Lithium Chloride Solution Research Articles

LiCl-enhanced capacitive humidity-sensing properties of cadmium sulfide grown on silicon nanoporous pillar array

The extensive application of humidity sensors has greatly stimulated the study on high-performance humidity-sensing materials. In the paper, we report that a prototype humidity sensor was prepared by growing cadmium sulfide (CdS) on silicon nanoporous pillar array (Si-NPA) through a successive ionic layer adsorption and reaction method followed by immersing the samples in the solution of lithium chloride (LiCl). It was demonstrated that through the immersion treatment, the humidity-sensing properties including the response and its linearity, response and recovery time, hysteresis, and measuring reproducibility and stability were improved significantly. These results indicated that LiCl-immersed CdS/Si-NPA might be a promising material for fabricating humidity sensors applied to medium and low humidity range.

Simplified Heat and Mass Transfer Model for Cross-Flow and Countercurrent Flow Packed Bed Tower Dehumidifiers with a Liquid Desiccant System

A mathematical model is developed using the Matlab/Simulink platform to investigate heat and mass transfer performance of cross-flow and counterflow dehumidifiers with Lithium Chloride (LiCl) solution. In the liquid desiccant dehumidifier, the orthogonal polynomial basis is used to simulate the combined processes of heat and mass transfer. The temperature profiles on cross-flow and countercurrent flow dehumidifiers are demonstrated. The resultant counter flow air changes the temperature profile of the LiCl solution in the longitudinal direction because of the drag forces. In addition, when inlet airflow rate reaches 15 kg·s−1, the temperature effect becomes less obvious and may be reasonably negligible. Under these conditions, the air changes the design factor and determines the interfacial temperature. It is demonstrated that the mathematical model can be of great value in the design and improvement of cross-flow and countercurrent flow dehumidifiers.

Modelling and Performance Analysis of U Type Evacuated Tube Solar Collector Using Different Working Fluids

Abstract This paper presents the mathematical modelling of a U type evacuated tube solar collector required for heating a working fluid. The developed mathematical model is used for predicting the outlet temperature and net heat gain by the working fluid. The model predictions are compared with experimental data and a good agreement is observed between them. Aqueous lithium chloride solution (LiCl-H2O), water and air are chosen as working fluids. The effects of working fluid flow rate and inlet temperature, collector length, ambient temperature and solar intensity on the performance of the system are investigated. It has been observed that collector length, working fluid flow rate and solar intensity have greater impact on performance of the collector. The working fluid inlet temperature doesn’t have significant effect. Also, a detailed analysis on aforementioned working fluids is carried out for U type copper tube and the results are presented in this paper.

Factors governing mass transfer during membrane electrodialysis regeneration of LiCl solution for liquid desiccant dehumidification systems

This study investigates the mass transfer mechanisms and the performance of membrane electrodialysis (ED) for regenerating lithium chloride (LiCl) solution commonly used in liquid desiccant dehumidification systems. Experiments were conducted using an ED experimental system while numerical simulation was performed using COMSOL Multiphysics. The results showed that the water flux transfer due to osmosis and electro-osmosis during ED regeneration of LiCl liquid desiccant was significant and could not be ignored. The water flux due to osmosis and electro-osmosis is directly associated with the osmotic gradient and the applied current between the cathode and anode, respectively. The average flux of water from the spent solution to the regenerated solution decreased from 0.292 to 0.161g/sm2 when the initial concentration of the solutions in the spent and regenerated tanks increased from 18 to 30% (wt/wt) with the same applied current of 12A and the same solution flow rate of 100L/h. On the other hand, the salt flux due to osmosis was insignificant. The average salt flux transfer was 0.0053g/sm2 when the initial concentration difference between the regenerated and the spent channels was 25% (wt/wt). Simulations were conducted to elucidate the relationship between the concentration profile of LiCl solution along the membrane surface and the concentration polarization in the ED channel with respect to the circulation flow rate and applied current. Overall, the results suggest that the concentration difference between the regenerated and spent LiCl solutions should be minimized for an optimum ED performance.

Effect of Corrosion of Stainless Steel Welded within Lithium Chloride

The difficulties experienced in welding processes of martensitic stainless steel led to development of a new class of them, known as stainless mild martensitic steels. Also, due to the current high demand for energy and materials to oil extraction at great depths, scientists have being developing specific researches about mechanical resistance and corrosion of steels and how these properties are influenced by high temperature processes. This research studies the effect of welding process over the corrosion resistance of the 13Cr4Ni0.02C steel in a lithium chloride solution with a concentration of 120,000 PPM Cl-. The corrosion tests were conducted by cyclic potentiodynamic polarization in the base metal, weld bead and heat affected zone (HAZ) areas of the steel, in average temperatures of 23°C (as reference) and 3°C. The results revealed that the weld bead and heat affected zones of the 13Cr4Ni0.02C steel in a temperature of 3°C are less resistant to corrosion in this environment than the base metal in the same conditions.

