Wet Spinning of ToughAlginate/NanomicrocelluloseFibers from Waterborne Bioinks

Here, cellulose fibers, turned into nano/microcellulose (NMC), were combined with different ratios of alginate (Alg) to formulate a series of waterborne bioinks, which were subsequently processed via coagulation-based wet-spinning technique. Water was the sole solvent in both the bioink and coagulation bath. The resulting fibers exhibited tensile strength, elastic modulus, and strain at breaking point values on the order of 250 MPa, 5–8 GPa, and 15%, respectively, approaching those of commercial cellulosic fibers such as cotton, wool, and Lyocell. A maximum elastic modulus of ca. 8 GPa was achieved with 90% (w/v) of NMC. Nevertheless, the toughness appeared to decrease with the addition of the NMC. SAXS and WAXS studies showed that NMC is highly aligned with the fiber axis, causing an internal orientation of the fibers. This was supported by the micrographic analysis. These findings show that by combining Alg/NMC mechanically, robust biofibers can be fabricated by sustainable means. The range of properties of these fibers offers promising alternatives for applications in the textile and biomedical fields.