Use of Mg(OH)2 particles as stabilisers in Pickering emulsions

Turner, Daniel J.

Abstract

Twenty-six different samples of magnesium hydroxide particles were formed from various reactants and under varied reaction conditions. The morphologies of the different magnesium hydroxide samples were assessed via SEM and TEM and their zeta potentials were also measured. The particles were also characterised by XRD and FT-IR. The majority of the samples were of around 150-250 nm in diameter and had either a rod-like morphology or were platelets. However, some rod-like samples grew much larger, being around 2 μm in length. Zeta potential of the samples did not greatly vary and for each of the twenty-six samples; zeta potential was in the range of 15 mV ±6 mV.
Isooctane–in–water and methyl methacrylate–in–water emulsions were produced from the samples of magnesium hydroxide. Isooctane–in–water emulsions had much better long-term stability than MMA-in-water emulsions, which underwent complete phase separation very quickly; the most stable MMA-in-water emulsion destabilised within a week. The long-term stability of MMA-in-water emulsions improved upon the addition of an electrolyte, but the emulsions destabilised within a month. Factors such as particle concentration, presence of electrolyte and temperature were varied for isooctane–in–water emulsions. Emulsions containing isooctane and MMA as the oil phase were also prepared, with varied fractions of each oil. The greater the fraction of isooctane when in mixtures with MMA, the more stable the subsequent emulsion. Contact angle measurements were conducted on brucite, raw magnesium hydroxide, proving magnesium hydroxide is hydrophilic.

Citation

Turner, D. J. Use of Mg(OH)2 particles as stabilisers in Pickering emulsions. (Thesis). University of Hull. https://hull-repository.worktribe.com/output/4223312

• Thesis Type: Thesis
• Deposit Date: Aug 6, 2021
• Publicly Available Date: Feb 23, 2023
• Keywords: Chemistry
• Public URL: https://hull-repository.worktribe.com/output/4223312
• Additional Information: Department of Chemistry, The University of Hull
• Award Date: Sep 1, 2017