Study on thermoplastic-modified multifunctional epoxies: Influence of heating rate on cure behaviour and phase separation

2009 ◽  
Vol 69 (7-8) ◽  
pp. 1172-1179 ◽  
Author(s):  
Jin Zhang ◽  
Qipeng Guo ◽  
Bronwyn L. Fox
Keyword(s):  
Phase Separation ◽  
Heating Rate ◽  
Cure Behaviour

Crystallization of Perovskites from Solutions

1996 ◽  
Vol 453 ◽  
Author(s):  
I. Maurin ◽  
P. Barboux ◽  
J. P. Boilot
Keyword(s):  
Phase Separation ◽  
Heating Rate ◽  
Perovskite Structure ◽  
Reaction Rate ◽  
Sol Gel ◽  
Diffusion Limited ◽  
History Of

AbstractLaMnO3 and PbZrO3 perovskites have been synthesized through coprecipitation and sol-gel techniques. After the drying and calcination steps, amorphous mixtures of oxides have been obtained. They are unstable towards phase separation. Therefore, their homogeneity and reactivity strongly depend on the parameters of the calcination, such as the temperature and heating rate. In all cases, the perovskite structure crystallizes around 600°C through nucleation- or diffusion-limited kinetics. The reaction rate depends on the history of the material. A mechanistic interpretation of the reaction, based on the similarity between the structures of PbO, ZrO2, Mn2O3 and La2O3 is proposed.

Phase separation and physico-chemical processes at microscopic and macroscopic levels in MWCNT laden polymer blends using a unique droplet based architecture

2017 ◽  
Vol 19 (36) ◽  
pp. 24961-24970 ◽  
Author(s):  
Binita Pathak ◽  
Goutam Prasanna Kar ◽  
Suryasarathi Bose ◽  
Saptarshi Basu
Keyword(s):  
Phase Separation ◽  
Polymer Blends ◽  
Polymer Solution ◽  
Heating Rate ◽  
Chemical Processes ◽  
Binary Polymer ◽  
Physico Chemical ◽  
Phase Separation Behavior ◽  
Contact Free ◽  
Separation Behavior

We propose a unique contact-free droplet based architecture to alter the phase separation behavior in binary polymer solution (PS/PVME in toluene) by tuning the external heating rate and concentration of added MWCNT particles.

Bulk standards for low-temperature biological x-ray microanalysis

1984 ◽  
Vol 42 ◽  
pp. 282-283
Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  
Keyword(s):  
Phase Separation ◽  
Low Temperature ◽  
Analytical Method ◽  
Salt Solutions ◽  
Absolute Concentration ◽  
Cooling Process ◽  
X Ray ◽  
The Absolute ◽  
Analytical Procedures ◽  
Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

A TEM study of the influence of microstructure on the superplastic behavior of a U-5.8 wt.% Nb alloy

1986 ◽  
Vol 44 ◽  
pp. 568-569
Author(s):  
G. Mackiewicz Ludtka
Keyword(s):  
Grain Size ◽  
Heating Rate ◽  
Phase Field ◽  
Single Phase ◽  
Superplastic Behavior ◽  
Two Phase ◽  
Single Phase Field

Historically, metals exhibit superplasticity only while forming in a two-phase field because a two-phase microstructure helps ensure a fine, stable grain size. In the U-5.8 Nb alloy, superplastici ty exists for up to 2 h in the single phase field (γ1) at 670°C. This is above the equilibrium monotectoid temperature of 647°C. Utilizing dilatometry, the superplastic (SP) U-5.8 Nb alloy requires superheating to 658°C to initiate the α+γ2 → γ1 transformation at a heating rate of 1.5°C/s. Hence, the U-5.8 Nb alloy exhibits an anomolous superplastic behavior.

Phase separation in sol gel-derived ceramic films of silica-zirconia, alumina-zirconia, and titania-zirconia system

1994 ◽  
Vol 52 ◽  
pp. 646-647
Author(s):  
J. Tong ◽  
L. Eyring
Keyword(s):  
Fracture Toughness ◽  
Phase Separation ◽  
Sol Gel ◽  
Great Influence ◽  
High Strength ◽  
Chemical Durability ◽  
Separation Method ◽  
Toughening Mechanism ◽  
Ceramic Films ◽  
Zirconia Toughened Alumina

There is increasing interest in composites containing zirconia because of their high strength, fracture toughness, and its great influence on the chemical durability in glass. For the zirconia-silica system, monolithic glasses, fibers and coatings have been obtained. There is currently a great interest in designing zirconia-toughened alumina including exploration of the processing methods and the toughening mechanism.The possibility of forming nanocrystal composites by a phase separation method has been investigated in three systems: zirconia-alumina, zirconia-silica and zirconia-titania using HREM. The morphological observations initially suggest that the formation of nanocrystal composites by a phase separation method is possible in the zirconia-alumina and zirconia-silica systems, but impossible in the zirconia-titania system. The separation-produced grain size in silica-zirconia system is around 5 nm and is more uniform than that in the alumina-zirconia system in which the sizes of the small polyhedron grains are around 10 nm. In the titania-zirconia system, there is no obvious separation as was observed in die alumina-zirconia and silica-zirconia system.

Phase separation in fluid additive hard sphere mixtures?

1998 ◽  
Vol 95 (2) ◽  
pp. 131-135 ◽  
Author(s):  
DOUGLAS HENDERSON DEZSO BODA KWONG-YU CHAN
Keyword(s):  
Phase Separation ◽  
Hard Sphere

The plant response to heat requires phase separation

Nature ◽  
2020 ◽  
Vol 585 (7824) ◽  
pp. 191-192 ◽  
Author(s):  
Simon Alberti
Keyword(s):  
Phase Separation ◽  
Plant Response
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