Fine needlelike crystals of C60 have been formed by a liquid–liquid interfacial precipitation method which uses an interface of the concentrated toluene solution of C60/isopropyl alcohol. The needlelike crystals of C60 with a diameter of submicrons (“C60 nanowhiskers”) were found to be single crystalline and composed of thin slabswith a thickness of about 10 nm. The intermolecular distance of the C60 nanowhiskerswas found to be shortened along the growth axis as compared with the pristine C60crystals, indicating a formation of strong bonding between C60 molecules. TheC60 nanowhiskers are assumed to be polymerized via the “2 + 2” cycloaddition inthe close-packed [110]c direction.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S088429140006026X

C60 Nanowhiskers Formed by the Liquid–liquid Interfacial Precipitation Method

The present paper considers the state of investigations and developments in form-stable phase change materials for thermal energy storage. Paraffins, fatty acids and their blends, polyethylene glycol are widely used as latent heat storage component in developing form-stable materials while high-density polyethylene (HDPE), styrene–butadiene–styrene (SBS) triblock copolymer, Eudragit S, Eudragit E, poly (vynil chloride) (PVC), poly (vynil alcohol) (PVA) and polyurethane block copolymer serve as structure supporting component. A set of organic and metallo-organic materials with high transition heat in solid–solid state is considered as perspective for-stable materials to store thermal energy. Another perspective class of form-stable materials are the materials on the basis of such porous materials as expanded perlite and vermiculite impregnated with phase change heat storage materials. The technology of producing new form-stable ultrafine heat storage fibers is developed. It opens availability to produce the clothers with improved heat storage ability for extremely cold regions. The perspective fields of application of form-stable materials are discussed. The further directions of investigations and developments are considered.

Form-stable phase change materials for thermal energy storage

Crystal Growth & Design

A compendium of phase change enthalpies published in 2010 is updated to include the period 1880–2015. Phase change enthalpies including fusion, vaporization, and sublimation enthalpies are included for organic, organometallic, and a few inorganic compounds. Part 1 of this compendium includes organic compounds from C1 to C10. Part 2 of this compendium, to be published separately, will include organic and organometallic compounds from C11 to C192. Sufficient data are presently available to permit thermodynamic cycles to be constructed as an independent means of evaluating the reliability of the data. Temperature adjustments of phase change enthalpies from the temperature of measurement to the standard reference temperature, T = 298.15 K, and a protocol for doing so are briefly discussed.

Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds. Sublimation, Vaporization and Fusion Enthalpies From 1880 to 2015. Part 1. C1-C10

Experimental and literature data concerning the solubility of individual light fullerenes (C60 and C70) in binary (individual fullerene + solvent), ternary (C60 + C70 fullerenes + solvent; C60 or C70 fullerenes + solvent 1 + solvent 2), and multicomponent (fullerenes + natural fats and oils) systems as well as the data on solubility of industrial fullerene mixtures and fullerene derivatives in various organic solvents are presented and discussed.

Solubility of Light Fullerenes in Organic Solvents

(MnNiSi)1−x(FeCoGe)x undergoes a magnetostructural phase transition near room temperature that is acutely sensitive to applied hydrostatic pressure, which presents as a marked shift in the martensitic transition temperature (TM) by about –7.5 K/kbar. The magnetostructural transition can therefore be induced by applied hydrostatic pressure or by magnetic field. The barocaloric and magnetocaloric effects were measured across TM (for the sample with x = 0.38), and the corresponding entropy changes were +74 J/kg K (P = 2.7 kbar) and –58 J/kg K (μ0 H = 5 T), respectively. It was observed that the transition entropy change increases with pressure, which results in an enhancement of the barocaloric effect. Our measurements show that the transformed phase fraction associated with magnetostructural transition does not depend on pressure and, therefore, this enhancement cannot be attributed to a pressure-assisted completion of the phase transformation.

/pdf/barocaloric-and-magnetocaloric-effects-in-mnnisi-1-x-fecoge-21fxl6yl81.pdf

Barocaloric and magnetocaloric effects in (MnNiSi) 1− x (FeCoGe) x

We probe the temperature- and pressure-dependent specific volume (v) and dipolar dynamics of the amorphous phase (in both the supercooled liquid and glass states) of the ternidazole drug (TDZ). Three molecular dynamic processes are identified by means of dielectric spectroscopy, namely the α relaxation, which vitrifies at the glass transition, a Johari-Goldstein β JG relaxation, and an intramolecular process associated with the relaxation motion of the propanol chain of the TDZ molecule. The lineshapes of dielectric spectra characterized by the same relaxation time (isochronal spectra) are virtually identical, within the studied temperature and pressure ranges, so that the time-temperature-pressure superposition principle holds for TDZ. The α and β JG relaxation times fulfil the density-dependent thermodynamic scaling: master curves result when they are plotted against the thermodynamic quantity Tv γ , with thermodynamic exponent γ approximately equal to 2. These results show that the dynamics of TDZ, a system characterized by strong hydrogen bonding, is characterized by an isomorphism similar to that of van-der-Waals systems. The low value of γ can be rationalized in terms of the relatively weak density-dependence of the dynamics of hydrogen-bonded systems.

