# Organosolv Lignin-Based Electrospun Nanofibers: Stable Compositions and Morphological Insights

## TL;DR

This paper explores using lignin from wood sources to create nanofibers through electrospinning, focusing on stable compositions and fiber structure.

## Contribution

The study identifies stable lignin-based electrospinning compositions and proposes a fiber formation mechanism.

## Key findings

- Stable electrospinning was achieved with lignin from softwood and hardwood sources.
- Higher lignin content led to smaller fiber diameters, especially with hardwood lignin.
- Internal voids were observed in all fiber compositions using FIB-FESEM.

## Abstract

Lignin, a major component
of lignocellulosic biomass, has been
gaining interest as a sustainable alternative to petroleum-based polymers
(e.g., polyacrylonitrile, PAN), and its valorization has included
the production of nanofibers by electrospinning. In this work, we
identify stable compositions leading to robust electrospinning from
two different sources of organosolv lignin (OL), softwood (SOL), and
hardwood (HOL), combined with variable concentrations of poly­(ethylene
oxide) (PEO) of different molecular weights. Robust spinning of the
solutions is sought while minimizing the required binder polymer and
maximizing the lignin content in the produced fibers. The stability
of the electrospinning process was rigorously monitored by imaging
the Taylor cone (TC) during fiber formation by high-speed video, while
solution rheology was analyzed to characterize the solutions and aid
in understanding the fiber formation mechanism. The internal structure
of the fibers was characterized by focused ion beam field emission
scanning electron microscopy (FIB-FESEM), revealing the presence of
internal voids in all compositions. When lignin was predominant, the
fiber diameter was systematically smaller for HOL than for SOL, possibly
due to the smaller molecular weight, revealing submicrometer fiber
diameters in both cases. Finally, on the basis of these findings,
a fiber formation mechanism is proposed.