Wet-Spun Carbon Nanotube/Polymeric Ionic Liquid Composite Fibers

Composite fibers of carbon nanomaterials and polymers can result in high-performance fibers when spun by the wet-spinning method if efficient interfacial interaction occurs between the carbon nanomaterials and the selected polymers used as coagulants [1-4]. This process implies the fabrication of gel fibers as a result of the collapse of dispersions of carbon nanomaterials when injected into a coagulation bath. When dried, those gel fibers become solid fibers with high carbon nanomaterial contents (≥ 50 wt.%), significantly higher than those achieved by other fiber spinning technologies, such as melt-spinning or electrospinning.

The high affinity of ionic liquids (ILs) and polymeric ionic liquids (PILs) for carbon nanotubes (CNTs) and the multifunctional characteristics of their composites inspired us to consider the use of PIL solutions as coagulation baths in fiber wet-spinning processes. Hence, we here report on the use of an imidazolium-based PIL for the fabrication of CNT/PIL composite fibers. These fibers were wet-spun by injecting anionic surfactant-assisted aqueous dispersions of single walled CNT (SWCNT) in a PIL solution that acted as flocculation agent. SWCNT/PIL fibers were highly conducting (90-130 S·cm^-1), displayed remarkable electrochemical capacitance (40 F·g^-1), and percentage of capacitance retention (~50%) values, comparable to those of thermally rGO fibers (50 F·g^-1 and ~30%, respectively). Fiber spinning mechanism for SWCNT/PIL fibers is here discussed in terms of an ion exchange reaction involving SWCNT/PIL and the anionic surfactant used [5].

The authors acknowledge support from Fundación Domingo Martínez and the Aragón regional government (project E25_23R).

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2. E. Muñoz et al., Adv. Eng. Mater., 6 (2004) 801.

3. E. Muñoz et al., Adv. Mater., 17 (2005) 1064.

4. Z. Lin, et al., Carbon 248 (2026) 121105.

5. E. Muñoz et al., submitted.