33,607 research outputs found

    Self-Driven Sustainable Oil Separation from Water Surfaces by Biomimetic Adsorbing and Transporting Materials

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    Oil films on water are an increasingly major contamination problem worldwide. In 2020, we published a novel adsorption and transportation technology for oil–water separation based on biological role models like the floating fern Salvinia. This application provides an unexpected ability for the fast and efficient removal of oil films, particularly in ecologically important freshwater biota. A single small Bionic Oil Adsorber (BOA) with 1 m2^2 functional textile can collect up to 4 L of oil per hour, which equals about 100 m2^2 of oil film from a water surface into a collecting vessel. This is a safe, fast, and sustainable solution for the ubiquitous contaminations of, e.g., fuel oil in freshwater environments. Here, we present updated, new experimental data, and a review of the literature published since

    Advanced 3D Electrospinning “Xspin” System: Fabrication of Bifiber Floating Oral Pharmaceutical Scaffolds for Controlled Drug Delivery

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    Electrospinning has become a widely used and efficient method for manufacturing nanofibers from diverse polymers. This study introduces an advanced electrospinning technique, Xspin - a multi-functional 3D printing platform coupled with electrospinning system, integrating a customised 3D printhead, MaGIC - Multi-channeled and Guided Inner Controlling printheads. The Xspin system represents a cutting-edge fusion of electrospinning and 3D printing technologies within the realm of pharmaceutical sciences and biomaterials. This innovative platform excels in the production of novel fiber with various materials and allows for the creation of highly customized fiber structures, a capability hitherto unattainable through conventional electrospinning methodologies. By integrating the benefits of electrospinning with the precision of 3D printing, the Xspin system offers enhanced control over the scaffold morphology and drug release kinetics. Herein, we fabricated a model floating pharmaceutical dosage for the dual delivery of curcumin and ritonavir and thoroughly characterized the product. Fourier transform infrared (FTIR) spectroscopy demonstrated that curcumin chemically reacted with the polymer during the Xspin process. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) confirmed the solid-state properties of the active pharmaceutical ingredient after Xspin processing. Scanning electron microscopy (SEM) revealed the surface morphology of the Xspin-produced fibers, confirming the presence of the bifiber structure. To optimize the quality and diameter control of the electrospun fibers, a design of experiment (DoE) approach based on quality by design (QbD) principles was utilized. The bifibers expanded to approximately 10–11 times their original size after freeze-drying and effectively entrapped 87% curcumin and 84% ritonavir. In vitro release studies demonstrated that the Xspin system released 35% more ritonavir than traditional pharmaceutical pills in 2 h, with curcumin showing complete release in pH 1.2 in 5 min, simulating stomach media. Furthermore, the absorption rate of curcumin was controlled by the characteristics of the linked polymer, which enables both drugs to be absorbed at the desired time. Additionally, multivariate statistical analyses (ANOVA, pareto chart, etc.) were conducted to gain better insights and understanding of the results such as discern statistical differences among the studied groups. Overall, the Xspin system shows significant potential for manufacturing nanofiber pharmaceutical dosages with precise drug release capabilities, offering new opportunities for controlled drug delivery applications

    Electrospun Polyacrylonitrile-Fluorinated Polyurethane/Polysulfone Nanofiber Membranes for Oil–Water Separation

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    Electrospun nanofiber membranes exhibit efficient oil–water separation performance, owing to their fine and controllable fiber diameters. However, the three-dimensional dense stacking of nanofibers leads to low porosity, decreasing the oil flux in oil–water separation. Here, a composite nanofiber membrane with a dual-scale structure was designed to achieve a high oil–water separation efficiency and high oil flux simultaneously. In detail, a dense polyurethane/fluorinated polyurethanes (PAN-FPU) nanofiber layer with a fine fiber diameter (150 nm) and a small pore size (3–4 μm) was combined with a fluffy polysulfone (PSF) nanofiber layer with a coarse diameter (1200 nm) and a large pore size (8–9 μm). Using the PAN-FPU nanofiber layer as the inlet layer, modular electrospinning equipment was used to prepare dual-scale nanofiber membranes with a high oil–water separation efficiency and high flux in one step. When the fiber ratio of PAN-FPU/PSF was 1:2, the resulting composite nanofiber film could achieve a separation efficiency of 99.58% and an oil flux of 4630 L m–2 h–1 for an oil–water mixture. For a water-in-oil emulsion, the separation efficiency and oil flux reached 99.37% and 1124 L m–2 h–1, respectively. In addition, the separation efficiency and flux of the biscale nanofiber membrane were simulated by establishing a fluid model, and the simulation results confirmed that the fiber membrane had excellent separation performance. Dual-scale composite nanofiber membranes have potential applications in the field of oily wastewater treatment and locomotive filters compared with monolayer membranes

