Electrospun Fibrous Membranes Research Articles

Recycled PET as a PDMS-Functionalized electrospun fibrous membrane for oil-water separation

In recent years, low-cost and effective technologies for oil-water separation have been highly desired due to an increase of oily wastewater and frequent oil spill accidents. This study demonstrates a cost-effective and sustainable preparation of flexible fibrous membranes with high oil-water separation performance using recycled polyethylene terephthalate (rPET). The rPET fibrous membrane was prepared via electrospinning; in the following step, the rPET membrane was dip-coated with polydimethylsiloxane (PDMS) to improve the water intrusion pressure and anti-water-fouling property of the rPET fibrous membrane. The effect of PDMS concentration on the membrane morphology, surface chemistry, thermal and mechanical properties, surface wettability and oil-water separation performance was evaluated. The membranes are superoleophilic with an oil contact angle of 0° and exhibit excellent anti-water-fouling properties. The PDMS-functionalized rPET membranes can effectively separate various oil-water mixtures driven by gravity, with a high flux (∼ 20,000 L m−2 h-1) and a high separation efficiency (> 98 %) for up to ten cycles and thus has potential industrial application.

Tb3+/Eu3+ Complex-Doped Rigid Nanoparticles in Transparent Nanofibrous Membranes Exhibit High Quantum Yield Fluorescence.

In this study, transparent membranes containing luminescent Tb3+ and Eu3+ complex-doped silica nanoparticles were prepared via electrospinning. We prepared the electrospun fibrous membranes containing Tb(acac)3phen- (acac = acetylacetone, phen = 1,10-phenanthroline) and/or Eu(tta)3phen- (tta = 2-thenoyltrifluoroacetone) doped silica (M-Si-Tb3+ and M-Si-Eu3+) and studied their photoluminescence properties. The fibrous membranes containing the rare earth complexes were prepared by electrospinning. The surface morphology and thermal properties of the fibrous membrane were studied by atomic force microscopy (AFM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. Fluorescence spectroscopy was used to characterize the fluorescence properties of the membranes. During the electrospinning process, the PVDF transitions from the α phase to the β phase, which exhibits a more rigid structure. The introduction of rigid materials, like PVDF and silica, can improve the fluorescence properties of the hybrid materials by reducing the rate of nonradiative decay. So the emission spectra at 548 nm (Tb) and 612 nm (Eu) were enhanced, as compared to the emission from the pure complex. Furthermore, the fluorescence lifetimes ranged from 0.6 to 1.5 ms and the quantum yields ranged from 32% to 61%. The luminescent fibrous membranes have potential applications in the fields of display panels, innovative electronic and optoelectronic devices.

Tailored PCL Scaffolds as Skin Substitutes Using Sacrificial PVP Fibers and Collagen/Chitosan Blends.

Electrospinning is a versatile technique for fabrication of made-on-purpose biomimetic scaffolds. In this study, optimized electrospun fibrous membranes were produced by simultaneous electrospinning of polycaprolactone (PCL) and polyvinylpyrrolidone (PVP), followed by the selective removal of PVP from the PCL/PVP mesh. After aminolysis, a blend of collagen/chitosan was grafted on the surface. Physicochemical characterizations as well as in vitro evaluations were conducted using different methods. Successful cell infiltration into samples was observed. It seems that the positive trend of cell ingress originates from the proper pore size obtained after removal of pvp (from 4.46 μm before immersion in water to 33.55 μm after immersion in water for 24 h). Furthermore, grafting the surface with the collagen/chitosan blend rendered the scaffolds more biocompatible with improved attachment and spreading of keratinocyte cell lines (HaCaT). Viability evaluation through MTT assay for HDF cells did not reveal any cytotoxic effects. Antibacterial assay with Staphylococcus aureus as Gram-positive and Escherichia coli as Gram-negative species corroborated the bactericidal effects of chitosan utilized in the composition of the coated blend. The results of in vitro studies along with physicochemical characterizations reflect the great potentials of the produced samples as scaffolds for application in skin tissue engineering.

