Protonated betaine bis(trifluoromethylsulfonyl)imide is an ionic liquid with the ability to dissolve large quantities of metal oxides. This metal-solubilizing power selective. Soluble are oxides trivalent rare earths, uranium(VI) oxide, zinc(II) cadmium(II) mercury(II) nickel(II) copper(II) palladium(II) lead(II) manganese(II) and silver(I) oxide. Insoluble or very poorly soluble iron(III), manganese(IV), cobalt oxides, as well aluminum oxide silicon dioxide. The metals can be stripped from...

An adiabatic scanning calorimeter has been used to study the thermal behavior of liquid-crystal octylcyanobiphenyl (8CB) in temperature range between 10 and 50\ifmmode^\circ\else\textdegree\fi{}C. The solid---to---smectic-$A$ ($\mathrm{KA}$), smectic-$A$---to---nematic ($\mathrm{AN}$), as well nematic-to-isotropic (NI) phase transitions, which fall this range, have investigated great detail. From our measuring procedure enthalpy (including latent heats) heat capacity obtained. For KA...

From adiabatic-scanning calorimetric results it is demonstrated that in mixtures of 9CB and 10CB, two compounds the alkylcyanobiphenyl ($n\mathrm{CB}$) series, nematic ($N$) to smectic-$A$ ($A$) transition becomes first order for narrow $N$ ranges. latent heats a tricritical point located phase diagram. Measurements 7CB+ 8CB show specific-heat exponent $\ensuremath{\alpha}$ depends on width range continuous $\mathrm{AN}$ transitions.

Liquid-crystalline blue phases exhibit exceptional properties for applications in the display and sensor industry. However, single component systems, they are stable only very narrow temperature range between isotropic chiral nematic phase, a feature that severely hinders their applicability. Systematic high-resolution calorimetric studies reveal phase III is effectively stabilized wide by mixing surface-functionalized nanoparticles with liquid crystals. This effect present two crystals,...

The electrical conductivities of 1-alkyl-3-methylimidazolium tetrafluoroborate ionic liquids and 1-hexyl-3-methylimidazolium with different anions were determined in the temperature range between 123 393K on basis dielectric measurements frequency from 1to107Hz. Most form a glass conductivity values obey Vogel-Fulcher-Tammann equation. transition temperatures are increasing length alkyl chain. fragility is weakly dependent chain but highly sensitive to structure anion.

Ultrasonic imaging is the noninvasive clinical modality of choice for diagnosing heart disease. At present, two-dimensional ultrasonic grayscale images provide a relatively cheap, fast, bedside method to study morphology heart. Several methods have been proposed assess myocardial function. These based on either or motion (velocity) information measured in real-time. However, quantitative assessment regional function remains an important goal cardiology. To do this, strain and strain-rate...

The ionic liquid (2-hydroxyethylammonium)trimethylammonium) bis(trifluoromethylsulfonyl)imide (choline bistriflimide) was obtained as a supercooled at room temperature (melting point = 30 °C). Crystals of choline bistriflimide suitable for structure determination were grown from the melt in situ on X-ray diffractometer. cation adopts folded conformation, whereas anion exhibits transoid conformation. and are held together by hydrogen bonds between hydroxyl proton sulfonyl oxygen atom. This...

We describe the order parameter S(T) of liquid crystals in nematic state by a four-parameter expression which is consistent with mean-field theory. A two-step fitting method applied to high resolution refractive index data for nCB (n=5–8) crystals, processed according Vuks and Neugebauer models. find quasi-universal values. The average critical exponent β=0.241±0.012, agreement prediction tricritical point. Thus temperature dependence quasi-tricritical all cases. at effective transition...

Abstract Measurements of the relative static permittivity ε octylcyanobiphenyl (8CB) in smectic A, nematic and isotropic phases between 22°C 140°C are reported. The resolution measurements was better than 0.01% temperature stability 0.01 °C. Detailed have been carried out near AN NI transitions. For transition. no discontinuity ε|| or ε| observed, which is consistent with second-order nature this transition 8CB. From dielectric anisotropy N-phase, a critical exponent β ≃ 0.25 obtained for...

Abstract An adiabatic scanning calorimeter has been used in a calorimetric investigation of alkyl-cyanobiphenyl (nCB) liquid crystals. Measurements near solid to smectic (KA), A nematic (AN) and isotropic (NI) or (AI) phase transitions have carried out for rates as low few μKs−1. Results the temperature dependence heat capacity well enthalpy (including latent heats) obtained 8CB, 9CB, 10CB 11CB. Latent values are reported different KA, NI AI transitions. For two compounds 8CB which show AN...

