New Simple and Robust Method for Determination of Polarity of Deep Eutectic Solvents (DESs) by Means of Contact Angle Measurement
Łukasz Cichocki,
Dorota Warmińska,
Justyna Łuczak,
Andrzej Przyjazny,
Grzegorz Boczkaj
Affiliations
Łukasz Cichocki
Department of Process Engineering and Chemical Technology, Faculty of Chemistry, Gdansk University of Technology, G. Narutowicza St. 11/12, 80-233 Gdansk, Poland
Dorota Warmińska
Department of Physical Chemistry, Faculty of Chemistry, Gdansk University of Technology, G. Narutowicza St. 11/12, 80-233 Gdansk, Poland
Justyna Łuczak
Department of Process Engineering and Chemical Technology, Faculty of Chemistry, Gdansk University of Technology, G. Narutowicza St. 11/12, 80-233 Gdansk, Poland
Andrzej Przyjazny
Department of Natural Sciences, Kettering University, 1700 University Avenue, Flint, MI 48504, USA
Grzegorz Boczkaj
Advanced Materials Center, Gdansk University of Technology, G. Narutowicza St. 11/12, 80-233 Gdansk, Poland
The paper presents a new method for evaluating the polarity and hydrophobicity of deep eutectic solvents (DESs) based on the measurement of the DES contact angle on glass. DESs consisting of benzoic acid derivatives and quaternary ammonium chlorides–tetrabutylammonium chloride (TBAC) and benzyldimethylhexadecylammonium chloride (16-BAC)—in selected molar ratios were chosen for the study. To investigate the DESs polarity, an optical goniometer and an ET(30) solvatochromic scale based on Reichardt’s dye were used. The research demonstrated the high accuracy and precision of the developed procedure. The simplicity of the examination and the availability of basic equipment allow for the implementation of the developed method in routine investigations of DESs.
