Academia.edu no longer supports Internet Explorer.
To browse Academia.edu and the wider internet faster and more securely, please take a few seconds to upgrade your browser.
A novel high-performance polyamide 6, polyacrylonitrile and polyvinylidene fluoride nanofibers were fabricated using industrial production Nanospider equipment for liquid filtration as microfilters. The application of nanofibers has been hindered by their poor mechanical strength. This work developed a feasible approach to preparing mechanically strong nanofiber webs. The mechanical strength of the nanofibers was enhanced using special lamination technique on a supporting layer. Experimental results show that the mechanical strength of the nanofibers enhanced more than 5 times while high porosity and liquid permeability retain. The separation results indicate that nanofibers have a potential to be used in liquid filters.
In the new century, electrospun nanofibrous webs are widely employed in various applications due to their specific surface area and porous structure with narrow pore size. The mechanical properties have a major influence on the applications of nanofiber webs. Lamination technology is an important method for improving the mechanical strength of nanofiber webs. In this study, the influence of laminating pressure on the properties of polyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF) nanofibers/laminate was investigated. Heat-press lamination was carried out at three different pressures, and the surface morphologies of the multilayer nanofibrous membranes were observed under an optical microscope. In addition, air permeability, water filtration, and contact angle experiments were performed to examine the effect of laminating pressure on the breathability, water permeability and surface wettability of multilayer nanofibrous membranes. A bursting strength test was developed and applied to measure the maximum bursting pressure of the nanofibers from the laminated surface. A water filtration test was performed using a cross-flow unit. Based on the results of the tests, the optimum laminating pressure was determined for both PAN and PVDF multilayer nanofibrous membranes to prepare suitable microfilters for liquid filtration.
Wastewater treatment is one of the urgent need because of increasing water pollution. Polymeric nanofibrous composite membranes have been developed for the purpose of wastewater filtration due to small pore size and highly porous structure. In this work, various nanofibrous composite membranes were prepared, and flux performance was compared using a custom-built cross-flow unit. Membranes were prepared according to area weight of electrospun nanofiber mat, supporting layers and lamination methods.
Membranes are considered as a promising technology for separation and filtration processes. Here, novel polyvinylidene fluoride (PVDF) nanofibrous multilayer membranes were fabricated by wire-based industrial electrospinning equipment following by a lamination process. The lamination process was optimised under various applied temperature, force of lamination, and lamination time. Air permeability and burst-pressure tests were run to determine the optimum membranes for filtration application. The structures of the prepared membranes were characterised by scanning electron microscopy and pore-size analysis. The hydrophilic properties of the membranes were evaluated using water contact angle measurement, and the mechanical strength of the membranes was analysed. Air and water filtration tests were run to find the possible application of prepared membranes. The air filtration results showed that membranes had high filtration efficiencies: Over 99.00% for PM 2.5 , and PM 0.1. The water filtration results indicated that permeability of the membranes changed from 288 to 3275 L/m 2 hbar. The successful preparation of such an interesting material may provide a new approach for the design and development of electrospun filter membranes.
A facile and low-cost method has been developed for separation of oily wastewater. Polyvinylidene fluoride/polyacrylonitrile (PVDF/PAN) nanofibers laminated on a supporting layer were tested. In order to create highly permeable and fouling-resistant membranes, surface modifications of both fibers were conducted. The results of oily wastewater separation showed that, after low vacuum microwave plasma treatment with Argon (Ar) and chemical modification with sodium hydroxide (NaOH), the membranes had excellent hydrophilicity, due to the formation of active carboxylic groups. However, the membrane performance failed during the cleaning procedures. Titanium dioxide (TiO 2) was grafted onto the surface of membranes to give them highly permeable and fouling-resistance properties. The results of the self-cleaning experiment indicated that grafting of TiO 2 on the surface of the membranes after their pre-treatment with Ar plasma and NaOH increased the permeability and the anti-fouling properties. A new surface modification method using a combination of plasma and chemical treatment was introduced.
