Extraction and Modification of Greener Surfactants from Natural Sources and their use in Development of Delivery Methods for Active Compounds

  • Naomi Elstone

Student thesis: Doctoral ThesisPhD


The main aim of this work was to investigate more sustainble surfactant systems using X-Ray and neutron scattering, in combination with other scattering and surface sensitive techniques, to investigate the structure and interactions which are present within pure and mixed systems and their likely effects upon their stability and applicability.

This thesis contains two related but different bodies of work. The main focus of this thesis has been the investigation amino acid surfactants prepared with three amino acids. The three amino acids used were selected as they are the main components of a waste product of the brewing industry which we were interested in valorising. To determine whether surfactants prepared from these amino acids and their mixtures were likely to be of interest for applications fundamental studies were carried out, in which the structure of mixed and pure amino acid surfactants were investigated. These measurements were carried out in solution and for Langmuir monolayers of insoluble surfactants using SANS and reflectometry respectively.

The second study involved the investigation into mixtures of sulfobetaines and
phospholipids at the air-water interface. These were of particular interest from both a fundamental perspective, as the headgroups of these two compounds have the opposite charge orientation, and from a more application based perspective as sulfobetaines have been found to be biocompatible and therefore of use in drug delivery applications. The structure of these monolayers was also investigated using a combination of X-ray and neutron reflectometry. The isotopic sensitivity of neutron reflectometry was exploited to determine the structure of the tails of the components of the monolayers separately within the mixed monolayers.
Date of Award24 Jun 2020
Original languageEnglish
Awarding Institution
  • University of Bath
SupervisorDavid Leak (Supervisor), Karen Edler (Supervisor), Simon Lewis (Supervisor) & Thomas Arnold (Supervisor)


  • Surfactant
  • Reflectometry
  • SANS
  • amino acid
  • sulfobetaine

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