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Yuming Zheng - One of the best experts on this subject based on the ideXlab platform.
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flexible and porous tio2 sio2 carbon composite electrospun Nanofiber Mat with enhanced interfacial charge separation for photocatalytic degradation of organic pollutants in water
Journal of Colloid and Interface Science, 2019Co-Authors: Zaidong Shao, Qing Liu, Zongli Xie, Fei Zhao, Yuming ZhengAbstract:Abstract Semiconductor photocatalysis has long been considered as a promising approach for remediation of polluted water. However, the high recombination rate of electrons and holes, as well as a low reaction rate, have impeded its large-scale applications. Therefore, it is of great importance to develop appropriate photocatalysts for promoting its practical application. In this study, a novel TiO2/SiO2/carbon electrospun Nanofiber Mat (TSC NFM) with flexibility and porous hierarchy has been successfully designed and fabricated by a facile method of electrospinning and carbonization. Characterization results show that the TSC NFM consists of closely-packed and well-distributed anatase (TiO2) nanocrystals, amorphous SiO2 nanoparticles, and carbon with interconnected meso- and macro-pores. The photocatalytic performance of the TSC NFM was evaluated by degrading rhodamine B and 4-nitrophenol in batch systems. The results show that TSC NFM exhibits a higher photocatalytic activity than TiO2/SiO2 Nanofiber Mat, which does not contain carbon. The enhanced performance of the TSC NFM can be attributed to the improved adsorption capacity toward the organic pollutants due to the presence of carbon and to the enhanced interfacial charge separation between TiO2 nanoparticles and carbon. Besides, the as-prepared TSC NFM displays good stability and reusability. Notably, the flexible TSC NFM can be used in a continuous-flow reactor to efficiently treat wastewater. Our work provides new insights into the fabrication of carbon-based inorganic Nanofiber Mats, which have great potential in water treatment.
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enhanced adsorption of arsenite from aqueous solution by an iron doped electrospun chitosan Nanofiber Mat preparation characterization and performance
Journal of Colloid and Interface Science, 2019Co-Authors: Lingli Min, Lubin Zhong, Liming Yang, Zhihua Yuan, Yuming ZhengAbstract:Abstract A novel iron-doped chitosan electrospun Nanofiber Mat (Fe@CTS ENM) was synthesized, which was proven to be effective for the removal of arsenite (As(III)) from water at neutral pH condition. The physiochemical properties and adsorption mechanism were explored by SEM-EDS and X-ray photoelectron spectroscopy (XPS). Batch adsorption experiments were carried out to evaluate the As(III) adsorption performance of the Fe@CTS ENM with various process parameters, such as adsorbent dose, solution pH, initial As(III) concentration, contact time, ionic strength, coexisting anions, and natural organic Matter. The experimental results indicated that the maximum adsorption capacity was up to 36.1 mg g−1. Especially, when the adsorbent dosage was higher than 0.3 g L−1, the As(III) concentration was reduced from 100 µg L−1 to less than 10 µg L−1, which indicated the Fe@CTS ENM could effectively remove trace As(III) from water over a wide pH range (from 3.3 to 7.5). Kinetics study demonstrated that the adsorption equilibrium was achieved within 2.0 h, corresponding to a fast uptake of As(III). The presence of common co-ions and humic acid had little effect on the As(III) adsorption. XPS analysis suggested that the Fe O, C OH, C O C and C N groups on the adsorbent surface play dominant roles in the adsorption of As(III). Adsorption-desorption regeneration test further demonstrated that no appreciable loss in the adsorption capacities was observed, which confirmed that the Fe@CTS ENM maintained a desirable life cycle that was free of complex synthesis processes, expensive and toxic Materials, qualifying it as an efficient and low-cost As(III) adsorbent.
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synthesis of silver nanoparticles embedded electrospun pan Nanofiber thin film composite forward osmosis membrane to enhance performance and antimicrobial activity
Industrial & Engineering Chemistry Research, 2019Co-Authors: Shufang Pan, Qing Liu, Lubin Zhong, Tingyu Wang, Yuming ZhengAbstract:Enhancing antimicrobial activity is an effective strategy to mitigate membrane biofouling. In this study, an antimicrobial electrospun polyacrylonitrile (PAN) Nanofiber Mat decorated with in situ s...