Electrospun fibrous membranes of poly (lactic-co-glycolic acid) with β-tricalcium phosphate for guided bone regeneration application

Guided bone regeneration (GBR) have been proved great success for the treatment of bone defects in oral implantology. Bone defects are reconstructed by the use of a barrier membrane which prevents the invasion of soft tissue and create a space for guiding new bone growth into the bone defect. To develop GBR membranes with higher bioactivity, poly (lactic-co-glycolic acid) (PLGA) fibrous membranes containing β-tricalcium phosphate (β-TCP) were fabricated via electrospinning. The presence of 5 wt% and 10 wt% of β-TCP in the fibers improved mechanical properties. In vitro biocompatibility results have shown that all membranes are non-cytotoxic and the presence of β-TCP increased cell adhesion and proliferation. Furthermore, cell viability results demonstrated that the presence of 5 wt% β-TCP is advantageous for osteoblast proliferation. Therefore, the results suggest that PLGA with 5 wt% β-TCP fibrous membranes meet the requirement of morphological, physical, mechanical and bioactive properties for an effective GBR membrane.

White Magnetic Paper with Zero Remanence Based on Electrospun Cellulose Microfibers Doped with Iron Oxide Nanoparticles.

The preparation procedure of zero magnetic remanence superparamagnetic white paper by means of three-layer membrane configuration (sandwiched structure) is presented. The cellulose acetate fibrous membranes were prepared by electrospinning. The middle membrane layer was magnetically loaded by impregnation with an aqueous ferrofluid of 8 nm magnetic iron oxide nanoparticles colloidally stabilized with a double layer of oleic acid. The nanoparticles show zero magnetic remanence due to their very small diameters and their soft magnetic properties. Changing the ferrofluid magnetic nanoparticle volume fraction, white papers with zero magnetic remanence and tunable saturation magnetization in the range of 0.5–3.5 emu/g were prepared. The dark coloring of the paper owing to the presence of the black magnetite nanoparticles was concealed by the external layers of pristine white cellulose acetate electrospun fibrous membranes.

640 Mussel-inspired Polydopamine-assisted Bromelain Immobilization onto Electrospun Fibrous Membrane for Potential Application as Wound Dressing

640 Mussel-inspired Polydopamine-assisted Bromelain Immobilization onto Electrospun Fibrous Membrane for Potential Application as Wound Dressing

Lithium garnet incorporated 3D electrospun fibrous membrane for high capacity lithium-metal batteries

A new class of electrolytes with enhanced flexibility, high lithium ion (Li+) conductivity, excellent electrochemical stability, good cyclic ability and improved safety are crucial for high performance of lithium-metal batteries. Composite polymer electrolytes assist in overwhelming safety-related issues faced by Li+ batteries with organic liquid electrolytes. Herein, we report on polymer nanocomposite electrospun fibrous membranes (PNEFM) comprising of Li6.28Al0.24La3Zr2O12 (LLZA) garnet oxide nano-fillers in poly (vinylidene fluoride-co-hexafluoropropylene) P(VDF-HFP) co-polymer prepared by electrospinning technique. Li+ conductivity of the PNEFM is remarkably improved by the addition of LLZA garnet filler. The PNEFM-8 (with 8 wt% of LLZA) exhibits a maximized Li+ conductivity of 2.25 × 10−3 S cm−1 at room temperature (25 °C). The PNEFM-8 exhibits a wide electrochemical potential window up to 5.5 V. A full cell with Li||PNEFM-8||LiFePO4 configuration at 25 °C displayed first discharge capacity of 160 mA h g−1 and a reversible discharge capacity of 145 mA h g−1 for 100th cycle at 0.1 C with Coulombic efficiency of 98.78%. Furthermore, PNEFM-8, integrated with composite sulphur cathode exhibits an excellent first discharge capacity of 1311 mA h g−1 and a reversible discharge capacity of 1105 mA h g−1 after 10th cycles with 98.30% Coulombic efficiency. The present study could contribute towards the development of higher performance and safe room temperature Li-metal batteries.

Development of PCL/PEO electrospun fibrous membranes blended with silane-modified halloysite nanotube as a curcumin release system

In this work, electrospun fibrous membranes based on the polycaprolactone (PCL)/polyethylene oxide (PEO) blended with pure, 3-Aminopropyltriethoxysilane (APTES) or 3-Glycidoxypropyltrimethoxysilane (GPTMS) modified halloysite nanotubes (HNT) were prepared by electrospinning for curcumin (Cur) delivery system. The morphological and physicochemical properties of the fabricated membranes were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). In vitro release of from the Cur loaded fibrous membranes was examined in simulated physiological condition by ultraviolet–visible spectroscopy. Besides, in vitro cytotoxicity on the MCF-7 breast carcinoma cells was evaluated. The results demonstrated that the silane-modified HNTs (HNT-APTES and HNT-GPTMS) displayed a much higher Cur loading capacity while APTES modified HNT had the maximum encapsulation efficiency. Moreover, in vitro Cur release studies demonstrated that PCL/PEO-Cur/HNT-APTES membrane has a slower release profile. The release mechanism of Cur from all membranes was fitted by the Peppas-Sahlin kinetic model indicating a pseudo-Fickian and non-Fickian release. Additionally, the PCL/PEO-Cur/HNT-APTES membrane showed the highest toxicity against MCF-7 breast cancer cells. In conclusion, the uses of this Cur loaded PCL/PEO electrospun fibrous membranes blended with the APTES modified HNT can be used to loading of other drugs for controlled drug delivery system, especially as an anticancer carrier.

