Electrospinning Oriented Self‐Cleaning Porous Crosslinking Polymer for Efficient Dyes Removal

Abstract

used to selectively separate molecules on the basis of their electrical properties or shapes. [8-10] The topological morphology of the interfacial polymerization substrate is very important for the construction of supramolecular crosslinking polymers. We believe that the combination of interfacial polymerization [11,12] and electrospinning technology [13] could be a good universal method for preparing composite nanofiltration membranes, the structures and properties of which can be controlled by means of surface modification, [14] adjustment of the electrospinning parameters, [15] and the addition of functional nanoparticles to the spinning solution. Membrane separation technology is now widely used in pollutant treatment. [16-18] However, contamination of porous membrane surfaces is a bottleneck that prevents even wider use of this technology. [19-22] After dye-containing wastewater is filtered, membranes are generally recycled by washing with organic solvents, but this process generates dye-containing organic solvent waste. If this new waste is not handled properly, the dissolved dyes can re-enter the environment and cause secondary pollution. Therefore, the development of innovative methods for controlling membrane surface structure and preparing self-cleaning membranes would be highly valuable. [23,24] Self-cleaning membranes responding to environmental stimuli such as magnetic fields, [25] temperature fluctuations, [26] and light [27,28] can cause changes in water flux and surface characteristics. Among the various stimulusresponsive materials, photocatalytic materials have attracted considerable attention; [29-31] and TiO 2 is of particular interest because of its high catalytic activity, good chemical stability, low cost, and low toxicity. [32,33] In the current study, we interfacially polymerized β-cyclodextrin and four crosslinking agents on polyacrylonitrile (PAN) electrospun nanofibrous substrates with different morphologies (depending on the PAN concentration and the spinning orientation), and we investigated the utility of the resulting composite membranes for dye removal from aqueous solution. If TiO 2 was incorporated in the PAN electrospun nanofibrous substrate, UV irradiation of the used composite membranes efficiently degraded the adsorbed dye, rendering the composite membranes self-cleaning and thus reusable (Scheme 1). First, electrospinning technology was used to fabricate nanofibrous PAN and PAN/TiO 2 membranes with controlled fiber diameter and morphology. Then, β-cyclodextrin and The separation of harmful substances by supramolecular crosslinking polymers is the focus of current research. As far as it is known, supramolecular crosslinking systems based on electrospun nanofibers are rarely reported. However, electrospun nanofibers should be promising candidates for interfacial crosslinking substrates because of their adjustable morphology and can be doped with different functional nanoparticles. In this study, β-cyclodextrin and acyl chloride compounds are interfacially polymerized on polya...

Directional Water Transfer Janus Nanofibrous Porous Membranes for Particulate Matter Filtration and Volatile Organic Compound Adsorption

“…Taking the PAN/β-CD/PCL/ZnO membrane as an example, water stained by ethyl violet could penetrate the membrane from hydrophobic PCL side to hydrophilic PAN side with low hydraulic pressure and it would not spread in the hydrophobic layer (Figure 3a, Supporting Information, Movie S1). It is reported that the PAN electrospun nanofibrous membrane has certain ethyl violet filtration ability, 13 and the Janus membrane contains PAN electrospun nanofibers. Therefore, the purple aqueous solution becomes colorless after passing through the membrane (Supporting Information, Movie S1).…”

“…Compared with common filter membranes, the air permeability is higher under the same filtering effect. Electrospinning produces nanofibers with controlled size, morphology, and functional groups . The resulting fibrous membranes have high PM removal efficiency and low airflow resistance, making them ideal candidate for air filtration applications.…”

“…Electrospinning produces nanofibers with controlled size, morphology, and functional groups. 13 The resulting fibrous membranes have high PM removal efficiency and low airflow resistance, making them ideal candidate for air filtration applications. Therefore, polymers such as polyacrylonitrile (PAN), 14,15 polycarbonate, 16 chitosan, 17 polycaprolactone (PCL), 18 polyethylene oxide, 19 and polyurethane 20 have been used to prepare electrospun membranes as air filter.…”

Calixpyridinium–Polyoxometalate Nanoparticle Assemblies for the Removal of Organic Dyes from Wastewater

“…Dyes are highly stable and difficult to remove because they have one or more benzene rings in their structures, so they can exist in the environment for a long time. − With the development of textile, food, paint, and paper industries, dye wastewater with a strong absorption in the visible region has become one of the main harmful industrial pollutants. − If dye wastewater is not properly treated, it will accumulate in the food chain, causing great harm to the environment and human health. − Therefore, a great deal of efforts have been expended in the removal of dyes in recent years. − Dye wastewater treatment technology can be divided into three categories: physical, chemical, and biological methods . Solar energy is the most abundant environmentally friendly and clean energy. , Photocatalysis, a chemical process that has the potential to convert solar energy into chemical energy, has emerged as a promising environmentally friendly technology in recent years because of its great potential in splitting water, decomposing organic pollutants, and reducing CO 2 . − …”

Novel Porous Rhodium Metal–Organic Aerogel for Efficient Removal of Organic Dyes and Catalysis of Si–H Insertion Reactions

“…Because these contaminants can float on the water surface, they can reduce light penetration into the water, thus hindering photosynthesis by phytoplankton; more importantly, some of these compounds are toxic and even carcinogenic to organisms . Several techniques have been used for organic dye removal, including photocatalytic degradation, membrane filtration, electrolysis, and adsorption . Of these techniques, adsorption is considered as the most promising because of its low cost and operational simplicity .…”