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removal of tetracycline from aqueous solution by a fe3o4 incorporated pan electrospun Nanofiber Mat
Journal of Environmental Sciences-china, 2015Co-Authors: Qing Liu, Yuming Zheng, Lubin Zhong, Xiaoxia ChengAbstract:Pollution of antibiotics, a type of emerging contaminant, has become an issue of concern, due to their overuse in human and veterinary application, persistence in environment and great potential risk to human and animal health even at trace level. In this work, a novel adsorbent, Fe3O4 incorporated polyacrylonitrile Nanofiber Mat (Fe-NFM), was successfully fabricated via electrospinning and solvothermal method, targeting to remove tetracycline (TC), a typical class of antibiotics, from aqueous solution. Field emission scanning electron microscopy and X-ray diffraction spectroscopy were used to characterize the surface morphology and crystal structure of the Fe-NFM, and demonstrated that Fe-NFM was composed of continuous, randomly distributed uniform Nanofibers with surface coating of Fe3O4 nanoparticles. A series of adsorption experiments were carried out to evaluate the removal efficiency of TC by the Fe-NFM. The pseudo-second-order kinetics model fitted better with the experimental data. The highest adsorption capacity was observed at initial solution pH4 while relative high adsorption performance was obtained from initial solution pH4 to 10. The adsorption of TC on Fe-NFM was a combination effect of both electrostatic interaction and complexation between TC and Fe-NFM. Freundlich isotherm model could better describe the adsorption isotherm. The maximum adsorption capacity calculated from Langmuir isotherm model was 315.31 mg/g. Compared to conventional nanoparticle adsorbents which have difficulties in downstream separation, the novel Nanofiber Mat can be simply installed as a modular compartment and easily separated from the aqueous medium, promising its huge potential in drinking and wastewater treatment for micro-pollutant removal.
Yichun Liu - One of the best experts on this subject based on the ideXlab platform.
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An antimicrobial peptide-immobilized Nanofiber Mat with superior performances than the commercial silver-containing dressing.
Materials science & engineering. C Materials for biological applications, 2020Co-Authors: Qianwen Yang, Sisi Cui, Xiaoyu Song, Yifa Zhou, Yichun LiuAbstract:Abstract Silver-containing dressings are widely used for the treatment of infected wounds in clinics, but the potential risks of heavy metals are still a common concern. In this study, we prepared a type of electrospun starch Nanofiber Mat containing the antimicrobial peptide e-poly-lysine (Starch-EPL) and compared its relevant properties with a representative silver-containing dressing 3M™ Tegaderm™ Alginate Ag (Alginate-Ag). SEM, FTIR and EDAX results show the two samples have similar fiber structures and are loaded with antibacterial agents. The comparison results indicate that the Starch-EPL Nanofiber Mat has equivalent permeability and absorbency with Alginate-Ag but higher mechanical property and wettability. Moreover, the Starch-EPL Nanofiber Mat has comparable antibacterial activity against both Gram-negative and Gram-positive bacteria with Alginate-Ag, but markedly better biocompatibility than that. The Starch-EPL Nanofiber Mat can inhibit the growth of bacteria for at least 14 days by sustainably releasing EPL, showing great potential as a long-term antibacterial dressing. All these results demonstrate that the Starch-EPL Nanofiber Mat may be a good candidate to replace the traditional silver-containing dressings.
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Pectinate Nanofiber Mat with High Absorbency and Antibacterial Activity: a Potential Superior Wound Dressing to Alginate and Chitosan Nanofiber Mats
Carbohydrate polymers, 2017Co-Authors: Sainan Chen, Sisi Cui, Yifa Zhou, Yichun LiuAbstract:Polysaccharides including pectin, alginate and chitosan are fabricated into dressings of micrometer-scaled architecture (micro- fiber or particle) and widely applied in wound treatments clinically. This work characterized and compared the properties of electrospun nanofibrous dressings of these polysaccharides. We found that although the three polysaccharide Nanofiber Mats had comparable mechanical strength and vapour permeability, the pectinate Nanofiber Mat could absorb 1.2 times and 3.6 times more exudates than the alginate and chitosan Nanofiber Mats, respectively, within less time. Moreover, the pectinate Nanofiber Mat showed much higher antibacterial activity (73.1%) than the alginate and chitosan Nanofiber Mats (11.8% and 17.1%, respectively). Further examinations demonstrated that the superior absorbency and antibacterial activity of the pectinate Nanofiber Mat were associated with the moderate extent of swelling of pectinate Nanofibers under hydrated conditions. All these results suggest that the pectinate Nanofiber Mat might be a superior wound dressing to the alginate and chitosan Nanofiber Mats.
Andrea Ehrmann - One of the best experts on this subject based on the ideXlab platform.
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Stabilization of Electrospun Nanofiber Mats Used for Filters by 3D Printing.
