Sousa A.M.M.,University of Porto |
Sousa A.M.M.,Dairy Functional Food Research Unit |
Souza H.K.S.,University of Porto |
Uknalis J.,Dairy Functional Food Research Unit |
And 4 more authors.
International Journal of Biological Macromolecules | Year: 2015
Very recently our group has produced novel agar-based fibers by an electrospinning technique using water as solvent and polyvinyl alcohol (PVA) as co-blending polymer. Here, we tested the deep eutectic solvent (DES), (2-hydroxyethyl)trimethylammonium chloride/urea prepared at 1:2 molar ratio, as an alternative solvent medium for agar electrospinning. The electrospun materials were collected with an ethanol bath adapted to a previous electrospinning set-up. One weight percent agar-in-DES showed improved viscoelasticity and hence, spinnability, when compared to 1. wt% agar-in-water and pure agar nanofibers were successfully electrospun if working above the temperature of sol-gel transition (~80. °C). By changing the solvent medium we decreased the PVA concentration (5. wt% starting solution) and successfully produced composite fibers with high agar contents (50/50 agar/PVA). Best composite fibers were formed with the 50/50 and 30/70 agar/PVA solutions. These fibers were mechanically resistant, showed tailorable surface roughness and diverse size distributions, with most of the diameters falling in the sub-micron range. Both nano and micro forms of agar fibers (used separately or combined) may have potential for the design of new and highly functional agar-based materials. © 2015.