  
G Okude ◽  
T Fujii ◽  
A Uehara ◽  
S Sekimoto ◽  
K Minato ◽  
...  
Keyword(s):  
Calcium Nitrate ◽  
Nitrate Hydrate ◽  
Extraction Behavior

Spectroscopic study of trivalent rare earth ions in calcium nitrate hydrate melt

2006 ◽  
Vol 408-412 ◽  
pp. 989-994 ◽  
Author(s):  
Toshiyuki Fujii ◽  
Hideki Asano ◽  
Takaumi Kimura ◽  
Takeshi Yamamoto ◽  
Akihiro Uehara ◽  
...  
Keyword(s):  
Rare Earth ◽  
Spectroscopic Study ◽  
Calcium Nitrate ◽  
Rare Earth Ions ◽  
Nitrate Hydrate ◽  
Trivalent Rare Earth

scholarly journals Synthesis of Fibrous Hydroxyapatite through Sol-Gel Route

2009 ◽  
Vol 6 (2) ◽  
pp. 379-385
Author(s):  
Baghdad Science Journal
Keyword(s):  
Growth Rate ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Morphological Characteristics ◽  
Phosphate Solution ◽  
Agar Gel ◽  
Gel Temperature

The sol-gel route using an agar gel with calcium nitrate and phosphate solution as starting materials for producing hydroxyapatite (HAP). The product formed were needle like, zigzag and straight fibres. The fibrous products on sintering transformed into stoichiometric HAP with a biological Ca/P ratio of 1.67. The influences of pH, temperature, nature of base and phosphate solution on the growth of fibrous HAP were studied. The pH of the solution was found to greatly influence the growth rate and morphology of the resultant product. The optimum gel temperature was found to be 60oC and sintering temperature of 900oC for 1 hour. The crystalline, thermal, functional and morphological characteristics of the fibrous HAP were investigated.

Chlortetracycline and barley papilla formation: localization of calcium and alteration of the response induced by Erysiphe graminis

1985 ◽  
Vol 63 (5) ◽  
pp. 876-880 ◽  
Author(s):  
M. R. Marshall ◽  
M. G. Smart ◽  
J. R. Aist ◽  
H. W. Israel
Keyword(s):  
Calcium Phosphate ◽  
Incubation Medium ◽  
Cell Walls ◽  
Calcium Nitrate ◽  
Erysiphe Graminis ◽  
Phosphate Solution ◽  
Bright Yellow ◽  
Host Penetration ◽  
Papilla Formation ◽  
Wall Appositions

Previous results had suggested that Ca(H2PO4)2 may be directly inhibitory to host penetration from appressoria of Erysiphe graminis f. sp. hordei and that Ca and P are found in much higher amounts in oversized papillae (resistant to penetration) than in normal papillae (not resistant to penetration). In the present study, chlortetracycline was used as a calcium-selective fluorescent probe to examine the occurrence and distribution of calcium in papillae of barley coleoptile epidermal cells. When stained with chlortetracycline, normal and oversized papillae fluoresced bright yellow, indicating the presence of calcium. Oversized papillae, produced in the presence of calcium phosphate solution, could be either poststained or stained during papilla formation by including chlortetracycline in the incubation medium. Such attempts to stain normal papillae during their formation in the presence of calcium nitrate resulted in the formation of oversized papillae similar in appearance to those produced in the presence of Ca(H2PO4)2; however, penetration from appressoria was not inhibited by chlortetracycline. In some cases, this treatment resulted in the formation of chlortetracycline-fluorescent wall appositions on lower periclinal cell walls far removed from the fungus; these appositions were interpreted as calcium-containing wound plugs. None of the chlortetracycline-associated phenomena were seen without calcium in the incubation medium. These results confirm the occurrence and demonstrate the distribution of calcium in papillae and show that chlortetracycline, like phosphate, can act in conjunction with calcium to enhance secretion of papilla material.

Preparation of Alginate/Silica Composite Beads with In Vitro Apatite-Forming Ability

2011 ◽  
Vol 236-238 ◽  
pp. 1889-1892 ◽  
Author(s):  
Fan Xiao ◽  
Fei Gao ◽  
Zhi Xian Zhang ◽  
Wei Li
Keyword(s):  
Biomedical Applications ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Phosphate Solution ◽  
X Ray Diffraction ◽  
Silica Composite ◽  
Composite Beads ◽  
Ft Ir ◽  
Diffraction Peaks

Alginate/silica composite beads of mm-size for biomedical applications were prepared from water glass and sodium alginate via a simple sol-gel route. They kept their original shapes when soaked in the phosphate solution of lower pH. In this case, faint calcium phosphate peaks were observed in X-ray diffraction. Peaks corresponding to phosphate group were also found in FT-IR. Apatite was obtained on the surface of beads made with calcium chloride after soaking in phosphate solution while monetite was formed on the surface of beads made with calcium nitrate.

Calcium phosphate with high specific surface area synthesized by a reverse micro-emulsion method

MRS Advances ◽  
2016 ◽  
Vol 1 (11) ◽  
pp. 723-728 ◽  
Author(s):  
Tomoaki Sugiyama ◽  
Shusuke Akiyama ◽  
Toshiyuki Ikoma
Keyword(s):  
Calcium Phosphate ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Nitrate Solution ◽  
Calcium Nitrate ◽  
Phosphate Solution ◽  
Crystalline Phases ◽  
Emulsion Method ◽  
Micro Emulsion

ABSTRACTA reverse micro-emulsion method has been investigated to control crystal morphology in a nanometer region and to increase specific surface area for calcium phosphate. The nanocrystals with the control of its morphology is a candidate of drug delivery carriers. This study investigated the effects of mixing volume ratios of two surfactants, tween80 (T) and aliquate 336 (A) in kerosene as an oil phase, and pH values in the nano-region on crystalline phases and specific surface area of calcium phosphate synthesized by the reverse micro-emulsion method. A di-ammonium hydrogen phosphate solution including phosphoric acid at pH of 6.3 and a calcium nitrate solution at pH of 5.7 were adjusted, and both the solutions were separately added into the kerosene with the surfactants. Both the emulsions were then mixed at the same volume and the Ca/P ratio of 1.0, and stirred at room temperature for 24 hours. The crystalline phases were dependent on the T amounts; pure DCPD with the specific surface area of 6.7 to 12 m2/g was obtained at the T/A ratio of 4, the mixture of DCPD and DCPA with that of 48 to 162 m2/g was at the ratios of 5 to 8, and a low crystalline HAp with 163 m2/g was at the ratio of 9. These specific surface areas of DCPD (T/A=4) and HAp (T/A=9) were apparently higher than those prepared with a wet method, 7.8 times and 1.8 times respectively. DCPA with 43 m2/g was successfully produced to decrease the pH of phosphate solution at T/A of 9. The change of crystalline phases would be explained as follows; the increase of T amount decreased the micro-emulsion sizes to reduce bulk water to be DCPA, and increased the pH to precipitate HAp nanocrystals.

Sign in / Sign up

Export Citation Format

Share Document