Use of Nano Fibers in Filtration -A Review (original) (raw)
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Application of Nanofibres in Filtration Processes
Mechanisms of capture of dust particles, two-and three dimensional modelling of properties of filtration materials and effect of selected variables on electrospinning of polyurethane (PU) solutions are discussed with the aim to prepare a nanofibre structure capable of capturing ultrafine particles. The two-dimensional modelling is used to gain an idea of the effect of mass per square area, thickness of nanofibre layers and nanofibre diameter on filtration efficiency of ultrafine particles. Values of filtration efficiency calculated at the three-dimensional modelling of the filtration process are compared with experimental measurements for sets of filtered particles 100 nm in diameter or bigger. The most important characteristics affecting quality of nanofibre materials are nanofibre diameter, porosity and homogeneity of nanofibre layers. The method making possible to achieve the required diameter of the nanofibres is demonstrated on the influence of relative humidity and solvent type on the fibre-forming process taking place in an electrostatic field. The effect of homogeneity of the nanofibre deposition on the collecting substrate is assessed employing images from scanning electron microscopy (SEM) and tests of filtering abilities of the nanofibre layers. Also, some measurements obtained when nanofibres were used in filtration of air, liquids and dispersions of carbon nanotubes in a liquid are presented.
Nanofibers for Filtration Applications
Advanced Biopolymeric Systems for Drug Delivery, 2020
Due to their interconnected nanoscale pore structures, highly specific surface areas, fine diameters, and porous structure as well as their ability to incorporate active chemistry on nanoscale surface, electrospun fibers are becoming a promising versatile platform for filtration. In the current chapter, we will focus on nanofibers by electrospinning method. Special attention will be focused on antimicrobial nano-fibrous membranes as antimicrobial filters, fibers for oil spill cleanup, fibers for nanoparticles removal from aqueous solution. Also, examples for antimicrobial nano-fibrous membranes developed from electrospun polymers and applications will be discussed.
Nanofibers for High Efficiency Filtration
Journal of Material Science & Engineering, 2017
Nanofiber is a broad phrase generally referring to a fibre with a diameter less than 1 micron. While glass fibres have existed in the sub-micron range for some time and polymeric meltblown fibres are just beginning to break the micron barrier, sub-half-micron diameters have been used for air filtration in commercial, industrial and defence applications for more than twenty years. They have been shown to deliver improved filter life, increased contaminate holding capacity and enhanced filtration efficiency. Small fibres in the sub-micron range, in comparison with larger ones, are well known to provide higher filter efficiency at the same pressure drop in the interception and inertial impaction stages of the filtration process. In particular, nanofibers provide marked increases in filtration efficiency at relatively small (and in some cases immeasurable) decreases in permeability. Nanofiber filter media have enabled new levels of filtration performance in several diverse applications with a broad range of environments and contaminants. While nano fibre size lead to a higher pressure drop, interception and inertial impaction efficiencies will increase faster, and therefore more than compensating for the rise in pressure drop. Thus, in the particle size of interest, i.e. from sub-micron upwards, better filter efficiency can be achieved at the same pressure drop, or conversely, the same filter efficiency at a lower pressure drop can be achieved with nanofibres. This paper will discuss a process for making nanofibers, as well as the benefits, limitations, construction, and applications of filters using nanofiber media.
Morphology of Nano and Micro Fiber Structures in Ultrafine Particles Filtration
2011
Selected procedures permitting to prepare homogeneous nanofibre structures of the desired morphology by employing a suitable combination of variables during the electrospinning process are presented. A comparison (at the same pressure drop) was made of filtration capabilities of planar polyurethane nanostructures formed exclusively by nanofibres, space polycarbonate nanostructures having bead spacers, structures formed by a combination of polymethyl methacrylate micro-and nanofibres and polypropylene meltblown microstructures, through which ultrafine particles of ammonium sulphate 20-400 nm in size were filtered. The structures studied were described using a new digital image analysis technique based on black and white images obtained by scanning electron microscopy. More voluminous structures modified with distance microspheres and having a greater thickness and mass per square area of the material, i.e. structures possessing better mechanical properties, demanded so much in nanostructures, enable preparation of filters having approximately the same free volume fraction as flat nanofibre filters but an increased effective fibre surface area, changed pore size morphology and, consequently, a higher filter quality.