The Study of Osmotic and Activity Coefficients for the Ternary System, (1-Ethyl-3-Methyl Imidazolium Chloride + Lithium Chloride + Water) and Their Corresponding Binary Systems at T = 298.15 K

In this work the thermodynamic properties of an ionic liquid, 1-ethyl-3-methylimidazolium chloride ([Emim][Cl]), in aqueous lithium chloride (LiCl) solutions, have been investigated. Osmotic and activity coefficients for the ternary system ([Emim][Cl] + LiCl + H2O) and their corresponding binary mixtures at 298.15 K were measured using the “improved” isopiestic method. Using these data, the vapor pressures for these systems were determined. For the binary systems, osmotic coefficients are satisfactorily correlated using the Pitzer and modified-Pitzer models. Osmotic coefficients for the ternary systems are fitted to the Scatchard neutral-electrolyte model and corresponding mean activity coefficients for the binary and ternary systems are appraised.

Improved Butanol-Methanol (BUME) Method by Replacing Acetic Acid for Lipid Extraction of Biological Samples.

Extraction of lipids from biological samples is a critical step in lipidomics, especially for shotgun lipidomics where lipid extracts are directly infused into a mass spectrometer. The butanol-methanol (BUME) extraction method was originally developed to extract lipids from plasma samples with 1% acetic acid. Considering some lipids are sensitive to acidic environments, we modified this protocol by replacing acetic acid with lithium chloride solution and extended the modified extraction to tissue samples. Although no significant reduction of plasmalogen levels in the acidic BUME extracts of rat heart samples was found, the modified method was established to extract various tissue samples, including rat liver, heart, and plasma. Essentially identical profiles of the majority of lipid classes were obtained from the extracts of the modified BUME and traditional Bligh-Dyer methods. However, it was found that neither the original, nor the modified BUME method was suitable for 4-hydroxyalkenal species measurement in biological samples.

Empirical model for predicting the dehumidification effectiveness of a liquid desiccant system

The main purpose of this research was to propose a practical correlation for predicting the dehumidification effectiveness of a liquid desiccant (LD) system. The experimental data were collected during the operation of a typical liquid desiccant dehumidification unit. A lithium chloride (LiCl) solution was used as the liquid desiccant solution. The 2000m3/h LD unit was installed in a real building, and the variation of the dehumidification effectiveness values was monitored under various operating conditions. The data were statistically analyzed by the response surface methodology (RSM), and the impact of each system operation parameter on the dehumidification effectiveness was estimated quantitatively. Six operating parameters – the mass flow rate of process air, the mass flow rate of the desiccant solution, the dry-bulb temperature and the humidity ratio of the inlet air, and the inlet temperature and concentration of the desiccant solution – significantly affected the dehumidification performance of the LD unit. Consequently, a simplified linear equation model was derived as a function of the operation parameters that significantly impacted the dehumidification effectiveness. The proposed model was verified by comparison with existing models.

Presence of Li Clusters in Molten LiCl-Li.

Molten mixtures of lithium chloride and metallic lithium are of significant interest in various metal oxide reduction processes. These solutions have been reported to exhibit seemingly anomalous physical characteristics that lack a comprehensive explanation. In the current work, the physical chemistry of molten solutions of lithium chloride and metallic lithium, with and without lithium oxide, was investigated using in situ Raman spectroscopy. The Raman spectra obtained from these solutions were in agreement with the previously reported spectrum of the lithium cluster, Li8. This observation is indicative of a nanofluid type colloidal suspension of Li8 in a molten salt matrix. It is suggested that the formation and suspension of lithium clusters in lithium chloride is the cause of various phenomena exhibited by these solutions that were previously unexplainable.

