Electrospun polymer nanofibers (EPNFs) as one-dimensional nanostructures are characterized by a high surface area-to-volume ratio, high porosity, large number of adsorption sites and high adsorption ...capacity. These properties nominate them to be used as an effective adsorbent for the removal of water pollutants such as heavy metals, dyes and other pollutants. Organic dyes are considered one of the most hazardous water pollutants due to their toxic effects even at very low concentrations. To overcome this problem, the adsorption technique has proven its high effectiveness towards the removal of such pollutants from aqueous systems. The use of the adsorption technique depends mainly on the properties, efficacy, cost and reusability of the adsorbent. So, the use of EPNFs as adsorbents for dye removal has received increasing attention due to their unique properties, adsorption efficiency and reusability. Moreover, the adsorption efficiency and stability of EPNFs in aqueous media can be improved via their surface modification. This review provides a relevant literature survey over the last two decades on the fabrication and surface modification of EPNFs by an electrospinning technique and their use of adsorbents for the removal of various toxic dyes from contaminated water. Factors affecting the adsorption capacity of EPNFs, the best adsorption conditions and adsorption mechanism of dyes onto the surface of various types of modified EPNFs are also discussed. Finally, the adsorption capacity, isotherm and kinetic models for describing the adsorption of dyes using modified and composite EPNFs are discussed.
The rapid growth of the dye and textile industry has raised significant public concerns regarding the pollution caused by dye wastewater, which poses potential risks to human health. In this study, ...we successfully improved the adsorption efficiency of activated carbon derived from pomegranate peel waste (PPAC) through a single-step and surface modification approach using 5-sulfonate-salicylaldehyde sodium salt. This innovative and effective sulfonation approach to produce sulfonated activated carbon (S-PPAC) proved to be highly effective in removing crystal violet dye (CV) from polluted water. The prepared PPAC and S-PPAC were characterized via FESEM, EDS, FTIR and BET surface area. Characterization studies confirmed the highly porous structure of the PPAC and its successful surface modification, with surface areas reaching 1180.63 m
/g and 740.75 m
/g for the PPAC and S-PPAC, respectively. The maximum adsorption capacity was achieved at 785.53 mg/g with the S-PPAC, an increase of 22.76% compared to the PPAC at 45 °C. The isothermic adsorption and kinetic studies demonstrated that the adsorption process aligned well with the Freundlich isotherm model and followed the Elovich kinetic model, respectively. The thermodynamic study confirmed that the adsorption of CV dye was endothermic, spontaneous and thermodynamically favorable onto PPAC and S-PPAC.
Electrospun membrane-based adsorbents are gaining widespread use in water treatment due to their ease of handling and effectiveness in removing a variety of pollutants from polluted aqueous media. ...However, the preparation of some nanofibrous membranes often requires the use of organic solvents, which can pollute the environment. In this study, an environmentally friendly nanofibrous adsorbent without using any organic solvent based on polyvinyl alcohol/poly sodium acrylate (PVA/PANa NFs) was fabricated using an electrospinning and thermal crosslinking process. The fabricated PVA/PANa NFs were characterized using various techniques, including FE-SEM, ATR-FTIR, XRD, DSC and the drift method measurement method. The addition of PANa to PVA NFs led to a decrease in the average diameter of nanofibers and played a prominent role in improving their adsorption performance for methylene blue (MB) dye removal. In alkaline media (pH 9.0) and temperatures of 25 °C, 35 °C, and 40 °C, the calculated maximum adsorption capacity of MB dye was found to be 544.28, 538.98 and 530.25 mg g
−1
, respectively. The pseudo-second-order model provided a good fit to the kinetic data, whereas the Temkin model was found to be well-suited for describing the isotherm data. The negative free Gibbs energy values, which range between 39.6 and 41.5 kJ mol
−1
, and the negative enthalpy value (−2.41 kJ mol
−1
), indicate that the adsorption process was feasible, spontaneous, and exothermic. Desorption studies also revealed that the PVA/PANa NFs retained their adsorption capacity even after six consecutive adsorption/desorption cycles, showing their effective reusability.
A water-resistant nanofibrous adsorbent based on polyvinyl alcohol/polyacrylate was fabricated by electrospinning followed by heat treatment as a reusable and effective adsorbent for the removal of cationic methylene blue dye.
