Preparation of cellulose acetate-polyacrylonitrile composite nanofibers by multi-fluid mixing electrospinning method: Morphology, wettability, and mechanical properties

Electrospun cellulose acetate-polyacrylonitrile (CA-PAN) nanofibrous membranes with controllable spatial structure were fabricated by a multi-fluid mixing electrospinning process. SEM showed that morphologies of membranes transformed from smooth to rough surface upon changing the weight ratios of CA to PAN, whereas their average diameters increased from 303 to 502 nm. The static contact angle value of membranes increased from 86 to 131° with increase in CA content. The hydrophilic-hydrophobic properties were affected by the Mixture Rule of surface microstructure and spatial structure. The PAN nanofibers had higher elongation at break (εb), however their yield strengths were lower, while CA fibers exhibited poor mechanical properties. After introduction of CA fibers into CA-PAN membranes, the mechanical properties were improved significantly. The 33%CA(67PAN) nanofibers showed highest tensile strengths (σmax, 5.0 MPa) and εb (29.2%) values. Moreover, the composition, roughness and thermal stabilities of nanofibers were also analyzed. The structure-property relationship was clarified.