Coaxial Electrospinning Technique Research Articles

Washable and stable coaxial electrospinning fabric with superior electromagnetic interference shielding performance for multifunctional electronics

There is an urgent need for multifunctional and wearable smart devices to address the growing environmental impact on the human body, especially for pregnant women. However, it is big challenge to explore fabric combined multi-functions, such as EMI shielding, electrical therapy and biomotion detection while maintaining their intrinsic durability and washability. Here, we have employed an efficient coaxial electrospinning technique, followed by Ag precursor reduction and polydimethylsiloxane spraying to fabricate a multifunctional film which contains core–shell fibers with polyurethane/carbon nanotube (CNT) as core and polyurethane/Fe3O4 as shell. The CNT and the Ag nanoparticles (AgNPs) form double conductive network for EMI shielding, electrical heating and biological motion detection. The Fe3O4 provides magnetic loss and helps the fibers to provide rich attachment sites for AgNPs. The obtained film has an excellent combination of high EMI SE (110.0 dB in X-band), large Joule heating (up to 230 °C at 3 V), good sensing performance and large sensing range of 230 % strain. In addition, it showed an extremely superior durability and stability in complex conditions, good breathability and wash stability, ensuring the comfort wearing. This study offers an outstanding paradigm to construct next generation intelligent fabric combined versatility, stability and wearing comfort for protection of pregnant women and military solider.

Coaxial electrospun PVA-SAP functional nanofibers embedded with betel leaf extract for enhanced germicidal activity and breathability

This study investigates the formation of coaxial electrospun nanofibrous membrane with enhanced germicidal activity and breathability using superabsorbent polymer and polyvinyl alcohol integrated with betel leaf extract and its utilization for developing performance textiles. The functional nanofibrous membrane was fabricated through the coaxial electrospinning technique and characterized for the intended applications. The morphological investigation of the developed nano-membrane using scanning electron microscopy revealed the formation of regular nanofibers with diameters ranging from 154 to 200 nm. The FTIR spectra suggested the existence of functional compounds in the nanofibers from their characteristic peaks. The presence of the bioactive compounds in the ethanolic extract of betel leaf was explored using phytochemical screening. The analysis of antibacterial activity against S. aureus and E.coli using the agar disc diffusion method showed an enhanced zone of inhibition with a maximum dimension of 27 mm and 24 mm against S. aureus and E.coli, respectively. The developed coaxial nanofibrous membranes also demonstrated acceptable particle barrier performance with greater than 95 % efficiency and a superior tensile strength of 99.5 N. Besides, the improved moisture management and air permeability of coaxial nano-membranes embedded with betel leaf extracts suggested an easy transfer of fluid and moisture vapor from the body to the environment via the membrane. Hence, the improved germicidal activity with acceptable particle filtration efficiency and enhanced breathability of the developed coaxial electrospun nano-membranes indicated their potentiality of utilizing them in designing performance textiles with simultaneous barrier performance and breathability for comfort.

Synthesis and Characterization of Hybridfiber from Gelatin Modified by PVACOS Using Coaxial Electrospinning Techniques as an Advanced Medical Textile Material

The synthesis of hybrid fiber based on bovine bone gelatin combined with polyvinyl alcohol-chitosan-oxidized sucrose (PVACOS) has been successfully carried out using the coaxial electrospinning technique. The presence of oxidized sucrose can improve the diameter and the tensile strength of hybrid fibers due to the formation of new covalent bonds. The combination of gelatin with PVACOS material aims to increase the strength of the hybrid fiber so that it has better tensile strength characteristics and improves the diameter of the resulting hybrid fiber. The characterization of the resulting material was tested using FTIR, SEM, EDX, XRD, and TGA. Based on FTIR analysis, there is an increase in absorption intensity in the 2900 cm-1 – 3000 cm-1 band, which indicates the occurrence of covalent bond interactions so that it can increase the bond strength between materials with the performance of crystalline materials. Apart from that, the morphological structure of the hybrid fibers was also investigated using scanning electron microscopy (SEM), and the resulting fiber diameter for Ge-Ch, Ge-Ch-PVA, Ge-PVACOS 3%, and Ge-PVACOS 5%, respectively, was 0.4049 µm. 0.3735 µm, 0.3388 µm, and 0.3206 µm. The tensile strengths of hybrid fiber for Ge-PVACOS 3% and Ge-PVACOS 5%, respectively, are 39.91935 N/m2 and 76.12507 N/m2. Statistical tests show that the concentration of oxidized sucrose has a significant influence on hybrid fiber performance. The significance values for diameter and tensile strength are 0.0486 and 0.0325, respectively. According to this performance, the Ge-PVACOS hybrid fiber is recommended as a material for advanced medical textiles. Doi: 10.28991/ESJ-2024-08-02-022 Full Text: PDF

