Thermal Conductivity Of Aqueous Solutions Research Articles

Thermal conductivity of aqueous solutions of reline, ethaline, and glyceline deep eutectic solvents; a molecular dynamics simulation study

Accurate knowledge and control of thermal conductivities is central for the efficient design of heat storage and transfer devices working with deep eutectic solvents (DESs). The addition of water is a straightforward and cost-efficient way of tuning many properties of DESs. In this work, the thermal conductivities of aqueous solutions of reline, ethaline, and glyceline are reported for the first time. The non-equilibrium molecular dynamics Müller-Plathe (MP) method was used, along with the well-established GAFF and SPC/E force fields for DESs and water, respectively. We show that thermal conductivities of neat DESs are in excellent agreement with available experimental data. The addition of 25 wt% water results in nearly 2 times higher thermal conductivities in all DESs. A further increase in the fraction of water to 75 wt%, causes an increase in the thermal conductivities of DESs ca. 3 times. This behaviour is mainly due to the change in the microscopic structure of the DESs (i.e. hydrogen bonding) upon the addition of water. Our simulations reveal that thermal conductivities of aqueous DESs do not significantly depend on temperature. We also show that thermal conductivities strongly depend on system-size. System-sizes bigger larger than ca. 5 nm should be used.

Soret coefficients and thermal conductivities of alkali halide aqueous solutions via non-equilibrium molecular dynamics simulations

ABSTRACTThermal gradients induce thermodiffusion, the Ludwig–Soret effect, which might be exploited in biotechnological, chemical, micro and nanofluidic applications. It has been shown that thermodiffusion depends very sensitively on the nature of the solute, suggesting that water–solute interactions play an important role in determining the preference of solutes to move towards hot or cold regions. Here we employ non-equilibrium molecular dynamics computations to gain insight into the role of water–ion interactions on the strength and sign of the Soret coefficient of alkali halide solutions. By performing simulations with different force-fields, we draw conclusions on the dependence of the thermodiffusive response with the properties of the first hydration shell of the ions. We further compute the thermal conductivity of aqueous solutions. State-of-the art force-fields reproduce the decrease of the thermal conductivity with increasing salt concentration when the thermal conductivity of pure water is corrected to match experimental data.

An experimental investigation of the temperature and pressure dependences of the thermal conductivity of aqueous solutions of trimethylhydrazine

The results of an experimental investigation of the thermal conductivity of aqueous solutions of trimethylhydrazine in the 293.5–568.9 K temperature range and the 0.101–49.1 MPa pressure range are presented. Empirical equations are obtained using the experimental data and the law of corresponding states.

Thermal conductivity of aqueous solutions of salts for high parameters of state

New generalized formulas for calculation of thermal conductivity of aqueous solutions of binary and multicomponent inorganic substances under high values of state parameters were derived. New values of thermal conductivity were calculated for aqueous solutions of salts within the ranges of temperatures of 293–473 K. concentrations of 0–25 mass % and pressures Ps of 100 MPa.

Thermal Conductivity and Viscosity of Aqueous of Mg(NO3)2, Sr(NO3)2, Ca(NO3)2, and Ba(NO3)2 Solutions

The experimental data of thermal conductivity and dynamic viscosity of aqueous solutions of the alkaline earth metals' nitrates in temperature range (298.15 to 598.15) K, pressure (0.1 to 40) MPa, and molality for H2O + Mg(NO3)2 (0.7507, 1.689, 2.8950, and 4.5040) mol·kg-1, for H2O + Sr(NO3)2 (0.525, 1.181, 2.025, and 3.150) mol·kg-1, for H2O + Ca(NO3)2 (0.6771, 1.5235, 2.598, and 4.063) mol·kg-1, and for H2O + Ba(NO3)2 (0.0781, 0.1594, 0.2442, and 0.3327) mol·kg-1 have been summarized. The measured values of thermal conductivity and viscosity were compared with data and correlations reported in the literature. A relationship between relative dynamic viscosity and relative thermal conductivity is established. A correlation equation relating relative dynamic viscosity and thermal conductivity of aqueous solutions was obtained as a function of temperature and composition. The equation describes values of viscosity within ± 2.2 %.

Thermal conductivity of aqueous solutions of ZnI2 in a wide range of parameters of state

Thermal conductivity of aqueous solutions of ZnI2 in a wide range of parameters of state

Density, Viscosity and Thermal Conductivity of Aqueous Solutions of Propylene Glycol, Dipropylene Glycol, and Tripropylene Glycol between 290 K and 460 K

The density, viscosity, and thermal conductivity of propylene glycol + water, dipropylene glycol + water, and tripropylene glycol + water mixtures were measured at temperatures ranging from 290 K to 460 K and concentrations ranging from 25 mol % glycol to 100 mol % glycol. Our data generally agreed with the limited data available in the literature and were correlated using empirical expressions, the modified rough hard-sphere model, and the generalized corresponding states principle (GCSP). The GCSP method, with two adjustable parameters for each property, offers the potential for judicious extrapolation of density and transport property data for all glycol + water mixtures.

