Biobased Dyes as Conductive Additives to Reduce the Diameter of Polylactic Acid Fibers during Melt Electrospinning

Abstract

Electrospinning is widely used for the manufacture of fibers in the low-micrometer to nanometer range, allowing the fabrication of flexible materials with a high surface area. A distinction is made between solution and melt electrospinning. The former produces thinner fibers but requires hazardous solvents; whereas the latter is more environmentally sustainable because solvents are not required. However, the viscous melt requires high process temperatures and its low conductivity leads to thicker fibers. Here, we describe the first use of the biobased dyes alizarin; hematoxylin and quercetin as conductive additives to reduce the diameter of polylactic acid (PLA) fibers produced by melt electrospinning; combined with a biobased plasticizer to reduce the melt viscosity. The formation of a Taylor cone followed by continuous fiber deposition was observed for all PLA compounds; reducing the fiber diameter by up to 77% compared to pure PLA. The smallest average fiber diameter of 16.04 µm was achieved by adding 2% (w/w) hematoxylin. Comparative analysis revealed that the melt-electrospun fibers had a low degree of crystallinity compared to drawn filament controls—resembling partially oriented filaments. Our results form the basis of an economical and environmentally friendly process that could ultimately, provide an alternative to industrial solution electrospinning

Morphological Structures and Drug Release Effect of Multiple Electrospun Nanofibre Membrane Systems Based on PLA, PCL, and PCL/Magnetic Nanoparticle Composites

“…Electrospinning is a material fabrication technique that produces functional and economical three-dimensional fibrous structures [1,2]. The electrospun fibres result in the formation of a fabric network in possession of high porosity, small pore size, and large surface area to volume ratio [3,4].…”

The Effect of Electrical Polarity on the Diameter of Biobased Polybutylene Succinate Fibers during Melt Electrospinning

“…Several challenges must be overcome to achieve the larger-scale production of nanofibers [ 12 , 13 , 14 ]. One of these challenges is the high viscosity and low electrical conductivity of polymer melts [ 13 , 15 , 16 , 17 ], which can be addressed in part by the inclusion of additives [ 18 ]. For example, in our previous study, we investigated the use of curcumin and silver nanoparticles as multifunctional additives to reduce the viscosity of molten polybutylene succinate (PBS) while increasing its electrical conductivity [ 11 ].…”

Detailed Process Analysis of Biobased Polybutylene Succinate Microfibers Produced by Laboratory-Scale Melt Electrospinning

“…Nevertheless, an additional solvent recovery step is required, increasing the overall process costs [ 12 ]. For example, the production of 1 kg of PLA fibers, when processed as a 10% solution, requires 10 L of solvent with only 90% recovered in a typical process [ 20 ]. In contrast, melt electrospinning does not require solvents, but the melt must be held at high process temperatures in order to facilitate extrusion [ 21 ].…”