Polymers, 2019Co-Authors: Tomasz Kozior, Al Mamun, Lilia Sabantina, Marah Trabelsi, Andrea EhrmannAbstract:Electrospinning is a well-known technology used to create Nanofiber Mats from diverse polymers and other Materials. Due to their large surface-to-volume ratio, such Nanofiber Mats are often applied as air or water filters. Especially the latter, however, have to be mechanically highly stable, which is challenging for common Nanofiber Mats. One of the approaches to overcome this problem is gluing them on top of more rigid objects, integrating them in composites, or reinforcing them using other technologies to avoid damage due to the water pressure. Here, we suggest another solution. While direct 3D printing with the fused deposition modeling (FDM) technique on macroscopic textile fabrics has been under examination by several research groups for years, here we report on direct FDM printing on Nanofiber Mats for the first time. We show that by choosing the proper height of the printing nozzle above the Nanofiber Mat, printing is possible for raw polyacrylonitrile (PAN) Nanofiber Mats, as well as for stabilized and even more brittle carbonized Material. Under these conditions, the adhesion between both parts of the composite is high enough to prevent the Nanofiber Mat from being peeled off the 3D printed polymer. Abrasion tests emphasize the significantly increased mechanical properties, while contact angle examinations reveal a hydrophilicity between the original values of the electrospun and the 3D printed Materials.
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Wet Relaxation of Electrospun Nanofiber Mats
Technologies, 2019Co-Authors: Timo Grothe, Lilia Sabantina, Michaela Klöcker, Irén Juhász Junger, Christoph Döpke, Andrea EhrmannAbstract:Electrospinning can be used to produce Nanofiber Mats. One of the often used polymers for electrospinning is polyacrylonitrile (PAN), especially for the production of carbon Nanofibers, but also for a diverse number of other applications. For some of these applications—e.g., creation of nano-filters—the dimensional stability of the Nanofiber Mats is crucial. While relaxation processes—especially dry, wet and washing relaxation—are well-known and often investigated for knitted fabrics, the dimensional stability of Nanofiber Mats has not yet been investigated. Here we report on the wet relaxation of PAN Nanofiber Mats, which are dependent on spinning and solution parameters such as: voltage, electrode distance, Nanofiber Mat thickness, and solid content in the solution. Our results show that wet relaxation has a significant effect on the samples, resulting in a dimensional change that has to be taken into account for Nanofiber Mats in wet applications. While the first and second soaking in pure water resulted in an increase of the Nanofiber Mat area up to approxiMately 5%, the dried sample, after the second soaking, conversely showed an area reduced by a maximum of 5%. For soaking in soap water, small areal decreases between approxiMately 1–4% were measured.
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Preliminary Study of Ultrasonic Welding as a Joining Process for Electrospun Nanofiber Mats
Nanomaterials (Basel Switzerland), 2018Co-Authors: Emilia Wirth, Lilia Sabantina, Marcus O. Weber, Karin Finsterbusch, Andrea EhrmannAbstract:Electrospinning can be used to create Nanofiber Mats for diverse applications, from wound dressings and tissue engineering to filters for medical and biotechnological applications. In most of these applications, it is necessary to fix the Nanofiber Mat on a macroscopic textile fabric, on another Nanofiber Mat or within a frame to keep it at the desired position. Due to their extremely low thickness and areal mass, however, Nanofiber Mats are easily destroyed by sewing, and in several situations glued bonds are too thick and not flexible enough. Here we report on ultrasonic welding of polyacrylonitrile Nanofiber Mats, suggesting this method as a joining process without destruction of the Mat morphology for thermoplastic Nanofiber Mats. A variety of welding patterns results in different adhesion forces between both joined Nanofiber Mats and different failure mechanisms, with some welding patterns enabling bonding stronger than the Mats themselves. Our findings show that ultrasonic welding is a possible joining method for polyacrylonitrile Nanofiber Mats.
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dye sensitized solar cells with electrospun Nanofiber Mat based counter electrodes
Materials, 2018Co-Authors: Irén Juhász Junger, Timo Grothe, Daria Wehlage, Robin Bottjer, Laszlo Juhasz, Carsten Grassmann, Tomasz Blachowicz, Andrea EhrmannAbstract:Textile-based dye-sensitized solar cells (DSSCs) can be created by building the necessary layers on a textile fabric or around fibers which are afterwards used to prepare a textile layer, typically by weaving. Another approach is using electrospun Nanofiber Mats as one or more layers. In this work, electrospun polyacrylonitrile (PAN) Nanofiber Mats coated by a conductive polymer poly(3,4-ethylenedioxythiopene) polystyrene sulfonate (PEDOT:PSS) were used to produce the counter electrodes for half-textile DSSCs. The obtained efficiencies were comparable with the efficiencies of pure glass-based DSSCs and significantly higher than the efficiencies of DSSCs with cotton based counter electrodes. The efficiency could be further increased by increasing the number of PEDOT:PSS layers on the counter electrode. Additionally, the effect of the post treatment of the conductive layers by HCl, acetic acid, or dimethyl sulfoxide (DMSO) on the DSSC efficiencies was investigated. Only the treatment by HCl resulted in a slight improvement of the energy-conversion efficiency.
