Poly(methacrylic acid-co-vinyl sulfonic acid)-grafted-magnetite/nanocellulose superabsorbent composite for the selective recovery and separation of immunoglobulin from aqueous solutions

A novel multi-component superabsorbent polymer, poly(methacrylic acid-co-vinyl sulfonic acid)-grafted-magnetite/nanocellulose composite (P(MAA-co-VSA)-g-MNCC) was prepared by graft copolymerization technique. The characteristics of the P(MAA-co-VSA)-g-MNCC were investigated using XRD, FTIR, ESR and TG analyses. The swelling of P(MAA-co-VSA)-g-MNCC was found to be increased with increase of time and pH. The antibody, Immunoglobulin (IgG) was adsorbed onto P(MAA-co-VSA)-g-MNCC, under different optimized conditions. An adsorbent dose of 3.0 g/L was sufficient for the complete recovery of IgG from aqueous solutions. The maximum IgG adsorption on the ion-exchange adsorbent was observed at pH 6.8 with an equilibrium time of 3.0 h. Pseudo-second-order kinetic model adequately described the kinetic rate in comparison to pseudo-first-order model. The experimental adsorption isotherms of IgG were well fitted by Sips model and maximum adsorption capacity based on Langmuir model was 200.21 mg/g at 30 degrees C. IgG adsorption was highly dependent on ionic strength. Studies on the separation of IgG from mixture of proteins were carried out to ensure its better applicability in the biotechnological and biomedical fields. Regeneration of the spent adsorbent was done with 0.01 M KOH without significant loss in adsorption capacity. (C) 2013 Elsevier B.V. All rights reserved.