Effect of co-electrospinning system on morphology and oil adsorption of helical nanofibers

Abstract

In this study, inspired by cucumber tendrils, nanofibers with helical morphology are fabricated in co-electrospinning systems with different spinneret configurations. Poly(m-phenylene isophthalamide) (Nomex) and thermoplastic polyurethane are chosen as the two components in co-electrospinning. Using simulation and experimental methods, the electric field distribution and the morphology of nanofibers from the three co-electrospinning systems are analyzed. The helical nanofibers generated from the off-centered spinneret co-electrospinning system possess a helical shape with larger curvature and show higher tensile strain. In addition, the helical nanofibers show an oil adsorption capacity up to 79.3 g g−1 and high oil retention (91%). This study may help control helical fiber morphology and extend the applications of helical materials.

Electrospinning Nonspinnable Sols to Ceramic Fibers and Springs

“…During jet thinning, the highly reactive sol rapidly condenses and solidifies into a rigid xerogel. This rigid core bonds to the shell at the interface and constrains the further thinning of the ductile polymer shell, causing the fiber surface to shrink against the stretching direction. , Such longitudinal compression leads to cracks on the fiber shell, which distribute asymmetrically about the fiber axis and rotate along the change of the curving direction (Figure S13 in the Supporting Information). To validate these assumptions, we conducted coelectrospinning of TiP sol and PVP solution at a reduced polymer solution feeding rate of 0.5 mL/h.…”

“…Helical structures in nature, such as tendrils, awns, and the xylem vessels of vascular plants, are formed due to asymmetric contraction of the cells and the chirality of the molecules. Electrospun fibers have potential in creating periodically curved structures because the electrified jets carrying multiple bending instabilities undergo mechanical buckling upon landing on the collector surface. , However, helical fibers only form at the beginning of the electrospinning process, i.e., appearing at the first several layers of the deposited fiber, so prior work relied on generating helical fibers by blending different polymers and using non-centrosymmetric nozzles. − Herein, we report the creation of ceramic springs based on the sol/polymer coelectrospinning method. Figure a shows a typical TiO 2 spring, where the geometrical parameters are the fiber diameter (2 r ), spring diameter (2 D ), and pitch ( P ).…”