The effect of end-tabbing methods on the tensile properties of electro-spun highly aligned PAN nano-fibres

A novel electro-spinning method was used to produce highly aligned polyacrylonitrile (PAN) nano-fibre arrays. The tensile properties of the aligned fibres were investigated where three different adhesives were used in the end-tabs, namely, a photo-curable UV resin, super-glue and double-sided adhesive tape. The photo-curable UV adhesive and the super-glue were effective in enabling thorough impregnation of the nano-fibre arrays. However, the UV-resin offered greater control with regard to maintaining the impregnated area to within the end-tab region. On inspecting the stress/strain plots, it was concluded that the load-transfer from the end-tabs with the UV-adhesive was comparatively more uniform, repeatable and efficient. The ultimate tensile strength for the UV-adhesive, super-glue and double-sided adhesive tape were 76.71 ± 3.34, 68.80 ± 4.41 and 67.38 ± 2.21 MPa respectively and the Young's moduli were 4.05 ± 1.17, 2.50 ± 0.53 and 1.86 ± 0.53 GPa respectively. The failure strains for the test specimens with the three end-tab resins were similar and ranged between 22.46 ± 2.88 % and 23.73 ± 2.23 %. A phenomenological tensile model was applied to assess the tensile properties of the electro-spun PAN nano-fibres. The stress and stiffness calculated using the phenomenological tensile model were in agreement with the experimentally derived tensile data.