Isochoric measurement of the evaporation point of pure fluids in bulk and nanoporous media using differential scanning calorimetry

2020 ◽  
Vol 22 (13) ◽  
pp. 7048-7057 ◽  
Author(s):  
Xingdong Qiu ◽  
Sugata P. Tan ◽  
Morteza Dejam ◽  
Hertanto Adidharma
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heating Process ◽  
Scanning Calorimetry ◽  
Point Measurement ◽  
Pure Fluids ◽  
Nanoporous Media ◽  
Isochoric Heating

Evaporation-point measurement of pure fluids in bulk and nanopores using an isochoric heating process.

PHASE TRANSFORMATIONS DURING HEATING OF AMORPHOUS/NANOCRYSTALLINE Ni–Ti POWDERS

2010 ◽  
Vol 24 (09) ◽  
pp. 1137-1140 ◽  
Author(s):  
M. M. VERDIAN ◽  
M. SALEHI ◽  
K. RAEISSI
Keyword(s):  
Differential Scanning Calorimetry ◽  
Solid State ◽  
Phase Transformations ◽  
Low Energy ◽  
Heating Process ◽  
Study Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Niti Phase

Amorphous/nanocrystalline 50 Ni –50 Ti powders were synthesized from elemental Ti and Ni powders by solid state synthesis utilizing low energy mechanical alloying with times up to 100 h. The produced powders were investigated by X-ray diffraction and differential scanning calorimetry to study phase transformations that occurred during heating in the calorimeter. It was found that at the first stage of the heating process, a disordered NiTi phase was formed at temperature of about 400°C. Further investigations indicated that this phase transformed into the Ni 3 Ti and Ti 2 Ni intermetallic compounds after heating at a temperature of about 800°C.

scholarly journals Phase Transition and Melt-Recrystallization Behavior of Poly(Butylene Adipate) Investigated by Simultaneous Measurements of Wide-Angle X-Ray Diffraction (WAXD) and Differential Scanning Calorimetry (DSC)

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 75
Author(s):  
Mengfan Wang ◽  
Weiyu Cao
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Heating Process ◽  
Wide Angle ◽  
Melt Crystallization ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Β Phase ◽  
Simultaneous Measurements

Simultaneous measurements of wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) were carried out to investigate the phase transition and melting behaviors of poly(butylene adipate) (PBA). Thermal expansion changes along the a and b axes of the β form unit cell are different from each other during the heating process. At the beginning of the β to αH (high-temperature α phase) phase transition, the β phase melts very fast, while the recrystallization of the αH phase is delayed and slowed. With the further increment of the temperature, the melting rate of the β phase slows down, while the recrystallization of the αH phase accelerates. The diffraction peak intensity ratios of the β(020):β(110) and αH(020):αH(110) diffraction peaks during the first heating process have similar value. However, the above value is different from the value of α(020):α(110) during the following melt-crystallization process. This difference comes from the different orientations of the crystal lattices of the α and αH(β) crystals to the substrate plane, which indicates that the αH phase inherits the orientation of the β phase during phase transition and the orientation of αH form crystals is different from the α form crystals that crystallized from the melt.

Thermal Energy Storage System of Sulfate / Fiber Matrix Composite

2008 ◽  
Vol 368-372 ◽  
pp. 1077-1079 ◽  
Author(s):  
Xue Tan Ren ◽  
Ling Ke Zeng ◽  
Ping An Liu ◽  
Hui Wang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Molten Salts ◽  
Heating Process ◽  
Storage Material ◽  
Scanning Calorimetry ◽  
Fiber Matrix

The K2SO4-Na2SO4 system was studied by differential scanning calorimetry (DSC) with the aim of developing a new phase-change thermal energy storage material. The temperature range of phase change is from 800°C to 1069°C according to the phase diagram. A new shape-stabilized phase-change material made of molten salts impregnated by capillary forces in a porous-fiber matrix was presented. These materials were characterized by X-ray diffraction analysis and differential scanning calorimetry analysis. The results indicated that the compound included 70~80% of molten salts, meanwhile the heat storage material could keep its shape without any leakage during the heating process.

Probe into CO2-Coal Interactions with Differential Scanning Calorimetry

2014 ◽  
Vol 953-954 ◽  
pp. 1286-1292 ◽  
Author(s):  
Li Jiang Duan ◽  
Liang Chao Qu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Chemical Reactions ◽  
Active Sites ◽  
Bituminous Coal ◽  
Shanxi Province ◽  
Heating Process ◽  
Side Chains ◽  
Scanning Calorimetry ◽  
Slow Cooling ◽  
Two Factors

In order to probe CO2-coal interactions, differential scanning calorimetry (DSC) experiment was carried out in the atmosphere of He and CO2with coals from Huozhou, Changzhi and Jincheng areas in Shanxi Province (classified as high-volatile bituminous coal, low-volatile bituminous coal and anthracite, respectively). It was found that, in a He atmosphere, all the three curves show no enthalpy and are almost reversible, indicating no adsorption occurs. However, in a CO2atmosphere, all the three curves show exothermic peaks and endothermic peaks and are irreversible, indicating, except for physical reactions, chemical reactions may also occur. It was proposed that the C atom of CO2accepted electrons from coal molecular, and formed an electron donor-acceptor complex (i.e., an EDA complex), in other words, chemical reactions occured, hence exothermic peaks occured. The interconnections of the active sites to other groups in coal molecular are weakened due to the formation of EDA complexes, so easily to be broken during heating, hence endothermic peaks occured. The irreversibility of the curves indicate structure change of coal, which may be influenced by two factors: a) during slow cooling, the ordering of side chains, which were expanded in high temperature, leads to a less associated structure; b) in heating process, the breakage of side chains enhances the associations of coal macromolecular, and leads to a more highly associated structure.