Abstract An adiabatic scanning calorimeter has been used to investigate the temperature dependence of enthalpy and heat capacity near smectic A (A) nematic (N) phase transition in mixtures alkylcyanobiphenyl (nCB) liquid crystals. Mixtures 8CB + 10 CB with small N-ranges undergo first-order transitions, but large exhibit continuous ones. tricritical point could be located for 10CB mole fraction 0.3135. For a nearly mixture, critical exponent α = 0.50 ± 0.02 observed. AN transitions it is...

An adiabatic scanning calorimeter has been used to study the thermal behavior of liquid-crystal cholesteryl nonanoate in a temperature range covering all phase transitions involving three different blue phases occurring this substance. Results for dependence enthalpy and heat capacity are reported. It is found that thermodynamically stable observed first order.

The anomaly in the specific heat Cpx has been investigated by means of a constant heating rate method. Accurate results could be obtained for ‖T-Tc‖/Tc values as small 7×10−6. From range shrinking procedure and nonlinear-least-squares fits to data we α=α′=0.107±0.002, which is close renormalization group (RG) value αRG=0.110±0.008 Ising model dimensionality d=3. For universal amplitude ratio A′/A diverging part above below Tc, 1.75±0.03 obtained. This also agreement with theoretical...

The specific heat Cpx has been measured for the binary system triethylamine–water as a function of temperature near critical solution at concentration. Simple power law fits data resulted in rather large values (around 0.25) exponent α. For fixed value α equal to Ising αI=0.125 good could only be obtained if more complex expressions were used fitting data. this case best result was by including correction-to-scaling term. Combining our amplitude singularity with correlation length allowed us...

It is demonstrated that interactions between nanoparticles and topological defects induce a twist-grain boundary phase in chiral liquid crystal. The occurrence of this phase, the analogue Shubnikov type-II superconductors, driven by direct surface-functionalized CdSe quantum dots screw dislocations. shown that, within an adaptive-defect-core-targeting mechanism, appropriate size functionalization adapt to qualitatively different cores such as disclination lines This mechanism enables...

The idea that rodlike molecules possessing an electric dipole moment could exhibit a ferroelectric nematic phase was suggested more than century ago. However, only recently such has been reported for two quite different liquid crystals: RM734 [4-[(4-nitrophenoxy)carbonyl)]phenyl 2,4-dimethoxybenzoate] and DIO [2.3',4',5'-tetrafluoro[1,1'-biphenyl]-4-yl 2.6-difluoro-4-(5-propyl-1,3-dioxan-2-yl) benzoate]. For direct (N_{F}) to classical N transition reported, whereas intermediate N_{x}...

Correlations between material properties are useful in engineering, and addition, the underlying common mechanisms allow for a better understanding of origins properties. Properties related to phase changes an example, being important, e.g., thermodynamic applications. For n-alkanes used, as change materials thermal energy storage, linear correlations enthalpy entropy transitions, well number carbon atoms n, have been observed described by many researchers. Different odd even n were found,...

Laser ultrasonics is used to optically excite and detect acoustic waves at the interface between a liquid solid or coated solid. Several case studies show that this technique feasible investigate experimentally theoretically predicted fundamental properties of different aspects liquid-solid interfaces characterize elastic soft solids. The theoretical prediction leaky Rayleigh (LR)-type root characteristic determinant becomes forbidden when shear velocity lies below bulk was confirmed. depth...

Photothermal techniques offer a nice tool for the determination of changes in thermal parameters different types samples. Using very thin pyroelectric transducer, simple and versatile ac calorimeter can be built. The described inverse technique allows high-resolution ac-calorimetric measurements temperature dependence specific heat capacity. Since measuring frequencies up to few hertz used, which are higher than most alternative setups, noise reduced times shortened. With small modification...

The concept of viscous characteristic length is used to describe the acoustical behavior fluid-saturated porous media in high-frequency regime. A method determine this parameter consists measuring wave attenuation limit. This has already been for materials saturated by superfluid 2He. It tested case air-filled absorbent a frequency range [50–600 kHz]. thermal assumed be known or measured independently. Two examples are presented. In first one usable and Λ deduced from per cycle. second...

Sound velocity and absorption have been measured at frequencies of 0.6, 1, 3 MHz for xenon along the liquid-vapor coexistence curve several near-critical isotherms. By simultaneously measuring dielectric constant, local density was determined level in fluid where ultrasonic results were obtained. The shape obtained from data gave a critical exponent $\ensuremath{\beta}$ 0.357 \ifmmode\pm\else\textpm\fi{} 0.002. sound dispersion analyzed terms our modification Fixman-Kawasaki theory. It is...

High-resolution calorimetric techniques have substantially contributed in characterising and understanding the delicate thermal behaviour near many phase transitions liquid crystals. In this paper we describe a high-resolution adiabatic scanning technique that has proven to be an important tool discriminating between first-order second-order addition rendering information on fluctuations-induced pretransitional specific heat capacity behaviour. The capabilities of calorimetry are illustrated...