EDNMR and ENDOR Study of the .beta.-.gamma. Phase Transition in Malonic Acid Crystals

1995 ◽  
Vol 99 (1) ◽  
pp. 402-409 ◽  
Author(s):  
J. Krzystek ◽  
Andrew B. Kwiram ◽  
Alvin L. Kwiram
Keyword(s):  
Phase Transition ◽  
Malonic Acid ◽  
Gamma Phase

Vacuum FTIR observation on hygroscopic properties and phase transition of malonic acid aerosols

2017 ◽  
Vol 483-484 ◽  
pp. 7-11 ◽  
Author(s):  
Xu Shao ◽  
Yun Zhang ◽  
Shu-Feng Pang ◽  
Yun-Hong Zhang
Keyword(s):  
Phase Transition ◽  
Malonic Acid ◽  
Hygroscopic Properties

scholarly journals A study of the phase transition behavior of mixed ammonium sulfate – malonic acid aerosols

2004 ◽  
Vol 4 (3) ◽  
pp. 2949-2971 ◽  
Author(s):  
C. F. Braban ◽  
J. P. D. Abbatt
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Relative Humidity ◽  
Ammonium Sulfate ◽  
Malonic Acid ◽  
Binary Systems ◽  
Dry Mass ◽  
The Other ◽  
Phase Transition Behavior ◽  
Infrared Extinction

Abstract. This is a study into the phase transitions of aerosol composed of the ternary system ammonium sulfate (AS) – malonic acid (MA) – water using infrared extinction spectroscopy. Twelve compositions were studied in both deliquescence and efflorescence mode experiments. The presence of a MA fraction, by dry mass, (fMA) of 0.1 in an AS aerosol altered the relative humidity at which the phase transitions occur in an atmospherically significant manner. For compositions with 0.25<fMA<0.90, no distinct "deliquescence" was observed, contrary to the observed behavior in the binary systems. The crystallization of both the MA and AS components is suppressed by the presence of the other component in the aerosol. At fMA=0.9, the crystallization relative humidity of MA was lowered from RH=6% to less than 1%. Similarly, at fMA=0.4, the AS component did not crystallize. The atmospheric implications of the results are discussed.

A phase transition in the novel three-dimensional compound [Eu2(mal)3(H2O)6] (H2mal = malonic acid)

2002 ◽  
pp. 3462-3470 ◽  
Author(s):  
María Hernández-Molina ◽  
Pablo Lorenzo-Luis ◽  
Catalina Ruiz-Pérez ◽  
Trinidad López ◽  
Inocencio R. Martín ◽  
...  
Keyword(s):  
Phase Transition ◽  
Malonic Acid ◽  
Three Dimensional ◽  
The Novel

Raman study of the high-temperature phase transition of malonic acid

1984 ◽  
Vol 15 (1) ◽  
pp. 41-46 ◽  
Author(s):  
J. de Villepin ◽  
M.-H. Limage ◽  
A. Novak ◽  
N. Toupry ◽  
M. Le Postollec ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Malonic Acid ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Temperature Phase Transition ◽  
Raman Study

Phase transition in malonic acid: An infrared study

1980 ◽  
Vol 69 (2) ◽  
pp. 227-229 ◽  
Author(s):  
Somnath Ganguly ◽  
Jacob R. Fernandes ◽  
Gautam R. Desiraju ◽  
C.N.R. Rao
Keyword(s):  
Phase Transition ◽  
Malonic Acid ◽  
Infrared Study

The beta , gamma phase transition in the system NH4Cl1-xBrx

1975 ◽  
Vol 8 (20) ◽  
pp. 3280-3286 ◽  
Author(s):  
I R Jahn ◽  
I H Brunskill ◽  
H Dacts ◽  
R Bausch
Keyword(s):  
Phase Transition ◽  
Gamma Phase

Deep Eutectic Solvent——A Novel Additive to Induce Gamma Crystallization and Alpha‐to‐gamma Phase Transition of PVDF

2022 ◽  
pp. 2100416
Author(s):  
Muhua Yuan ◽  
Haijun Wang ◽  
Huihui Li ◽  
Chunlei Yuan ◽  
Tong Wang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Deep Eutectic Solvent ◽  
Gamma Phase

scholarly journals A study of the phase transition behavior of internally mixed ammonium sulfate - malonic acid aerosols

