Aqueous Solutions Of LiCl Research Articles

Transition of interfacial capacitors in electrowetting on a graphite surface by ion intercalation.

The low voltage electrowetting response of a LiCl aqueous solution on a freshly cleaved surface of highly oriented pyrolytic graphite (HOPG) is presented. For applied voltages below 1 V, the energy stored in the electrical double layer (EDL) is insufficient to drive the spreading of the drop due to the pinning of the three phase contact line at the step edges. Electrochemical impedance spectroscopy shows a dramatic increase in capacitance above 1 V, which provides a sufficient electrowetting force for depinning the contact line, resulting in a subsequent decrease of the contact angle. The transition of the interfacial capacitance from the EDL to the many-fold high capacitance of the pseudocapacitor drives the electrowetting transition on the HOPG surface. The observed changes in the capacitances above 1 V are correlated with the cyclic voltammetry and atomic force microscopy results, which show that the Cl- ions intercalate into the graphite galleries upon acquiring sufficient energy to overcome the van der Waals attraction between the graphene layers through the side of the step edge of the basal planes. To the best of our knowledge, this is the first study on the voltage dependent intercalation mediated transition of interfacial capacitance driving the spreading of an aqueous electrolyte drop on the HOPG surface, which provides a fundamental understanding of the mechanism and opens up potential applications in microfluidics and charge storage technologies.

Ion-Molecule Complex Dissociation and Formation Dynamics in LiCl Aqueous Solutions from 2D IR Spectroscopy.

Ion-molecule complex dynamics as well as water dynamics in concentrated lithium chloride (LiCl) solutions are examined using ultrafast two-dimensional infrared (2D IR) spectroscopy with the CN stretching mode of methyl thiocyanate (MeSCN) as the vibrational probe. In pure water, MeSCN has a narrow symmetric absorption line shape. 2D IR spectral diffusion measurements of the CN stretch give the identical time dependence of water dynamics, as previously observed using the OD stretch of HOD in H2O. In concentrated LiCl solutions, the IR absorption spectrum of MeSCN displays two distinct peaks, one corresponding to water H-bonded to the N lone pair of MeSCN (W) and the other corresponding to Li+ associated with the N (L). These two species are in equilibrium, and switching of the CN bonding partner from Li+ to H2O and vice versa was observed and explicated with 2D IR chemical exchange spectroscopy. The MeSCN·Li+ complex dissociation time constant, τLW, and the MeSCN·H2O dissociation time constant, τWL, were determined. The observed τLW chemical exchange dissociation time constant changes from 60 to 40 ps as the LiCl concentration decreases from ∼10.7 to ∼7.7 M, mainly due to the increase of the water concentration as the LiCl concentration is reduced. The observed time constants are independent of the model for the chemical reaction. With the assumption of a simple chemical equation, MeSCN·Li+ + H2O ⇄ MeSCN·H2O + Li+, the equilibrium equation rate constants were obtained from the observed chemical exchange time constants. It was determined that the equilibrium rate constants barely change even though the viscosity changes by a factor of 2 and the ionic strength changes by a factor of 1.4. Extrapolation to dilute LiCl solution estimates the τLW to be ∼30 ps. The orientational relaxation (anisotropy decay) of both the W and L complexes was measured using polarization selective 2D IR experiments. The lithium-bonded species undergoes orientational relaxation ∼3 times slower than the water-bonded species in each LiCl solution studied. The difference demonstrates the distinct interactions with the medium experienced by the neutral and charged species in the concentrated salt solutions.

Nonisothermal Evaporation of Layers of Aqueous Salt Solutions

Evaporation of layers of aqueous solutions of salts (LiBr, CaCl2, NaCl, MgCl2, BaCl2, and CsCl) is studied experimentally. Experimental data are compared with evaporation of the water layer. The solution is placed on a horizontal surface of a cylindrical heating section. Experiments on surface crystallization of salts are carried out. For aqueous solutions of salts LiBr, LiCl, and CaCl2, there is an extremum for the heat transfer coefficient αl. For water and for solutions of salts NaCl and CsCl, the extremum is absent. The first factor is a decreasing function of time, and the second factor is an increasing function of time. For the water layer, both factors continuously increase with time, and the maximum evaporation rate corresponds to the final stage of evaporation. The heat balance for interface layer is made up. The role of the free gas convection in the heat balance strongly depends on the salt concentration and varies with the rise of evaporation time. For low salt concentrations the influence of free convection in the gas phase on heat transfer in the liquid phase can be neglected; however, for high concentrations this effect is comparable with other factors. The curves for the rate of crystallization have been built. More than two time differences between the experiment and the calculation are associated with the kinetics of dendritic structures.

