Viscosity of Binary Aqueous Solutions Involving Malonic, Maleic, Malic, Tartaric, and Citric Acids in the Temperature Range between 303 and 363 K: Experimental Data and Modeling

Abstract

Kinematic viscosity is a key property for the design of flow systems. This transport property is directly dependent on temperature and concentration and indirectly dependent on molecular interactions that take place in a mixture. Carboxylic acids are a class of chemical compounds with employment in a large variety of processes and applications. The viscosity of carboxylic acid solutions changes due to the acid size and its concentration. The application of models can provide property prediction and generate information about molecular interactions in a mixture. This work studies the kinematic viscosity of binary aqueous solutions of carboxylic acids (malonic, maleic, malic, tartaric, and citric acids) at different temperatures (from 303.2 to 363.2 K with an increment of 10 K) and concentrations (from 0.5 to 3.0 mol•kg −1 with an increment of 0.5 mol• kg −1 ). The data were treated by the Eyring equation combined with the UNIFAC model. The experimental results and thermodynamic properties indicate that the kinematic viscosity is strongly influenced by the size of carboxylic acid and the molar mass of the binary solution. The suggested modeling showed capability of correlating the experimental data.

Solid–Liquid Equilibria, Density, Viscosity, Metastable Zone Width, and Thermal Conductivity of a Binary System of Ethylene Glycol and 1,2-Butanediol from a Coal-to-Ethylene Glycol Process

“…The kinematic viscosity of EG/BDO increased sharply with the increasing mass fraction of BDO and falling temperature. This behavior was probably because a decrease in the kinetic energy of the molecules resulted in an increase in the intermolecular interactions between adjacent layers . For liquids, the internal friction was determined by the attraction between molecules.…”

“…This behavior was probably because a decrease in the kinetic energy of the molecules resulted in an increase in the intermolecular interactions between adjacent layers. 20 For liquids, the internal friction was determined by the attraction between molecules. The kinematic viscosity ν could be fitted by the least-squares method as follows (eq 17).…”

“…Precise and reliable SLE data are crucial for predicting the thermal behavior of the mixtures at different operation conditions. SLE of the mixtures, obtained by a solubility method combined with correlation with the classical modified Apelblat model, constitutes the investigation for the operation limitations. − Second, when the mass fraction of EG and operating temperature change, its density and kinematic viscosity also change obviously. − In industrial production, the concentration of a substance is usually determined quickly by measuring the density of the substance. The increase of kinematic viscosity will reduce the fluidity and increase the difficulty of separation and purification and its fundamental role in the design of process equipment and flow systems.…”