A Review on the Drawbacks of Nano-Filtration of Textile Wastewater Treatment
Southeast University Journal of Textile Engineering, 2020
Wastewater is the output from dyeing, printing and finishing steps in the textile industries, consisting of extremely toxic materials including both organic and inorganic compounds. This is essential to treat wastewater before discharging into environment. The treatment method to be applied to wastewater depends on the its characterization of, costs of plant, maintenance and availability of infrastructure. Nano-filtration is a modern treatment method. This paper has been focused on the drawbacks of Nano-filtration techniques for wastewater treatment, its impact and some possible ways to overcome treatment difficulties.
Assessment of Nanofibers Filtration for Textile Waste-water Treatment
The finished fabrics need to be bleached, dyed, and printed and these processes require at least 100 liters of water for each ton of fabric. The recycle of industrial wastewater is one of the solutions for efficient use of water resources. In this work, designed filter unit was suggested to be used for the filtration of the wastewater from textile dyeing and finishing mill. Three designs were manufactured using yarns and yarns covered with nanofibers layers were introduced. The results of testing different designs indicate the improvement in the filtration efficiency. Moreover, a case study in the dyeing and finishing textile mill designated that the treatment of the wastewater by the designed filters advanced the filtration efficiency. Unit performance of wastewater treatment was: COD decreased to 52 mg/L, TSS decreased to 300 mg/L, and Turbidity to 70 NTU. The designed filtration unit is suitable to be used, in particular in textile dyeing and finishing SME with small discharge, and can produce treated effluent satisfying the standards regulating wastewater.
Initial testing of electrospun nanofibre filters in water filtration applications
Water SA, 2010
The aim of this study was to evaluate the use of nanofibre microfiltration membranes, spun by an innovative electrospinning technique, in water filtration applications. As such, this study bridges the gap between developments in electrospinning techniques for the production of flat-sheet membranes and the application of these membranes in water filtration. Three different applications were examined. Firstly, the use of the membrane (functionalised or non-functionalised) for the removal of pathogens was investigated. Secondly, the electrospun flat-sheet membranes were applied for wastewater treatment in a laboratory-scale submerged membrane bioreactor (MBR). In addition to these applications, physical properties such as clean water permeability (CWP) and strength were also examined. The tests showed that the electrospun membranes can be used for water filtration applications, but that further improvements are necessary before these membranes can be practically employed. In particular, the level of functionality and the properties of irreversible fouling require further research.
Importance of Technical Textiles as Filtration Media-A Review
2019
Textiles are widely used in our day-to-day needs like filtration of air, liquids, food preparation as well as industrial production in large to keep us healthier from the surrounding environment. A variety of fibres, yarns and fabrics both in woven and nonwoven types are used in the field of filtration techniques. The innovative applications of textile filtration fabrics is widely accepted in the pharmaceutical industry in the process of separation of liquids, gases, powders and suspensions involved in the filtration processes. Textile materials in any form play an important role the industrial filtration. In the present industrial processes, there is hardly any process is left where filtration is not involved. In the filtration process, where any textile material used it is called as the filter media or medium. In general filter media is used either in the solid-gas and/or solid-liquid separation. The use of latest technologies with filters and filtration media, the effective time ...
Journal of Aerosol Science, 2017
A robust simplified method was developed to study the effect of electrospinning processing parameters on the morphological properties of electrospun nano-fibrous web, its air permeability, and filtration efficiency against aerosol particles. The developed predictive model related the electrospinning processing parameters to the nano-fibrous web properties. The model was validated experimentally and then is used to study the effect of each electrospinning processing parameters (flow rate, electric field, concentration, and time of electrospinning) on the nanofibrous web properties. For example, it is shown that only 20 min of electrospinning is able to reduce the air permeability by 66% while one hour of electrospinning coating time is able to increase the filtration efficiency to reach 100% for a range of aerosol particle diameters from 300 to 1000 nm. The validated systematic model is used for developing design charts that allow the determination of the desired air permeability and the filtration performance of the nano-fibrous web from the electrospinning parameters and vice versa within a wide range of feasible processing parameters and fiber diameters.
Can Nanofibers Replace Current Microfiltration Materials
2013
Filtration materials are included in recent technologies for water treatment. Huge variety of filters is recently produced. However, a significant technical improvement was achieved in electrospinning of polymeric nanofibers and methods of their parameters definition in the last decade. According to many previous studies and publications, the nanofibrous structures show almost three-times smaller pressure losses than current filtration materials together with excellent filtration. Results of both experimental and pilot-scale application of nanofibrous filtration materials for microfiltration of artificially polluted water are presented and discussed. Nanofibrous filtration materials made of polyurethane (PU) with average diameter of pore size 0.25 µm was used. Filtration efficiency of microbiological pollution removal for both model and real wastewater was evaluated. Our results were compared to values of commonly used filtration material Pragopor 6 in obtained under the same condit...