Boosting operating voltage of vanadium oxide-based symmetric aqueous supercapacitor to 2 V

Vanadium oxides have great potentials in high voltage symmetric supercapacitors, benefiting from the available multiple oxidation states of vanadium. In this work, charge storage in a wide potential window of −1.1 to 0.9 V vs. SCE is achieve for vanadium oxide through vanadium valence tuning and incorporation in functionalized carbon nanowire array. The functionalized carbon nanowire array provides a good three dimensional conductive scaffold for the oxide nanowires, leading to high electron and ion transportation for the pseudo-capacitive materials. A high areal capacitance of 1.31 F cm−2 is achieved for the obtained vanadium oxide electrode (at 1 mA cm−2 in 5 M LiCl aqueous solution). It also displays good rate capability, demonstrating a quite high areal capacitance of 687 mF cm−2 at 100 mA cm−2. The assembled symmetric supercapacitor can be operate with a large voltage of 2 V and so can deliver a high volumetric energy density of 3.61 mWh cm−3 at 0.01 W cm−3. The supercapacitor also shows good stability, it can retain 91% of its capacitance after 10 000 galvanostatic charge-discharge cycles.

Microscopic insight into the ion aggregation characteristics in aqueous MgCl2 and MgCl2–LiCl solutions: Implications for Mg2+/Li+ separation

The ion aggregation trend for nucleation in MgCl2 and MgCl2–LiCl solutions has been investigated by density functional theory (DFT) and molecular dynamics (MD) simulations. The DFT results show that the solvent-separated Mg2+–Cl− conformers of the mixed LiCl·MgCl2·7H2O clusters are more stable than their contact-associated Mg2+–Cl− isomers in the dilute MgCl2–LiCl aqueous solution. The contact-associated Mg2+−Cl− structures become dominant in the concentrated MgCl2 and MgCl2–LiCl solutions, while the Cl− ions can be more frequently found in the second shell than in the first shell of the Mg2+ ions. The aggregation characteristics indicate that the solvent-separated Mg2+–Cl− association is more likely correlated to the aggregation process for nucleation in MgCl2 and MgCl2–LiCl solutions, whereas the contact-associated Mg2+–Cl− structures may be correlated to the supersaturation of the MgCl2 aqueous solution or MgCl2–LiCl brines. The evolution of the clusters shows that the solvent-separated Mg2+–Cl− mixed clusters can markedly enlarge, while this is not the case for contact associated Mg2+–Cl− mixed clusters during the simulation. The MD simulations reveal that the trends of solvent-separated Mg2+–Cl− association and contact Li+–Cl− association around Mg2+ ions become synchronized in MgCl2–LiCl brines with a low Mg/Li ratio, in which LiCl·MgCl2·7H2O double salt can be formed.

Synthesis and Characterization of the New Dicyanamide LiCs2[N(CN)2

Crystals of LiCs2[N(CN)2]3 were obtained from the reaction of stoichiometric amounts of aqueous solutions of LiCl and CsBr with Ag[N(CN)2]. X-ray single-crystal structure analysis showed that LiCs2[N(CN)2]3 crystallizes isotypically to NaCs2[N(CN)2]3 and adopts the hexagonal space group P63/m (No. 176), with a = 6.8480(8), c = 14.1665(17) Å, and Z = 2. The IR and Raman spectra of the title compound exhibit modes typical for the dicyanamide anion.

Investigations of a Dehumidifier in a Solar-Assisted Liquid Desiccant Demonstration Plant

A solar-assisted liquid desiccant demonstration plant was built and experimentally evaluated. Humidity of the air, density of the desiccant, and all relevant mass flow rates and temperatures were measured at each inlet and outlet position. Adiabatic dehumidification experiments were performed in different seasons of the year under various ambient air conditions. The moisture removal rate m˙v, the mass balance factor κm, and the absorber effectiveness, εabs, were evaluated. An aqueous solution of LiCl was used as liquid desiccant with an initial mass fraction of about 0.4 kgLiCl/kgsol. The mass flow rate of the air through the absorber was about 1100 kg/h. The experimental results showed a reduction in the air humidity ratio in the range of 1.3–4.3 g/kg accompanied with an increase in the air temperature in the range of 3–8.5 K, depending on the inlet and operating conditions. For the air to desiccant mass flow ratio of 82, a mass fraction spread of 5.7% points in the desiccant and a volumetric energy storage capacity of 430 MJ/m3 were achieved. By operating the desiccant pump in an intermittent mode, a mass fraction spread of about 13% points in the desiccant and an energy storage capacity of about 900 MJ/m3 were reached. In addition, the experimental results were compared with results from a numerical model. The numerical model overestimates the heat and mass transfer because it assumes ideal surface wetting and uniform distribution of the circulated fluids.

