# Rheological Behavior of Poly(Styrene-Co-Acrylonitrile)/Carbon Nanotube Sponges for Fiber Electrospinning Applications

## TL;DR

This paper studies how adding carbon nanotube sponges affects the flow properties of polymer solutions used in electrospinning to make nanofibers.

## Contribution

The study reveals how varying CNT-sponge content influences rheological behavior, guiding optimal electrospinning conditions.

## Key findings

- Low CNT-sponge concentrations promote liquid-like behavior, suitable for electrospinning.
- Higher CNT-sponge content leads to solid-like behavior and fiber agglomeration.
- Rheological analysis helps predict viscoelastic parameters for electrospun nanofiber production.

## Abstract

Polymeric composite solutions (PCSs) reinforced with carbon nanotubes sponges (CNT-sponges) have attracted interest in material science and engineering due to their physicochemical properties. Understanding the influence of CNT-sponges content (0.1 wt.%, 0.3 wt.% and 0.5 wt.%) on rheological behavior of poly(styrene-co-acrylonitrile) P(S:AN) (0:100, 20:80, 40:60 and 50:50, wt.%:wt.%) solutions synthesized by emulsion polymerization can predict the viscoelastic parameters for their possible application in electrospinning processes. The obtained nanofibers can be used as sensors, textiles, purifying agents or artificial muscles and tissues. For this, amplitude and frequency sweeps were performed to measure the viscosity (η), storage (G’) and loss (G”) moduli and loss factor (tan δ). Most PCSs showed a shear thinning behavior over the viscosity range of 0.8 < η/Pa·s < 20. At low CNT-sponges concentration in the polymer matrix, the obtained loss factor indicated a liquid-like behavior, while as CNT-sponges content increases, the solid-like behavior predominated. Then, the polymeric solutions were successfully electrospun; however, some agglomerations were formed in materials containing 0.5 wt.% of CNT-sponges attributed to the interaction forces generated within the structure. Finally, the rheological analysis indicates that the PCS with a low percentage of CNT-sponges are highly suitable to be electrospun.