Stage 2018:

Synthesis and characterization of ligand-functionalized polysaccharides.
A1.1. Functionalization of polysaccharides with aminopolycarboxilic acid moieties by chemical modification of biopolymer functional groups.

Results

• In a preliminary step, functionalization of chitosan (CS) with ethylenediaminetetraacetic dianhydride (EDTA) was performed as “proof-of-concept”, according to Scheme 1:

• To obtain sorbent materials with high stability during multiple sorption/desorption cycles, the attachment of EDTA ligand groups was further carried out onto cross-linked CS-based beads. The schematic representation of the synthetic route involved in preparation of EDTA-functionalized sorbents is indicated in Scheme 2.

• Attachment of EDTA groups onto CS chains was proved by 1H-RMN and FTIR spectroscopy.
• Formation of EDTA-functionalized 3D porous CS-based beads was evaluated by several methods of characterization (FTIR spectroscopy, optical microscopy, SEM, copper (II) retention capacity).
• SEM micrographs indicated the formation of cryogels with unidirectional oriented porous channels; the distance between the channels walls was around 20 ± 3 µm.
• Preliminary sorption tests pointed out the high potential of EDTA-functionalized CS-based beads for copper ion retention.