Levofloxacin loaded poly (ethylene oxide)-chitosan/quercetin loaded poly (D,L-lactide-co-glycolide) core-shell electrospun nanofibers for burn wound healing.

This study developed a new burn wound dressing based on core-shell nanofibers that co-deliver antibiotic and antioxidant drugs. For this purpose, poly(ethylene oxide) (PEO)-chitosan (CS)/poly(D,L-lactide-co-glycolide) (PLGA) core-shell nanofibers were fabricated through co-axial electrospinning technique. Antibiotic levofloxacin (LEV) and antioxidant quercetin (QS) were incorporated into the core and shell parts of PEO-CS/PLGA nanofibers, respectively. The drugs could bond to the polymer chains through hydrogen bonding, leading to their steady release for 168h. An in vitro drug release study showed a burst effect followed by sustained release of LEV and QS from the nanofibers due to the Fickian diffusion. The NIH 3T3 fibroblast cell viability of the drug loaded core-shell nanofibers was comparable to that in the control (tissue culture polystyrene) implying biocompatibility of the nanofibers and their cell supportive role. However, there was no significant difference in cell viability between the drug loaded and drug free core-shell nanofibers. According to in vivo experiments, PEO-CS-LEV/PLGA-QS core-shell nanofibers could accelerate the healing process of a burn wound compared to a sterile gauze. Thanks to the synergistic therapeutic effect of LEV and QS, a significantly higher wound closure rate was recorded for the drug loaded core-shell nanofibrous dressing than the drug free nanofibers and control. Conclusively, PEO-CS-LEV/PLGA-QS core-shell nanofibers were shown to be a promising wound healing material that could drive the healing cascade through local co-delivery of LEV and QS to burn wounds.

Preparation and properties of nano B/NC/AP@F2602 double-layer energetic fiber

The nano-boron powder (n-B) exhibits remarkable efficacy as a combustion catalyst, making it a prime candidate for use in solid propellant metal burners. Nevertheless, throughout the storage phase, the surface of n-B powder is prone to oxidation and substantial agglomeration, resulting in challenges with ignition and incomplete energy dissipation when utilizing boron powder. In this study, we utilized the coaxial electrospinning technique to produce nanofibers comprised of nano-boron /nitrocellulose/ammonium perchlorate@fluororubber (n-B/NC/AP@F2602), with the nano boron uniformly distributed within the core-shell fibers. In the course of combustion, the fibrous composite of n-B/NC/AP@F2602 undergoes an escalation in the rates of energy output and energy release, owing to the constraints imposed by external F2602((C₂H₂F₂)n and (C₃F₆)n). The n-B/NC/AP@F2602 demonstrates a 1.4-fold increase in peak pressure and a 3.6-fold increase in maximum boost rate when compared to the n-B/NC/AP. The energy performance evaluation results reveal that the mean molecular weight (MC) of combusted products from n-B/NC/AP@F2602 is 29.2 g·mol−1, representing a substantial increase compared to that of n-B/NC/AP. The aforementioned findings exemplify that coaxial electrospinning is an exceedingly efficacious technique for enhancing nanostructures, thereby amplifying the reactivity of energetic particles and offering novel insights into their application in energetic materials.