The Respective Roles of Metal Salts in The Dissolution Process of Poly(1-oxotrimethylene) in Their Aqueous Solutions

The respective roles of the aqueous solutions of zinc chloride (ZnCl2), calcium chloride (CaCl2), and lithium chloride (LiCl) in the dissolution process of poly(1-oxotrimethylene) (ECO) were investigated. The ECO was soluble only in the ZnCl2-based aqueous solutions. The ZnCl2 aqueous solutions dissolved ECO when the metal salt content exceeded 65 wt%, following a mechanism analogous to Lewis acid/base reaction. In the case of the aqueous solution of 70 wt% ZnCl2, the ECO solubility was limited to 6 wt% because of heterogeneity of the resultant solution. However, an addition of CaCl2 (10 wt%) or LiCl (10 wt%) to the ZnCl2 aqueous solution widened the soluble range of ECO up to 8 wt%. The Cole-Cole plot exhibited that CaCl2 improved homogeneity of the solution but LiCl reduced it. In addition, the addition of both LiCl and CaCl2 decreased the dynamic viscosity of the ECO solutions, which was more noticeable with LiCl.

All‐cellulose composites from pineapple leaf microfibers: Structural, thermal, and mechanical properties

Pineapple leaf microfibers (PALM) were used to prepare all‐cellulose composites using the surface selective dissolution method. Effect of dissolution times on mechanical and physical properties of the all‐cellulose composites was investigated. The structural transformation from cellulose I to cellulose II was observed when the fibers were dissolved in a mixed solution of lithium chloride (LiCl) and N,N‐dimethylacetamide (DMAc). Values of 42.8 MPa and 1.2 GPa for tensile strength and Young's modulus, respectively, were obtained from the composites with 120 min dissolution time in the LiCl/DMAc solution, whereas the tensile strength and Young's modulus of the undissolved PALM mats were found to be only 1.5 MPa and 0.1 GPa, respectively. The failure mechanism of the composites was changed from the fiber pull‐out to the fiber breakage when the dissolution time was longer. However, lower thermal stability and degree of crystallinity of the composites were caused by the change of the cellulose structure. The composites prepared in this work can be called as biodegradable materials, and could be the potential candidates to replace nonbiodegradable materials. POLYM. COMPOS., 39:895–903, 2018. © 2016 Society of Plastics Engineers

Experimental and numerical investigation on the performance of an internally cooled dehumidifier

Liquid desiccant based dehumidifiers are important components of the air conditioning applications. Internally cooled dehumidifiers with liquid desiccants are deemed to be superior to the adiabatic types, thanks to the cooling medium which takes away the latent heat of vaporization occured when moist air contacts with liquid desiccant. However, its utilization in industrial applications is restricted due to the inherent corrosive characteristics of the liquid desiccants. In this study, an experimental chamber is built for epoxy coated plate fin type dehumidifier which is used in order to diminish the corrosive effect of the lithium chloride aqueous solution. Dehumidification effectiveness and moisture removal rate, two parameter indices, are adopted to measure the performance of the air conditioning system. The effect of inlet operating parameters on moisture removal rates is extensively analyzed. Two dimensional numerical model adapted from the conservation principles is utilized for obtainment of output parameters. Experimental results are compared with the numerical model and comparisons show that numerical outputs agrees with the experimental results. And also, dehumidification performance of lithium chloride and lithium bromide aqueous solutions are evaluated and compared against each other.

Using electrodialysis for regeneration of aqueous lithium chloride solution in liquid desiccant air conditioning systems

This study evaluates the potential of using electrodialysis (ED) technology to regenerate the aqueous lithium chloride (LiCl) solution, a commonly used liquid desiccant in liquid desiccant air conditioning (LDAC) systems. Experiments were performed using an ED system with ten cell pairs of ion-exchange membranes. A range of tests were carried out to examine the effects of the circulation flow rate, supplied current density, solution initial concentration and the concentration difference between the regenerated and spent solutions on the performance of ED for regenerating LiCl liquid desiccant solutions. The results showed that the regeneration capability of the ED stack decreased with the increase of the circulation flow rate. Regeneration performance in terms of the concentration enrichment increased as the supplied current density increased and the solution initial concentration decreased. It is also shown that the concentration difference between the regenerated and spent solutions is critical for the regeneration performance of ED. The ED stack can continuously increase the concentration of the regenerated solution when the concentration difference between the regenerated and spent solutions is below 5.86% (wt/wt), under the supplied current density of 57.1mA/cm2, circulation flow rate of 100L/h, and the initial concentrations of the solutions in the regenerated and spent tanks of 28.77% and 23.96% (wt/wt), respectively. The current efficiency of the ED in two hours running for all experiments was in the range of 55.17–73.54%. The results obtained from this study would be useful for the ED regenerator design and system integration.

