Regeneration of jute through electrospinning

Regenerating jute into high-tech nanofibres is an alternative way to use jute fibres. However, dissolving jute has always been a challenge. The complex hierarchal structure of lignin is the main obstacle for hydrolysis of lignocellulosic fibres in obtaining value-added products. This work aims to develop regenerated jute nanofibres through electrospinning.

A literature review was conducted to investigate on the methods of regenerating jute for value added products. Literature review revealed that, growing efforts have been directed to the development of high-performance nanofibres/nanocomposites/nanocrystals from natural cellulosic resources. In this research, jute fibres were used in two ways: raw jute and alkali-treated jute. Both raw jute and treated jute were left in five ionic liquids (ILs) named propylammonium acetate (PAA), ethanolammonium formate (EOAF), 1-butyl-3-methylimidazolium acetate (BmimOAc), ethylammonium formate (EAF), 1-butyl-3-methylimidazolium chloride (BmimCl). Among the ILs only 1-butyl-3-methylimidazolium chloride (BmimCl) and 1-butyl-3-methylimidazolium acetate (BmimOAc) could dissolve jute fibres in a controlled temperature and with continuous mechanical stirring. Electrospinning trials were also made with the dissolved jute solutions. Due to the nonvolatility of the ILs, there were no nanofibres on the collector. However, trifluoroacetic acid (TFA) successfully dissolved both pre-treated and raw jute fibres and showed good spinnability in electrospinning. The needle-to-collector distance and solution flowrate were maintained in accordance with the ease of continuous jet formation. FTIR analysis showed the chemical structures of jute fibre after the fibre was dissolved in ILs and TFA. Nanofibres from raw jute (JNFs) and treated jute fibres (TJNFs) were successfully fabricated via a needle-based electrospinning setup. Experimental parameters, such as polymer concentration, applied voltage, and flow rate, were investigated. The morphology of the electrospun JNFs and TJNFs were characterized by scanning electron microscopy (SEM) and the chemical structure by Fourier Transform Infrared (FTIR) analysis. To determine the thermal stability and decomposition pattern, thermogravimetric analysis (TGA) of the electrospun nanofibres was performed. SEM analysis showed there were no significant differences in surface morphology between JNFs and TJNFs. The TGA results confirmed the excellent thermal stability of the as-spun nanofibres, which were less prone to degradation.

Furthermore, the fabrication, characterisation, and a comparative analysis have done between electrospun cotton nanofibres (CNFs) and jute nanofibres (JNFs). Both fibres were used without chemical pretreatment. TFA was used as the electrospinning solvent. The viscosity and conductivity values were measured of both the TFA dissolved solutions. The morphology of the electrospun JNFs and CNFs was characterized by scanning electron microscopy (SEM) and the chemical structure by Fourier Transform Infrared (FTIR) analysis. To determine the thermal stability and decomposition pattern, thermogravimetric analysis (TGA) of the electrospun nanofibres was performed. SEM analysis showed no major differences in surface morphology between JNFs and CNFs. The TGA results confirm that the as-spun nanofibres have excellent thermal stability up to 210ºC temperature before cellulose decomposition.  The tested JNFs show a similar degradation pattern as the tested CNFs.

This work provides insights in converting jute fibres to high-performance nanofibres. Overall, the results indicate that JNFs have a potential application in the fields of food, paper, paints, optics, pharmaceuticals, environment remediation, composite synthesis, etc., identical with cellulose nanofibres.