On December 17, 2024, Catarina Araujo presented her doctorate thesis titled “Exploring the Structural Landscape of Disordered Materials: A Computational Spectroscopy Approach”, delivering an excellent and highly engaging presentation.

Her thesis focuses on understanding the molecular-level behavior of disordered materials, specifically deep eutectic solvents (DESs) and furanic polyesters, using computational spectroscopy techniques. Below is the abstract of her groundbreaking research:

Abstract

This thesis explores the molecular-level behavior of disordered materials, focusing on two classes: deep eutectic solvents (DESs) and furanic polyesters. A computational spectroscopy strategy is followed to gain insight into their structural and dynamical properties, using a diverse toolkit that includes infrared, Raman, and inelastic neutron scattering (INS) spectroscopy, as well as discrete and periodic density functional theory (DFT) calculations.

The first part of the thesis examines DESs, starting with a literature review on vibrational studies of eutectic systems. Subsequent papers investigate hydrogen bonding networks and the enthalpic and entropic drivers of melting point depression. Vibrational analyses, supported by DFT calculations, identify key interactions between choline chloride, urea, and modified hydrogen bond donors. A particularly novel aspect is the identification of a eutectic system, based on urea and an asymmetric tetraalkylammonium salt, where entropic rather than enthalpic factors govern deep eutectic behavior.

The second part focuses on furanic polyesters, with an emphasis on poly(ethylene 2,5-furandicarboxylate) (2,5-PEF), poly(trimethylene 2,5-furandicarboxylate) (2,5-PTF), poly(butylene 2,5-furandicarboxylate) (2,5-PBF), and poly(ethylene 2,4-furandicarboxylate) (2,4-PEF). Their conformational preferences, in both amorphous and crystalline domains, are explored. Novel crystal structures for 2,5-PTF and 2,5-PBF are proposed. For the 2,5-PEF to PBF series, C-H···O hydrogen bonds act as conformational drivers, stabilizing extended conformations which would be energetically inaccessible in the absence of intermolecular contacts. The crystallization of 2,4-PEF is hampered by the random orientation distribution of its asymmetric furanic moieties.

Overall, the thesis highlights the potentialities of computational spectroscopy in elucidating the behavior of DES and furanic polyesters at the molecular level, offering new structural models and a deeper understanding of structure-property relationships. These findings pave the way for further exploration of disordered systems, an essential step towards reaching the goal of designing novel materials with tailor-made properties.