Elucidating Li-ion adsorption and diffusion behavior on the surface of Cu0.7Co2.3O4 and improvement of performance as flexible full solid-state supercapacitor

Flexible lightweight supercapacitors are now actively investigated as one of the most promising power supplies for the portable and wearable electronics. Herein, radial nanowire arrays of Cu0.7Co2.3O4 are grown on the carbon fiber for a flexible electrode by hydrothermal process and subsequent thermal annealing. The Cu0.7Co2.3O4 electrode, with large exposure of low adsorption energy sites for Li ions due to the nanowires assembled by nanoparticles, displays superior electrochemical performance in 1 M LiCl aqueous solution and demonstrates areal capacitance of 340 mF cm−2 and 685Fg-1 at scan rate of 5 mV s−1. The contribution of Faraday process and capacitive process are analyzed in detail. The density functional theory is employed to calculate the Li+ ion adsorption energy and diffusion barrier, and the results indicate that Li ion can adsorb on 001 facet of the Co2.3Cu0.7O4 easily and the Li ion diffusion barrier along 001 plane is as low as 0.16 eV. Furthermore, a flexible full solid-state supercapacitor is obtained by assembling two pieces of Co2.3Cu0.7O4 electrode face to face, which presents good performance (112.5 mF cm−2 at 5 mV s−1), stability (74% after 5000 cycles), flexibility and wide operating voltage range. Three charged solid-state supercapacitors in series can light 48 green light emitting diodes for 150 s. The Cu0.7Co2.3O4 electrode is expected to be a potential candidate for actual applications.

NMR studies on the coupling of ion and water dynamics on various time and length scales in glass-forming LiCl aqueous solutions.

We combine 1H, 2H, and 7Li NMR methods to investigate the dynamics of water molecules and lithium ions in LiCl aqueous solutions over wide ranges of time and length scales down to their glass transitions. Structural relaxation times τ and self-diffusion coefficients D reveal that water and lithium dynamics are faster for lower salt content at ambient temperatures, while the differences vanish upon cooling when fractional freezing leads to similar salt concentrations in the remaining liquid phases. Relaxation times and diffusion coefficients of water molecules agree with those of lithium ions in the weakly supercooled regime, indicating that the dynamics are strongly coupled. Furthermore, non-Arrhenius temperature dependence is found and the Stokes-Einstein relation is obeyed in this temperature range. However, we observe various decoupling phenomena for the motion of the constituents and for dynamics on different length scales in the deeply supercooled regime. Most notably, the rotational motion of the water molecules does not follow the glassy slowdown of the studied salt solutions below ∼145 K, but it rather resembles that in nanoscopic confinement, molecular solutions, and high-density amorphous ice at low temperatures. This common low-temperature water dynamics is characterized by large-angle reorientation and Arrhenius temperature dependence.

Effect of Interfacial Cations of MnO2 Nanosheet-Based Catalystson Air-Electrode Reaction for Rechargeable Li-Air Batteries

