Electrospinning Conditions Research Articles

Dynamic behavior of melt electrospinning of blended polypropylene

Melt electrospinning is a promising process for fiber production without the need for solvents and with potential applications in various fields. In this study, we investigated the dynamic behavior of melt electrospinning under different blending ratios and process conditions. We used high melt flow index polypropylene and low molecular weight polypropylene, which were blended to lower the melt viscosity, and fibers were successfully manufactured through the melt electrospinning process. The effects of blending ratio and applied voltage on jet and drop formation, as well as fiber morphology, were examined. The results showed that blending low-molecular-weight polypropylene significantly influenced the jet and drop areas, leading to fluctuations in jet morphology. The size of the applied high voltage also had a high effect on the fiber diameter. Additionally, the viscosity reduction achieved through blending allowed for continuous jet formation and improved fiber production. These results provide valuable insights into controlling the process parameters and blending ratios in melt electrospinning, enabling the establishment of stable electrospinning conditions and precise control of fiber diameter.

Optimisation of Electrospinning Parameters for High-Strength Oriented Pan Nanofibre Mats

Abstract This study explores the optimisation of electrospinning parameters to enhance the strength and orientation of polyacrylonitrile (PAN) nanofibre mats, which are pivotal in filtration applications and other areas requiring high-strength, uniformly distributed nanofibres. The focus is on the electrospinning process, particularly on a rotating drum collector, which is instrumental in determining the morphology of nanofibres. Key process variables, including the distance between the collector and the syringe, feed rate, applied voltage, and polymer concentration, have been meticulously examined to understand their influence on the physical properties of PAN nanofibres. Our findings indicate that parameters such as voltage, collector-to-syringe distance, and drum rotation speed (RPM) significantly impact the mechanical performance of the nanofibre mats. The optimised electrospinning conditions produced PAN nanofibre mats with tensile strengths ranging from 1.61 MPa to 21.78 MPa, demonstrating a notable improvement in strength due to controlled fluid dynamics and expulsion of polymer solution during the process.

Tuning Electrospinning Conditions to Tailor the Diameter and Morphology of Polycaprolactone Nanofibers

Tuning Electrospinning Conditions to Tailor the Diameter and Morphology of Polycaprolactone Nanofibers

The Characterization of Electrospun PANI/PEO Nanofibers at Different Electrospinning Conditions at Room Temperature

The Characterization of Electrospun PANI/PEO Nanofibers at Different Electrospinning Conditions at Room Temperature

Scanning electron microscopy-based quantification of keratin and hyaluronic acid microstructure in electrospun scaffolds

BackgroundThe extracellular matrix (ECM) structural deficiencies in chronic wounds prevent the wounds from healing through natural physiological processes. Electrospun biocompatible polymers offer a platform to produce microstructure wound dressing materials that mimic the ECM containing various bioactives to address the deficiencies in the chronic wound healing process. Quantitative characterization of the electrospun fiber microstructure could provide valuable information on using fiber constructs to facilitate wound healing. This work employed a validated image analysis tool to quantitatively explain various parameters for the microstructure of six electrospun fiber constructs, D1{Polycaprolactone (PCL), Polyvinyl alcohol (PVA), Keratin}, D2{PCL, PVA, keratin, Co-enzyme Q10 (CoQ10)}, D3 (PCL, PVA, keratin, mupirocin), D4 (PCL, PVA, keratin, CoQ10, mupirocin, valsartan), D5 {PVA, Hyaluronic acid (HA)}, and D6 (PVA), using scanning electron microscopy imaging modality.ResultsThe fiber intersection density (FID) parameter was quantified in the formulations, e.g., 0.272% for D5 and 0.416% for D4. Orientation histograms for D1 and D6 are characteristic of isotropic materials, while orientations for D2 and D3 indicate anisotropy with 2 preferred orientations in each formulation. D4 and D5 present orientations characteristic of transversely isotropic materials. The tortuosity for D2 and D4 indicates almost straight fiber segments, in contrast with undulated fiber segments in all other formulations. Furthermore, the mean fiber diameter was quantified, e.g., 1.414 and 1.630 mm for D3 and D4, respectively.ConclusionCo-electrospun PVA/PCL microfibers offer great potential for controlled delivery of bioactives needed to accelerate the healing of chronic wounds. This image-based analysis technology quantitatively characterized different formulations of electrospun fiber scaffolds. This analysis sets the stage for future study that utilizes microstructural information in finite element biomechanical modeling, to investigate possible influence of structure-based mechanical factors on the ECM restorative potential of wound dressings. Adjustment of electrospinning conditions could produce fabricated constructs like the native ECM structural components with a functional role in wound healing.

