Ionic liquid assisted electrospinning of quantum dots/elastomer composite nanofibers

Quantum dots (QDs)/elastomer (VM) composite nanofibers have been fabricated via electrospinning method with the assistance of small amount (1 wt%) of ionic liquid. Without ionic liquid, polymer solution underwent an electrospraying process within the electric field and only individual droplets rather than continuous fibers were observed. Both fixed electrode and rotating disk electrode were used to collect the products. The latter one turned out to be much more advanced in collecting separated, aligned and narrow-size distributed composite nanofibers. With fixed electrode, even though nanofibers were obtained initially, the as-spun fibers were easily to merge together due to the flexible non-crystalline nature of the VM chains and finally formed a condensed thin film. Strong fluorescent emission was observed in the composite nanofibers with a QD loading of 3 and 5 wt%, respectively. The optical property of QDs was not degraded after dispersing in the polymer solution as evidenced by the UV-Vis absorption at 562 nm and 592 nm, and strong photoluminescent emission at 612 nm. In addition, differential scanning calorimetry (DSC) analysis revealed a strong interaction between ionic liquid and the polymer chains, which well explains the function of the ionic liquid on producing fiber structure of VM. An enhanced thermal stability of the elastomer in the composite nanofibers is observed as compared to that of the pure elastomer fibers.