In recent years, development of new-generation batteries with high energy densities exceeding that of Li-ion batteries (LIBs) has been intensively studied. One of the candidates is a non-aqueous Li-air (O2) battery (LAB) and the energy density is more than 5 times larger than those of LIBs. Also, the cost is relatively low because of no containing of precious metals in the positive electrode (PE). However, for the practical use, the LAB still have some problems, e.g., Li metal dendrite growth at the negative electrode, electrochemical durability for electrolytes especially against O2 - radical at the PE, large overpotential to decompose the Li2O2 deposition as a discharge product, because it leads to deteriorate the air-electrode and electrolyte, and then lowers the energy efficiency of LABs. Therefore, many researchers have researched on air-electrode catalysts, e.g., noble metal nanoparticles (Pt, Au) and oxides (Co3O4, RuO2) loaded on nano-carbon materials. However, such kinds of solid electro-catalysts have not exhibited sufficient performance yet because the Li2O2 product generates and covers on the catalysts. To prevent this problem, we have synthesized a new composite catalyst composed of MnO2 nanosheets (Mn-NS) and Ketjen black (KB), i.e. a KB-comp. Mn-NS catalyst, and investigated the electro-catalytic activity against Li2O2 deposition/ decomposition reaction using a LAB cell, together with the durability [1]. In this study, we focused on the effect of interfacial cations for the MnO2 nanosheets on the ORR/OER reactions by comparing the performance of Li+, Na+ and K+-form KB-comp. MnNS catalysts. Mn-NS colloid solution was synthesized by a one-step solution method [1, 2], and then a KB ethanol dispersion was added to form a mixed solution. Afterward, 0.10 M LiCl, NaCl and KCl aqueous solutions were gradually dropped into the mixture to form the KB-comp. MnNS catalysts with each cation (Li+, Na+ and K+). Characterization of the obtained catalysts was carried out by a XRD, TG-DTA, BET measurement and TEM observation. The electro-catalytic activities were evaluated by using a LAB cell using the catalysts, Li metal NE and 0.20 M LiN(SO2CF3)2/diglyme (G2) electrolyte, and tested in constant current (CC) mode at 0.20 mA cm-2 at 30oC. Cyclic voltammetry (CV) and AC impedance measurements were also conducted to elcidate the reaction mechanism for ORR and OER at the PE. From XRD analysis, crystal phases of the synthesized KB-comp. Mn-NS catalysts clearly correspond to the birnessite-type MnO2 layer (JCPDS No. 80-1098) with different distance between the nanosheets, implying the existence of each cation. Fig. 1 shows charge/discharge curves and cycleability of the capacities for the LAB cells using the KB-comp. Mn-NS catalysts, respectively. As a result, the Li+ form clearly exhibited the lowest overpotential during both discharge and charge processes and the best cycle performance among them. This indicates the Li+ ions around the MnO2 nanosheets enabled to promote a Li2O2 generation near them, and keep good contact between the catalytic sites and Li2O2 product. From the CV measurement (Fig. 2), the order of magnitude for both ORR and OER currents was Li+ > Na+ > K+. This was equal to the trend of cell performance. The AC impedance suggested that the Li-form KB-comp. Mn-NS catalyst enhanced the Li2O2 decomposition reaction during charge process as compared with the other cation-form ones. The enhancement mechanism in more detail will be reported in the meeting. This work was supported by JST “A Tenure-track Program” and JSPS “KAKENHI” (25870899), Japan. [1] M. Saito et al., Electrochim. Acta, 252, 192 (2017). [2] K. Kai et al., J. Am. Chem. Soc., 130, 15938 (2008). Figure 1

Studying the Concentration Dependences of IR Spectra for Aqueous Solutions of Alkali Metal Chlorides at a Negative Temperature

In this work, the concentration dependences of IR spectra were studied for aqueous LiCl, NaCl, RbCl, and CsCl solutions within the range from 4 to 0.2 M and an aqueous KCl solution within the range from 3 to 0.2 M at a temperature of –3.5°C in the middle IR region. The wavenumbers of the absorption band maxima were determined for stretching (ν1, ν3), combined (ν2 + νL), and bending ν2 vibrations at these concentrations. The established trends of the shift in the considered absorption bands provided a basis to make several conclusions about the structural transformations of the studied solutions with a decrease in concentration within the studied range. The calculations demonstrated an increase in the energy of hydrogen bonds between water molecules and their reduction in length with decreasing concentration for all of the studied solutions.

Experimental analysis of a novel internally-cooled dehumidifier with self-cooled liquid desiccant

With respect to air dehumidification, an internally-cooled dehumidifier is more efficient than an adiabatic dehumidifier. In the present study, a new method to control the increase in the temperature of the liquid dehumidifier solution was presented. A self-cooled liquid desiccant solution was defined and prepared. Anhydrous ethanol was added into the lithium chloride (LiCl) aqueous solution as the vaporizable coolant to control the increase in the temperature of the solution. A working hypothesis for the self-cooled solution dehumidification was established with a main feature wherein the heat exchangers in conventional internally-cooled dehumidifier were replaced by using self-cooled liquid desiccant solution. Its performance was compared and experimentally investigated. An environmental chamber and a visible experimental setup were established. Experimental results under different operating conditions were obtained. The performance indices including moisture removal rate and dehumidification efficiency were analysed. When compared with conventional LiCl liquid desiccant solution, the current analysis indicated that the self-cooled solution is superior with respect to the above performance indices.

