Electrospinning of 100% Carboxymethyl Chitosan Nanofibers

Abstract

Carboxymethyl chitosan (CMC), one of the most important chitosan derivatives, is synthesized by alkalization of chitosan, followed by carboxymethylation. CMC has higher moisture absorption and moisture retention, higher chelating and sorption abilities as well as better biological properties than chitosan. Polymeric nanofibrous mats produced through electrospinning have high specific surface area and high porosity which are beneficial for various applications. Up to present time, the electrospinning of CMC has only been possible by the addition of polymers such as polyvinyl alcohol or polyethylene oxide. The present study focuses on the electrospinning of 100% CMC. It was found that the solution of CMC (5–6%) in trifluoroacetic acid (TFA) was electrospinnable, producing nanofibers containing some beads. However, adding dichloromethane (DCM) to TFA made the electrospinning uniform, and bead-free CMC nanofibers with an average diameter of 260 nm was possible. This study shows that viscosity and surface tension of the electrospinning solution of CMC plays an important role in making CMC solution electrospinnable.