Factors affecting the refractive index of amino acid-based deep eutectic solvents

Abstract Effect of hydrogen-bonding donor, hydrogen-bonding acceptor, mole ratio, components and temperature on the refractive index of amino acid-based DESs is investigated. Results show that decreasing the mole ratio of hydrogen-bonding donor to hydrogen-bonding acceptor would decrease the refractive index. Refractive index of amino acid-based DESs shows negatively linear correlation with the temperature. This work would expand the application of amino acid-based DESs for the green optical device and sustainable characterization.