Mussel-inspired polydopamine-assisted bromelain immobilization onto electrospun fibrous membrane for potential application as wound dressing

There has been a recent increase in research interest regarding the development of wound dressings containing bioactive compounds capable of improving outcomes for complex healing needs. In the present study, we describe the generation of bromelain immobilized eletrospun poly(ε-caprolactone) (PCL) fibers (BrPDA-PCL fibers) using the dopamine-assisted co-deposition strategy. We wanted to combine the structural advantage of electrospun fiber and the activity of bromelain and PDA to develop functional wound dressings. We found that bromelain activity could be better stabilized when via its immobilization on electrospun fibers. The resultant BrPDA-PCL fibers exhibited promising properties including optimal mechanical stability, wettability, and rates of water vapor transmission. In addition, these BrPDA-PCL fibers were biocompatible, allowing for effective cellular adhesion and proliferation. The results of zone of inhibition testing further confirmed that these fibers achieved effective antibacterial activity against Escherichia coli and Staphylococcus aureus. When used in vivo, as compared with PCL fibers or control animals the BrPDA-PCL fibers enhanced wound healing rates while reducing associated inflammation. As such, these results indicate that these biocompatible BrPDA-PCL fibers exhibit desirable physicochemical properties making them ideal for use as a wound dressing to enhance the repair of full-thickness wounds to the skin.

Flexible and High‐Loading Lithium–Sulfur Batteries Enabled by Integrated Three‐In‐One Fibrous Membranes

AbstractLithium–sulfur batteries are appealing as high‐energy storage systems and hold great application prospects in wearable and portable electronics. However, severe shuttle effects, low sulfur conductivity, and especially poor electrode mechanical flexibility restrict sulfur utilization and loading for practical applications. Herein, high‐flux, flexible, electrospun fibrous membranes are developed, which succeed in integrating three functional units (cathode, interlayer, and separator) into an efficient composite. This structure helps to eliminate negative interface effects, and effectively drives synergistic boosts to polysulfide confinement, electron transfer, and lithium‐ion diffusion. It delivers a high initial capacity of 1501 mA h g−1 and a discharge capacity of 933 mA h g−1 after 400 cycles, with slow capacity attenuation (0.069% per cycle). Even under high sulfur loading (13.2 mg cm−2, electrolyte/sulfur ratio = 6 mL g−1) or in an alternative folded state, this three‐in‐one membrane still exhibits high areal capacity (11.4 mA h cm−2) and exceptional application performance (powering an array of over 30 light‐emitting diodes (LEDs)), highlighting its huge potential in high‐energy flexible devices.

Preparation and characterization of composite fibrous membranes for oil spill cleanup

In this study, polyacrylonitrile (PAN) electrospun fibrous membranes were manufactured and applied for oil spill cleanup. Two kinds of composite fibrous membranes composed of PAN electrospun fibrous membranes and polyethylene/polyethylene terephthalate (PE/PET) core-shell fiber nonwoven fabric were fabricated. The fibrous structure, mechanical properties and surface wettability for water and oil, as well as oil absorption capacities and dynamic oil retention of the membranes, were investigated in detail. The addition of nonwoven fabric significantly enhanced the tensile strength of the PAN fibrous membranes. The oil absorption mechanisms of different membranes were studied as well. The sandwich structure composite fibrous membranes exhibited excellent mechanical property and oil absorption capacity, making it a promising candidate for treatment of oily wastewater.

