Physical and morphological characterisation of poly(L-lactide) acid-based electrospun fibrous structures: tunning solution properties

Abstract

Poly(l-lactide) nano/micro fibres were produced using the electrospinning technique. The influence of solvent type and solution concentration on the morphology and structure of electrospun fibres were investigated. For this purpose, the electrospinning was performed using 2, 2, 2-trifluoroethanol (TFE) or dichloromethane (DCM) solvents at solution concentrations in a range of 5-9 wt-%. Morphological studies showed that versus DCMbased fibres with beaded structures and porous surface, when using TFE as a solvent, the uniform bead-free fibres with a smooth surface morphology were produced. Compared to DCM, the fibre diameter decreased using TFE as a solvent with lower vapour pressure while the crystallinity of the fibres increased. By increasing the solution concentration up to 9 wt-%, uniform fibres were produced with growing average diameters. Following these results, we conclude that varying the solution concentration and solvent type can modulate the final properties of electrospun fibres.

Bio-Based Electrospun Fibers for Wound Healing

“…Depending on the characteristics of the PLA solutions, the process parameters and ambient conditions, the diameter and morphology of the PLA fibers produced by electrospinning will differ. As an example, in research works performed by Maleki et al the influence of the solvent system on the electrospinning of PLLA fibers is investigated [57,66]. The results demonstrated that the dielectric constant and vapor pressure of the solvent are important parameters, which significantly affect the fiber morphology, diameter, and crystallinity and hence influence the mechanical properties of the fibrous structures.…”

“…Solvents with a low vapor pressure like 2,2,2-trifluoroethanol (TFE) provided enough time for crystals to grow during fiber formation resulting in a high crystallinity. Solutions obtained from chloroform with lower conductivity caused less stretching of the charged jet in the electrostatic field and resulted in larger diameters of fibers [57,66]. In another study by Maleki et al, in order to investigate the effect of solvent type on the mechanical properties of electrospun PLLA structures, a double nozzle electrospinning set-up was used to fabricate continuous twisted yarns from PLLA fibers.…”

“…The PLA-based solution properties like concentration and viscosity are the other factors that affect the ultimate characteristics of the electrospun PLA fibers and have been considered by several researchers. It was shown that, by increasing the solution concentration, uniform fibers were produced with growing average diameters [57,65].…”

“…The porous morphology of the electrospun fibers with small pore size can enhance hemostasis, and effectively protect the wound from bacterial permeation [ 56 ]. Those with tiny pores and increased surface to volume ratio can also influence the release behavior of the loaded biomolecules in the fibrous structures [ 57 , 58 , 59 ]. Although beadless fibers are usually preferred to improve the uniformity of the electrospun nanofibers, bead-on-string nanofibers ( Figure 2 d), with suitable control of the bead diameter, shape, and surface morphology, have provided efficient encapsulation of biomolecules and controlled release suitable for tissue engineering and wound dressing applications.…”

Application of electrospinning technique in development of intelligent food packaging: A short review of recent trends

“…The properties of nanofibers are significantly affected by various processing parameters, such as the instrumental conditions (applied voltage, flow rate, and distance to the collector), polymer solution properties (viscosity, surface tension, conductivity, and solvent polarity), and the ambient conditions (temperature and humidity) (Maleki, Semnani Rahbar, Saadatmand, & Barani, 2018; Rostami et al., 2019).…”