The Effect of Common Cations on DNA Degradation

The process of DNA degradation is important to many scientific studies. Heat treatment is the standard procedure used to degrade genetic material by heating DNA-containing media past the DNA melting temperature, but certain chemical alternatives have been explored. More specifically, the presence of cations, such as Mg²⁺, has been linked to increased stability of DNA molecules subjected to high temperatures. However, the possible effects of other ions have not been extensively studied; perhaps cations similar to magnesium may offer more versatile effects. This study examines the effects that NH₄⁺, Ni²⁺, and Li⁺ have on the heat degradation and melting temperature of DNA. Magnesium chloride, magnesium sulfate, ammonium sulfate, nickel chloride, and lithium chloride solutions of different concentrations were mixed with DNA samples; the resulting mixture was heated and subsequently analyzed using gel electrophoresis. Treatment with NH₄⁺ did not yield effects that significantly differed from Mg²⁺, while Li⁺ proved effective at preserving DNA even at high temperatures. Treatment with Ni²⁺ resulted in marked degradation of DNA. These results show that magnesium, ammonium, and especially lithium ions can be used for the preservation of DNA. The specific effects of Li⁺ and Ni²⁺ on DNA are promising subjects for future research.

Characterization of cellulose degradation during accelerated ageing by SEC-MALS, SEC-DAD, and A4F-MALS methods

Size exclusion chromatography (SEC) is currently the method most frequently used for molar mass determination of cellulose, being applied to either derivatized cellulose in the form of tricarbanilates (CTC) or nonderivatized cellulose in solution of lithium chloride in dimethylacetamide or 1,3-dimethyl-2-imidazolidinone. In this work, we compared three methods of analysis of cellulose in paper subjected to accelerated ageing: size exclusion chromatography in combination with multiangle light scattering (SEC-MALS) detection, size exclusion chromatography in combination with diode-array detector and calibration using polystyrene standards (SEC-DAD), and asymmetric flow field–flow fractionation in combination with multiangle light scattering (A4F-MALS). Prior to separation, cellulose samples were derivatized with phenyl isocyanate to CTC and dissolved in tetrahydrofuran. Each of the methods provided different absolute values of molar mass, but pairwise correlations between them were linear with high correlation coefficients (r = 0.990–0.992). The highest molar mass values were obtained by the A4F-MALS method; SEC-MALS and SEC-DAD methods provided lower values, especially due to shear degradation of high-molecular cellulose chains.

Thermodynamic study on removal of magnesium from lithium chloride solutions using phosphate precipitation method

The separation of magnesium and lithium is the key issue of preparation of pure lithium product due to their similar chemical property. Thermodynamic analysis was conducted on the removal of magnesium from lithium chloride solutions with phosphate precipitation method. The thermodynamic equilibrium diagrams of Mg2+-PO43--H2O,Li+-Mg2+-PO43--H2O and Li+-Mg2+-NH4+-PO43--H2O systems at 298 K were established, separately. The effect of process parameters on the removal of magnesium was also investigated. The results revealed that the existence of Li+ was not beneficial to the removal of magnesium, and the precipitation method of MgNH4PO4 performed better than that of Mg3(PO4)2 for the separation of magnesium from lithium chloride solutions. The equilibrium concentration of magnesium decreased with the increase in total concentration of NH4+ and the decrease in concentration of Li+. With the precipitation method of MgNH4PO4, there are four regions of stable solid phase in the pH range of 4.5–13.0 in lithium chloride solutions containing 1 mol/L Li+, 0.03 mol/L NH4+, 0.01 mol/L Mg2+ and 0.03 mol/L PO43-, which are MgHPO4 (5.9 < pH < 6.6), MgNH4PO4 (6.6 < pH < 9.6), Mg(OH)2 (10.0 < pH < 13.0) and Li3PO4 (6.6 < pH < 1.3), respectively. The verification experiment results showed that the concentration of magnesium can be reduced to 0.011 g/L from a feed solution containing 14.95 g/L (∼1 mol/L) Li2O and 0.45 g/L (∼0.02 mol/L) Mg2+ by adding 0.025 mol/L (NH4)3PO4·3H2O at pH 8 and 25 °C, while the concentration of residual phosphorus in purified solution was only 0.004 g/L, which was consistent with the thermodynamic analysis.

