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The present contribution reports the fabrication and characterization of ultrafine polyacrylonitrile (PAN) fibers by electrospinning and further development of the as‐spun PAN fibers into ultrafine carbon fibers. The effects of solution conditions (i.e., solution concentration, viscosity, conductivity, and surface tension) and process parameters (i.e., applied electrostatic field strength, emitting electrode polarity, nozzle diameter, and take‐up speed of a rotating‐drum collector) on morphological appearance and average diameter of the as‐spun PAN fibers were investigated by optical scanning (OS) and scanning electron microscopy (SEM). The concentration, and hence the viscosity, of the spinning solutions significantly affected the morphology and diameters of the as‐spun PAN fibers. The applied electrostatic field strength and nozzle diameter slightly affected the diameters of the as‐spun fibers, while the emitting electrode polarity did not show any influence over the morphology and size of the as‐spun fibers. Utilization of the rotating‐drum collector enhanced the alignment of the as‐spun fibers. Within the investigated concentration range, the average diameter of the fibers ranged between 80 and 725 nm. Finally, heat treatment of the as‐spun fibers with their average diameter of about 450 nm was carried out at 230 and 1000 °C, respectively. Various characterization techniques revealed successful conversion into carbon fibers with an average diameter of about 250 nm. Copyright © 2006 Society of Chemical Industry

Abstract. Electrospun polyacrylonitrile nanofiber mats (es-PAN nanofiber mats) were surface modified by 2,4-dinitrophenyl-hydrazine (2,4-DNPH) to yield the metal ion adsorption material (es-PAN-DNPH nanofiber mats) and were investigated their adsorption behaviors. Functional modification of the es-PAN nanofiber mats and conventional polyacrylonitrile fibers (c-PAN fibers) were prepared by using 4% (w/v) of 2,4-DNPH in 1,2-ethandiol at 110°C for 6 h to obtained c-PAN-DNPH fibers. The average diameter of the es-PAN-DNPH nanofiber mats was 0.25 !m, which was comparatively smaller than the es-PAN precursor. Their functional groups were confirmed by Fourier transform infrared spectroscopy (FT-IR) and their adsorption behaviors to trace Ag(I), Bi(III), Ga(III), and In(III) from aqueous solutions and were investigated by the induced couple plasma technique. The FT-IR spectra showed the existence of NN=C-NHNH-, O=C-NHNH-, and -NO 2 functional groups for metal complexes. The adsorption capacities of the obtained es-PAN-DNPH were 7.14 to 36.36% higher than those of c-PAN-DNPH fibers. All adsorption plots onto es-PAN-DNPH nanofiber mats and c-PAN-DNPH fibers followed the Langmuir isotherm and indicated monolayer adsorption characteristics.

This research was to investigate the effect of silanization of 3-(trimethoxysilyl) propyl methacrylate of polyvinyl alcohol (PVA) as a binder and compatibilizer for the production of a pulp fibre sheet based agricultural waste of banana pseudo stem fibre and laminating with polylactic acid (PLA), respectively. The modification of PVA was successful by a confirmation of FTIR. As a result of mechanical-thermal analysis (DMTA), the modified PVA performed prominence as a compatibilizer in the combination of PLA and pulp sheet for the lamination process. It influenced to improve storage modulus roughly up to 50% while performing more viscous. Similarly, the tensile test also confirmed the improved properties. Interestingly, the biocomposite laminate as used in the modified PVA showed more hydrophilic rather than unmodified. A microbial growth test by Aspergillus niger also revealed the modified PVA influencing more severe biodegradation on the laminate.