Developments of Core/Shell Chitosan-Based Nanofibers by Electrospinning Techniques: A Review

This review is focused on the recent development of various chitosan-based nanofibers (membranes, patches, mats, and scaffolds) that have been designed into core and shell structures using emulsion and coaxial electrospinning techniques. Chitosan, a promising polysaccharide derived from natural sources, holds potential for diverse applications, including nanofiber production, aimed at fostering sustainability. Core/shell chitosan-based nanofibers offer appealing features, including drug encapsulation and sustained release capabilities, with a higher efficiency than uniaxial fibers. The fabrication of core/shell chitosan-based nanofibers, including the co-spinning agents and various spinning parameters, such as spinning voltage, needle size, spinning flow rate, distance from needle tip to collector, temperature, and humidity, is summarized in this work. The review also explores updated applications in various fields, such as textiles, medical dressings, drug release systems, filtration membranes, and food packaging. It highlights the current advancements in core/shell chitosan-based nanofibers produced via electrospinning techniques. The innovative insights presented in the recent literature and the challenges associated with these sustainable materials are thoroughly examined, offering valuable contributions to the field.

Electrospun L-Lysine/Amorphous Calcium Phosphate Loaded Core-Sheath Nanofibers for Managing Oral Biofilm Infections and Promoting Periodontal Tissue Repairment.

Periodontitis, a chronic inflammatory disease prevalent worldwide, is primarily treated through GTR for tissue regeneration. The efficacy of GTR, however, remains uncertain due to potential infections and the intricate microenvironment of periodontal tissue. Herein, We developed a novel core-shell structure multifunctional membrane using a dual-drug-loaded coaxial electrospinning technique (Lys/ACP-CNF), contains L-lysine in the outer layer to aid in controlling biofilms after GTR regenerative surgery, and ACP in the inner layer to enhance osteogenic performance for accelerating alveolar bone repair. The biocompatibility and cell adhesion were evaluated through CCK-8 and fluorescence imaging, respectively. The antibacterial activity was assessed using a plate counting assay. ALP, ARS, and RT-qPCR were used to examine osteogenic differentiation. Additionally, an in vivo experiment was conducted on a rat model with acute periodontal defect and infection. Micro-CT and histological analysis were utilized to analyze the in vivo alveolar bone regeneration. Structural and physicochemical characterization confirmed the successful construction of the core-shell fibrous structure. Additionally, the Lys/ACP-CNF showed strong antibacterial coaggregation effects and induced osteogenic differentiation of PDLSCs in vitro. The in vivo experiment confirmed that Lys/ACP-CNF promotes new bone formation. Lys/ACP-CNF rapidly exhibited excellent antibacterial activity, protected PDLSCs from infection, and was conducive to osteogenesis, demonstrating its potential application for clinical periodontal GTR surgery.

Enhanced hemocompatibility and rapid magnetic anastomosis of electrospun small-diameter artificial vascular grafts.

Background: Small-diameter (<6mm) artificial vascular grafts (AVGs) are urgently required in vessel reconstructive surgery but constrained by suboptimal hemocompatibility and the complexity of anastomotic procedures. This study introduces coaxial electrospinning and magnetic anastomosis techniques to improve graft performance. Methods: Bilayer poly(lactide-co-caprolactone) (PLCL) grafts were fabricated by coaxial electrospinning to encapsulate heparin in the inner layer for anticoagulation. Magnetic rings were embedded at both ends of the nanofiber conduit to construct a magnetic anastomosis small-diameter AVG. Material properties were characterized by micromorphology, fourier transform infrared (FTIR) spectra, mechanical tests, in vitro heparin release and hemocompatibility. In vivo performance was evaluated in a rabbit model of inferior vena cava replacement. Results: Coaxial electrospinning produced PLCL/heparin grafts with sustained heparin release, lower platelet adhesion, prolonged clotting times, higher Young's modulus and tensile strength versus PLCL grafts. Magnetic anastomosis was significantly faster than suturing (3.65 ± 0.83 vs. 20.32 ± 3.45min, p < 0.001) and with higher success rate (100% vs. 80%). Furthermore, magnetic AVG had higher short-term patency (2days: 100% vs. 60%; 7days: 40% vs. 0%) but similar long-term occlusion as sutured grafts. Conclusion: Coaxial electrospinning improved hemocompatibility and magnetic anastomosis enhanced implantability of small-diameter AVG. Short-term patency was excellent, but further optimization of anticoagulation is needed for long-term patency. This combinatorial approach holds promise for vascular graft engineering.