Engineering antimicrobial and biocompatible electrospun PLGA fibrous membranes by irradiation grafting polyvinylpyrrolidone and periodate

Postoperative adhesion may form as the result of a complicated fibrosis and inflammatory response, thus leads to a series of complications or increases the risk of surgery failure. Herein, we prepared poly (lactic-co-glycolic acid)-graft-polyvinylpyrrolidone/polyiodide (PLGA-g-PVP/I) electrospun fibrous membranes to prevent postoperative adhesion and infection formation. Firstly, hydrophilic PVP molecules were grafted on the surface of PLGA powders by gamma ray, and then iodine ions were coordinated with the grafted PVP. Subsequently, PLGA-g-PVP/I fibrous membranes were prepared by electrospinning. The PLGA-g-PVP/I membranes were analyzed via UV–vis, FTIR, Raman, and XPS. The formed polyiodide endowed the membranes with sustained antibacterial activity. The antimicrobial property of PLGA-g-PVP/I membranes was ascribed to the synergistic effect of intracellular ROS production and glutathione oxidation. Furthermore, the prevention efficacy of postoperative abdominal adhesion from the PLGA-g-PVP/I composite membranes was characterized in a rat model of sidewall defect-cecum abrasion. The results demonstrated that the PLGA-g-PVP/I fibrous membranes could prevent the postoperative abdominal adhesion effectively. Therefore, to endow the PLGA-g-PVP/I electrospun fibrous membranes with durable antibacterial property may be a promising strategy towards an anti-bacterial and anti-adhesion system for commercial and clinical uses.

Tailoring waterproof and breathable properties of environmentally friendly electrospun fibrous membranes by optimizing porous structure and surface wettability

Developing a feasible and efficient waterproof and breathable (W&B) membrane with environmentally friendliness for high-end protective garments is of great significance but very challenging. Herein, an environmentally friendly and high-performing W&B membrane via a facile strategy of one-step electrospinning is created. It has been confirmed that the porous structure and surface wettability greatly affected W&B properties of the electrospun membranes, and excessive utilization of fluorinated segments with low surface energy would not further enhance the hydrophobicity . Consequently, the prepared composite membranes exhibit an exceptional hydrostatic pressure of 88.2 kPa, high water vapor transmission (WVT) rate of 11.8 kg m −2 d −1 , together with comparable mechanical strength of 11.4 MPa, which are expected to reach the requirements of upscale market for high-performing protective garments. • Porous structure and surface chemical properties of the fibrous membranes were subtly regulated. • The effects of pore size and surface wettability on waterproof breathable properties were thoroughly investigated. • The resultant environmentally friendly fibrous membranes exhibited good comprehensive properties.

Membrane technology in air pollution control: prospect and challenge

Rapid growth in environmental awareness raised the strict regulations on air pollution control and led to great developments in air filtration or cleaning technologies. The membrane is one of the promising technologies for air filtration due to its high efficiency, low cost, and easy to scale-up. Two types of air filtration membranes have been used to provide high efficiencies in contaminant removal, namely electro-spun fibrous and microporous polymeric membranes. The fibrous membranes composed of randomly oriented fibers, either micro-or nano-fiber, and have been widely used to remove fine particles, such as aerosols. Meanwhile, the microporous membranes have a pore size that can remove both particulate and molecular, such as toxic gases. This paper reviews the role of membrane technologies in air pollution control. The performances of the membranes are presented comprehensively. Besides, the developments of the membranes to improve the filtration efficiency and reduce air-flow resistance are also discussed.

The Study on Semi-Blunt Puncture Behavior of Nanofiber Membrane/ Non-Woven Composite Material.

Nanofiber membrane/non-woven composite material is composed of electrospinning nanofiber membrane and non-woven fabric, which combines the supporting role of nonwoven material and the special nano-size effect of nanomaterials. These composite material can be widely used in biomedical, filtration and other related fields. In the actual use process, nanofiber membrane/non-woven composite material is often subjected to external forces such as puncture or bursting. As a result, the mechanical study of nanofiber membrane/ non-woven composite materials has a high value and practical significance. The nanofiber membrane/non-woven composite material was obtained by spraying solution (different concentrations of titanium dioxide-loaded Poly (vinyl alcohol) (PVA)) on meltblown polyester non-woven fabric. The surface morphology and fiber diameter of different concentrations nanotitanium dioxide-loaded Poly (vinyl alcohol) fiber were investigated by Field Emission Scanning Electron Microscopy (FESEM). The surface distribution of TiO2 on the electrospun fibrous membranes was characterized by Energy Disperse Spectroscopy (EDS). The semi-blunt puncture behavior of different concentrations of nano-titanium dioxide-loaded nanofiber membrane/non-woven composite material was conducted by universal material machine. With the increase of concentrations of nano-titanium dioxide particles, the surface smoothness of nanofibers diminishes, the unevenness of the diameter distribution of the fiber increased and the maximum semi-blunt puncture strength increased. The addition of hard particles does contribute to improving the puncture properties of the composite materials. Several patents, related to electrospinning and bubble electrospinning equipment for nanofiber fabrication, have been reported.