Electrospun glass nanofibers (EGNFs) were prepared to reinforce polyethylene (PE) plastic waste towards the development of photochromic anti‐counterfeiting patterns and long‐persistent ...photoluminescent materials, such as smart windows and concrete. By physical integration of lanthanide‐doped aluminate (LdA) nanoparticles (NPs) into polyethylene plastic reinforced with EGNFs, a transparent lanthanide‐doped aluminate nanoparticles (LdANPs)/EGNFs@PE sheet was produced. The colorless EGNFs@PE hybrids became green under ultraviolet (UV) rays and greenish‐yellow in a darkened room as proved by CIE Lab and photoluminescence analysis. In the luminescent LdANPs/EGNFs@PE hybrids, the identified photochromism was promptly reversed at low concentrations of LdANPs to designate fluorescence emission. Photoluminescence was maintained with slow reversibility for the high phosphor concentrations to designate afterglow emission. LdANPs exhibit diameters of 5–12 nm, whereas glass nanofibers have diameters of 70–120 nm. The morphologies of LdANPs/EGNFs@PE substrates were studied by energy‐dispersive x‐ray spectroscopy (EDX), scanning electron microscopy (SEM), and x‐ray fluorescence (XRF). The mechanical properties of the prepared polyethylene plastic were enhanced by reinforcement with glass nanofibers as a roughening agent. The photoluminescent substrates showed markedly improved scratch resistance in comparison to LdANPs‐free EGNFs@PE substrate. The obtained luminescence spectra displayed an emission band at 519 nm upon excitation at 365 nm. The results demonstrated that the luminous plastic has improved hydrophobicity and UV shielding upon increasing the LdANPs content.
Glass nanofibers were electrospun to function as reinforcement agent to prepare photochromic, ultraviolet protective, transparent, superhydrophobic, photostable and photoluminescent smart polyethylene plastic sheet.
Grafting of poly(para-, ortho- and meta-phenylenediamine (PPDA)) onto electrospun carbon nanofibers was performed via oxidative polymerization of o-, p-, m-PDA onto the surface of ECNFs to produce ...PPDA-g-ECNFs. The well characterized PPDA-g-ECNFs and their precursors were applied as effective nanoadsorbent for the removal of Coomassie brilliant blue R-250 (CBB) from aqueous solutions. The obtained results indicated that the surface modification of ECNFs by conjugated polymers enhanced its adsorption capacity with respect to CBB and was dependent on the nature of surface functionalization, concentration of CBB, pH, and contact time. The equilibrium isotherm and kinetic parameters on the adsorption of CBB onto the functionalized ECNFs were evaluated and analyzed by non-linear isotherm and kinetic models. The results of the kinetic and isotherm studies revealed that the Elovich kinetic model and the Redlich–Peterson isotherm model were more suitable to describe the adsorption of CBB from an aqueous solution. Furthermore, the thermodynamic parameters exhibited spontaneity of CBB adsorption and its endothermic characteristic, thereby demonstrating the high efficiency of the introduced adsorbents for CBB adsorption. A possible mechanism of adsorption was suggested wherein electrostatic interaction, π–π interactions, and intermolecular H-bonding control the CBB adsorption.
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•Poly(phenylenediamine) grafted electrospun carbon nanofibers (PPDA-g-ECNFs) were successfully prepared and characterized.•PPDA-g-ECNFs were used as an effective nanoadsorbent for the removal of toxic dye.•The effect of different parameters on the adsorption was investigated in detail.•The adsorption capacity of PPDA-g-ECNFs is higher than most reported results.•The mechanism was systematically discussed and proposed with kinetics, isotherms and thermodynamics.
The use of some hydrogels as adsorbents for pollutants removal from wastewater is limited due to their high swelling properties and the difficulty in recovering them after the adsorption process. To ...overcome these problems, a new hydrogel nanocomposite based on chitosan-grafted-polyacrylic acid/oxidized electrospun carbon nanofibers (CT-
-PAA/O-ECNFs) was prepared by an in situ grafting polymerization process. The prepared hydrogel nanocomposite was used as a novel effective and highly reusable adsorbent for the removal of methylene blue (MB) from polluted water with low cost. The morphology and the structure of CT-
-PAA/O-ECNFs were investigated by numerous techniques. The effect of incorporating O-ECNFs on the swelling capability of the prepared hydrogel was explored in distillated water and MB solution at normal pH. The effect of parameters including ratio of O-ECNFs, contact time, pH, initial concentration, and temperature on adsorption process were explored. The adsorption isotherm and kinetic were studied by numerous non-linear models. The obtained results confirmed that the incorporation of O-ECNFs into the hydrogel network decreased the swelling capacity and improved its ability towards MB dye removal. The adsorption process depended on the pH value of the dye solution. Additionally, the adsorption and kinetic results were fitted using the Freundlich isotherm model and pseudo second order model (PSO), respectively. Moreover, the new adsorbents can be recycled for at least five cycles keeping its adsorption capacity and can be easily recovered without loss in its initial weight.
