scholarly journals Cement Mortar Porosity by Modified Analysis of Differential Scanning Calorimetry Records

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1080 ◽  
Author(s):  
Piotr Stępień ◽  
Zbigniew Rusin ◽  
Karol Skowera
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Energy Distribution ◽  
Cement Mortar ◽  
Thermal Inertia ◽  
Scanning Calorimetry ◽  
Modified Method ◽  
Original Apparatus ◽  
Temperature Ranges ◽  
20 Nm

A modified method of interpreting a heat flux differential scanning calorimetry records in pore structure determination is presented. The method consists of determining the true phase transition energy distribution due to the melting of water during a differential scanning calorimetry (DSC) heating run. A set of original apparatus functions was developed to approximate the recorded calorimetric signals to the actual processes of the water phase transition at a given temperature. The validity of the proposed calorimetric curves-based algorithm was demonstrated through tests on a cement mortar sample. The correct analysis required taking into account both the thermal inertia of the calorimeter and the thermal effects that are associated with water transitions over the fairly narrow temperature ranges close to 0 °C. When evaluating energy distribution without taking the shifts of the proposed modified algorithm into account, the volume of the pores with radii bigger than 20 nm was greatly overestimated, while that of the smaller pores (rp < 20 nm) was underestimated, in some cases by approximately 70%.

scholarly journals The Influence of the Nature of Redox-Active Moieties on the Properties of Redox-Active Ionic Liquids and on Their Use as Electrolyte for Supercapacitors

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6344
Author(s):  
Philipp S. Borchers ◽  
Patrick Gerlach ◽  
Yihan Liu ◽  
Martin D. Hager ◽  
Andrea Balducci ◽  
...  
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Binary Mixtures ◽  
Thermal Characteristics ◽  
The Other ◽  
Scanning Calorimetry ◽  
Imidazolium Ionic Liquids ◽  
Redox Active

In this work, two new redox-active ionic liquids, one based on 2,2,6,6-tetramethylpiperidine-N-oxide and the other based on 4,4′-bipyridine, are synthesized and characterized. A ferrocene-based redox-active ionic liquid is used for referencing the results. All ionic liquids are formed via salt-metathesis from halogenate to bis(trifluoromethylsulfonyl)imide. Their fundamental thermal characteristics are assessed with differential scanning calorimetry. While the imidazolium ionic liquids show no melting point, the phase transition is well observable for the viologen-based ionic liquid. The properties of the neat redox-active ionic liquids and of binary mixtures containing these ionic liquids (0.1 m) and 1-butyl-1-methyl pyrrolidinium-bis(trifluoromethylsulfonyl)imide have been investigated. Finally, the use of these binary mixtures in combination with activated carbon-based electrodes has been considered in view of the use of these redox-active electrolytes in supercapacitors.

DIFFERENTIAL SCANNING CALORIMETRY INVESTIGATION OF PHASE TRANSITION IN BaZrXTi1-XO3

2009 ◽  
Vol 108 (1) ◽  
pp. 106-115 ◽  
Author(s):  
B. GARBARZ-GLOS ◽  
R. BUJAKIEWICZ-KOROŃSKA ◽  
D. MAJDA ◽  
M. ANTONOVA ◽  
A. KALVANE ◽  
...  
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Scanning Calorimetry

Dependence of Phase Transition of a Bent-Core Liquid Crystal on the Heating Rate

2010 ◽  
Vol 663-665 ◽  
pp. 787-790 ◽  
Author(s):  
Qing Lan Ma ◽  
Yuan Ming Huang
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Optical Microscopy ◽  
Heating Rate ◽  
Broad Peak ◽  
Crystal Phase ◽  
Scanning Calorimetry ◽  
Polarized Optical Microscopy ◽  
Crystal Compound

A bent-core liquid crystal compound N,N-bis (4-propoxybenzylidene)benzene- 1,3-diamine was synthesized. Phase transition properties of the synthesized compound with the deferent heating rate were characterized with differential scanning calorimetry and polarized optical microscopy. , respectively. Our results demonstrated that the bent-core compound exhibited the completely undivided multi-phases in heating-rate ranges from 1oC/min to 6oC/min while it showed a broad-peak crystal phase in higher heating-rate ranges of 7-10oC/min for the first heating.

SAXS Study of Selected Cationic Surfactant Influence on the DSPC-Based Model Phospholipid System

2007 ◽  
Vol 130 ◽  
pp. 257-262
Author(s):  
Maciej Kozak ◽  
Ludwik Domka ◽  
Stefan Jurga
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Small Angle ◽  
Phase Behaviour ◽  
Lamellar Phase ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering ◽  
Hydrocarbon Chains ◽  
Main Transition

The phase behaviour of lipid bilayer systems prepared with 1,2-distearoyl-sn-glycero-3- phosphocholine (DSPC) with dodecyldimethyl(benzyloxymethyl)ammonium chloride (BzMDDAC) (at concentrations 0.1, 1 and 5%) has been studied by small angle X-ray scattering and differential scanning calorimetry. The SAXS and DSC results of the hydrated 10% DSPC revealed one typical phase transition corresponding to melting of the hydrocarbon chains at 55 °C. In the system of 10% DSPC - 0.1 % BzMDDAC the main transition was somewhat shifted towards lower temperatures, while at 1% concentration of BzMDDAC in the mixture, the lamellar phase disappeared, as evidenced by SAXS and DSC. The increase in BzMDDAC concentration to 5% in the mixture with 10% DSPC resulted in formation of a new lamellar phase.

Amorphous iron oxide prepared by microwave heating

2000 ◽  
Vol 15 (10) ◽  
pp. 2176-2181 ◽  
Author(s):  
Oleg Palchik ◽  
Israel Felner ◽  
Gina Kataby ◽  
Aharon Gedanken
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Iron Oxide ◽  
Iron Pentacarbonyl ◽  
Microwave Oven ◽  
The Other ◽  
Scanning Calorimetry ◽  
Amorphous Iron ◽  
Domestic Microwave Oven ◽  
Crystalline Phase Transition

Amorphous iron oxide (Fe2O3) was prepared by the pyrolysis of iron pentacarbonyl [Fe(CO)5] in a modified domestic microwave oven in refluxing chlorobenzene as a solvent under air. The reaction time was 20 min. Partially separated particles of iron oxide, 2–3 nm in diameter, were obtained. The other part showed aggregated spheres with a diameter of 25–40 nm. Differential scanning calorimetry measurements showed an amorphous/crystalline phase transition at about 250 °C.

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