Microfluidic fabrication of core–shell fucoxanthin nanofibers with improved environmental stability for reducing lipid accumulation in vitro

Fucoxanthin is a xanthophyll carotenoid that possesses potent antioxidant, anti-obesity, and anti-tumor properties. However, its limited solubility in water and susceptibility to degradation create challenges for its application. In this study, a microfluidic coaxial electrospinning technique was used to produce core–shell zein-gelatin nanofibers for encapsulating fucoxanthin, enhancing its bioavailability, and improving its stability. In comparison to uniaxially-loaded fucoxanthin nanofibers, the encapsulation efficiency of fucoxanthin reached 98.58 % at a core–shell flow rate ratio of 0.26:1, representing a 14.29 % improvement. The photostability of the nanofibers increased by 74.59 % after three days, UV stability increased by 38.82 % after 2 h, and temperature stability also significantly improved, demonstrating a protective effect under harsh environmental conditions (P < 0.05). Additionally, nanofibers effectively alleviated oleic acid-induced reactive oxygen species production and reduced fluorescence intensity by 54.76 %. MTT experiments indicated great biocompatibility of the nanofibers, effectively mitigating mitochondrial membrane potential polarization and lipid accumulation in HepG2 cells. Overall, the microfluidic coaxial electrospinning technique enables promising applications of fucoxanthin delivery in the food industry.

Coaxial electrospun Ag-NPs-loaded endograft membrane with long-term antibacterial function treating mycotic aortic aneurysm

The use of endovascular stent-graft has become an important option in the treatment of aortic pathologies. However, the currently used endograft membranes have limited ability to prevent bacterial colonization. This makes them unsuitable for the treatment of mycotic aneurysms, as the infection is prone to progress after endograft implantation. Moreover, even in non-mycotic aortic pathologies, endograft infections can occur in the short or long term, especially for patients with diabetes mellitus or in immune insufficiency conditions. So, this study aimed to develop a kind of Ag-NPs-loaded endograft membrane by coaxial electrospinning technique, and a series of physical and chemical properties and biological properties of the Ag-NPs-loaded membrane were characterized. Animal experiments conducted in pigs confirmed that the Ag-NPs-loaded membrane was basically non-toxic, exhibited good biocompatibility, and effectively prevented bacterial growth in a mycotic aortic aneurysm model. In conclusion, the Ag-NPs-loaded membrane exhibited good biocompatibility, good anti-infection function and slow-release of Ag-NPs for long-term bacteriostasis. Thus, the Ag-NPs-loaded membrane might hold potential for preventing infection progression and treating mycotic aortic aneurysms in an endovascular way.

PH-responsive nanofiber membranes for superior controlled release of poorly water-soluble drug and its release mechanism study

Antibiotics delivery using dressings is an effective manner to treat chronic infected wounds, but it still faces the challenge of uncontrolled drug release. To address this issue, we developed pH-responsive electrospun nanofibers for controlled release of poorly water-soluble antibiotics. Specifically, the drug-loaded electrospun nanofibers were fabricated via coaxial electrospinning technique, with polycaprolactone (PCL) and drug acting as the core and pH-responsive acrylic copolymer Eudragit L100–55 serving as the sheath layer. Under alkaline conditions, all drugs release rapidly due to the dissolution of Eudragit L100–55, and first-order model well fits the release behavior. In contrast, the sheath layer swells under acidic conditions, causing poorly water-soluble drugs to be firmly trapped. Moreover, the drug-loaded nanofibers display completely different antibacterial activities due to distinct drug release behaviors under alkaline or acidic conditions. The current pH-responsive nanofibers shows superior controllability of poorly water-soluble drug release, revealing great prospects for treating chronic infected wounds.

Irisin-loaded electrospun core-shell nanofibers as calvarial periosteum accelerate vascularized bone regeneration by activating the mitochondrial SIRT3 pathway.

