Solution blow spinning–polyacrylonitrile–assisted cellulose acetate nanofiber membrane

Abstract

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.

Solution Blow Spinning of Polycaprolactone—Rheological Determination of Spinnability and the Effect of Processing Conditions on Fiber Diameter and Alignment

“…The minimum polymer solution concentration value to allow for macromolecular entanglement in a given polymer-solvent system is known as the critical overlap concentration C*, a boundary value between dilute and semi-dilute polymer solution concentration regimes [47]. In dilute polymer solutions or solutions with poor solvents, polymer chains do not generally overlap [41].…”

“…Polymer macromolecule extension and entanglement vary between dilute, semi-dilute unentangled, and semidilute entangled polymer concentration regimes [35,38]. In principle, low to no interaction between polymer chains leads to spraying and solidification of the solution droplets as polymer film on the surface of the collector (dilute regime), low interaction and entanglement between macromolecules cause so-called beads to appear in the fiber network (semi-dilute unentangled regime) [39], and high macromolecular entanglement in the polymer solution causes the fiber formation process to stabilize and yield uniform fibers [40,41]. Critical values limiting these regimes constitute a so-called spinnability window, or a set of conditions where uniform fiber spinning should be possible.…”

Are Natural-Based Composites Sustainable?

“…This is an important issue to consider, as many of the NFs found on the market and used within the composite industry come from economically disadvantaged countries, and, as explained above, sustainable development also needs social and economic benefits to be truly considered as such; besides, it is of key importance to use fibers that do not displace food production. Cellulose is considered as a viable source to produce nanofibers available to substitute petroleum-based polymers, especially in spinning processes, as cellulose and its derivatives are easily processed [ 49 ].…”

Solution Blow Spinning (SBS): A Promising Spinning System for Submicron/Nanofibre Production

“…The fabrication of cellulose-based nanofibres remains a global challenge, particularly in terms of using alternative cellulosic materials. However, cellulose-based nanofibre membrane can be successfully fabricated through the assistance of an easy-to-spin polymer precursor (e.g., PAN) by using solution blow spinning (SBS) [97]. Zein fibres were successfully produced through (SBS) by using acetic acid as the solvent [98].…”