    In Situ Synthesis of NH<sub>2</sub>‑MIL-53-Al/PAN Nanofibers for Removal Co(II) through an Electrospinning Process

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    In this study, researchers developed a novel composite material called NH2-MIL-53-Al/PAN, which consists of metal–organic frameworks (MOFs) grown on electrospun PAN nanofibers (NFs). The successful formation of the composite was confirmed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR), and the hydrophilicity of NH2-MIL-53-Al/PAN was demonstrated by the water contact angle (WCA). Batch experiments were conducted to investigate the adsorption performance of Co(II) under different conditions. The maximum adsorption capacity reached 58.72 mg/g, and almost 95% of the adsorption was achieved within the first 6 h. The adsorption process was found to be spontaneous and endothermic and followed the pseudo-second-order kinetics and Langmuir models. Chemisorption and molecular layer adsorption are the main mechanisms of adsorption, and X-ray photoelectron spectroscopy (XPS) analysis further reveals that the interaction between the adsorbent and cobalt is a coordination interaction. In this study, NH2-MIL-53-Al was grown in situ on PAN to ensure effective loading of MOFs and prevent agglomeration during the NF mixing process. This approach successfully addressed the challenge of exposing active sites within the embedded MOF crystals. Additionally, it overcame the difficulty of recycling traditional MOF adsorbents. As a result, the exceptional performance of MOF NFs offers a promising solution for the efficient removal of cobalt-containing wastewater

    Rational Design of a Hydrophilic Core–Hydrophobic Shell Yarn-Based Solar Evaporator with an Underwater Aerophilic Surface for Self-Floating and High-Performance Dynamic Water Purification

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    Interfacial solar vapor generation holds great promise for alleviating the global freshwater crisis, but its real-world application is limited by the efficiently choppy water evaporation and industrial production capability. Herein, a self-floating solar evaporator with an underwater aerophilic surface is innovatively fabricated by weaving core–shell yarns via mature weaving techniques. The core–shell yarns possess capillary water channels in the hydrophilic cotton core and can trap air in the hydrophobic electrospinning nanofiber shell when submerged underwater, simultaneously realizing controllable water supplies, stable self-flotation, and great thermal insulation. Consequently, the self-floating solar evaporator achieves an evaporation rate of 2.26 kg m–2 h–1 under 1 sun irradiation, with a reduced heat conduction of 70.18 W m–2. Additionally, for the first time, a solar evaporator can operate continuously in water with varying waveforms and intensities over 24 h, exhibiting an outdoor cumulative evaporation rate of 14.17 kg m–2 day–1

    Exploring the role of nanocellulose as potential sustainable material for enhanced oil recovery:New paradigm for a circular economy

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    Presently, due to growing global energy demand and depletion of existing oil reservoirs, oil industry is focussing on development of novel and effective ways to enhance crude oil recovery and exploration of new oil reserves, which are typically found in challenging environment and require deep drilling in high temperature and high-pressure regime. The nanocelluloses with numerous advantages such as high temperature and pressure stability, ecofriendly nature, excellent rheology modifying ability, interfacial tension reduction capability, etc., have shown a huge potential in oil recovery over conventional chemicals and macro/micro sized biopolymers-based approach. In present review, an attempt has been made to thoroughly investigate the potential of nanocellulose (cellulose nanocrystals/nanofibers) in development of drilling fluid and in enhancement of oil recovery. The impact of various factors such as nanocellulose shape, charge density, inter-particle or inter-fibers interactions after surface functionalization, rheometer geometries, additives, post processing techniques, etc., which provides insight into the attributes of nanocellulose suspension and exemplify their behaviour during oil recovery have also been reviewed and discussed. Finally, the conclusion and challenges in utility of nanocellulose for oilfield applications are addressed. Knowing how to adjust/quantify nanocrystals/nanofibers shape and size; and monitor their interactions might promote their utility in oilfield industry.</p

