Thermally and mechanically stable β-cyclodextrin/cellulose acetate nanofibers synthesized using an environmentally benign procedure

Abstract

Electrospun cyclodextrin (CD)-based nanofibers with capabilities to remove pollutants from water have been synthesized and characterized. The high-quality nanofibers presented here were synthesized in two simple steps that involved in-situ electrospinning of the nanofibers and all nanocomponents, followed by the reduction of silver (Ag+) and iron (Fe3+) ions to nanoparticles using an environmentally benign process that involved irradiation of the electrospun fibers using a tailor-made UV-equipped furnace at low temperatures. In the previously reported study it was observed that Ag and Fe nanoparticles effectively removed a range of different strains of Gram-negative and Gram-positive bacteria from water. As such, this study focused on improving the thermal and mechanical properties of the nanofibers prepared from polymer blends of β-CDs with cellulose acetate (CA) and small additions (2 wt%) of functionalized multiwalled carbon nanotubes (f-MWCNTs). The electrospinning parameters were varied to determine the optimum conditions for preparation of uniform non-beaded nanofibers. Bead-free and uniform nanofibers were obtained at a polymer concentration of 32% at the ratio of 1:1 β-CDs:CA, syringe injection flow rate of 0.7 mL h−1, 15 cm between the tip of the spinneret and the collector, and a voltage of 16 kV. The addition of f-MWCNTs was found to improve the tensile strength of the nanofibers by twofold, relative to nanofibers with no f-MWCNTs. The thermal degradation of the nanofibers was improved by a magnitude of 50°C. The study has shown that adding small amounts of f-MWCNTs improved the thermal stability and mechanical strength of the CD/CA nanofibers significantly.

Keywords

• β-Cyclodextrins
• cellulose acetate
• mechanical strength
• nanofibers
• thermal stability