Efficient preparation of poly(lactic acid) nanofibers by melt differential electrospinning with addition of acetyl tributyl citrate

Poly(lactic acid) (PLA) nanofibers, as a biodegradable and environmentally friendly material, have potential applications such as biological medicine, efficient filter material, and so on. PLA nanofibers are usually prepared by solution electrospinning method with toxic solvents, such as chloroform, chloromethane, and N,N-dimethyl formamide. In this work, PLA nanofibers were fabricated with a self-designed melt differential electrospinning device, assisted by addition of nontoxic acetyl tributyl citrate (ATBC) and by airflow. Molecular dynamics simulations were performed to understand the experimental results. The results revealed that the fiber diameter decreased with increasing airflow velocity, and fibers with a diameter as small as 236 nm were obtained at the highest airflow velocity of 25 m/s (with 6 wt % of ATBC). Furthermore, a significantly accelerated falling speed of the jets of about 347 times of that without airflow was achieved at a flow rate of 25 m/s. These results demonstrated that the combination of adding ATBC and airflow assistance was a good strategy to achieve finer fibers with improved stability and efficiency, making it a promising way for mass green production of PLA nanofibers.