Highly aligned PAN nanofiber bundles prepared via a novel Venturi tube high-speed airflow drafting (VAD) method

In this paper, highly aligned electrospinning polyacrylonitrile (PAN) nanofiber bundles with excellent mechanical properties were successfully fabricated via a novel Venturi tube high-speed airflow drafting (VAD) method, which was proved to be an effective way for preparing well-aligned nanofibers. The drafting force imposed by the high-speed airflow had significant effects on the alignment and mechanical properties of PAN nanofibers. Specially, the vacuum attractive force driven by Venturi tube made the nanofibers easy to bundle which further improved their orientation and mechanical properties. The results demonstrated that with the increase of high-speed airflow, the degree of orientation and mechanical properties of the PAN nanofiber bundles increased initially and then decreased. Compared with other wind pressure conditions, when the high-speed airflow was 0.1 MPa, the PAN nanofiber bundles alignment degree was optimum, and its breaking strength reached 155.76 CN. The drafting and attractive force of Venturi tube provides a new strategy for preparing nanofiber bundles with high orientation and outstanding mechanical properties.