2004 ◽  
Vol 4 (5) ◽  
pp. 1451-1459 ◽  
Author(s):  
C. F. Braban ◽  
J. P. D. Abbatt
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Relative Humidity ◽  
Ternary System ◽  
Ammonium Sulfate ◽  
Malonic Acid ◽  
Dry Mass ◽  
Phase Transition Behavior ◽  
Transition Behavior ◽  
Infrared Extinction

Abstract. This is a study into the phase transitions of aerosol composed of the ternary system ammonium sulfate (AS) - malonic acid (MA) - water using infrared extinction spectroscopy. Twelve compositions were studied in both deliquescence and efflorescence mode experiments. The presence of a MA fraction, by dry mass, (fMA) of 0.1 in an AS aerosol altered the relative humidity at which the phase transitions occur in an atmospherically significant manner. For compositions with 0.25

Temperature-induced phase transition of isonicotinamide-malonic acid (2/1) and supramolecular construct analysis of isonicotinamide structures

2018 ◽  
Vol 233 (8) ◽  
pp. 539-554
Author(s):  
Tze Shyang Chia ◽  
Ching Kheng Quah
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
High Temperature ◽  
Low Temperature ◽  
Malonic Acid ◽  
Structural Phase ◽  
Molecular Cluster ◽  
Conformational Transformation ◽  
Temperature Phase ◽  
Acid Molecule

Abstract The isonicotinamide-malonic acid (2/1) co-crystal salt (2IN·C3) exhibits a first-order displacive structural phase transition from low-temperature triclinic P1̅ crystal structure to high-temperature monoclinic C2/c crystal structure and vice versa at the transition temperatures of 298 (1) and 295 (1) K, respectively, as determined by variable-temperature SCXRD analysis and DSC measurements. The asymmetric unit of 2IN·C3 comprises three malonic acid molecules and six isonicotinamide molecules at the low-temperature phase, and this is reduced to a half-molecule of malonic acid and an isonicotinamide molecule in the high-temperature phase. The carboxyl and pyridinium H atoms are disordered at both phases. The observed phase transition near room temperature is triggered by the molecular displacement of the isonicotinamide molecule and the syn-anti conformational transformation of the malonic acid molecule with deviation angles of 10.4 and 11.7°, respectively, which induced an energy change of 19.1 kJ mol−1 in the molecular cluster comprising a central isonicotinamide molecule and eight neighboring molecules. However, the total interaction energy of the molecular cluster of a central malonic acid molecule and eight neighboring molecules does not change significantly upon the phase transition. The molecules of isonicotinamide structures except IN·IN+·triazole‒ form zero-dimensional finite arrays or one-dimensional chains as the primary supramolecular construct by carboxyl···pyridyl (−35.9 to −56.7 kJ mol−1) and carboxamide···carboxamide (−53.6 to −68.7 kJ mol−1) or carboxyl···carboxamide (−52.6 to −67.1 kJ mol−1) synthons.

Microstructure of laser-irradiated, conducting Kapton polyimide

1995 ◽  
Vol 53 ◽  
pp. 502-503
Author(s):  
D. L. Callahan ◽  
Z. Ball ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Film Surface ◽  
Cross Sectional ◽  
General Utility ◽  
Transmission Electron ◽  
Considerable Debate ◽  
Potential Applications

Ultraviolet laser-irradiation can be used to induce an insulator-to-conductor phase transition on the surface of Kapton polyimide. Such structures have potential applications as resistors or conductors for VLSI applications as well as general utility electrodes. Although the percolative nature of the phase transformation has been well-established, there has been little definitive work on the mechanism or extent of transformation. In particular, there has been considerable debate about whether or not the transition is primarily photothermal in nature, as we propose, or photochemical. In this study, cross-sectional optical microscopy and transmission electron microscopy are utilized to characterize the nature of microstructural changes associated with the laser-induced pyrolysis of polyimide.Laser-modified polyimide samples initially 12 μm thick were prepared in cross-section by standard ultramicrotomy. Resulting contraction in parallel to the film surface has led to distortions in apparent magnification. The scale bars shown are calibrated for the direction normal to the film surface only.

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