From nanoparticles to fibres: effect of dispersion composition on fibre properties

Abstract

A polyvinyl alcohol (PVA)-stabilized polypyrrole nanodispersion has been optimised for conductivity and processability by decreasing the quantity of PVA before and after synthesis. A reduction of PVA before synthesis leads to the formation of particles with a slight increase in dry particle diameter (51 ± 6 to 63 ± 3 nm), and conversely a reduced hydrodynamic diameter. Conductivity of the dried nanoparticle films was not measureable after a reduction of PVA prior to synthesis. Using filtration of particles after synthesis, PVA content was sufficiently reduced to achieve dried thin film conductivity of 2 S cm -1 , while the electroactivity of the dispersed particles remained unchanged. The as-synthesized and PVA-reduced polypyrrole particles were successfully spun into allnanoparticle fibres using a wet-extrusion approach without the addition of any polymer or gel matrix. Using nanoparticles as a starting material is a novel approach, which allowed the production of macroscale fibres that consisted entirely of polypyrrole nanoparticles. Fibres made from PVA-reduced polypyrrole showed higher electroactivity compared to fibres composed of the dispersion high in PVA. The mechanical properties of the fibres were also improved by reducing the amount of PVA present, resulting in a stronger, more ductile and less brittle fibre, which could find potential application in various fields.

A robust free-standing MoS2/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) film for supercapacitor applications

“…[20][21][22] The composites based on CPs and 2D materials exhibit properties of each of the individual components with synergistic effect due to the facile charge transfer between these two constituents. [23] The addition of CPs to 2D semiconductors (i.e. MoS 2 in this work) is valuable because CPs can function as the conducting platform for charge delivery between 2D sheets.…”

High-strength graphene and polyacrylonitrile composite fiber enhanced by surface coating with polydopamine

“…Large sheets of GO that can form liquid crystalline dispersions are a robust template for matrix-guided molecular level self-assembly of polymers [12,23,24]. This process allows for the production of composite materials with enhanced mechanical performance by simple mixing a polymer with LCGO [25,26].…”

“…Dispersed liquid crystalline graphene oxide (LCGO) (10 mg/ml) in water was prepared using previously published methods [9,11,23], the mean size of GO flakes was 37 ± 23 µm. PAN homopolymer (molecular weight: 200,000) was purchased from Polysciences, Inc. (USA).…”