/pdf/thermodynamic-scaling-of-the-dynamics-of-a-strongly-hydrogen-3nsqvtucmu.pdf

Thermodynamic Scaling of the Dynamics of a Strongly Hydrogen-Bonded Glass-Former

–OH) is revealed to be a complexproblem and only two stable solid phases, denoted on cooling from the liquid as phases I and II, are foundusing static ~thermodynamic and x-ray diffraction! as well as dynamic ~dielectric spectroscopy! experimentaltechniques. Both solid phases are known to exhibit glass transitions if they are cooled down fast enough toprevent transition to ordered crystalline states. Although glass transitions corresponding to both phases hadbeen well documented by means of speciﬁc heat measurements, x-ray measurements constitute, as far as weknow, the ﬁrst evidence from the structural point of view. In addition, a great amount of dielectric worksdevoted to phase I and its glass transition, were published in the past but next to nothing relating to thedielectric properties of phase II and its glass transition. The nature of the disorder of phase II will be discussed.DOI: 10.1103/PhysRevB.69.224202 PACS number~s!: 61.43.2j, 64.70.Pf, 65.60.1a, 77.22.2dI. INTRODUCTION

/pdf/thermodynamic-crystallographic-and-dielectric-study-of-the-49wmpm7sug.pdf

Thermodynamic, crystallographic, and dielectric study of the nature of glass transitions in cyclo-octanol.

The experimental phase diagram between the plastic crystals neopentyl glycol (NPG) and tris(hydroxymethyl)aminomethane (TRIS) has been established The importance of the use of complementary techniques with different timescales in order to obtain the most realistic phase diagram is underlined The miscibility is discussed on the basis of the geometric conditions (size and shape of molecules and unit-cell dimensions) and of the role of the intermolecular interactions in the structure of the mixed crystals Binary phase diagrams formed by related, previously reported neopentane derivatives are also analysed in the same manner

Degree of miscibility between non-isomorphous plastic phases: binary system NPG (neopentyl glycol)-TRIS[tris(hydroxymethyl)aminomethane]

Modulated differential scanning calorimetry (MDSC) has been used to obtain specific heat measurements on octyloxycyanobiphenyl (8OCB), octylcyanobiphenyl (8CB) and nonyloxycyanobiphenyl (9OCB) liquid crystals and on several binary mixtures of 8OCB + 9OCB and 8CB + 9OCB. The order of the mesophase transitions, smectic A(SmA) to nematic(N) and N to isotropic (I) on pure components and on binary mixtures has been studied and, in addition, both binary mesophase diagrams have been built. For each set of mixtures, there exists a tricritical point (TCP) composition at the SmA–N transition. The TCP compositions have been found to be X9OCB = 0.63 for the system 8OCB + 9OCB and X9OCB = 0.42 for the system 8CB + 9OCB. In addition, the specific heat
critical exponents (α) through second order SmA to N transition have been obtained between 8OCB(or 8CB) and the TCP composition for the two sets of binary mixtures. When these α-values were plotted against the normalised nematic range, a common and uniform crossover trend was found. Indeed, this fact suggests a uniform behaviour in terms of the McMillan ratio for the nCB and nOCB series of liquid crystals. Moreover, for these compounds there exists a common value of (TAN/TNI)TCP of 0.99 and also a value of (TAN/TNI)3D-XY of about 0.96.

Josep Ll. Tamarit

Papers

Barocaloric and magnetocaloric effects in (MnNiSi) 1− x (FeCoGe) x

Thermodynamic Scaling of the Dynamics of a Strongly Hydrogen-Bonded Glass-Former

Thermodynamic, crystallographic, and dielectric study of the nature of glass transitions in cyclo-octanol.

Degree of miscibility between non-isomorphous plastic phases: binary system NPG (neopentyl glycol)-TRIS[tris(hydroxymethyl)aminomethane]

Binary mixtures of nCB and nOCB liquid crystals. Two experimental evidences for a smectic A nematic tricritical point