A comparative study on electrospun fibers of cyanobiphenyl liquid crystal homologues

Abstract

Cyanobiphenyl homologues are important liquid crystals to use in some applications since they exhibit intrinsic properties in a certain temperature interval including room temperature. Recently, generating composites with polymers and liquid crystals by electrospinning has drawn great interest. Here, cyanobiphenyl homologues of chain carbon numbers 5-8 and polyacrylonitrile were spun using single-needle electrospinning for the first time. Morphological, optical, aligning, and thermal properties of spun fibers investigated. The thinnest and thickest fibers were obtained in fibers involving cyanobiphenyl of chain carbon number 5 and 6, respectively considering the scanning electron microscopy images. Also, it was proved that all the cyanobiphenyl members were self-aligned throughout the fibers as a core using polarized optical microscopy. The existence of the cyanobiphenyl homologues in the structure of the fibers was presented by infrared spectroscopy results. In addition, the mass variation depending on temperature and calorimetric measurements were studied. Phase transition temperatures of the bulk cyanobiphenyls and the fibers were compared. The results showed that cyanobiphenyl homologues of chain carbon numbers 5-8 and polyacrylonitrile were able to be spun successfully and the fibers had the potential to be used in applications because the physical properties of the fibers were attractive.