Polymer Solid-Phase Grafting at Temperature Higher than the Polymer Melting Point through Selective Heating

2019 ◽  
Vol 52 (9) ◽  
pp. 3222-3230 ◽  
Author(s):  
Songhe Wang ◽  
Xiaohong Zhang ◽  
Chao Jiang ◽  
Haibin Jiang ◽  
Yujing Tang ◽  
...  
Keyword(s):  
Melting Point ◽  
Solid Phase ◽  
Selective Heating ◽  
Polymer Melting

Simultaneous sintering of low-melting-point Mg with high-melting-point Ti via a novel one-step high-pressure solid-phase sintering strategy

2021 ◽  
Vol 858 ◽  
pp. 158344
Author(s):  
Xuecheng Cai ◽  
Shuaijun Ding ◽  
Zhongjie Li ◽  
Xin Zhang ◽  
Kangkang Wen ◽  
...  
Keyword(s):  
High Pressure ◽  
Melting Point ◽  
Solid Phase ◽  
High Melting ◽  
High Melting Point ◽  
One Step

Non-Isothermal Phase Change Behaviors of Binary Mixtures of D-Dulcitol and Pentaerythritol As Novel Heat Storage Materials

2018 ◽  
Author(s):  
Xue-Feng Shao ◽  
Jun Wang ◽  
Li-Wu Fan
Keyword(s):  
Melting Point ◽  
Phase Change ◽  
Binary Mixtures ◽  
Latent Heat ◽  
Mass Fraction ◽  
Heat Storage ◽  
Solid Phase ◽  
Sugar Alcohols ◽  
Nucleation Agent ◽  
Latent Heat Storage

As a promising Phase Change Material (PCM) candidate for low-to-medium temperature (100–250 °C) latent heat storage, sugar alcohols undergo serious supercooling during cool-down for crystallization. Technical efforts need to be dedicated to suppression or control of the supercooling of sugar alcohols. In this work, the supercooling of D-dulcitol, with a melting point of around 186 °C, was attempted to be reduced by mixing with a solid-solid PCM Pentaerythritol (PE) as the nucleation agent, which has a solid-solid phase transition temperature (∼186 °C) similar to the melting point of d-dulcitol. Such novel binary mixtures were prepared by dispersing PE powders at various mass fractions into d-dulcitol melt. The non-isothermal phase-change-related properties, with emphasis on the crystallization properties, were tested on a heat-flux differential scanning calorimeter at a constant heating/cooling rate of 5 °C/min. The preliminary results showed that both the crystallization point and latent heat of crystallization strongly depend on the mass fraction of PE, and both decrease in magnitude with the increasing in mass fraction of PE. The degree of supercooling of the binary mixtures also depend on the mass fraction of PE, and a reduction of up to 10 °C was obtained at 50 wt.% PE, as a result of the decrease in the melting points of the binary mixtures.

scholarly journals Printing low-melting-point alloy ink to directly make a solidified circuit or functional device with a heating pen

2014 ◽  
Vol 470 (2172) ◽  
pp. 20140609 ◽  
Author(s):  
Lei Wang ◽  
Jing Liu
Keyword(s):  
Melting Point ◽  
Electronic Circuit ◽  
Printed Electronics ◽  
Solid Phase ◽  
Electronic Devices ◽  
Change Mechanism ◽  
Short Period ◽  
Control Switch ◽  
Double Diamond ◽  
Rapidly Solidified

A new method to directly print out a solidified electronic circuit through low-melting-point metal ink is proposed. A functional pen with heating capability was fabricated. Several typical thermal properties of the alloy ink Bi 35 In 48.6 Sn 16 Zn 0.4 were measured and evaluated. Owing to the specifically selected melting point of the ink, which is slightly higher than room temperature, various electronic devices, graphics or circuits can be manufactured in a short period of time and then rapidly solidified by cooling in the surrounding air. The liquid–solid phase change mechanism of the written lines was experimentally characterized using a scanning electron microscope. In order to determine the matching substrate, wettability between the metal ink Bi 35 In 48.6 Sn 16 Zn 0.4 and several materials, including mica plate and silicone rubber, was investigated. The resistance–temperature curve of a printed resistor indicated its potential as a temperature control switch. Furthermore, the measured reflection coefficient of a printed double-diamond antenna accords well with the simulated result. With unique merits such as no pollution, no requirement for encapsulation and easy recycling, the present printing approach is an important supplement to current printed electronics and has enormous practical value in the future.