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Influence of Substrate Materials on Electrospun PAN Nanofiber Mats
2018 IEEE 8th International Conference Nanomaterials: Application & Properties (NAP), 2018Co-Authors: Friederike Beermann, Mona Schwakenberg, Anna-lena Voigt, Andrea EhrmannAbstract:Nanofibers can be produced, e.g., by electrospinning. Different electrospinning technologies can be used to create Nanofiber Mats from diverse polymers, often blended with other polymeric or ceramic Materials. While the influence of solution and spinning parameters is often reported in the literature, the effect of the substrate is mostly ignored. Here we give an overview of the influence of diverse substrates which were used for electrospinning polyacrylonitrile Nanofibers. The polypropylene nonwoven which is typically used in a Nanospider electrospinning machine is compared with sticky tape, baking paper, wrapping film, aluminum foil and other easily available substrates, showing that fiber Mat densities and fiber diameters change with the substrate. This finding opens a new possibility to tailor Nanofiber Mat morphologies without changing the spinning solution or the process parameters. Additionally, an interesting effect was found during electrospinning on aluminum foil - only on this Material, the Nanofiber Mat adhered strongly on the substrate. Abrasion tests performed with a linear abrasion tester underlined the strong adhesion between both Materials.
Xianmei Zhang - One of the best experts on this subject based on the ideXlab platform.
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one step fabrication and characterization of a poly vinyl alcohol silver hybrid Nanofiber Mat by electrospinning for multifunctional applications
RSC Advances, 2017Co-Authors: Chungang Yuan, Shiwei Guo, Jian Song, Can Huo, Bing Gui, Xianmei ZhangAbstract:A poly(vinyl alcohol)/silver (Ag–PVA) Nanofiber Mat was synthesized by electrospinning. The fabricated composite was characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), FT-IR spectroscopy, and energy dispersive spectroscopy (EDS). The obtained Mat showed good capacity for the removal of mercury ions from water and antibacterial activity. The possible interaction mechanisms between PVA, silver nanoparticles and mercury were investigated by X-ray photoelectron spectroscopy (XPS). The batch adsorption experiment showed that the composite had good performance for removing mercury ions with good stability to pH and temperature. The adsorption capacity of the composite could be easily regenerated via thermal treatment. The influences of parameters including coexisting ions and the initial concentration of mercury were investigated. The adsorption process followed pseudo-second-order kinetics and the Langmuir isotherm model. The thermodynamic parameters (enthalpy (ΔH), entropy (ΔS) and free energy (ΔG)) of Hg2+ sorption were evaluated. The antibacterial tests revealed that the membrane had excellent antibacterial properties. The composite Mat has potential for both mercury pollution control and antibacterial applications for water treatment.
Kan Wang - One of the best experts on this subject based on the ideXlab platform.
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large scale synthesis of flexible free standing sers substrates with high sensitivity electrospun pva Nanofibers embedded with controlled alignment of silver nanoparticles
ACS Nano, 2009Co-Authors: Qiaofeng Yao, Kan WangAbstract:A new and facile way to synthesize a free-standing and flexible surface-enhanced Raman scattering (SERS) substrate has been successfully developed, where high SERS-active Ag dimers or aligned aggregates are assembled within poly(vinyl alcohol) (PVA) Nanofibers with chain-like arrays via electrospinning technique. The aggregation state of the obtained Ag nanoparticle dimers or larger, which are formed in a concentrated PVA solution, makes a significant contribution to the high sensitivity of SERS to 4-mercaptobenzoic acid (4-MBA) molecules with an enhancement factor (EF) of 109. The superiority of enhancement ability of this Ag/PVA Nanofiber Mat is also shown in the comparison to other substrates. Furthermore, the Ag/PVA Nanofiber Mat would keep a good reproducibility under a low concentration of 4-MBA molecule (10−6 M) detection with the average RSD values of the major Raman peak less than 0.07. The temporal stability of the substrate has also been demonstrated. This disposable, easy handled, flexible fre...
