Electrospinning of Light-emitting Fibers from a Tertiary Blend Solution of an Inert Polymer and Two Conjugated Polymers

Abstract

Ultra-fine PS/BEH-PF/EHO-OPPE fibers with average diameters ranging from 0.67 to 0.92 μm were successfully prepared by electrospinning a 8.5% (w/v) tertiary blend of PS/BEH-PF/EHO-OPPE (PS/BEH-PF/EHO-OPPE = 7.5:0.5:0.5 w/w/w) in chloroform (CF) with the addition of 8% (v/v) pyridinium formate (PF). Electrospun fibers from binary blends of PS/BEH-PF and PS/EHO-OPPE (PS/BEH-PF or PS/EHO-OPPE = 7.5:1 w/w) were also prepared in the same condition for comparison. Scanning electron microscopy and Fourier-transform infrared spectroscopy were respectively used to explore morphology and chemical functionality of the electrospun fibers. The optical properties of the as-prepared blend solutions, corresponding electrospun fibers, and annealed fibers at different temperatures were studied by UV-visible and photoluminescence spectroscopy. Upon increasing the annealing temperature, the fibers from the binary blend of PS/BEH-PF showed a much more red shift than those from the tertiary blend of PS/BEH-PF/EHO-OPPE, while the fibers from the binary blend of PS/EHO-OPPE showed a much more blue shift when compared with the pristine fibers. Supposedly, the incorporation of BEH-PF and EHO-OPPE molecules helped to reduce the aggregation occurring from the π-π interaction stacking as the lesser red shift was observed in the fibers from the tertiary blend.