Biomimetic synthesis of titania with chitosan-mediated phase transformation at room temperature

2011 ◽  
Vol 21 (29) ◽  
pp. 10755 ◽  
Author(s):  
Yong Yan ◽  
Bo Hao ◽  
Ge Chen
Keyword(s):  
Phase Transformation ◽  
Room Temperature ◽  
Biomimetic Synthesis

scholarly journals Phase Transformation of Kaolin-Ground Granulated Blast Furnace Slag from Geopolymerization to Sintering Process

2021 ◽  
Vol 7 (3) ◽  
pp. 32
Author(s):  
Noorina Hidayu Jamil ◽  
Mohd. Mustafa Al Bakri Abdullah ◽  
Faizul Che Pa ◽  
Mohamad Hasmaliza ◽  
Wan Mohd Arif W. Ibrahim ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Room Temperature ◽  
Curing Temperature ◽  
Curing Process ◽  
Sintering Process ◽  
Granulated Blast Furnace Slag ◽  
Fluxing Agent ◽  
Furnace Slag

The main objective of this research was to investigate the influence of curing temperature on the phase transformation, mechanical properties, and microstructure of the as-cured and sintered kaolin-ground granulated blast furnace slag (GGBS) geopolymer. The curing temperature was varied, giving four different conditions; namely: Room temperature, 40, 60, and 80 °C. The kaolin-GGBS geopolymer was prepared, with a mixture of NaOH (8 M) and sodium silicate. The samples were cured for 14 days and sintered afterwards using the same sintering profile for all of the samples. The sintered kaolin-GGBS geopolymer that underwent the curing process at the temperature of 60 °C featured the highest strength value: 8.90 MPa, and a densified microstructure, compared with the other samples. The contribution of the Na2O in the geopolymerization process was as a self-fluxing agent for the production of the geopolymer ceramic at low temperatures.

One-step room temperature rapid synthesis of Cu2Se nanostructures, phase transformation, and formation of p-Cu2Se/p-Cu3Se2heterojunctions

CrystEngComm ◽  
2016 ◽  
Vol 18 (27) ◽  
pp. 5202-5208 ◽  
Author(s):  
Lianjie Zhu ◽  
Yanxing Zhao ◽  
Wenjun Zheng ◽  
Ningning Ba ◽  
Guangzhi Zhang ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Room Temperature ◽  
Rapid Synthesis ◽  
One Step

Analyses of Eutectoid Phase Transformations in Nb–SilicideIn SituComposites

2004 ◽  
Vol 10 (4) ◽  
pp. 470-480 ◽  
Author(s):  
B.P. Bewlay ◽  
S.D. Sitzman ◽  
L.N. Brewer ◽  
M.R. Jackson
Keyword(s):  
Crystal Structure ◽  
Phase Transformation ◽  
High Temperature ◽  
Room Temperature ◽  
Bulk Composition ◽  
High Strength ◽  
Eutectoid Decomposition ◽  
Quaternary Alloys ◽  
Temperature Fracture

Nb–silicide in situ composites have great potential for high-temperature turbine applications. Nb–silicide composites consist of a ductile Nb-based solid solution together with high-strength silicides, such as Nb5Si3and Nb3Si. With the appropriate addition of alloying elements, such as Ti, Hf, Cr, and Al, it is possible to achieve a promising balance of room-temperature fracture toughness, high-temperature creep performance, and oxidation resistance. In Nb–silicide composites generated from metal-rich binary Nb-Si alloys, Nb3Si is unstable and experiences eutectoid decomposition to Nb and Nb5Si3. At high Ti concentrations, Nb3Si is stabilized to room temperature, and the eutectoid decomposition is suppressed. However, the effect of both Ti and Hf additions in quaternary alloys has not been investigated previously. The present article describes the discovery of a low-temperature eutectoid phase transformation during which (Nb)3Si decomposes into (Nb) and (Nb)5Si3, where the (Nb)5Si3possesses the hP16 crystal structure, as opposed to the tI32 crystal structure observed in binary Nb5Si3. The Ti and Hf concentrations were adjusted over the ranges of 21 to 33 (at.%) and 7.5 to 33 (at.%) to understand the effect of bulk composition on the phases present and the eutectoid phase transformation.

