Controlled Hydrothermal Growth of CuO-Based Nanostructures from Copper Alginate

2011 ◽  
Vol 688 ◽  
pp. 19-22 ◽  
Author(s):  
Bing Bing Wang ◽  
Qing Shan Kong ◽  
Jian Ping Sun ◽  
Quan Feng Yu ◽  
Quan Ji ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Growth Mechanism ◽  
Hydrothermal System ◽  
Ph Value ◽  
Structure Evolution ◽  
Structure Directing Agent ◽  
Aggregation State ◽  
Air Atmosphere ◽  
Morphology And Structure ◽  
Different Temperatures

Schistose and aciculate CuO nanostructures have been synthesized by a novel ammonia assisted hydrothermal method of copper alginate. The conversion processes of copper alginate are investigated by thermogravimetrics (TG) analyses under N2and air atmosphere. The morphology, structure, and composition of the obtained CuO are investigated using SEM,TEM and XRD. It is found that different temperature and pH value resulted in the morphology and structure evolution of CuO. Ammonia was used as structure-directing agent in the hydrothermal system. The aggregation state of the nanostructures was controlled by the temperature. Dispersive schistose structures about 1μm in diameter were synthesized with 0.5mL ammonia at different temperatures. Dispersive microspheres of about 4 μm in diameter were also synthesized with 1 mL ammonia. Microspheres composed of nanoneedles and nanoplates were synthesized at 120°C and 160°C, respectively. Moreover, a possible growth mechanism governing the formation of such a nanomicrostructure was primarily discussed.

Study of Fibrous AlPO4-5 via Hydrothermal Conditions: Morphology Evolution and Growth Mechanism

2012 ◽  
Vol 535-537 ◽  
pp. 2535-2539
Author(s):  
Chun Xia Zhao ◽  
Yun Xia Yang ◽  
Wen Chen ◽  
Paul Webley ◽  
Jin Qiao Cao
Keyword(s):  
Hydrothermal Method ◽  
Growth Mechanism ◽  
Molecular Sieves ◽  
Molar Ratio ◽  
Structure Evolution ◽  
Morphology Evolution ◽  
Hydrothermal Conditions ◽  
Morphology And Structure ◽  
Fibrous Morphology ◽  
Morphology Development

Aluminophosphate molecular sieves (AlPO4-5s) with fibrous morphology were readily prepared via hydrothermal method at 180 °C with the initial molar ratio of Al(OiPr)3: H3PO4: TrPA: HF: H2O as 1: 0.83: 1: 0.8: 70. The morphology and structure of the prepared AlPO4-5s were characterized by XRD, SEM, TEM and nitrogen sorption measurement. The morphology development and structure evolution mechanism were proposed.

scholarly journals In vitro tests of dense hydroxyapatite materials

2009 ◽  
Vol 11 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Agnieszka Sobczak ◽  
Anna Kida ◽  
Zygmunt Kowalski ◽  
Zbigniew Wzorek
Keyword(s):  
Ph Value ◽  
Calcium Content ◽  
In Vitro Tests ◽  
Distilled Water ◽  
Second Stage ◽  
Air Atmosphere ◽  
Different Temperatures ◽  
Main Component ◽  
Two Stages

In vitro tests of dense hydroxyapatite materials The paper presents the results of the calcining process of deproteinised and defatted bone pulp called bone sludge. The calcining process was performed in two stages. The first step of the calcining process was realized at the temperature of 600°C in a rotary kiln. In the second stage the obtained bone ashes were calcined at five different temperatures from 650°C to 950°C for 2 hours in a chamber kiln and in air atmosphere. The products of the calcining process were characterized by the XRD method. Calcium content was determined by titration whereas the contents of total phosphorus and acid-soluble phosphorus - by the spectrophotometric method. The X-ray analysis confirmed that hydroxyapatite is the main component of the calcining products. Calcium and phosphorus contents were kept at the level of 40% and 17.5%, respectively, which corresponded to the Ca/P ratio of not stechiometric hydroxyapatite. In vitro studies, in the simulated body fluid, Ringer liquid and distilled water were realised. The measurements of pH value of SBF and Ringer fluid were realized. Additionally electrical conductivity as well as pH for distilled water where conducted. The goal of these tests was to evaluate chemical durability of dense hydroxyapatite materials.

Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson
Keyword(s):  
Complex Formation ◽  
Significant Influence ◽  
Room Temperature ◽  
Ph Value ◽  
Maximum Activity ◽  
Reduction Step ◽  
Labelling Yield ◽  
Different Temperatures ◽  
Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

Influence of pH Value on the Performance of Composite Films Prepared from Chromium Residue by Hydrothermal Method

2013 ◽  
Vol 28 (4) ◽  
pp. 387-392
Author(s):  
Tong SUN ◽  
Lian-Li LIU ◽  
Shu-Ying XU ◽  
Xiao-Lin PENG ◽  
Hai-Long YANG
Keyword(s):  
Hydrothermal Method ◽  
Ph Value ◽  
Composite Films ◽  
Influence Of Ph

Studies on the Coordination Reaction of VO2+ and Tannic Acid in the Tannin Extract Desulfurization