One-Step Fabrication of Semi-Transparent Nanofibrous Lithium-Ion Battery

Flexibility and transparency of batteries greatly expand their application and offer new opportunities to electronic devices making them foldable, bendable, and not obstracting. Herein was proposed a facile and beneficial strategy to solve “hot” issues of such type of batteries by providing a uniform and stable framework for bendable, portable and semi-transparent "all-in-one" lithium-ion batteries (LIBs). The “all-in-one” flexible LIB was fabricated by one-stage electrospinning of PEO and PVDF-HFP-based precursor solution loaded with active materials. The electrochemical performance of the anode and cathode membranes was investigated in lithium half cells. To improve the electron-conductivity, CNTs were introduced inside the nanofibers in anode and cathode parts. The nanofibers containing active materials were successfully fabricated with the use of pre-synthesized nanosized LFP/C and graphite powders and loading them into the electrospinning solutions of the cathode and anode, respectively. The use of the same polymer to produce all three parts of the battery (anode, separator and cathode), as well as optimized electrospinning conditions, made it possible to obtain all-in-one flexible solo membrane. The concept was based on the application of nanofibers containing pre-synthesized active materials without carbonization, sintering or any other post-treatment. The developed “all-in-one” membrane assembled within copper and nickel meshes acting as anodic and cathodic current collectors demonstrated semi-transparency as can be seen from the figure. It is enabled by the swollen polymer fibers network, which provides transparent substrate for nano-sized particles of active materials. Additionally, the thin metallic mesh used as current collectors could maintain the overall transparency of the cell. Alternatively ITO glass and/or membrane with high content of CNT were used as a current collectors to provideimproved transparency and flexibility. Acknowledgment This research is funded by the Committee of Science of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. BR21882402) Figure 1

Fabrication of Magnetic Poly(L-lactide) (PLLA)/Fe3O4 Composite Electrospun Fibers.

Electrospinning technology is widely used for preparing biological tissue engineering scaffolds because of its advantages of simple preparation, accurate process parameters, and easy control. Poly(L-lactide) (PLLA) is regarded as a promising biomass-based polymer for use in electrospinning. The incorporation of Fe3O4 nanoparticles (NPs) could improve the osteogenic differentiation and proliferation of cells in the presence or absence of a static magnetic field (SMF). In this work, these two materials were blended together to obtain electrospun samples with better dispersibility and improved magnetic properties. First, composite PLLA and Fe3O4 NP fibers were prepared by means of electrospinning. The influence of electrospinning conditions on the morphology of the composite fibers was then discussed. Changes in magnetic properties and thermal stability resulting from the use of different PLLA/Fe3O4 mass ratios were also considered. Next, the morphology, crystal state, thermodynamic properties, and magnetic properties of the electrospun samples were determined using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and vibration sample magnetization (VSM). The results showed that the fibers prepared using PLLA with Mn = 170,000 exhibited good morphology when electrospun at 12 KV. The magnetic properties of PLLA/Fe3O4 composite electrospun fibers increased with the NP content, with the exception of thermal stability. The results of the present study may help to promote the further development of PLLA/Fe3O4 composite materials in the biomedical field.