Thermal Conductivity of Aqueous Solutions of KCl–NaCl–CaCl2 System at High Temperatures and Pressures

The experimental data are obtained on the thermal conductivity of mixed aqueous solutions of KCL, NaCl, and CaCl2 salts in a temperature range of 20–300°C, at a pressure of 5–50 MPa, and a concentration of 3–20 wt %. The experiments are carried out on a setup realizing the relative method of coaxial cylinders. The error of the experimental data is ±(1.3–1.8)%. An empirical formula is presented which correlates the thermal conductivity of the solution with the densities of the solvent and solution, as well as with the thermal conductivity of water. This formula enables one to calculate the thermal conductivity of aqueous solutions of salts at high temperatures. The error of calculation by this formula corresponds to the experimental error. As an example, the values of the thermal conductivity of the H2O–KCl–CaCl2 system are calculated in a temperature range of 20–80°C. The maximal discrepancy between the experimental and theoretical data is 1.4%.

Thermal conductivity of aqueous solutions of NaCl and KCI at high pressures

This paper presents new experimental measurements of the thermal conductivity of aqueous solutions of NaCl and KCl at high pressures. The measurements were made with a parallel-plate apparatus. The temperatures covered the range from 293 to 473 K at pressures up to 100 MPa and concentrations from 0.025 to 0.25 mass fraction of NaCl and KCl. The measurements included 6 isobars at pressures from 0.1 to 100 MPa at intervals of 20 MPa, 10 isotherms at temperatures from 293 to 473 K at intervals of 20 K, and 6 isopleths at concentrations from 0.025 to 0.25 mass fraction of NaCl and KCl at intervals of 0.05. The precision of the measurements was ±1.6%. The thermal conductivity obtained for NaCl + H2O and KCl + H2O was compared with data of other authors, with satisfactory agreement. The viability of the technique was confirmed and the essential features of a high-precision instrument were established.

Measurement of the Thermal Conductivity of Unfrozen and Frozen Food Materials by a Steady State Method with Coaxial Dual-cylinder Apparatus.

Coaxial dual-cylinder apparatus was used to measure the effective thermal conductivity of aqueous solutions of glucose, sucrose, gelatin and egg albumin over a temperature range from -20° to 20°C by the steady state method. The accuracy of the apparatus was confirmed by testing with water and ice. The effective thermal conductivity decreased with an increase in the total solid content in both the frozen and unfrozen states. In the unfrozen state, the effective thermal conductivity was slightly dependent on temperature. In the frozen state, however, the effective thermal conductivity was strongly dependent on temperature; lower temperatures gave higher effective thermal conductivity, reflecting the increase in the ice fration. For the unfrozen samples, the intrinsic thermal conductivity of each solid component was calculated by heat transfer models. All the models tested, series, parallel and Maxwell-Eucken, were equally applicable to describe the heat conduction in the unfrozen state. In the frozen state, however, the strong temperature dependency of the effective thermal conductivity suggests that the effect of the temperature dependency of the ice fraction should be incorporated into theoretical models.

Thermal conductivity of aqueous solutions of potassium chloride at 20?340�C

The experimental apparatus is described. Experimental data are given on the thermal conductivity of aqueous solutions of potassium chloride at concentrations 1% and 3% by mass and at temperatures 20–340°C.

Thermal conductivity of aqueous solutions of NaCl

We present the results of an experimental study of the thermal conductivity of aqueous solutions of sodium chloride at concentrations of 5, 10, 15, 20, and 25% NaCl over the temperature range 20–330°C.

Thermal conductivity determination for nonmetallic media by the cylindrical probe method

The problem of thermal conductivity for an infinitely long composite cylinder is solved. The solution obtained permits analysis of a probe of finite dimensions and the contact resistance between probe and casing. The experimental methodology is described and results are presented for determination of thermal conductivity of aqueous solutions of nitric and sulfuric acid at low temperatures.

Thermal conductivity of aqueous solutions of alkali hydroxides

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThermal conductivity of aqueous solutions of alkali hydroxidesZdenek LosenickyCite this: J. Phys. Chem. 1969, 73, 2, 451–452Publication Date (Print):February 1, 1969Publication History Published online1 May 2002Published inissue 1 February 1969https://doi.org/10.1021/j100722a036RIGHTS & PERMISSIONSArticle Views85Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (232 KB) Get e-Alerts