Experimental and theoretical research on the electrical conductivity of a liquid desiccant for the liquid desiccant air-conditioning system: LiCl aqueous solution

At present, the energy consumption in buildings occupies a large proportion of total energy use, and air-conditionings cost a large proportion of energy in the buildings. The liquid desiccant air-conditioning system has a good energy saving potential and the electrodialysis (ED) regeneration is a reliable choice for the liquid desiccant regeneration. In order to establish the energy consumption model and the performance coefficient model of liquid desiccant air-conditioning system based on ED regeneration using LiCl, experimental and theoretical research on the electrical conductivity of LiCl aqueous solution with a lot of concentrations and temperatures was conducted in this paper. The results show that when polynomial degrees of the mass concentration and the temperature of the LiCl aqueous solution are both 3, the electrical conductivity model for the LiCl aqueous solution is most suitable as its simplicity and high accuracy. Moreover, when the concentration is 36% and the temperature is 22 °C, the liquid desiccant cooling system has the maximum COP of about 5. Finally, a case study of a small office room was conducted, and the result shows that the liquid desiccant cooling system based on electrodialysis regeneration has a good energy-saving potential.

Evaporation modes of LiBr, CaCl2, LiCl, NaCl aqueous salt solution droplets on aluminum surface

The evaporation of droplets of the LiBr, CaCl2, LiCl and NaCl aqueous salt solutions were studied experimentally and their evaporation characteristics were compared to droplets of distilled water. The geometrical parameters of droplets (contact angle, height, and diameter) were measured using three methods of data processing: tangential methods (T) and the Young-Laplace method (Y-L). Scattering of the measured data does not depend on the processing method selected for large contact angles. However, in the case of small contact angles, the Y-L method exhibited the smallest measurement error. An optical method allowed for measuring the contact angle of salt solutions droplets just prior to crystallization. The experiments have shown that crystalline hydrates grow near the contact line and distort the droplet profile. The contact angles of salt solution droplets were found to depend on time in a non-linear manner. Typical evaporation modes of the studied aqueous salt solutions are detected: 1 – increasing the contact diameter; 2 – pinning the droplet; 3 – formation of salt crystals (NaCl) or crystalline hydrates (LiBr, CaCl2 and LiCl).

High density liquid structure enhancement in glass forming aqueous solution of LiCl.

We investigate using molecular dynamics simulations the dynamical and structural properties of LiCl:6H2O aqueous solution upon supercooling. This ionic solution is a glass forming liquid of relevant interest in connection with the study of the anomalies of supercooled water. The LiCl:6H2O solution is easily supercooled and the liquid state can be maintained over a large decreasing temperature range. We performed simulations from ambient to 200 K in order to investigate how the presence of the salt modifies the behavior of supercooled water. The study of the relaxation time of the self-density correlation function shows that the system follows the prediction of the mode coupling theory and behaves like a fragile liquid in all the range explored. The analysis of the changes in the water structure induced by the salt shows that while the salt preserves the water hydrogen bonds in the system, it strongly affects the tetrahedral hydrogen bond network. Following the interpretation of the anomalies of water in terms of a two-state model, the modifications of the oxygen radial distribution function and the angular distribution function of the hydrogen bonds in water indicate that LiCl has the role of enhancing the high density liquid component of water with respect to the low density component. This is in agreement with recent experiments on aqueous ionic solutions.

Performance of ceramic membrane in vacuum membrane distillation and in vacuum membrane crystallization

Membrane crystallization (MCr) is emerging as an interesting candidate to extract additional freshwater and raw materials from high-concentrated solutions. Traditionally, MCr has been carried out by using polymeric membranes that have limited chemical and mechanical stability. These shortcomings can be overcome by using ceramic membranes. The current study describes the preparation and testing of two hydrophobic ceramic membranes synthesized trough sol-gel process, and combined phase-inversion and sintering method. The first membrane (CM-L) was synthesized by coating hydrophobic polymethylsilsesquioxane aerogels on alumina membrane supports via a sol-gel process. The membrane showed stable hydrophobic character in membrane distillation and crystallization tests but very low flux. To obtain high flux, a second type (CM-S) membrane was prepared by applying Fluoroalkylsilanes (FAS) (1H, 1H, 2H, 2H‑perfluorooctyltriethoxysilane) hydrophobic agent at the relatively thin and more porous as-sintered alumina hollow fibers. The suitability of both membranes for MCr process was analyzed by crystallizing NaCl and LiCl. By using 1 M NaCl and 13 M LiCl aqueous solutions, and under the same operative conditions, CM-S membrane exhibited average flux higher than CM-L membrane. The performance of both the membranes, in terms of hydrophobic character, remained stable throughout the performed tests.