Controlled Synthesis of PbWO4 Crystals with Good Fluorescence Property by a Novel Duck Egg Membrane

2015 ◽  
Vol 33 ◽  
pp. 49-59
Author(s):  
Bao You Gong ◽  
Le Pan ◽  
Qing Feng Zhang ◽  
Hui Zhang ◽  
An Jian Xie ◽  
...  
Keyword(s):  
Outer Surface ◽  
Fluorescence Spectra ◽  
Room Temperature ◽  
Blue Shift ◽  
Biomimetic Synthesis ◽  
Reactant Concentration ◽  
Inner Surface ◽  
Egg Membrane ◽  
Duck Egg ◽  
Slight Blue Shift

PbWO4 crystals with different morphologies were readily induced by duck egg membrane via biomimetic synthesis at room temperature. The size and morphologies of the PbWO4 crystals could be controlled by outer or inner surface of duck egg membrane, the reactant concentration and the reaction time. The results show that spherical, flower-like and spindle-like crystals were obtained on the inner surface of membrane while rhombic, hexagon-like and chrysanthemum-like crystals were gained on the outer surface with the concentration of Pb2+ and WO42- increases. Room-temperature fluorescence spectra indicate the products on the inner surface of the duck egg membrane have a slight blue shift compared to that on the outer surface at the same condition. The PbWO4 crystals with small size obtained at a lower reactant concentration present a better fluorescence performance. The exploration of the reaction mechanism reveals that the interaction between Pb2+ ions and the proteins on the surface of duck egg membrane can make the conformation of the proteins more ordered. In general, the present synthesis route may be extended to prepare other inorganic functional micro-materials.

Invoking ultralong room temperature phosphorescence of purely organic compounds through H-aggregation engineering

2019 ◽  
Vol 6 (6) ◽  
pp. 1259-1264 ◽  
Author(s):  
Jie Yuan ◽  
Shuang Wang ◽  
Yu Ji ◽  
Runfeng Chen ◽  
Qi Zhu ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Organic Compounds ◽  
Room Temperature ◽  
Reversed Phase ◽  
Room Temperature Phosphorescence ◽  
Dark State ◽  
Thermally Activated ◽  
Splitting Energy ◽  
Allowed State

Splitting energy (Δε)-controlled thermally activated reversed phase transformation from the low-lying dark state to the high-lying transition-allowed state of H-aggregation plays a key role in the organic ultralong room-temperature phosphorescence.

Pseudoelasticity of D03 Ordered Monocrystalline Fe3Al

2004 ◽  
Vol 842 ◽  
Author(s):  
S. Kabra ◽  
H. Bei ◽  
D. W. Brown ◽  
M.A.M. Bourke ◽  
E. P. George
Keyword(s):  
Phase Transformation ◽  
Room Temperature ◽  
Plastic Region ◽  
Limited Range ◽  
Large Crystal ◽  
Parallel Surface ◽  
Diffraction Peaks ◽  
In Situ Neutron Diffraction ◽  
Wavy Slip

ABSTRACTPseudoelasticity in monocrystalline Fe3Al (23 at.% Al) was investigated by room-temperature mechanical testing along the <418> tensile and compressive axes. In tension, up to ∼10% strain is recoverable whereas only ∼5% strain is recoverable in compression. Straight, parallel, surface step lines were seen to appear/disappear as the specimens were pseudoelastically loaded/unloaded. In contrast, in the plastic region (ε >10%), wavy slip lines appeared on the specimen surfaces which did not disappear upon unloading. In-situ neutron diffraction was performed during compressive straining and the intensities of several diffraction peaks increase/decrease reversibly during loading/unloading. These changes are consistent with a deformation twin which produces large crystal rotations. They could also be indicative of a phase transformation. Unfortunately, we were able to sample only a limited range of 2θ in the present investigation and, within this range, none of the new peaks that appeared during the pseudoelastic deformation were disallowed peaks for the D03 crystal structure. Therefore we are unable at this time to distinguish between the two possible mechanisms, twinning and phase transformation.

Electrical study of an unusual phase transformation in a Bi2Sr2Ca2Cu3O10+xwhisker at room temperature

2006 ◽  
Vol 19 (10) ◽  
pp. 1003-1009 ◽  
Author(s):  
M Truccato ◽  
S Cagliero ◽  
A Agostino ◽  
M Panetta ◽  
G Rinaudo
Keyword(s):  
Phase Transformation ◽  
Room Temperature ◽  
Electrical Study
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