The effect of solution properties on the morphology of ultrafine electrospun egg albumen–PEO composite fibers

Abstract

Biocompatible composite fibers suitable for food and medical applications were electrospun from egg albumen (EA) and poly(ethylene oxide) (PEO) at a flow rate of 1.8 mL/min, at an applied voltage of 22 kV and a capillary to target distance of 15 cm. The ratio of EA to PEO dispersed in formic acid was varied from 1:0 to 1:0.1, 1:0.3, 1:0.6 and 0:1. The influence of dispersion properties such as viscosity, surface tension and electrical conductivity on the morphology of electrospun fibers was investigated. As the ratio of PEO increased, viscosity, surface tension, and conductivity decreased. Electrospun fibers had diameters of 188 ± 21, 289 ± 33, 470 ± 32 and 202 ± 20 nm for EA–PEO composite ratios of 1:0.1, 1:0.3, 1:0.6, and 0:1, respectively. Pure EA did not form fibers, but was deposited as beads instead. Results were attributed to increasing entanglement of the two polymers as the concentration of PEO in the solution increased leading to larger diameters of electrospun fibers. Compositional analysis of fibers spun from mixed dispersions using FTIR and TGA indicated that fibers were composed of both EA and PEO, but that fibers contained larger concentrations of PEO than the original dispersions. Investigation of thermal properties by DSC showed the absence of a melting point in 1:0.1 and 1:0.3 EA–PEO fibers. At an EA–PEO ratio of 1:0.6, a melting point characteristic of PEO was identified but enthalpy was significantly smaller than that of pure PEO which could possibly be attributed to molecular interactions between the two polymers.