Preparation and Property Analysis of Antibacterial Fiber Membranes Based on Hyperbranched Polymer Quaternary Ammonium Salts.

Due to their excellent properties, antimicrobial fiber membranes are widely applied in bioprotective materials. This work addresses the preparation of thermoplastic polyurethane (TPU)-based fiber membranes with active antimicrobial properties. 2-hydroxypropyl trimethyl ammonium chloride-terminated hyperbranched polymer (HBP-HTC) was synthesized and used as an antimicrobial agent. The fiber membranes were obtained by electrospinning a mixed solution of HBP-HTC and TPU. Different electrospinning conditions were investigated, such as the spinning voltage and drum rotation speed. The fiber membrane prepared under a 22 kV anode voltage and 100 rpm rotation speed had an average fiber diameter of 1.66 μm with a concentrated diameter distribution. Antibacterial tests showed that when the fiber membrane was loaded with 1500 mg/kg of HBP-HTC, the antibacterial rates of E. coli as well as S. aureus both reached 99.99%, exhibiting excellent proactive antimicrobial performance. Moreover, the protective performance of the fiber membrane was outstanding, with a filtration efficiency of 99.9%, a hydrostatic pressure resistance greater than 16,758 Pa, and a moisture permeability of 2711.0 g⋅(m2⋅d)-1.

Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) Self-Reinforced Composites via Solvent-Induced Interfiber Welding of Nanofibers.

In this study, we explore an approach to enhance the mechanical performance of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by utilizing the self-reinforcing effect of β-phase-induced PHBV electrospun nanofiber mats. This involves electrospinning combined with low-temperature postspun vapor solvent interfiber welding. Scanning electron microscopy imaging confirmed fiber alignment, while XRD diffraction revealed the presence of both α and β crystalline phases under optimized electrospinning conditions. The resulting composite exhibited significant improvements in mechanical properties attributed to the formation of more perfectly structured α and β polymorphs and enhanced interfacial adhesion of electrospun nanofibers after vapor solvent treatment. This approach offers entirely recyclable and biodegradable materials, presenting the potential for a new family of sustainable bioplastics.

Improved release of sulfamethoxazole from electrospun water soluble fibers

Electrospun fibers containing an active component, sulfamethoxazole, were successfully prepared from three water-soluble polymers, poly(vinyl pyrrolidone) (PVP), poly(vinyl alcohol) (PVA) and hydroxypropyl methylcellulose (HPMC). The conditions of electrospinning had to be optimized individually for the three systems. The presence of the drug did not influence fiber characteristics significantly, the diameter of the fibers increased only slightly upon the addition of the drug. Detailed investigations proved that the drug is located within the fibers in the amorphous form facilitating release. The strong pH sensitivity of the dissolution of the drug decreased considerably by encapsulation into the fibers. Drug release from the fibers is much faster than the dissolution of the neat drug and the relative amount of dissolved drug is also considerably larger (95 % vs. 30 %) from fibers encapsulating it. PVP seems to be the best selection for the preparation of electrospun fibers containing sulfamethoxazole, encapsulation is the largest (90.1 %) and drug release is the fastest from it among the three polymers. The preparation of formulations from sulfamethoxazole by electrospinning is clearly beneficial and must increase the bioavailability of this BCS IV drug.

A facile electrospinning strategy to prepare cost-effective carbon fibers as a self-supporting anode for lithium-ion batteries

