Behavior of Ternary Mixtures of Hydrogen Bond Acceptors and Donors in Terms of Band Gap Energies

Alberto Mannu; Francesca Cardano; Salvatore Baldino; Andrea Fin

doi:10.3390/ma14123418

Behavior of Ternary Mixtures of Hydrogen Bond Acceptors and Donors in Terms of Band Gap Energies

Materials (Basel). 2021 Jun 20;14(12):3418. doi: 10.3390/ma14123418.

Authors

Alberto Mannu¹, Francesca Cardano¹, Salvatore Baldino¹, Andrea Fin²

Affiliations

¹ Department of Chemistry, University of Turin, Via Pietro Giuria 7, I-10125 Turin, Italy.
² Department of Drug Science and Technology, University of Turin, Via Pietro Giuria 9, I-10125 Turin, Italy.

Abstract

Three ternary mixtures composed by choline chloride (ChCl), ethylene glycol (EG), and a second hydrogen bond donor (HBD) as ethanol (A), 2-propanol (B), and glycerol (C) were studied in terms of composition related to the band gap energy (BGE). A Design of Experiments (DoE) approach, and in particular a Simple Lattice three-components design, was employed for determining the variation of the BGE upon the composition of each system. UV-VIS analysis and subsequent Tauc plot methodology provided the data requested from the DoE, and multivariate statistical analysis revealed a drop of the BGE in correspondence to specific binary compositions for systems A and B. In particular, a BGE of 3.85 eV was registered for the mixtures ChCl/EtOH (1:1) and ChCl/2-propanol (1:1), which represents one of the lowest values ever observed for these systems.

Keywords: Tauc plot; band gap energy; design of experiments; eutectic mixtures; hydrogen bond acceptor; hydrogen bond donor.