Aligned porous fibrous membrane with a biomimetic surface to accelerate cartilage regeneration

Due to the poor self-regenerative capacity of native cartilage, the treatment of articular cartilage defects is a significant clinical challenge. The cartilage tissue engineered scaffolds with high chondrogenic capacity might provide an efficient strategy for the repair of cartilage defects. Herein, we report an aligned porous poly (l-lactic acid) (PLLA) electrospun fibrous membrane with a biomimetic surface for the rapid regeneration of cartilage tissue. The PLLA electrospun fibers aligned in a single direction and generated ellipse-shaped nanopores in situ onto the surface of the fibers. Subsequently, chondroitin sulfate (CS) was coated on the surface of the fibers using polydopamine (PDA) as an adhesive polymeric bridge. The in vitro results revealed that the aligned porous composite membranes with a biomimetic surface (PL/PDA/CS) could stimulate the attachment and proliferation of chondrocytes and rabbit bone marrow mesenchymal stem cells (rBMSCs), as well as inducing chondrogenic gene expression in rBMSCs. Furthermore, the PL/PDA/CS membranes significantly facilitated the filling of defects and the regeneration of hyaline cartilage-like tissue in vivo. The results suggested that the hierarchical aligned porous fibrous electrospun membrane with a biomimetic surface modification is a potential therapeutic strategy for highly efficient cartilage defect repair.

The mineralization of polymer electrospun fibrous membranes modified with tourmaline nanoparticles

Abstract

The role of emulsion parameters in tramadol sustained-release from electrospun mats

Tramadol is an analgesic usually prescribed for the management of pain, with a certain risk of addiction in chronic patients. The incorporation of tramadol in sustained-release systems results particularly attractive for the administration of accurate doses. In this work, emulsion electrospinning was used for the preparation of tramadol-loaded nanofibrous membranes based on poly(ε-caprolactone). Compositional and processing parameters were screened and evaluated in terms of the morphology of the resulting nanofibers, encapsulation efficiency and drug release in time. The polymer concentration, surfactant type and amount, and the homogenization rate used for the emulsions preparation were found to greatly affect the fluid stability and the resulting materials structure and functionality. The intrinsic features of the starting fluid studied in this work played a significant role for the modulation of tramadol release from nanofibrous matrices. The use of sodium dodecyl sulfate as surfactant with an optimal homogenization rate allowed the preparation of electrospun fibrous membranes with good encapsulation efficiency, a minimal burst release and a sustained delivery of tramadol in time.

Electrospun Fibrous Membranes with Dual-Scaled Porous Structure: Super Hydrophobicity, Super Lipophilicity, Excellent Water Adhesion, and Anti-Icing for Highly Efficient Oil Adsorption/Separation.

Developing highly efficient and multifunctional membranes toward oil adsorption and oil/water separation is of significance in oily wastewater treatment. Herein, a novel electrospun composite membrane with dual-scaled porous structure and nanoraised structure on each fiber was fabricated through electrospinning using biodegradable polylactide (PLA) and magnetic γ-Fe2O3 nanoparticles. The PLA/γ-Fe2O3 composite membranes show high porosity (>90%), superhydrophobic and superlipophilic performances with CH2I2 contact angle of 0°, good water adhesion ability like water droplets on a petal surface, excellent anti-icing performance, and good mechanical properties with a tensile strength of 1.31 MPa and a tensile modulus of 11.65 MPa. The superlipophilicity and dual-scaled porous structure endow the composite membranes with ultrahigh oil adsorption capacity up to 268.6 g/g toward motor oil. Furthermore, the composite membranes also show high oil permeation flux up to 2925 L/m2 h under the force of gravity. Even for oil/water emulsion, the composite membranes have high separation efficiency. We expect that the PLA/γ-Fe2O3 composite membranes can be used in oily wastewater treatment under various conditions through one-off adsorption or continuous oil/water separation, especially under low environmental temperature condition.

An electrospun fibrous platform for visualizing the critical pH point inducing tooth demineralization

The BCG–PS/PVP electrospun fibrous membrane can rapidly, sensitively and conveniently sense the critical pH point of 5.5 of dental caries.