Carbon materials with fibrous morphology and enhanced mechanical properties have shown to be promising materials as self-supporting anode materials for lithium-ion batteries (LIBs). In this study, coal-based carbon fibers (CFs) with favorable flexibility and superior tensile strength were prepared from lignite and coal derivatives such as coal-based humic acid and coal tar pitch via electrospinning in the assistance of polyacrylonitrile. All these coal-based CFs have an 1D dense fibrous microstructure with controllable diameter and appreciable specific surface area with enriched in O/N-containing groups by rationally choosing the precursor type. The organic macromolecules enriched aromatic ring in lignite and coal derivatives cross-link with linear polyacrylonitrile molecular chains to form a more solid three-dimensional (3D) network framework under the conditions of electrospinning and carbonization. Such 3D microstructure not only can significantly improve the flexibility and tensile strength of coal-based CFs, but also can increase the content of graphite-like microcrystalline carbon (sp2 carbon) in carbon fibers, thereby improving the electrical conductivity. Due to the smaller molecular structure, coal tar pitch can be more easily combined with polyacrylonitrile by electrostatic force. The CFs derived from coal tar pitch (CTP-CFs) exhibited the largest average diameter (156.2 nm), a higher microporous surface area (2.6 m2·g−1), higher pyrrole nitrogen and contained reasonable proportions of amorphous carbon (sp3 carbon) and sp2 carbon. As a consequence, among the various derived coal-based CFs applied as self-supporting anode materials for LIBs, CTP-CFs showed the highest first reversible capacity (770.8 mAh·g−1 at 20 mA·g−1) and excellent cycling performance with capacity retention rate of 89.1 % after 200 cycles. This work paves a new strategy to prepare CFs as flexible self-supporting anodes for LIBs from low-cost carbon precursors that can be rationally chosen to further tune the property of the CFs.

Rice Bran Valorization through the Fabrication of Nanofibrous Membranes by Electrospinning

The high production rate of fossil-based plastics, coupled with their accumulation and low degradability, is causing severe environmental problems. As a result, there is a growing interest in the use of renewable and natural sources in the polymer industry. Specifically, rice bran is a highly abundant by-product of the agro-food industry, with variable amounts of protein and starch within its composition, which are usually employed for bioplastic development. This study aims to valorize rice bran through the production of nanofiber membranes processed via electrospinning. Due to its low solubility, the co-electrospinning processing of rice bran with potato starch, known for its ability to form nanofibers through this technique, was chosen. Several fiber membranes were fabricated with modifications in solution conditions and electrospinning parameters to analyze their effects on the synthesized fiber morphology. This analysis involved obtaining micrographs of the fibers through scanning electron microscopy (SEM) and fiber diameter analysis. Potato starch membranes were initially investigated, and once optimal electrospinning conditions were identified, the co-electrospinning of rice bran and potato starch was conducted. Attempts were made to correlate the physical properties of the solutions, such as conductivity and density, with the characteristics of the resulting electrospun fibers. The results presented in this study demonstrate the potential valorization of a rice by-product for the development of bio-based nanofibrous membranes. This not only offers a solution to combat current plastic waste accumulation but also opens up a wide range of applications from filtration to biomedical devices (i.e., in tissue engineering).

Hyperbranched polymeric membranes for industrial water purification

This work aims at the preparation and characterization of dual-layer (DL) nano-fibrous mat (NFM) of hydrophobic and mechanical stable polyacrylonitrile (PAN) nano-fibers (NFs), as a supporter, and polyamide 6 (PA)/chitosan (Ch) NFs as a top hydrophilic coating layer.PAN and PA fibers, as residual wastes from textile processes, were collected and dissolved in their proper solvents. PAN was electro-spuned under certain conditions of electro-spinning (voltage, flow rate, and distance between spinneret and collector) to obtain PAN-NFM. Different ratios of PA/Ch composite were prepared and then electro-spun above the PAN-NFM that was previously prepared to obtain hydrophobic/hydrophilic functional dual-layer nano-fibrous membrane (DLNFM). The efficiency of the prepared DLNFM for capturing dye residues and heavy metals from wastewater was investigated.The viscosities of the prepared composite solutions were measured. The prepared dual-layer nano-fiber membranes (DLNFMs) were chemically and physically characterized by Fourier transform infrared spectroscopy, scanning electron microscope, X-ray diffraction, and thermogravimetric analyzer. The potential of the prepared mats for the adsorption of some heavy metal ions, i.e., Cu+2, Cr+3, and Pb+2 cations in addition to dyes from wastewater was evaluated. The effect of using different concentrations of PA/Ch composite as well as the thickness of the obtained DLNFM on the filtration efficiency was studied.The results of this study show the success of functional DLNFM in dye and heavy metal removal. The maximum removal efficiency of acid dyes was reached to 73.4 % and of reactive dye was approximately 61 % for PAN/PA-1.25%Ch DLNFM after 3 days at room temperature. The removal efficiency percent of heavy metal ions reached to 54 % by DLNFM. Additionally, the results showed that 0.08 mm is the ideal thickness for maximum absorption capacity. This value is correlated with the membrane's highest Ch percentage, which is (PAN/PA-1.25%Ch). Furthermore, the results demonstrate that the presence of the Ch polymer strengthened the produced bi-layered membrane to achieve the highest thermal stability when compared to the other nano-fibrous membranes (NFMs), with the breakdown temperature of the Ch functionalized dual-layer membranes (DLMs) reaching approximately 617 °C and a maximum weight loss of 60 %.