Molar conductivities of concentrated lithium chloride–glycerol solutions at low and high temperatures: application of a quasi-lattice model

Conductivities of concentrated solutions of lithium chloride in glycerol were measured for concentrations ranging from 0.005 to 1.5 mol.dm−3. The conductivity dependencies were analysed successively using the Debye–Huckel–Onsager limiting law (DHO) at very low concentrations, the Fuoss equation of 1978 up to 0.1 mol.dm−3, the Casteel–Amis empirical equation and the quasi-lattice model (QLM) at moderate and higher concentrations. The molar conductivities at infinite dilution, obtained using DHO and QLM were quite different from each other, because the salt forms contact pairs which were underestimated in the Λ = f(C1/3) in QLM, as it may well be proved by Raman spectroscopy. Besides, the value of Madelung constant suggests that LiCl crystallises face centred cubic (FCC) at higher concentrations. On the basis of Raman spectroscopy analysis of previous lithium salts, we assume that the dissociation coefficient varies slightly with concentration and fraction of paired ion constant, the QLM equation is applied successfully in the concentration range used in this study. The temperature dependency of conductivity was also described using the Vogel–Tamman–Fulcher (VTF) empirical equation where the Arrhenius type was found. The results also suggest that as NaCl, LiCl can be considered as a structure maker electrolyte.

Development of undersized (12.5 mm diameter) low‐dilution glass beads for X‐ray fluorescence determination of 34 components in 200 mg of igneous rock for applications with geochemical and archeological silicic samples

A low‐dilution, undersized (12.5 mm diameter) glass–bead technique was developed for X‐ray fluorescence determination of 34 components (Na2O, MgO, Al2O3, SiO2, P2O5, K2O, CaO, TiO2, MnO, Fe2O3, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Cs, Ba, La, Pr, Nd, Sm, Gd, Dy, Er, Yb, Hf, W, and Pb) in precious silicic samples for geochemistry and archeology. This preparation was consolidated based on the properties of the specimen, including disk formability and detachability from a small crucible, through variation of the amounts of the two samples (basaltic and granitic rocks) and releasing reagent. The specimen was prepared by fusing a mixture of 200 mg of powdered sample, 200 mg of lithium tetraborate as a flux, and 60 µl of 18.42 mass% lithium chloride solution as a releasing agent in a small platinum crucible. Calibration curves were drawn using synthetic calibration standards, which were prepared by compounding chemical reagents, such as oxides, carbonates, and diphosphates containing analytes. The calibration curves showed good linearity with correlation coefficient values greater than 0.990. Using the proposed method, we determined 34 components in five igneous rock reference samples. The results were in agreement with the recommended values, accounting for uncertainties. With this method, preparation requires only small amounts of the powdered sample and alkali flux; however, still allowing for determination of many analytes, which is advantageous when dealing with limited quantities of precious samples. The present method has potential applications in the chemical characterization of various geological and archeological samples. Copyright © 2015 John Wiley &amp; Sons, Ltd.

Relapse of generalized bait shyness in rats after constant and graded extinction procedures

Oral ingestion of a toxic lithium chloride (LiCl) solution yields a conditioned aversion to a safe sodium chloride (NaCl) solution in rats, presumably because of the common quality of saltiness. By using this generalized bait-shyness paradigm, we examined the relapse of acquired and subsequently extinguished salty taste aversion. After conditioning by oral ingestion of a 0.15M LiCl solution, extinction was induced by two different experimental procedures. In the constant extinction group, rats were repeatedly exposed to 0.15M NaCl solution. For rats in the graded extinction group, the concentration of NaCl was gradually increased from a low level to 0.15M and an additional interfering sweet taste was gradually faded out. Rats in the graded extinction group were more prone to relapse than animals that underwent the constant extinction treatment. This difference was manifested in the following three response reoccurrence phenomena: renewal upon return to the acquisition context (Experiments 1A–C), spontaneous recovery after a 23-day interval (Experiment 2), and reacquisition caused by the second LiCl intake (Experiment 3). Theoretical and clinical implications of these results are discussed.

Simplified model for packed-bed tower regenerator in a liquid desiccant system

The regeneration rate prediction model representing the regenerator performance in a liquid desiccant system was derived by statistically analyzing the empirical data collected from the real liquid desiccant unit operated under various conditions. In order to propose a simple empirical regenerator model with wide valid range, additional experimental data found in open literature were also considered in the model derivation. The lithium chloride (LiCl) solution was used as a working desiccant solution. Response surface methodology was used to identify operating parameters and their interactions affecting significantly on the regenerator performance in a liquid desiccant system. Consequently, a first-order linear regression equation was derived as a function of the major parameters and interactions, which returns the regeneration rate in various operating conditions. The reliability of the proposed model was confirmed via the analysis of variation (ANOVA). The proposed model agreed well with the experimental data and other existing models.