The role of clay-montmorillonite on thermal characteristics and morphology of electrospun PAN nanofibrous mats

Abstract

Polymer organic-inorganic hybrid nanofibers constitute a new class of materials in which the polymeric nanofibers are reinforced by uniformly dispersed inorganic particles having at least one dimension in nanometer-scale. In the present study, nanofibrous mats of neat and nanocomposite polyacrylonitrile (PAN) were fabricated by electrospinning process. Electrospun PAN and PAN/Na-MMT fibrous mats with the respective mean fiber diameter of about 220 and 160 nm were prepared. The influence of the clay-montmorillonite on the morphology and diameter of nanofibers was investigated by means of scanning electron microscope (SEM) and transmission electron microscope (TEM) techniques. The microscope techniques results suggested that the PAN/Na-MMT composite nanofibers showed the lower mean fiber diameter than the neat PAN nanofibers. Besides, the difference in nanoclay-content has a slight effect on the distribution of fibers diameter. Thermogravimetric analysis (TGA) results suggested that the introduction of clay-nanomaterials improve the decomposition onset and residual weight percentage of mats at about 31 C and 13 %, respectively. The results of X-ray diffraction (XRD) confirmed that the clay-montmorillonite layers were exfoliated in the polymer matrix. The exfoliation of clay layers was further supported by transition electron microscope (TEM) observations.

Nano-montmorillonite-doped lubricating grease exhibiting excellent insulating and tribological properties

“…The friction reducing and anti-wear properties can be illustrated by the following factors. First, the crystal cell of nano-montmorillonite is similar to a sandwich structure; the upper and lower layers are silicon-oxygen tetrahedrons and the middle layer is an aluminum-oxygen octahedron [14][15][16][17][18]. The primary connection forces between the two layers are molecular and hydrogen bonds [44].…”

“…Furthermore, MMT has a sandwich structure, wherein the upper and lower layers are silicon-oxygen tetrahedrons and the middle layer is aluminum-oxygen octahedron. Moreover, exchangeable cations, such as Na + , Mg + , and Al + , exist between the layers [14][15][16][17][18]. Due to its unique characteristics of having a nano-scale layered structure and exchangeable cations, MMT can be easily modified and used for various applications.…”