Temperature-responsive solid-liquid separations with charged block-copolymers of poly(N-isopropyl acryamide)
John-Paul O'Shea1, Greg G Qiao, George V Franks
1Department of Chemical and Biomolecular Engineering, Australian Mineral Science Research Institute, The University of Melbourne, Victoria, 3010 Australia.
Abstract:
Temperature responsive charged block-copolymers of poly(N-isopropylacrylamide) (PNIPAM) have been used in the solid-liquid separation of alumina mineral particles from aqueous solution. The effects of temperature, polymer charge-sign and fraction of charged segment have been investigated. Batch settling and adsorption studies showed that rapid sedimentation results for suspensions with polymers of opposite charge-sign to the particle surface-charge (counterionic) at 50 °C. Cooling the suspensions after flocculation at 50 °C was found to increase the final solids volume fraction of the sediment beds formed through a mechanism related to partial desorption of polymer and the reduction of the hydrophobic attraction. Suspension stability results after dosing with polymers of similar charge-sign to the particle surface-charge (co-ionic) at both 25 and 50 °C. Increasing the amount of polymer charge increased the influence of polymer charge-sign on the adsorption and solid-liquid separation behavior. The performance of the charged block copolymers are compared to that of the random charged copolymer and neutral homopolymer PNIPAM structures.
Related Concept Videos
Ion Exchange
Solid–Solid Solutions
Characteristics and Nomenclature of Copolymers


