Synthesis and characterization of magnetized poly (styrene-co-divinylbenzene) particles to be used as support for enzyme immobilization

Abstract

The requirements for industries to operate their processes under sustainable conditions allow the expansion of the use of enzymes as catalysts, since they operate under middle reaction conditions, reducing the generation of residues and by-products. However, the use of enzymes on a large scale is still limited due to its high cost and disadvantages of this type of process, such as the difficulty for biocatalyst recovery, insolubility of the enzyme in some reaction media and enzymatic instability. Thus, an alternative to improve the applicability of the enzymatic process, would be the fixation of these enzymes on solid matrices, enabling their reuse, the maintenance of the catalytic activity for an extended period of time, ease separation of the final product, higher thermal and pH stability. Nowadays different materials (natural, synthetic organic or inorganic and magnetized) have been used as support for the immobilization of enzymes, among them, the magnetized polymer hybrids have shown to be quite interesting for this application, since they present several advantages of operation, such as: high surface area, allowing greater availability to immobilize enzymes; low resistance to mass transfer, making the immobilized enzymes more stable. In addition, easy separation of the magnetic particles can be performed due to the possibility of using an external magnet, allowing the preservation of the immobilized enzyme in comparison to the traditional methods of centrifugation and filtration. In this context, the present project aims to synthesize and characterize styrene-based polymer particles magnetized by co-precipitation of Fe2+ and Fe3+ ions in alkaline media to be used as support for enzyme immobilization. For this purpose, the influence of some factors on suspension polymerization, such as: the use of different cross-linking agents, the study of the appropriate ratio between the organic-aqueous phases, the percentage of the suspending agent and the initiator on the reaction medium, as well as the suitability of the magnetization parameters, aiming at obtaining a solid matrix that presents adequate characteristics for the immobilization of enzymes, such as porosity, mechanical resistance, among others. The synthesized polymeric materials will be characterized morphologically and structurally and further used as a support to immobilize microbial lipase. (AU)