Effect of the electrode potential on the surface composition and crystal structure of LiMn2O4 in aqueous solutions

Cubic spinel LiMn2O4 has been studied for the reversible extraction of Li+ from natural brine after the application of suitable electrode potentials. In this work we report on the insertion/extraction of Li+ from natural brine of Olaroz salt flat (Jujuy, Argentina) and aqueous LiCl solutions into/from Li1-xMn2O4 (0 < x ≤ 1) to determine changes in the crystal structure and surface composition upon electrochemical polarization. In agreement with the behavior in organic electrolytes, we found that the insertion and extraction of Li+ proceeds via a two stage process and that the crystal structure undergoes two cubic phase transitions as the lattice is expanded or contracted. Contrary to the behavior in organic solvents, no decomposition layer is formed on the electrode surface and the surface composition can be controlled with the electrode potential. We also found that sodium cations present in natural brine are not inserted into the crystal lattice in the potential window explored, however they are adsorbed on the oxide surface blocking Li+ adsorption sites and decreasing the rate of Li+ exchange.

Aqueous lithium-air batteries with a lithium-ion conducting solid electrolyte Li1.3Al0.5Nb0.2Ti1.3(PO4)3

A rechargeable aqueous lithium-air battery with a water-stable high lithium-ion conductivity and an excellent bending strength solid electrolyte as a separator between the lithium metal anode and aqueous electrolyte was developed. The cell consists of a lithium metal anode, a buffer layer of 4 M lithium bis(fluorosulfonyl)imide in ethylene glycol dimethyl ether, a lithium-ion conducting solid electrolyte separator of Li1.3Al0.5Nb0.2Ti1.3(PO4)3 (LANTP), a 10 M LiCl aqueous solution with 1.5 M LiOH, and an activated MnO2 air electrode. The tape-cast water-impermeable LANTP film with a small amount of epoxy resin was used as the separator between the lithium anode and aqueous electrolyte. The conductivity and 3-point bending strength of the ca 0.2 mm thick film was 9.1 × 10−4 S cm−1 at 25 °C and 100 MPa, respectively. The cell with the LANTP film was operated successfully at 0.26 mA cm−2 for more than 30 cycles at room temperature in air.

Energetic Performances of Pure-Silica DDR Zeolite by High-Pressure Intrusion–Extrusion of Electrolyte Aqueous Solutions: A Shock-Absorber with Huge Absorbed Energy

Pure-silica DDR-type zeolite (zeosil) displays a porosity composed of two kinds of small cages (pore opening of 4–6 MR) and of a large nonadecahedron cage with pore windows of 8 MR. In order to study the energetic performances of this hydrophobic material by high-pressure intrusion–extrusion experiments, water and 10 and 20 M LiCl aqueous solutions were chosen as nonwetting liquids. The intrusion pressure increases from 60 to 357 MPa when using water and 20 M LiCl aqueous solution, respectively. The latter pressure is the highest ever found for a zeosil-based system. It is associated with a large intruded volume of 0.26 mL/g, which is close to the total theoretical porosity of the DDR structure. The corresponding “DDR-20 M LiCl aqueous solution” system demonstrates mainly shock-absorber behavior, and both features (high intrusion pressure and large intruded volume) lead to the highest amount of absorbed mechanical energy for such systems: 93 and 61 J/g for the first and the following intrusion cycles, res...

Calorimetric study of water's two glass transitions in the presence of LiCl.

A DSC study of dilute glassy LiCl aqueous solutions in the water-dominated regime provides direct evidence of a glass-to-liquid transition in expanded high density amorphous (eHDA)-type solutions. Similarly, low density amorphous ice (LDA) exhibits a glass transition prior to crystallization to ice Ic. Both glass transition temperatures are independent of the salt concentration, whereas the magnitude of the heat capacity increase differs. By contrast to pure water, the glass transition endpoint for LDA can be accessed in LiCl aqueous solutions above 0.01 mole fraction. Furthermore, we also reveal the endpoint for HDA's glass transition, solving the question on the width of both glass transitions. This suggests that both equilibrated HDL and LDL can be accessed in dilute LiCl solutions, supporting the liquid-liquid transition scenario to understand water's anomalies.