In Search of Stronger/Cheaper Chitin Nanofibers through Electrospinning of Chitin-Cellulose Composites Using an Ionic Liquid Platform

The ability of the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([C(2)mim][OAc]) to solubilize natural biopolymers (e.g., chitin and cellulose) without any chemical modification has been used to develop a one pot process to prepare a spinning dope by extracting chitin from shrimp shell, codissolving microcrystalline cellulose (MCC, DP = 270), and electrospinning nanomats from shrimp shell-extract/MCC solutions. The resulting spinning dopes were prepared with optimal viscosity of 380 to 900 cP, and conductivity and surface tension of similar to 2.8 mS/cm and similar to 36 dyn/cm, respectively; however, nanofibers could only be prepared when the chitin/MCC ratios in SS-extract/MCC solution were between 9/1 and 6/4. Compared to nanomats electrospun from shrimp shell-extract solution, 7/3 chitin/MCC composite nanomats demonstrated a 2-fold improvement in hardness and 3-fold improvement in elasticity, although further increase in MCC content resulted in lowering both parameters which nonetheless were higher than the pure chitin nanomats. This one pot process for preparing spinning dopes directly from shrimp shell-extract is a viable method to prepare chitin/MCC composites of improved strength/elasticity at lower costs.