Thermodynamics and Kinetic Considerations behind the Growth of AlN Whiskers Synthesized by Carbothermal Reduction

2007 ◽  
Vol 280-283 ◽  
pp. 1403-1408 ◽  
Author(s):  
Ren Li Fu ◽  
He Ping Zhou ◽  
Ke Xin Chen ◽  
José Maria F. Ferreira
Keyword(s):  
Melting Point ◽  
Liquid Phase ◽  
Carbothermal Reduction ◽  
Solid Phase ◽  
Dominant Role ◽  
Kinetic Studies ◽  
Synthesis Temperature ◽  
Screw Dislocations ◽  
Melting Point Eutectic ◽  
Kinetics Of

AlN whiskers have been successfully synthesized by carbothermal reduction. The thermodynamics and growth kinetics of AlN whiskers were studied at 1600°C using CaCO3 as a catalyst. The research indicated that AlN whiskers are more easily nucleated from the liquid phase than at the surface of solid phase. AlN whiskers are nucleated by VLS mechanism and the liquid, which plays a dominant role in the VLS mechanism, is formed by Al-Ca interphases, such as CaO×2Al2O3 and CaO×6Al2O3. Kinetic studies suggest that the catalyst reacts with Al2O3 to form a low melting point eutectic (1390°C). The liquid phase formed at this low melting point eutectic provides good conditions for nucleation of AlN whiskers. At the synthesis temperature, the liquid phase vaporizes, thus creating suitable conditions for the subsequent growing of whiskers by the VLS mechanism. This growing mechanism conforms to thermodynamics and a lot of proof indicates that screw dislocations play an important role in the process of the whiskers' formation.

Phonon spectra of ortho -dinitrotetramethylbenzene crystals

1987 ◽  
Vol 65 (9) ◽  
pp. 2122-2125 ◽  
Author(s):  
Paolo Sgarabotto ◽  
Mario Braghetti ◽  
Rosario Sergio Cataliotti ◽  
Giulio Paliani ◽  
Salvatore Sorriso ◽  
...  
Keyword(s):  
Group Theory ◽  
Phase Transitions ◽  
Solid State ◽  
Melting Point ◽  
Nitro Group ◽  
Vibrational Spectra ◽  
Lattice Dynamics ◽  
Solid Phase ◽  
Methyl Group ◽  
Phonon Spectra

We have studied the vibrational spectra and thermal behaviour of ortho-dinitrotetramethylbenzene (o-DNTMB) to learn more about its molecular and lattice dynamics. The molecule undergoes two solid–solid phase transitions, close to the melting point, which could be explained by the relaxation of forces hindering the methyl-group and nitro-group free rotations. We have deduced the nature of the solid state vibrational motions, particularly those of lattice phonons, using group theory.

Spin-lattice relaxation in solid and liquid CH4–Kr mixtures

1984 ◽  
Vol 62 (5) ◽  
pp. 431-434 ◽  
Author(s):  
P. Calvani ◽  
F. De Luca ◽  
B. Maraviglia
Keyword(s):  
Transition Temperature ◽  
Melting Point ◽  
Solid Phase ◽  
Molar Fraction ◽  
Lattice Relaxation ◽  
Intramolecular Interactions ◽  
Spin Lattice Relaxation ◽  
Solidus Curve ◽  
Spin Lattice ◽  
Dipolar Contribution

T1 has been measured at 4 MHz and 78 K < T < 120 K in mixtures having a Kr molar fraction c up to 0.8. The transition temperature Ts, corresponding to the solidus curve, has been determined for several values of c by observing the large discontinuity in T1 as in pure CH4. In the solid phase, the intermolecular dipolar contribution to the relaxation rate is found to be dominant at T > 80 K, and our data are in agreement with a simple model based on the Torrey–Sholl theory. Above the melting point, T1 becomes independent of c, thus suggesting that relaxation may be driven by intramolecular interactions in the liquid phase.

