Fabrication of electrospun chitosan/cellulose nanofibers having adsorption property with enhanced mechanical property

Abstract

Chitosan/cellulose (CS/CL) nanofibers were fabricated through electrospinning with a mixture of chitosan (CS) and cellulose acetate (CA) in a co-solvent system (trifluoroacetic/acetic acid) and afterward Na2CO3 treatment was followed. The treatment induces the neutralization of CS and deacetylation of CA, converted into cellulose (CL). The CS/CA nanofiber webs maintained the fibrous structure after treatment (converted into CS/CL nanofibers), which cannot be achieved by CS nanofibers. In addition, the combination of CS and CA enhanced the mechanical properties of the resultant nanofibers up to approximately 17 MPa in tensile strength and 5.5% in elongation at break. More importantly, the resulting nanofibers showed adsorptive characteristics; whereas, CL nanofibers showed no adsorption behavior. The incorporation of CS with CL offers the metal ion adsorption property to the composite nanofibers and gives them a waterproof property, which could be utilized in wastewater purification. The adsorption capacity of CS/CL nanofibers for As(V), Pb(II) and Cu(II) ions reached up to 39.4, 57.3 and 112.6 mg/g. Therefore, this nanofiber system showed effective removal behavior in aqueous solution with reasonable mechanical strength, unattainable with pure CS or CL nanofibers.