The Role of Electrical Polarity in Electrospinning and on the Mechanical and Structural Properties of As-Spun Fibers

Abstract

Electric field strength and polarity in electrospinning processes and their effect on process dynamics and the physical properties of as-spun fibers is studied. Using a solution of the neutral polymer such as poly(methyl methacrylate) (PMMA) we explored the electrospun jet motion issued from a Taylor cone. We focused on the straight jet section up to the incipient stage of the bending instability and on the radius of the disk of the fibers deposited on the collecting electrode. A new correlation formula using dimensionless parameters was found, characterizing the effect of the electric field on the length of the straight jet, L˜E~E˜0.55. This correlation was found to be valid when the spinneret was either negatively or positively charged and the electrode grounded. The fiber deposition radius was found to be independent of the electric field strength and polarity. When the spinneret was negatively charged, L˜E was longer, the as-spun fibers were wider. The positively charged setup resulted in fibers with enhanced mechanical properties and higher crystallinity. This work demonstrates that often-overlooked electrical polarity and field strength parameters influence the dynamics of fiber electrospinning, which is crucial for designing polymer fiber properties and optimizing their collection.

Electrospun PCL Patches with Controlled Fiber Morphology and Mechanical Performance for Skin Moisturization via Long-Term Release of Hemp Oil for Atopic Dermatitis

“…The decreased strength of porous compared to smooth fibers is also affected by the lower average fiber diameter that decreases the mechanical properties of PCL fibers [ 35 ] and high surface porosity [ 36 ], so the tested cross-sectional area is significantly lower which is not included in the calculation of the stress [ 37 ]. It demonstrates that the mechanical performance of electrospun fibers depends not only on fiber orientation but also on the interactions and adhesion forces between them [ 38 , 39 ] related to the changes in fibers morphologies or surface properties [ 40 , 41 ]. It was reported that the formation of the mechanical interlocking system strongly depends on surface properties and the presence of crevices, pores, roughness, and irregularities [ 42 ].…”

Enhanced Cells Anchoring to Electrospun Hybrid Scaffolds With PHBV and HA Particles for Bone Tissue Regeneration

“…The morphology and size of fibers prepared via electrospinning were affected by the polymer solution, environmental conditions, and applied electric field ( Krysiak et al, 2020 ; Szewczyk et al, 2020 ). It was followed by mechanical ( Ura et al, 2020 ) and surface properties ( Metwally et al, 2020 ). Therefore, PHBV-based scaffolds described in Suslu et al (2014) had significantly smaller diameters of 571 ± 160 nm compared to our study, however, similarly, they obtained increased fiber diameter with the addition of HA particles.…”

Advances in 3D Printing for Tissue Engineering

“…This method of scaffold fabrication allows the formation of fibrous nonwovens with morphology and architecture mimicking the fibrous structure of the extracellular matrix (ECM) which is crucial from the perspective of cells. In this process, a large number of various polymers and solvents can be used, both natural, such as gelatin, chitosan, collagen, etc., and synthetic, such as polycaprolactone (PCL) [21], polyvinylidene fluoride (PVDF) [22], poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) [23], poly(methyl methacrylate) (PMMA) [24], etc. By connecting different types of materials, hybrid materials can be developed, particularly as a mixture of synthetic and natural polymers.…”