Fabrication of ceramic nanofibers using polydimethylsiloxane and polyacrylonitrile polymer blends

Abstract

Nanofibers with several hundred of nanometers were successfully fabricated using electrospinning process and a mixture of two types of polymers which are: polydimethylsiloxane and polyacrylonitrile as precursors. After stabilization and carbonization at 1000 °C, three phases which are: silicon carbide (SiC), carbon, and oxy‐SiC were presented. Spectroscopic and microscopic techniques had confirmed the presence of nanocrystalline SiC and turbostratic carbons. These phases formed an intertwined network at the nanometric scale. In addition, the resulted fibers showed a core‐skin effect with skin richer in carbon and a core mainly dominated by silicon‐based phases in the form SiC or SiOC ceramics. A significant improvement was observed in both tensile strength and elastic modulus in these hybrid fibers. In term of crystallography, these nanofibers seem to exhibit similar microstructure that was observed in Nicalon fiber. However, it was difficult to determine the ratio of these phases and their influence on the physical properties of these hybrid fibers. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45967.

Design of polyurethane fibers: Relation between the spinning technique and the resulting fiber topology

“…The fibers are partially oriented in the horizontal direction as shown in Figure (c,e). This is due to the usage of high‐speed rotating collector in electrospinning . The strong rotational force is able to drive the fibers to align in the circumferential direction of the rotation indicated by the blue arrow as shown in Figure (c,e).…”

“…Two types of collectors are used, a stationary and rotating collector as shown in Figure (a,b), respectively. For the rotating collector, a high rotating speed of ±1000 rpm is applied to increase the alignment of the fibers . The processing parameters of the electrospinning techniques are as shown in Table .…”

“…This alignment of electrospun fibers is also commonly studied in the literature. Randomly oriented fibers can be easily fabricated using stationary collectors, whereas highly aligned fibers can be fabricated using high‐speed rotating collectors . Nonetheless, tedious parameters optimization may be needed to spin highly aligned fibers with high‐speed rotating collectors as the splaying and whipping instability of the solution jet during electrospinning will hinder the alignment of the fibers as stated by Kiselev et al .…”

Hybrid Carbon Nano-Fibers with Improved Oxidation Resistance

“…To fabricate carbon and silicon-based ceramics, a smart use of polymer (organic and inorganic) precursors can be utilized. It enables forming complex shapes at low temperatures [17][18][19]. Several studies used both carbon precursors with solid additives to produce a new nanocomposite, which leads to different material properties [20,21].…”

“…TGA results showed that the fibers had an excellent oxidation resistant. Saja et al [18] used an organic/inorganic polymer blend (polydimethylsiloxane and polyacrylonitrile) to fabricate hybrid ceramic fibers. The resulting structure consists of silicon carbide (SiC), carbon, and SiOC.…”