    The Potential of Electrospinning to Enable the Realization of Energy-Autonomous Wearable Sensing Systems

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    The market for wearable electronic devices is experiencing significant growth and increasing potential for the future. Researchers worldwide are actively working to improve these devices, particularly in developing wearable electronics with balanced functionality and wearability for commercialization. Electrospinning, a technology that creates nano/microfiber-based membranes with high surface area, porosity, and favorable mechanical properties for human in vitro and in vivo applications using a broad range of materials, is proving to be a promising approach. Wearable electronic devices can use mechanical, thermal, evaporative and solar energy harvesting technologies to generate power for future energy needs, providing more options than traditional sources. This review offers a comprehensive analysis of how electrospinning technology can be used in energy-autonomous wearable wireless sensing systems. It provides an overview of the electrospinning technology, fundamental mechanisms, and applications in energy scavenging, human physiological signal sensing, energy storage, and antenna for data transmission. The review discusses combining wearable electronic technology and textile engineering to create superior wearable devices and increase future collaboration opportunities. Additionally, the challenges related to conducting appropriate testing for market-ready products using these devices are also discussed

    Electrospinning polymersomes into bead-on-string polyethylene oxide fibres for the delivery of biopharmaceuticals to mucosal epithelia

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    Fibrous mucoadhesive polymer membranes prepared using electrospinning demonstrate many advantages for mucosal drug delivery compared to other formulations. Previous electrospun membrane formulations have been developed mainly for the delivery of small molecule drugs. There remains great potential to further develop the technology for the delivery of vesicular vectors that allow administration of advanced therapeutic agents. However, there are no previous reports demonstrating the release of intact drug delivery vesicles from electrospun materials. Here, we describe incorporation and release of protein-loaded polymersomes from polyethylene oxide (PEO)-based electrospun membranes. Polymersomes comprising a copolymer of glycerol monomethacrylate (GMA) and hydroxypropyl methacrylate (HPMA) were prepared using polymerization-induced self-assembly and incorporated within PEO membranes using bead-on-string electrospinning at approximately 40 % w/w by polymer mass. Super-resolution fluorescence imaging showed that the vesicles remained intact and retained their encapsulated protein load within the fibre beads. Transmission electron microscopy and dynamic light scattering demonstrated that polymersomes retained their morphology following release from the polymer fibres. F(ab) antibody fragments were encapsulated within polymersomes and then electrospun into membranes. 78 ± 13 % of the F(ab) remained encapsulated within polymersomes during electrospinning and retained functionality when released from electrospun membranes, demonstrating that the formulation is suitable for the delivery of biologics. Membranes were non-irritant to the oral epithelium and fluorescence microscopy detected accumulation of polymersomes within the epithelia following application. This innovative drug delivery approach represents a novel and potentially highly useful method for the administration of large molecular mass therapeutic molecules to diseased mucosal sites

    Parametric investigation of ultrashort pulsed laser surface texturing on aluminium alloy 7075 for hydrophobicity enhancement

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    Hydrophobicity plays a pivotal role in mitigating surface fouling, corrosion, and icing in critical marine and aerospace environments. By employing ultrafast laser texturing, the characteristic properties of a material’s surface can be modified. This work investigates the potential of an advanced ultrafast laser texturing manufacturing process to enhance the hydrophobicity of aluminium alloy 7075. The surface properties were characterized using goniometry, 3D profilometry, SEM, and XPS analysis. The findings from this study show that the laser process parameters play a crucial role in the manufacturing of the required surface structures. Numerical optimization with response surface optimization was conducted to maximize the contact angle on these surfaces. The maximum water contact angle achieved was 142º, with an average height roughness (Sa) of 0.87 ± 0.075 μm, maximum height roughness (Sz) of 19.4 ± 2.12 μm, and texture aspect ratio of 0.042. This sample was manufactured with the process parameters of 3W laser power, 0.08 mm hatch distance, and a 3 mm/s scan speed. This study highlights the importance of laser process parameters in the manufacturing of the required surface structures and presents a parametric modeling approach that can be used to optimize the laser process parameters to obtain a specific surface morphology and hydrophobicity
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