Electrospun Membranes Based on Quaternized Polysulfones: Rheological Properties-Electrospinning Mechanisms Relationship.

Composite membranes based on a polymer mixture solution of quaternized polysulfone (PSFQ), cellulose acetate phthalate (CAP), and polyvinylidene fluoride (PVDF) for biomedical applications were successfully obtained through the electrospinning technique. To ensure the polysulfone membranes' functionality in targeted applications, the selection of electrospinning conditions was essential. Moreover, understanding the geometric characteristics and morphology of fibrous membranes is crucial in designing them to meet the performance standards necessary for future biomedical applications. Thus, the viscosity of the solutions used in the electrospinning process was determined, and the morphology of the electrospun membranes was examined using scanning electron microscopy (SEM). Investigations on the surfaces of electrospun membranes based on water vapor sorption data have demonstrated that their surface properties dictate their biological ability more than their specific surfaces. Furthermore, in order to understand the different macromolecular rearrangements of membrane structures caused by physical interactions between the polymeric chains as well as by the orientation of functional groups during the electrospinning process, Fourier transform infrared (FTIR) spectroscopy was used. The applicability of composite membranes in the biomedical field was established by bacterial adhesion testing on the surface of electrospun membranes using Escherichia coli and Staphylococcus aureus microorganisms. The biological experiments conducted establish a foundation for future applications of these membranes and validate their effectiveness in specific fields.

The Impacts of the Sterilization Method and the Electrospinning Conditions of Nanofibrous Biodegradable Layers on Their Degradation and Hemocompatibility Behavior.

The use of electrospun polymeric biodegradable materials for medical applications is becoming increasingly widespread. One of the most important parameters regarding the functionality of nanofiber scaffolds during implantation and the subsequent regeneration of damaged tissues concerns their stability and degradation behavior, both of which are influenced by a wide range of factors (the properties of the polymer and the polymer solution, the technological processing approach, the sterilization method, etc.). This study monitored the degradation of nanofibrous materials fabricated from degradable polyesters as a result of the sterilization method applied (ethylene oxide and gamma irradiation) and the solvent system used to prepare the spun polymer solution. Aliphatic polyesters PCL and PLCL were chosen for this study and selected with respect to the applicability and handling in the surgical setting of these nanofibrous materials for vascular bandaging. The results revealed that the choice of solvent system exerts a significant impact on degradation during sterilization, especially at higher gamma irradiation values. The subsequent enzyme-catalyzed degradation of the materials following sterilization indicated that the choice of the sterilization method influenced the degradation behavior of the materials. Whereas wave-like degradation was evident concerning ethylene oxide sterilization, no such behavior was observed following gamma-irradiation sterilization. With concern for some of the tested materials, the results also indicated the potential for influencing the development of degradation within the bulk versus degradation from the surface of the material. Both the sterilization method and the choice of the spinning solvent system were found to impact degradation, which was observed to be most accelerated in the case of PLCL (L-lactide-co-caprolactone copolymer) electrospun from organic acids and subsequently sterilized using gamma irradiation. Since we planned to use these materials in cardiovascular applications, it was decided that their hemocompatibility would also be tested. The results of these tests revealed that changes in the structures of the materials initiated by sterilization may exert thrombogenic and anticoagulant impacts. Moreover, the microscopic analysis suggested that the solvent system used in the preparation of the materials potentially affects the behavior of erythrocytes; however, no indication of the occurrence of hemolysis was detected.

