Solution blow spinning-polyacrylonitrile-assisted cellulose acetate nanofiber membrane.

Cellulose-based nanofiber membrane fabrication remains a global challenge, especially the use of alternative and sustainable sources of cellulosic materials. Herein, an easy and highly scalable cellulose-based nanofiber membrane was successfully fabricated using a solution blow spinning (SBS) method. Such membrane fabrication was carried out with the assistance of an easy-to-spin precursor polymer (i.e. polyacrylonitrile (PAN)). Through this strategy, cellulose acetate (CA) was successfully spun into a ready-to-use membrane. The formation of CA with the PAN nanofiber is concentration-dependent and requires high air pressure to effectively overcome the composite precursor's surface tension and eventually produce nanofibers. Favourable CA concentration in PAN (i.e. 50%-65% v/v CAN/PAN) is important to the formation of sufficient molecular entanglement with PAN in solution. Upon fulfilling the optimized CA concentration, high air pressure (i.e. ≥3 bars) is used to produce jet-like polymeric fibers of PAN dragging off CA, forming numerous nanofibers which are then collected into a substrate forming a membrane. Characterizations of the CA/PAN composite nanofiber were carried out using scanning electron microscopy, Fourier transform infrared, thermogravimetric analysis and differential scanning calorimetry (DSC). Such unique composite nanofiber membranes have potential as filters and adsorbent membranes for air and water/wastewater applications, as well as for biorefinery applications.