The scarcity of native periosteum poses a significant clinical barrier in the repair of critical-sized bone defects. The challenge of enhancing regenerative potential in bone healing is further compounded by oxidative stress at the fracture site. However, the introduction of artificial periosteum has demonstrated its ability to promote bone regeneration through the provision of appropriate mechanical support and controlled release of pro-osteogenic factors. In this study, a poly (l-lactic acid) (PLLA)/hyaluronic acid (HA)-based nanofibrous membrane was fabricated using the coaxial electrospinning technique. The incorporation of irisin into the core-shell structure of PLLA/HA nanofibers (PLLA/HA@Irisin) achieved its sustained release. In vitro experiments demonstrated that the PLLA/HA@Irisin membranes exhibited favorable biocompatibility. The osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs) was improved by PLLA/HA@Irisin, as evidenced by a significant increase in alkaline phosphatase activity and matrix mineralization. Mechanistically, PLLA/HA@Irisin significantly enhanced the mitochondrial function of BMMSCs via the activation of the sirtuin 3 antioxidant pathway. To assess the therapeutic effectiveness, PLLA/HA@Irisin membranes were implanted in situ into critical-sized calvarial defects in rats. The results at 4 and 8 weeks post-surgery indicated that the implantation of PLLA/HA@Irisin exhibited superior efficacy in promoting vascularized bone formation, as demonstrated by the enhancement of bone matrix synthesis and the development of new blood vessels. The results of our study indicate that the electrospun PLLA/HA@Irisin nanofibers possess characteristics of a biomimetic periosteum, showing potential for effectively treating critical-sized bone defects by improving the mitochondrial function and maintaining redox homeostasis of BMMSCs.

Nanofibrous membranes with hydrophobic and thermoregulatory functions fabricated by coaxial electrospinning

AbstractIn the face of changing outdoor environments, it is necessary for us to develop advanced textiles with thermal regulation and hydrophobic properties. In order to create a fabric with both temperature control and waterproof properties, the study adjusted the ratio of polystyrene (PS) and polyvinylidene fluoride (PVDF) to produce nanofiber membranes with excellent morphology and dirt resistant properties. Furthermore, the hydrophobicity of the nanofibers was further improved by adding SiO2 to the spinning solution. Based on this, a core solution of octadecane (Oct) was used to give it thermal regulation functionality through coaxial electrospinning technique. The resulting composite nanofiber membrane exhibited excellent hydrophobicity and thermal regulation performance. The measurement results obtained from Differential Scanning Calorimetry (DSC) indicate that the maximum Oct encapsulation rate of the PS/PVDF/SiO2@Oct nanofiber membrane is 58.36%. The latent heat of the composite nanofiber membrane is 148.84 J/g, and the water contact angle (WCA) is 135°. The multifunctional composite nanofiber has great potential for applications in outdoor protective clothing and outdoor electronic device protection.

Mupirocin loaded core-shell pluronic-pectin-keratin nanofibers improve human keratinocytes behavior, angiogenic activity and wound healing

In the current study, a core-shell nanofibrous wound dressing based on Pluronic-F127 (F127) containing 2 wt% mupirocin (Mup) core and pectin (Pec)-keratin (Kr) shell was fabricated through coaxial electrospinning technique, and the blended nanofibers were also fabricated from the same materials. The fiber diameter and specific surface area of the blended nanofibers were about 101.56 nm and 20.16 m2/g, while for core-shell nanofibers they were about 97.32 nm and 25.26 m2/g, respectively. The resultant blended and core-shell nanofibers experienced a degradation of 27.65 % and 32.28 % during 7 days, respectively. The drug release profile of core-shell nanofibers revealed a sustained release of Mup over 7 days (87.66 %), while the blended F127-Pec-Kr-Mup nanofibers had a burst release within the first few hours (89.38 % up to 48 h) and a cumulative release of 91.36 % after 7 days. Due to the controlled release of Mup, the core-shell structure significantly improved the human keratinocytes behavior, angiogenic potential and wound healing in a rat model compared to the blended structure. In conclusion, the F127-Mup/Pec-Kr core-shell nanofibrous wound dressing appears to be a promising candidate for the prevention of infection, and can potentially accelerate the recovery and healing of chronic and ischemic wounds.

Hybrid Resorbable 3D-Printed Mesh/Electrospun Nanofibrous Drug/Biomolecule-Eluting Mats for Alveolar Ridge Preservation.