Quality-by-Design Optimization of Electrospinning Parameters to Formulate Scaffolds for Topical Inflammatory Disease Management <i>via</i> Drug Repurposing

This study investigates the fabrication of chitosan (CS)/polyvinyl alcohol (PVA) blend nanofibers via electrospinning, aiming to create nanofibers with enhanced properties for broad applications. The research focuses on optimizing electrospinning parameters to reduce bead formation and achieve uniform nanofiber morphology. A detailed experimental design, employing a nineteen-point plan developed with Design-Expert software, examined variables such as polymer concentration, distance from the needle to the collector, the required voltage, and the rate at which solution was ejected from the needle. Morphological characteristics of the nanofibers were analyzed using advanced microscopy, complemented by drug release and wound healing assessments. The optimal electrospinning conditions were determined to be a 1:3 CS/PVA solution concentration ratio, an 8 cm needle-to-collector distance, a 20 kV applied voltage, and a 1 mL/hour flow rate. Scanning electron microscopy revealed uniform nanofibers with diameters between 100 to 250 nm, devoid of bead defects. In-vitro analysis demonstrated a sustained release profile of azilsartan (AZL), while in-vivo studies on rats indicated enhanced wound healing, corroborated by histological examination. The findings suggest that CS/PVA nanofibers, fabricated under these conditions, possess promising characteristics for use as a drug-delivery scaffold in wound treatment applications.

Life Cycle of Functional All-Green Biocompatible Fibrous Materials Based on Biodegradable Polyhydroxybutyrate and Hemin: Synthesis, Service Life, and the End-of-Life via Biodegradation.

This article addresses the entire life cycle of the all-green fibrous materials based on poly(3-hydroxybutyrate) (PHB) containing a natural biocompatible additive Hemin (Hmi): from preparation, service life, and the end of life upon in-soil biodegradation. Fibrous PHB/Hmi materials with a highly developed surface and interconnected porosity were prepared by electrospinning (ES) from Hmi-containing feed solutions. Structural organization of the PHB/Hmi materials (porosity, uniform structure, diameter of fibers, surface area, distribution of Hmi within the PHB matrix, phase composition, etc.) is shown to be governed by the ES conditions: the presence of even minor amounts of Hmi in the PHB/Hmi (below 5 wt %) serves as a powerful tool for the control over their structure, performance, and biodegradation. Service characteristics of the PHB/Hmi materials (wettability, prolonged release of Hmi, antibacterial activity, breathability, and mechanical properties) were studied by different physicochemical methods (scanning electron microscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, differential scanning calorimetry, contact angle measurements, antibacterial tests, etc.). The effect of the structural organization of the PHB/Hmi materials on their in-soil biodegradation at the end of life was analyzed, and key factors providing efficient biodegradation of the PHB/Hmi materials at all stages (from adaptation to mineralization) are highlighted (high surface area and porosity, thin fibers, release of Hmi, etc.). The proposed approach allows for target-oriented preparation and structural design of the functional PHB/Hmi nonwovens when their structural supramolecular organization with a highly developed surface area controls both their service properties as efficient antibacterial materials and in-soil biodegradation upon the end of life.

Fabrication and Optimization of Electrospun Shellac Fibers Loaded with Senna alata Leaf Extract.

