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Title: Characterisation of surfactant mesophases in mult-phase systems : high sensitivity, surfactant specific electrodes
Author: Mahmood, Zahid
ISNI:       0000 0001 3616 7193
Awarding Body: University of Salford
Current Institution: University of Salford
Date of Award: 2006
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The project involves research being carried out on surfactants and the multi-phase systems that they produce. The aim is to understand the mesomorphous behaviour exhibited by different multi-phase systems when conditions (time, temperature, shear tension, concentration of surfactants) are altered. The characterisation of surfactant mesophases in multi-phase systems can be observed by methods involving: polarising optical microscopy, X-ray diffraction and use of surfactant-specific electrodes to measure conductivity (mV). Investigating ternary systems composed of surfactant: co-surfactant components led to the understanding of the behaviour surfactants exhibit, as they exist in different mesophases. The application of the surfactant ion-specific coated-wire electrode (CWE) to ternary system mixtures presenting liquid crystals of different morphological behaviour (i.e. mesophases), allowed to determine and distinguish between the differing properties of these mesophases in terms of monitoring free surfactant monomer levels. The CWE was applied to surfactant mixtures in the hope of determining important information, for example; observing Nernstian behaviour, monitoring the onset of aggregation, i.e. the CMC or more complex aggregates like the hexagonal or lamellar phase, along with the free surfactant monomer levels present in the latter part of these concentrated mixtures. Whilst also investigating the occurrence of phase transitions between different liquid crystal mesophases and how their effects on the CWE could be explained in terms of electrochemical response or free monomer concentrations. Further modelling allowed for the determination of the interaction behaviour between a surfactant and co-surfactant within a ternary system. To conclude, the limitations of the CWE were determined, along with propositions for future development of drug-selective electrodes, which may be applied in the research for investigating the chemical behaviour of drug systems in solution.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available