The aim of the study was to prepare a thin film nanofibrous composite membrane utilized for nanofiltration technologies. The composite membrane consists of a three-layer system including a nonwoven part as the supporting material, a nanofibrous scaffold as the porous surface, and an active layer. The nonwoven part and the nanofibrous scaffold were laminated together to improve the mechanical properties of the complete membrane. Active layer formations were done successfully via interfacial polymerization. A filtration test was carried out using solutions of MgSO 4 , NaCl, Na 2 SO 4 , CaCl 2 , and real seawater using the dead-end filtration method. The results indicated that the piperazine-based membrane exhibited higher rejection of divalent salt ions (>98%) with high flux. In addition, the m-phenylenediamine-based membrane exhibited higher rejection of divalent and monovalent salt ions (>98% divalent and >96% monovalent) with reasonable flux. The desalination of real seawater results showed that thin film nanofibrous composite membranes were able to retain 98% of salt ions from highly saline seawater without showing any fouling. The electrospun nanofibrous materials proved to be an alternative functional supporting material instead of the polymeric phase-inverted support layer in liquid filtration.
This paper provides a comprehensive analysis of microwave-induced low-vacuum argon plasma treatment effects on the hydrophilic stability of various polymeric nanofiber webs. After plasma modification, samples are kept dry at room temperature in a dark place for the experiments, and the wettability of the nanofibers is improved by plasma treatment. The stability of the plasma-treated hydrophilic nanofiber webs is observed for 55 days using water contact angle measurements. Different polymeric nanofiber webs show different stability. Based on the contact angle measurements, the surface starts to lose hydrophilicity during the first week after plasma treatment. The structural changes are examined by pore size measurements, scanning electron microscopy, and Fourier transform infrared spectroscopy. Two of the selected nanofiber webs are used as microfilters for separation of oily wastewater with a cross-flow separation unit to measure the effect of the plasma treatment under wastewater. The permeability and selectivity of the plasma-treated and untreated samples are compared. V
Due to growing demand for production of safe water a search of new materials for water purification is of critical issue. Their production should be of low cost and offers easily scalable manufacturing protocol. In this study, we have described preparation and properties of hydrophilic/oleophobic microfiltration membranes produced by means of wire electrospinning. Selective separation of oil or water was tested for oil-water emulsion by using a dead-end filtration unit. The obtained data allowed us to claim membranes as excellent separators for splitting emulsions.
2015 •
2017 •
2011 •
ACS applied materials & interfaces
Fouling-tolerant nanofibrous polymer membranes for water treatment2014 •
Springer-Nature
Electrospinning production of nanofibrous membranes2019 •
Cambridge University Press; 1 edition
Introduction to Nanofiber Materials2014 •
Journal of Applied Polymer Science
Recent progress in the preparation, characterization, and applications of nanofibers and nanofiber membranes via electrospinning/interfacial polymerization2010 •
2009 •
Conference Papers in Materials Science
Electrospun Nanomaterials: Biotechnology, Food, Water, Environment, and Energy2013 •
2013 •
2008 •
Journal of Materials Chemistry
Electrospun composite nanofibers and their multifaceted applicationsPolymer Journal
In situ polymerization of PVDF-HEMA polymers: electrospun membranes with improved flux and antifouling properties for water filtration2014 •
2019 •
Textile Progress
Nanotechnology in fibrous materials–a new perspectiveJournal of Nanoscience and Nanotechnology
Electrospun Nanofibers: From Filtration Membranes to Highly Specialized Tissue Engineering Scaffolds2014 •
Carbohydrate Polymers
Preparation and characterization of polysaccharides/PVA blend nanofibrous membranes by electrospinning method2014 •
Membrane Water Treatment
Progresses in membrane and advanced oxidation processes for water treatment2014 •
Acta Biomaterialia
Preparation and characterization of polysaccharidic microbeads by a microfluidic technique: Application to the encapsulation of Sertoli cells2010 •
Macromolecular Materials and Engineering
Biological, Chemical, and Electronic Applications of Nanofibers2013 •