Single-fluid electrospinning creates nanofibers from molten polymer solutions with active ingredients. This study utilized a combination of a fractional factorial design and a Box-Behnken design to examine crucial factors among a multitude of parameters and to optimize the electrospinning conditions that impact fiber mats' morphology and the entrapment efficiency of Senna alata leaf extract. The findings indicated that the shellac content had the greatest impact on both fiber diameter and bead formation. The optimum electrospinning conditions were identified as a voltage of 24 kV, a solution feed rate of 0.8 mL/h, and a shellac-extract ratio of 38.5:3.8. These conditions produced nanosized fibers with a diameter of 306 nm, a low bead-to-fiber ratio of 0.29, and an extract entrapment efficiency of 96% within the fibers. The biphasic profile of the optimized nanofibers was confirmed with an in vitro release study. This profile consisted of an initial burst release of 88% within the first hour, which was succeeded by a sustained release pattern surpassing 90% for the next 12 h, as predicted with zero-order release kinetics. The optimized nanofibers demonstrated antimicrobial efficacy against diverse pathogens, suggesting promising applications in wound dressings and protective textiles.

The impact of electrospinning conditions on the properties of enzymes immobilized on electrospun materials: Exploring applications and future perspectives

The electrospinning technique allows the production of materials from a wide range of polymers and biopolymers with designed and specified properties which positively affect the stability of the enzyme-support interactions and the activity of immobilized enzymes. This review focuses on electrospun materials, their fabrication, features and application in enzyme immobilization processes, and on electrospun-based heterogeneous biocatalysts in various fields such as environmental protection, biosensing, the food industry, medicine and pharmacy. Though numerous review articles have recently been published on enzyme immobilization, there is a lack of comprehensive studies addressing the effect of the functional and morphological characteristics of electrospun materials on the properties and practical application of the immobilized enzymes. The primary challenge in the production of electrospun fibers lies in optimizing the electrospinning parameters, including component concentration, voltage, needle tip-to-collector distance, flow rate, temperature, and humidity. Mismatched conditions or precursors can lead to failures in fiber formation and the emergence of beads within the fibers. It can compromise the mechanical stability of the materials produced and potentially impact the properties of enzyme immobilization and its potential applications. Our overview will therefore be valuable for the selection and production of electrospun materials with special applications in enzyme immobilization for various groups of enzymes. We also summarize and highlight current research gaps and possible future applications of electrospun fibers with immobilized enzymes.

Highly hydrophobic cellulose acetate mats modified with poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) triblock copolymer and TiO2 nanoparticles by electrospinning

Cellulose acetate (CA) mats modified with poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) (PEO-b-PPO-b-PEO or EPE) and sol–gel synthesised titanium oxide (TiO2) nanoparticles were successfully fabricated by using electrospinning technique. Under the same preparation conditions, higher spinnability was achieved for EPE triblock copolymers modified mats. All fabricated mats showed a micrometric multilayer structure, which enabled layer-by-layer peeling. The addition of TiO2 nanoparticles facilitated the peeling process. The diameter of the fibres was ~ 3 times lower after the incorporation of sol–gel synthesised TiO2 nanoparticles. TEM images confirmed that under electrospinning conditions the PPO block domains were able to microphase separated from the PEO block/CA phase. Additionally, the introduction of sol–gel synthesised TiO2 nanoparticles led to an inorganic network formation with nanoparticle size equal to ~ 8 nm in diameter. Moreover, the addition of TiO2 nanoparticles increased the hydrophobicity of the mats and their self-cleaning ability, being more effective for TiO2/CA than for TiO2-EPE/CA due to the partial absorption of water by EPE triblock copolymer. Young’s modulus of fabricated mats improved drastically with the addition of TiO2 nanoparticles, as well as their physical integrity in polar and nonpolar solvents. Fabricated mats with enhanced spinnability, which maintain CA mat features as well as the properties associated with sol–gel synthesised TiO2 nanoparticles, can find a wide range of applications.