Designing functional liquids

Student thesis: Doctoral ThesisDoctor of Philosophy

Abstract

The initial motivation for this work was inspired by the need for an in depth understanding between fundamental physical properties of functional liquids with relevance in industrial applications. Therefore, this work encompassed two strands. The first one was devoted to developing novel and potentially synergistic TOPO-based eutectic extractants. The second one, to unpacking the ‘black box’ related to the so far unknown reasons why Brønsted acidic protic ionic liquids (ILs) based on sulfuric acid exhibit favourable phase behaviour when compared to neat sulfuric acid in industrially relevant applications, such as catalysis or lignocellulosic biomass pre-treatment.

Following screening of 18 hydrogen bond donors, TOPO:malonic acid and TOPO:levulinic acid mixtures were chosen for further physico-chemical characterisation. A TOPO:malonic acid system was chosen as a gallium extractant and achieved distribution coefficients three orders of magnitude above that of the benchmark. Gallium was then quantitatively stripped from the eutectic using 1 M NH3(aq). Neutron scattering helped to elucidate the liquid structure of protic ionic liquids based on sulfuric acid and showed an extensive {SO4} network which was retained with water addition. Water was incorporated into the {SO4} network and is a likely cause of the preferential phase behaviour observed in these systems.
Date of AwardDec 2021
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SponsorsNorthern Ireland Department for the Economy
SupervisorGosia Swadzba-Kwasny (Supervisor) & John Holbrey (Supervisor)

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