Polysaccharide biocomposites with tunable adsorption and antipathogen activity via surface immobilization of chitosan onto modified flax fibers.

Flax fiber modified composite (FFMC) duplex systems with unique sorbent and antipathogen properties were developed by physisorption of chitosan onto modified flax fibers by a facile method. Complementary characterization of the FFMCs (Raman, NMR, and IR, SEM, XRD, TGA and BET analysis) revealed variable composite morphology with incremental chitosan doping and supramolecular interactions between the fiber substrate and immobilized chitosan. Dye adsorption profiles of FFMCs with Rose Bengal corroborated the role of physisorption with an adsorption capacity that rises to 17.9 mg/g, whereas the water sorption capacity reaches an impressive value ca. 11 g/g, which indicated the role of synergism upon chitosan immobilization. Anti-microbial/-fungal properties were supported by antipathogen tests. The FFMCs have high antimicrobial potency toward gram negative (E. coli), gram positive (S. aureus) and a fungal strain (C. albicans) based on the low FFMC dosages required to achieve 100 % microbial elimination. This versatile class of unique biocomposites displayed unique structure-function relationships related to synergistic water sorption and antipathogenic effects, as compared to available literature reports. FFMCs are a diversiform class of biocomposites with unique physicochemical and biological properties that are shown to extend the field of adsorption science and technology from environmental remediation to biomedical devices.