The unique combination of structural variability, ease of functionalization, thermoresponsiveness and biocompatibility has recently led to an increasing interest in an emerging class of polymers: poly(2-oxazoline)s. This pseudopeptide has not passed by the attention of the growing field of solvent electrospinning in which nanofibers with diameters below 500 nm are produced. Thanks to their thin fiber diameter and high porosity, nanofibers are characterized by a large specific surface area being a desired property in varying applications including biomedicine, sensors and filtration. In solvent electrospinning a strong electrical field draws a polymer solution into nanofibers which are deposited as a flexible, stand-alone, easy-to-handle membrane. Poly(2-oxazoline)s are of particular interest to this process as the polymers are soluble in more environmental friendly solvents, e.g., water and/or ethanol, compared to the commonly applied hydrophobic polymers needing deleterious solvent systems to be solubilized, a critical parameter in solvent electrospinning. Two types of well-defined poly(2-oxazoline)s, i.e., poly(2-ethyl-2-oxazoline) (PEtOx) and poly(2-n-propyl-2-oxazoline) (PnPrOx), have been successfully electrospun from aqueous solvent systems into uniform, bead-free nanofibers with interesting characteristics such as the rose-petal effect. This research paves the way towards electrospinning of other poly(2-oxazoline) polymers and investigation of their yet undiscovered properties. PEtOx and PnPrOx nanofibers are very sensitive to moist, particularly below the lower critical solution temperature (LCST), which might be inconvenient for some applications. Therefore, crosslinking strategies have been proposed for both polymers. PEtOx nanofibers were chemically crosslinked by selenol or benzophenone functionalization. PnPrOx was physically crosslinked upon addition of tannic acid.1 The fast and straightforward poly(2-oxazoline) nanofiber production combined with the possibility of crosslinking allows for application of these materials in for example sensor applications where a dye is either physically or chemically linked to the poly(2-oxazoline) nanofibers.

From polymer to application: solvent electrospinning of poly(2-oxazoline)s

2019 Spring National Meeting

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