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Title: Novel microgel suspensions : rheological, mechanical and adhesion properties and their filtration behaviour
Author: Griffin, James Martin
ISNI:       0000 0004 2737 4846
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2007
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Polyelectrolytes and polyampholytes are sensitive to external stimuli such as pH, or ionic strength and undergo volume phase transitions due to exposure to such stimuli. These polymers can be in or between one of two states; swollen or collapsed. The transition between these states can be used as a "switch" to change the rheological properties of a polymer solution or suspension. The resulting colloidal stimuli sensitive suspensions have a wide range of applications and there is significant interest in filtration and oil field applications. The research carried out, entailed the synthesis and characterisation of stimuli sensitive microgels. A novel and very simple mechanical cutting method to produce surfactant free responsive microgel particles is introduced. A series of pH, temperature and both pH and temperature sensitive hydrogels composed of various vinyl monomers such as methacrylic acid, 2- (dimethylamino) ethyl methacrylate, acrylamide and A'-isopropylacryrlamide were synthesised. Bulk hydrogels were crosslinked with varying amounts of N,Nmethylenebisacrylamide and characterised by swelling experiments and compression tests to determine the compression moduli. The hydrogels were dispersed using a high shear mechanical cutting technique to form surfactant free microgel suspensions. As the speed or duration of cutting was increased the mean particle size decreased. The resulting microgel suspensions were characterised by light scattering, microscopy, electrophoresis and rheological measurements.
Supervisor: Bismarck, Alexander Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available