Molecular dynamics and kinetics of isothermal cold crystallization with tunable dimensionality in a molecular glass former, 5′-(2,3-difluorophenyl)-2′-ethoxy-4-pentyloxy-2,3-difluorotolane

Abstract

This paper characterizes the molecular mobility that triggers the cold crystallization abilities in 5'-(2,3-difluorophenyl)-2'-ethoxy-4-pentyloxy-2,3-difluorotolane (short name DFP25DFT) material by broadband dielectric spectroscopy (BDS). We analyze the properties of identified molecular...

Vitrification of the smectic CA* phase and kinetics of cold crystallization investigated for a fluorinated compound with a chiral centre based on (S)-(+)-3-octanol

“…Under conditions of constant cooling, the crystal phase is not formed eventually and the glassy SmC A * is obtained. There are two discontinuous changes in luminance at 233 K and 213 K. The first one corresponds to T g obtained by DSC, the second one can be caused by small fractures in the vitrified sample, 27,28 even if they are not directly visible in textures. During heating, the glass softening is not detected by POM.…”

“…Their appearance is related to fractures in the material, which may be present below the glass transition temperature T g . 27,28…”

“…Their appearance is related to fractures in the material, which may be present below the glass transition temperature T g . 27,28 During heating of the sample, there is a visible step at 233 K, leading to the conclusion that the glass of the SmC A * phase softens. A large, wide exothermal anomaly from cold crystallization can be seen upon further heating.…”

Design of Crystal Growth Dimensionality in Synthetic Wax: The Kinetics of Nonisothermal Crystallization Processes

“…The activation energy of crystallization is contributed by the molecular structure and interactions, as well as the difference in the positional and conformational order of molecules between the initial phase and the forming crystal, and depends on thermodynamic and spatial conditions. In particular, molecular flexibility brings the additional activation barrier for crystal formation. , Therefore, high-weight flexible molecules exhibiting backbone conformations are prospective for a lower capability for melt crystallization than small ones . Additionally, in the wax material, a broad distribution of n -alkanes also favors an increase in the activation barrier for crystallization and thus the tendency to form an amorphous state.…”

Molecular aggregation by hydrogen bonding in cold-crystallization behavior of mixed nucleobases analyzed by temperature-controlled infrared spectroscopy

“…Recently, small molecules exhibiting cold crystallization via supercooled liquids, glass, [10][11][12][13][14][15][16][17][18][19] liquid crystals, [20][21][22][23][24] and ionic liquid crystals 25,26 have been reported. To develop better thermal-storage materials, the mechanism of the thermal behavior during cold crystallization must be analyzed in detail.…”