Magnetic adsorbents displaying switchable ion-exchange behaviour
Magnetic bioseparations based on non-porous adsorbents offer a low-fouling alternative to the porous materials required by conventional adsorbent separation techniques. Interest in magnetic bioseparations has been limited by the high cost of suitable magnetic absorbents. In this study a variety of t...
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ndltd-bl.uk-oai-ethos.bl.uk-5124922019-04-03T06:27:23ZMagnetic adsorbents displaying switchable ion-exchange behaviourWillett, Thomas Clifford2009Magnetic bioseparations based on non-porous adsorbents offer a low-fouling alternative to the porous materials required by conventional adsorbent separation techniques. Interest in magnetic bioseparations has been limited by the high cost of suitable magnetic absorbents. In this study a variety of techniques - including Ce(IV) initiation, surface ATRP and sulfonyl activation – were used to graft ion-exchanging polyelectrolyte surfaces on low cost non-porous polyvinyl alcohol-magnetite supports. Grafting of poly(2-vinyl pyridine) and poly(methacrylic acid) was fully characterised using solid and liquid state FTIR. Dense polyelectrolyte layers were seen, with Ce(IV) grafted layers accounting for up to 49% of grafted support mass. Values for ATRP and tresyl activations were 41% and 25% of support mass respectively. These included layers which correspond to the brush regime (2R\(_f\)/D > 8), as determined by Flory Radius calculations. The above matrices were subsequently analysed with bind and elute studies using a model mixture of acidic and basic proteins. Switchable ion-exchange behaviour was demonstrated, with anion binding capacity >25 mg/g support at pH 5 and cation binding >25 mg/g seen for Ce(IV) grafted supports. Improved elution by pH was also seen, with up to 73% of bound lysozyme removed during a single elution at pH 5.660.63TP Chemical technologyUniversity of Birminghamhttps://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.512492http://etheses.bham.ac.uk//id/eprint/507/Electronic Thesis or Dissertation |
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660.63 TP Chemical technology |
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660.63 TP Chemical technology Willett, Thomas Clifford Magnetic adsorbents displaying switchable ion-exchange behaviour |
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Magnetic bioseparations based on non-porous adsorbents offer a low-fouling alternative to the porous materials required by conventional adsorbent separation techniques. Interest in magnetic bioseparations has been limited by the high cost of suitable magnetic absorbents. In this study a variety of techniques - including Ce(IV) initiation, surface ATRP and sulfonyl activation – were used to graft ion-exchanging polyelectrolyte surfaces on low cost non-porous polyvinyl alcohol-magnetite supports. Grafting of poly(2-vinyl pyridine) and poly(methacrylic acid) was fully characterised using solid and liquid state FTIR. Dense polyelectrolyte layers were seen, with Ce(IV) grafted layers accounting for up to 49% of grafted support mass. Values for ATRP and tresyl activations were 41% and 25% of support mass respectively. These included layers which correspond to the brush regime (2R\(_f\)/D > 8), as determined by Flory Radius calculations. The above matrices were subsequently analysed with bind and elute studies using a model mixture of acidic and basic proteins. Switchable ion-exchange behaviour was demonstrated, with anion binding capacity >25 mg/g support at pH 5 and cation binding >25 mg/g seen for Ce(IV) grafted supports. Improved elution by pH was also seen, with up to 73% of bound lysozyme removed during a single elution at pH 5. |
author |
Willett, Thomas Clifford |
author_facet |
Willett, Thomas Clifford |
author_sort |
Willett, Thomas Clifford |
title |
Magnetic adsorbents displaying switchable ion-exchange behaviour |
title_short |
Magnetic adsorbents displaying switchable ion-exchange behaviour |
title_full |
Magnetic adsorbents displaying switchable ion-exchange behaviour |
title_fullStr |
Magnetic adsorbents displaying switchable ion-exchange behaviour |
title_full_unstemmed |
Magnetic adsorbents displaying switchable ion-exchange behaviour |
title_sort |
magnetic adsorbents displaying switchable ion-exchange behaviour |
publisher |
University of Birmingham |
publishDate |
2009 |
url |
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.512492 |
work_keys_str_mv |
AT willettthomasclifford magneticadsorbentsdisplayingswitchableionexchangebehaviour |
_version_ |
1719012709617369088 |