Simple and accurate isochoric differential scanning calorimetry measurements: phase transitions for pure fluids and mixtures in nanopores

2019 ◽  
Vol 21 (1) ◽  
pp. 224-231 ◽  
Author(s):  
Xingdong Qiu ◽  
Sugata P. Tan ◽  
Morteza Dejam ◽  
Hertanto Adidharma
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Transitions ◽  
Capillary Condensation ◽  
Scanning Calorimetry ◽  
Pure Fluids

A simple way to measure capillary condensation in nanopores for applications in engineering and science.

Thermal Stability of N-Heterocycle-Stabilized Iodanes – A Systematic Investigation

2019 ◽  
Author(s):  
Andreas Boelke ◽  
Yulia A. Vlasenko ◽  
Mekhman S. Yusubov ◽  
Boris Nachtsheim ◽  
Pavel Postnikov
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Systematic Investigation ◽  
Scanning Calorimetry ◽  
Thermal Stability Of

<p>The thermal stability of pseudocyclic and cyclic <i>N</i>-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-l<sup>3</sup>-iodanes (NHIs) through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is investigated. NHIs bearing <i>N</i>-heterocycles with a high N/C-ratio such as triazoles show among the lowest descomposition temperatures and the highest decomposition energies. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made and we further correlated their thermal stability with reactivity in a model oxygenation. </p>

Optimasi Proses Pembuatan dan Karakterisasi Fisik Niosom Sinkonin

2019 ◽  
Vol 16 (2) ◽  
pp. 178
Author(s):  
Hariyanti Hariyanti ◽  
Sophi Damayanti ◽  
Sasanti Tarini
Keyword(s):  
Differential Scanning Calorimetry ◽  
Particle Size ◽  
Hair Follicle ◽  
Scanning Calorimetry ◽  
Span 60

Sinkonin praktis tidak larut dalam air, sedikit larut dalam kloroform dan alkohol. Hal ini berdampak pada rendahnya penetrasi transfollicular sinkonin, karena hanya bahan aktif hidrofilik yang mampu melewati hair follicle. Dengan demikian dibutuhkan satu sistem penghantaran yang mampu menurunkan hidrofobisitas sinkonin untuk meningkatkan penetrasi sinkonin ke follicle. Niosom merupakan vesikel ampifilik dengan struktur lapisan rangkap yang terbentuk dari hidrasi kombinasi surfaktan nonionik dan kolesterol yang mampu menurunkan hidrofobisitas sinkonin. Penelitian ini bertujuan untuk menentukan proses pembuatan niosom sinkonin yang optimum. Pembuatan niosom sinkonin diawali dengan menentukan temperatur gelasi (Tg) dari span 60 dengan Differential Scanning Calorimetry (DSC), kemudian dilanjutkan dengan optimasi proses meliputi: optimasi kecepatan rotavapor pembentukan film lapis tipis, temperatur hidrasi, kecepatan rotavapor hidrasi, waktu hidrasi, dan waktu sonikasi. Karakteristik vesikel niosom yang optimal meliputi: ukuran partikel dan indeks polidispersitas dengan menggunakan Particle Size Analized (PSA) serta efisiensi penjeratan sinkonin dengan menggunakan KCKT. Temperatur gelasi (Tg) span 60 45±2 oC, kecepatan rotavapor pembentukan film lapis tipis niosom 210 rpm, temperatur hidrasi 55±2 oC, kecepatan rotavapor hidrasi 210 rpm, waktu hidrasi 20 menit, waktu sonikasi suspensi niosom 1 menit. Ukuran vesikel yang diperoleh adalah 100–200 nm, indeks polidispersitas 0,2–0,4 dan efisiensi penjeratan niosom sinkonin 84,49±0,0025%. Proses pembuatan niosom sinkonin memiliki pengaruh besar terhadap hasil ukuran vesikel dan efisiensi penjeratan niosom sinkonin.

Improving Wire Sweep Performance by Measuring Degree of Cure of Epoxy Mold Compounds

2011 ◽  
Author(s):  
Sheila Liza B. Dal
Keyword(s):  
Differential Scanning Calorimetry ◽  
Shelf Life ◽  
Trial And Error ◽  
Active Components ◽  
Scanning Calorimetry ◽  
Degree Of Cure ◽  
Electronic Package ◽  
Viscosity Changes ◽  
Epoxy Mold Compounds

Abstract The choice of epoxy mold compound (EMC) for an electronic package is based mostly on how much protection it provides to the active components in the package. But the choice is not a straightforward process. Rather it is mostly trial and error using different assembly parameters to find the most robust material while assembly defects are monitored. One such defect associated to EMC processing is wire sweep, and many studies have shown that it is mainly caused by viscosity changes in the EMC. In this study, samples of EMC in various stages of shelf life and staging times were analyzed for degree of cure using a method called differential scanning calorimetry (DSC). Samples are then processed at assembly for wire sweep measurement. It was found out that degree of cure increases with staging time at different rates for each shelf life. It was also found out that wire sweep did not only increase with degree of cure but it was also found to be predictable with respect to the latter. Using this information, the age and staging limit for each material was identified that would not cause wire sweep issues.

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