In this research study, we developed hybrid resorbable three-dimensional (3D)-printed mesh/electrospun nanofibrous biomolecule-eluting mats for alveolar ridge preservation. The fabrication process involved the use of 3D printing and coaxial electrospinning technologies. Specifically, we utilized a lab-developed solution-extrusion 3D printer to fabricate polycaprolactone (PCL) meshes. Then, bi-layered poly(lactic-co-glycolic acid) (PLGA) nanofibrous membranes, which embedded ibuprofen and epidermal growth factor (EGF), were prepared utilizing electrospinning and coaxial electrospinning techniques, respectively. To ensure the quality of the produced mesh and spun nanofibers, we carried out a characterization process. Furthermore, we estimated the in vitro and in vivo release characteristics of ibuprofen and EGF, respectively, using high-performance liquid chromatography and enzyme-linked immunosorbent assays. In addition, we assessed the effectiveness of hybrid nanofibrous mats for preserving the alveolar ridge by adopting an animal model and conducting a histology examination. The study findings demonstrate that the nanofibrous mats provided a continuous discharge of ibuprofen and EGF for more than four weeks. Moreover, the animal test carried out in vivo showed that animals implanted with this combination of mesh and drug-eluting mats displayed considerably greater mobility than those without mats. The histological analysis revealed no unfavorable impacts from the drug-eluting mats. Our study demonstrated the successful fabrication of resorbable drug-eluting nanofibrous mats for alveolar ridge preservation by utilizing both 3D printing and coaxial electrospinning technologies.

Highly Efficient CeO2–CuCrO2 Composite Nanofibers Used for Electrochemical Detection of Dopamine in Biomedical Applications

Dopamine (DA) plays a crucial role in the functioning of the human central nervous system, participating in both physiological and psychological processes. It is an important research topic in biomedical science. However, we need to constantly monitor the concentration of dopamine in the body, and the sensors required for this usually require good sensitivity in order to achieve fast and accurate measurements. In this research project, a CeO2 and CuCrO2 composite nanofiber was prepared for the electrochemical detection of dopamine. Coaxial electrospinning techniques were used to prepare CeO2–CuCrO2 composite nanofibers. The characterization techniques of X-ray diffractometer (XRD), Raman, and X-ray photoelectron spectroscopy (XPS) were used to analyze the composite’s crystal structure, vibrational bonds, and elemental composition, while SEM and TEM were used to analyze the composite’s surface structure, morphology, and microstructure. The prepared nanofiber outer layer was found to have an average thickness of 70.96 nm, average fiber diameter of 192.49 nm, and an average grain size of about ~12.5 nm. The BET analysis was applied to obtain the specific surface area (25.03 m2/gm). The proposed nanofiber-decorated disposable screen-printed carbon electrode acted as a better electrochemical sensor for the detection of dopamine. Moreover, the electrocatalyst had a better limit of detection, 36 nM with a linear range of 10 to 100 μM, and its sensitivity was 6.731 μA μM−1 cm−2. In addition, the proposed electrocatalyst was successfully applied to real-time potential applications, namely, to the analysis of human urine samples in order to obtain better recovery results.

Novel smart coaxial electrospinning textiles for efficient thermal interface management and electromagnetic compatibility in electronics

Phase change materials (PCMs) have attracted considerable attention for their energy storage and thermoregulatory properties. However, the solid–liquid leakage, low thermal conductivity, and single functionality of PCMs hinder their applications to electronic equipment. In this study, polyvinyl alcohol (PVA) and polyethylene oxide/ferric oxide (PEO/Fe3O4)-based core–sheath textiles are prepared using an eco-friendly coaxial electrospinning technique and simple steam crosslinking. The composite phase change fibers (CPCFs) and magnetic composite phase change fibers (MCPCFs) produced in this way show ultrahigh encapsulation ratios of 78.02 wt% and 69.11 wt%, respectively, and high phase change enthalpies of 106.96 J g−1 and 94.75 J g−1, respectively. The addition of Fe3O4 (20 wt%) introduces a saturation magnetization of 9.5 emu g−1, thereby realizing 3 dB electromagnetic shielding performance. The textiles exhibit excellent flexibility and can be formed into complex shapes. Owing to their core–sheath structure, the CPCFs and MCPCFs exhibit outstanding structural and thermal stabilities during 100 thermal cycles. Furthermore, the mechanical properties of the CPCF and MCPCF textiles can be enhanced by crosslinking.