2012 ◽  
Vol 239-240 ◽  
pp. 1573-1576
Author(s):  
Zhu Qing Gao ◽  
Xiao Dong Cai ◽  
Kai Cheng Ling
Keyword(s):  
Stability Constants ◽  
Tannic Acid ◽  
Ph Value ◽  
Protonation Constants ◽  
Conditional Stability ◽  
Tannin Extract ◽  
Acid Effect ◽  
Different Temperatures ◽  
The Stability ◽  
Apparent Stability

At different temperatures, the protonation constants of tannic acid and the complex apparent stability constants between tannic acid and VO2+ were determined by using pH potentimetric method. The results showed that the protonation constants and the complex apparent stability constants slightly decreased with the raising temperature. In accordance with the pH value in the tannin extract technology, the conditional stability constants of the complex were calculated on the basis of the acid effect of tannic acid and the hydrolysis effect of VO2+. It was found that pH greatly affected the stability constants of the complex , so pH must be strictly controlled in the tannin extract technology.

Morphology Evolution and Luminescence Properties of YF3: Sm Nano-/Microcrystals

2012 ◽  
Vol 463-464 ◽  
pp. 112-118
Author(s):  
Feng Tao ◽  
Geng Zhu ◽  
Zhi Jun Wang ◽  
Feng Pan ◽  
Yu Feng Sun ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Growth Mechanism ◽  
Room Temperature ◽  
Red Light ◽  
Environmentally Friendly ◽  
Morphology Evolution ◽  
Flat Panel Display ◽  
Flat Panel ◽  
Display Devices ◽  
Potential Applications

Abstract. Recently, there has been increasting interest in the doping of nano-/microcrystal hosts with Sm3+. However, very few examples of Sm3+doped YF3-based nanophosphors have been reported. In this paper, a variety of uniform YF3:Sm nano-/microcrystals have been successfully prepared by a facile, effective, and environmentally friendly hydrothermal method. The morphology evolution process has been investigated by quenching the reaction at different time. Based on the results, a possible growth mechanism is presented in detail. The as-obtained YF3:Sm nano-/microcrystals show strong yellow and red light emissions under room temperature, which is quite different from those reported previously and might find potential applications in fields such as light phosphor powers and advanced flat panel display devices.

Film evolution and growth mechanism of a Ni-based superalloy in the two models at the different temperatures

Vacuum ◽  
2021 ◽  
pp. 110538
Author(s):  
H.U. Ye-Bing ◽  
C.H.E.N.G. Cong-Qian ◽  
Tie-Shan Cao ◽  
Li Zhang ◽  
Jie Zhao
Keyword(s):  
Growth Mechanism ◽  
Different Temperatures

Observation of Morphology and Structure Evolution during Gelation of a Bis(Anhydrazide) Derivative

2017 ◽  
Vol 121 (37) ◽  
pp. 8795-8801 ◽  
Author(s):  
Wei Li ◽  
Xiangyang Che ◽  
Fangyi Chen ◽  
Chunxue Zhang ◽  
Tianren Zhang ◽  
...  
Keyword(s):  
Structure Evolution ◽  
Morphology And Structure

Controlling the Morphology and Size of GdF3:RE3+ (RE = Dy, Tb, and Sm) by pH Value: Growth Mechanism, Energy Transfer, and Luminescent Properties

2017 ◽  
Vol 121 (12) ◽  
pp. 6884-6897 ◽  
Author(s):  
Hongxia Guan ◽  
Chengyi Xu ◽  
Ye Sheng ◽  
Yanhua Song ◽  
Keyan Zheng ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Growth Mechanism ◽  
Ph Value ◽  
Luminescent Properties ◽  
Value Growth

scholarly journals Thermodynamic Investigations on the Inclusion Complexation of Piroxicam with Cyclodextrin Derivatives

2005 ◽  
Vol 73 (3) ◽  
pp. 147-161 ◽  
Author(s):  
Charumanee S. ◽  
Weiss-Greiler P. ◽  
Wolschann P. ◽  
Viernstein H. ◽  
Titwan A. ◽  
...  
Keyword(s):  
Ph Value ◽  
Equilibrium Constants ◽  
Inclusion Complexation ◽  
Solubility Diagram ◽  
Phase Solubility ◽  
Cyclodextrin Derivatives ◽  
Ph Values ◽  
Solubility Behavior ◽  
Solubility Method ◽  
Different Temperatures

Thermodynamic studies of piroxicam in aqueous solution complexed with β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD) and two β-cyclodextrin derivatives, hydroxypropyl-β-cyclodextrin (HP-P-CD) and methyl-β-cyclodextrin (Me-β-CD) were performed at different temperatures and pH values using the phase solubility method. The phase solubility diagrams of β-CD, γ-CD and HP-β-CD is of AL-type behavior, indicating the formation of 1:l complexes. The related stability constants range from β-CD > γ-CD > Me-β-CD > HP-β-CD, respectively. An Ap-type solubility diagram is observed for Me-β-CD, indicating the formation of 1:2 complexes at higher CD concentrations. From the temperature dependence of the equilibrium constants the reaction enthalpies and entropies have been determined. The contributions of the reaction entropies are small and no enthalpy-entropy-compensation is observed, except for γ-CD, where a very small negative reaction entropy could be estimated. Moreover, the influence of the pH value is rather high because the differently charged forms of piroxicam show different solubility behavior in water.

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