Emission behaviours of novel V- and X-shaped fluorophores in response to pH and force stimuli

2017 ◽  
Vol 19 (18) ◽  
pp. 11563-11570 ◽  
Author(s):  
Hong-Yu Fu ◽  
Ning Xu ◽  
Yi-Min Pan ◽  
Xiao-Lin Lu ◽  
Min Xia
Keyword(s):  
Solid State ◽  
Mechanical Force ◽  
Morphology Effect ◽  
Size And Morphology

The solid-state emission behaviours of a series of V- and X-shaped fluorophores exposed to mechanical force and pH stimuli are dependent on the ICT effect as well as the size- and morphology-effect.

Preparation of High-Purity Ultrafine α-Al2O3 by Solid-State Reaction at Room Temperature

2008 ◽  
Vol 368-372 ◽  
pp. 683-685
Author(s):  
Cheng Wei Hao ◽  
Bo Lin Wu ◽  
Ji Yan Li
Keyword(s):  
Solid State ◽  
High Purity ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Raw Materials ◽  
Phase Particle ◽  
Phase Transformation Temperature ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Α Al2o3

Ammonium aluminium carbonate hydroxide (AACH), with a small quantity of γ-AlOOH, was synthesized through solid-state reaction at room temperature using AlCl3·6H2O and NH4HCO3 as raw materials and polyethylene glycol (PEG-10000) as the dispersant. After calcined at 1100°C for 1.5h, α-Al2O3 powders with primary particle sizes of 20~30nm were obtained. The crystal phase, particle size and morphology of the high-purity ultrafine α-Al2O3 were characterized. The results showed that a small quantity of γ-AlOOH in the AACH decomposed and formed crystal seeds. The presence of crystal seeds reduced the nucleation activation energy and therefore reduced the phase transformation temperature.

Supercritical Fluids as New Reaction Media to Synthesize Nanostructured Materials

2003 ◽  
Vol 775 ◽  
Author(s):  
Cyril Aymonier ◽  
Sophie Desmoulins-Krawiec ◽  
Anne Loppinet-Serani ◽  
François Weill ◽  
François Cansell
Keyword(s):  
Solid State ◽  
Nanostructured Materials ◽  
Supercritical Fluid ◽  
Supercritical Fluids ◽  
Nanostructured Material ◽  
Solid State Chemistry ◽  
Material Synthesis ◽  
Fluid Properties ◽  
Size And Morphology ◽  
Reaction Media

AbstractSupercritical fluids exhibit a range of unusual properties that can be exploited for the development of new reactions for material synthesis. These reactions are different from those performed in classical solid-state chemistry. Supercritical fluids are interesting as reaction media for the synthesis of nanostructured materials because fluid properties such as density, viscosity, diffusivity and solubility of reagents can be continuously tuned from gas to liquid with small variations in pressure and temperature. Moreover, supercritical fluid processing offers the possibility of using solvents with low toxicity that result in nanostructured materials free of solvent contamination. The process developed at ICMCB obtains nanostructured materials by chemically transforming a metal precursor inside a supercritical fluid. The synthesis of nanostructured materials such as metals, oxides or nitrides is possible at lower temperatures than the classic solid-state chemistry route. Based on experimental results and simulations, the nanostructured material nature, size and morphology can be continuously adjusted as a function of the operating condutions. Our process provides a great contribution in the development of self-assembled nanostructured materials by controlling the chemical composition, size, morphology and the surface properties of nanobricks.

STUDY ON SYNTHESIS AND EVOLUTION OF NANOCRYSTALLINE Mg4Ta2O9 BY AQUEOUS SOL–GEL PROCESS

2012 ◽  
Vol 19 (03) ◽  
pp. 1250024 ◽  
Author(s):  
H. T. WU ◽  
C. H. YANG ◽  
W. B. WU ◽  
Y. L. YUE
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Sol Gel ◽  
Phase Evolution ◽  
Solid State Method ◽  
Conventional Solid State Method ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
State Method ◽  
Size And Morphology

Nanosized and highly reactive Mg4Ta2O9 were successfully synthesized by aqueous sol–gel method compared with conventional solid-state method. Ta-Mg-citric acid solution was first formed and then evaporated resulting in a dry gel for calcination in the temperature ranging from 600°C to 800°C for crystallization in oxygen atmosphere. The crystallization process from the gel to crystalline Mg4Ta2O9 was identified by thermal analysis and phase evolution of powders was studied using X-ray diffraction (XRD) technique during calcinations. Particle size and morphology were examined by transmission electron microscopy (TEM) and high resolution scanning electron microscopy (HR-SEM). The results revealed that sol–gel process showed great advantages over conventional solid-state method and Mg4Ta2O9 nanopowders with the size of 20–30 nm were obtained at 800°C.

Mechanically Activated Synthesis of CaTiO3 from Mixture of CaO and TiO2

2005 ◽  
Vol 494 ◽  
pp. 393-398 ◽  
Author(s):  
V.M. Vukotić ◽  
N. Radojević ◽  
Ljiljana Živković ◽  
Z. Vuković ◽  
B.D. Stojanović
Keyword(s):  
Solid State ◽  
Mechanical Activation ◽  
Ball Mill ◽  
Calcium Titanate ◽  
Powder Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bet Analysis ◽  
Size And Morphology ◽  
Modification Of Titanium

Crystalline calcium titanate was synthesized by mechanical activation of a mixture of CaO, obtained by thermal treatment of CaCO3, and TiO2 in anatase or rutile form, in a planetary ball mill for 30, 60, 120 and 240 min.. The effect of milling on the solid-state reaction was followed by X-ray diffraction. Changes in powder size and morphology due to milling were determinate by SEM, while BET analysis was made to determine the specific surface area of powders. It was pointed out that the formation of calcium titanate was more easily achieved by mechanical activation synthesis of the mixture of calcium oxide and anatase modification of titanium oxide compared to the rutile form.

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