Advancing Nanofiber Research: Assessing Nonsolvent Contributions to Structure Using Coaxial Electrospinning.

In this study, we explored the influence of molecular interactions and solvent evaporation kinetics on the formation of porous structures in electrospun nanofibers, utilizing polyacrylonitrile (PAN) and polystyrene (PS) as model polymers. The coaxial electrospinning technique was employed to control the injection of water and ethylene glycol (EG) as nonsolvents into polymer jets, demonstrating its potential as a powerful tool for manipulating phase separation processes and fabricating nanofibers with tailored properties. Our findings highlighted the critical role of intermolecular interactions between nonsolvents and polymers in governing phase separation and porous structure formation. Additionally, we observed that the size and polarity of nonsolvent molecules affected the phase separation process. Furthermore, solvent evaporation kinetics were found to significantly impact phase separation, as evidenced by less distinct porous structures when using a rapidly evaporating solvent like tetrahydrofuran (THF) instead of dimethylformamide (DMF). This work offers valuable insights into the intricate relationship between molecular interactions and solvent evaporation kinetics during electrospinning, providing guidance for researchers developing porous nanofibers with specific characteristics for various applications, including filtration, drug delivery, and tissue engineering.

Multiferroic CoFe2O4–Ba0.95Ca0.05Ti0.89Sn0.11O3 Core–Shell Nanofibers for Magnetic Field Sensor Applications

Multiferroic materials with coexisting of at least two ferroic orders (ferromagnetic, ferroelectric, or ferroelastic) have recently attracted the interest of researchers due to their potential applications as multifunctional devices. Herein, we report the synthesis and detailed characterization of the multiferroic CoFe2O4–Ba0.95Ca0.05Ti0.89Sn0.11O3 core–shell nanofibers (CFO@BCTSn NFs) prepared by a sol–gel coaxial electrospinning technique. The scanning and transmission electron microscopes were used to check nanofibers’ core–shell structure/configuration, with fiber diameters ranging from 150 to 250 nm. The X-ray diffraction analysis confirms the presence of both the spinel structure of the CFO and the perovskite structure of the BCTSn. Piezoresponse force microscopy and magnetic hysteresis were used to confirm the multiferroicity of CFO@BCTSn NFs. Notably, the maximum magnetization and remanent magnetization of NFs are found to be 11.63 emu g–1 and 1.43 emu g–1, respectively. Meanwhile, the maximum piezoelectric response d33eff is around 6 pm V–1. The magnetoelectric (ME) coefficient obtained for the CFO@BCTSn NFs is 346 mV cm–1 Oe–1 at the field of 10 kG. These findings may lead to development of nanoscale Pb-free magnetic field sensors and magnetoelectric device applications.

Titanium (IV) oxide composite hollow nanofibres with silver oxide outgrowth by combined sol–gel and electrospinning techniques and their potential applications in energy and environment

A two-dimensional nanostructure composed of Ag2O nanobranches attached to TiO2 hollow nanofibres (denoted as 2D Ag2O/TiO2) was successfully prepared via sol–gel and coaxial electrospinning techniques. The Ag/TiO2 hollow nanofibres were fabricated and calcined in ambient air at 500 °C. By calcination, the removal of organic materials and the formation of anatase TiO2 were achieved with a well-retained hollow structure. The embedded Ag nanoparticles functioned as seeds for the Ag2O outgrowth on the TiO2 surface using a hydrothermal treatment at different times and temperatures, which caused the change in physical appearance, surface area, and electrical conductivity of 2D Ag2O/TiO2. A high quantity of Ag2O nanobranches on TiO2 nanofibres were obtained with increasing the temperature from 110 to 115 °C and the reaction time to 60 min. Consequently, the electrochemical active surface area (EASA) value was maximised to 65.25 cm2 per cm2 with an enhanced electrical conductivity of 91.3 ± 3.9 × 10−2 S cm−1. Further studies on the depth-profiles of Ag, Ti, and O revealed the presence of Ag2O attached to the core structure of TiO2. The photoelectrochemical and photocatalytic tests confirmed the excellent physical and electrochemical properties of 2D Ag2O/TiO2 (@115 °C, 60 min) for use in energy and environmental applications.Graphical