Rheology and electrospinning of neat and laponite-filled poly(ethylene oxide) solutions
Date
2006
Authors
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Publisher
University of Delaware
Abstract
Aqueous solutions composed of dispersed nanoparticles and entangled polymers are shown to exhibit a common viscoelasticity over a range of particle and polymer concentrations. Time-temperature superposition and time-concentration superposition are applied to generate master curves for the linear viscoelasticity of neat and laponite RD-filled viscoelastic solutions of poly(ethylene oxide) in water. The shift factors were correlated in terms of temperature and concentration and explained qualitatively in terms of the molecular interactions in concentrated and entangled polymer solutions and polymer-nanoclay solutions. The addition of laponite is more effective in modifying the solution rheology than the addition of an equivalent weight of polymer. Ageing studies show that, unlike the polymer solutions which are stable, the addition of laponite leads to ageing on the timescale of days. ☐ In parallel with the rheology, electrospinning is reported for the same systems to explore the effects of change in the rheology of polymer and polymernanoclay formulations. A correlation between fiber diameter and the spinning solution’s zero-shear viscosity is observed and compared to previous work reported by (McKee et al., 2004). The addition of laponite nanoclay to the PEO solutions, which results in rheologically simple solutions, leads to different fiber morphologies for the same shear viscosity in contradiction with earlier reports for titania particles (Drew et al., 2003). The research identifies additional physicochemical properties that are important in setting electrospun fiber morphology.