CALCULATION OF THE MOLAR VOLUME IN THE SOLID AND LIQUID PHASES OF CCl4

2010 ◽  
Vol 24 (01) ◽  
pp. 75-80 ◽  
Author(s):  
H. YURTSEVEN ◽  
D. KAVRUK
Keyword(s):  
Melting Point ◽  
Molar Volume ◽  
Solid Phase ◽  
Anomalous Behavior ◽  
Thermal Expansivity ◽  
Temperature Variations ◽  
Liquid Phases ◽  
Temperature Ranges ◽  
Temperature And Pressure ◽  
The Given

The molar volume of carbon tetrachloride is calculated as functions of temperature and pressure close to the melting point. By analyzing the experimental data for the pressure dependence of the thermal expansivity according to a power-law formula, the molar volume is calculated for the solid and liquid phases of this molecular organic compound. Our calculations show that the molar volume of the solid phase increases almost linearly as the temperature and pressure increase, so that there is no anomalous behavior close to the melting point in CCl 4. In the liquid phase, it does not vary considerably within the given pressure and temperature ranges. Our calculated molar volumes can be compared with measurements for CCl 4 under the given pressure and temperature variations.

scholarly journals Thermal Conductivity of Metastable Ionic Liquid [C2mim][CH3SO3]

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4290 ◽  
Author(s):  
Daniel Lozano-Martín ◽  
Salomé Inês Cardoso Vieira ◽  
Xavier Paredes ◽  
Maria José Vitoriano Lourenço ◽  
Carlos A. Nieto de Castro ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Ionic Liquid ◽  
Melting Point ◽  
Solid Phase ◽  
Freezing Point ◽  
Phase Region ◽  
Heat Transfer Fluid ◽  
Diphenyl Oxide ◽  
Conductivity Models

Ionic liquids have been suggested as new engineering fluids, namely in the area of heat transfer, as alternatives to current biphenyl and diphenyl oxide, alkylated aromatics and dimethyl polysiloxane oils, which degrade above 200 °C and pose some environmental problems. Recently, we have proposed 1-ethyl-3-methylimidazolium methanesulfonate, [C2mim][CH3SO3], as a new heat transfer fluid, because of its thermophysical and toxicological properties. However, there are some interesting points raised in this work, namely the possibility of the existence of liquid metastability below the melting point (303 K) or second order-disorder transitions (λ-type) before reaching the calorimetric freezing point. This paper analyses in more detail this zone of the phase diagram of the pure fluid, by reporting accurate thermal-conductivity measurements between 278 and 355 K with an estimated uncertainty of 2% at a 95% confidence level. A new value of the melting temperature is also reported, Tmelt = 307.8 ± 1 K. Results obtained support liquid metastability behaviour in the solid-phase region and permit the use of this ionic liquid at a heat transfer fluid at temperatures below its melting point. Thermal conductivity models based on Bridgman theory and estimation formulas were also used in this work, failing to predict the experimental data within its uncertainty.

Solid-Phase Reduction of Iron from Suroyam Titanomagnetite Ore during Metallization in Rotary Kiln

2019 ◽  
Vol 946 ◽  
pp. 512-516
Author(s):  
K.I. Smirnov ◽  
S.P. Salikhov ◽  
V.E. Roshchin
Keyword(s):  
Electron Microscope ◽  
Melting Point ◽  
Rotary Kiln ◽  
Solid Phase ◽  
Reduction Process ◽  
Reducing Agent ◽  
Continuous Processing ◽  
Phase Reduction ◽  
Reduction Of Iron ◽  
Electron Microscope Analysis

In this work the solid-phase reduction of iron from the Suroyam titanomagnetite ore was studied during metallization in a rotary kiln. The technique of preparation of the ore and reducing agent for metallization and the process of continuous processing of materials in a rotary kiln were described in detail. For metallization the temperature was chosen 1150°C, due to low melting point of apatite from one of the components. The results of the electron microscope analysis of the initial ore and samples subjected to metallization for 1-hour reduction time were presented. The reduction of iron occurred despite absence of pores and contact with a reducing agent in the grains of titanomagnetite. Iron in the grains of titanomagnetite surrounded by apatite was reduced to wustite; whereas, iron surrounded by clinopyroxene was reduced to metallic iron. This indicated the effect of composition of the gangue materials on the reduction process.

scholarly journals Poly(lactide)-block-poly(ε-caprolactone-co-ε-decalactone)-block-poly(lactide) copolymer elastomers

2015 ◽  
Vol 6 (19) ◽  
pp. 3641-3651 ◽  
Author(s):  
Deborah K. Schneiderman ◽  
Erin M. Hill ◽  
Mark T. Martello ◽  
Marc A. Hillmyer
Keyword(s):  
Melting Point ◽  
Tensile Properties ◽  
Block Polymer ◽  
Polymer Melting

The midblock composition of poly(lactide)-block-poly(ε-caprolactone-co-ε-decalactone)-block-poly(lactide) is used to tune block polymer melting point, crystallinity, segregation strength and tensile properties.

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