The main objective of this work is to develop biodegradable active films through the combination of the extracts with different solvents sourced from Eucalyptus citriodora leaves, with films made of ...chitosan (Cs) and polyvinylpyrrolidone (PVP). Chromatographic profiling investigations were carried out to examine the antibacterial characteristics of E. citriodora extracts before their direct incorporation into the polymer films. At this point, the potent antimicrobial properties of the phenol compounds and bioactive components demonstrated an antibacterial activity that was particularly noticeable at a hexane resolution. Different morphological characteristics were seen on films made from these solvent extracts, such as Cs/PVP-AE, Cs/PVP-EAE, and Cs/PVP-HE, when scanning electron microscopy was used. Numerous other outcomes of all the interactions between the extract particles and the film were shown by the pores defined by the Cs/PVP film's porous nature. The addition of the extracts, either alone or in combination, greatly enhanced the Cs/NC/PVP films' mechanical characteristics. It has also been shown that adding plant extracts greatly increased the antibacterial activity of these films. These findings reveal that Cs/PVP films loaded with extract may be utilized as more environmentally acceptable substitutes for possible food packaging application by increasing shelf life of food products.
Abstract Recent years have seen an increase in research on biodiesel, an environmentally benign and renewable fuel alternative for traditional fossil fuels. Biodiesel might become more cost-effective ...and competitive with diesel if a solid heterogeneous catalyst is used in its production. One way to make biodiesel more affordable and competitive with diesel is to employ a solid heterogeneous catalyst in its manufacturing. Based on X-ray diffraction (XRD) and Fourier Transform infrared spectroscopy (FTIR), the researchers in this study proved their hypothesis that iron oxide core–shell nanoparticles were generated during the green synthesis of iron-based nanoparticles (FeNPs) from Camellia Sinensis leaves. The fabrication of spherical iron nanoparticles was successfully confirmed using scanning electron microscopy (SEM). As a heterogeneous catalyst, the synthesised catalyst has shown potential in facilitating the conversion of algae oil into biodiesel. With the optimal parameters (0.5 weight percent catalytic load, 1:6 oil—methanol ratio, 60 °C reaction temperature, and 1 h and 30 min reaction duration), a 93.33% yield was attained. This may be due to its acid–base property, chemical stability, stronger metal support interaction. Furthermore, the catalyst was employed for transesterification reactions five times after regeneration with n-hexane washing followed by calcination at 650 °C for 3 h.
This study presents a novel approach in the synthesis and characterization of nanocomposites comprising cationic chitosan (CCS) blended with varying concentrations of silver ...nanoparticles/montmorillonite (AgNPs/MMT). AgNPs/MMT was synthesized using soluble starch as a reducing and stabilizing agent. Subsequently, nanocomposites, namely CCS/AgMMT-0, CCS/AgMMT-0.5, CCS/AgMMT-1.5, and CCS/AgMMT-2.5, were developed by blending 2.5 g of CCS with 0, 0.5, 1.5, and 2.5 g of AgNPs/MMT, respectively, and the corresponding nanocomposites were prepared using ball milling technique. Transmission electron microscopy (TEM) analysis revealed the formation of nanocomposites that exhibiting nearly spherical morphologies. Dynamic light scattering (DLS) measurements displayed average particle sizes of 1183 nm, 131 nm, 140 nm, and 188 nm for CCS/AgMMT-0, CCS/AgMMT-0.5, CCS/AgMMT-1.5, and CCS/AgMMT-2.5, respectively. The narrow polydispersity index (~0.5) indicated uniform particle size distributions across the nanocomposites, affirming monodispersity. Moreover, the zeta potential values exceeding 30 mV across all nanocomposites that confirmed their stability against agglomeration. Notably, CCS/AgMMT-2.5 nanocomposite exhibited potent antibacterial and antibiofilm properties against diverse pipeline materials. Findings showed that after 15 days of incubation, the highest populations of biofilm cells, Pseudomonas aeruginosa biofilm, developed over UPVC, MDPE, DCI, and SS, with corresponding HPCs of 4.79, 6.38, 8.81, and 7.24 CFU/cm2. The highest cell densities of Enterococcus faecalis biofilm in the identical situation were 4.19, 5.89, 8.12, and 6.9 CFU/cm2. The nanocomposite CCS/AgMMT-2.5 exhibited the largest measured zone of inhibition (ZOI) against both P. aeruginosa and E. faecalis, with measured ZOI values of 19 ± 0.65 and 17 ± 0.21 mm, respectively. Remarkably, the research indicates that the youngest biofilm exhibited the most notable rate of inactivation when exposed to a dose of 150 mg/L, in comparison to the mature biofilm. These such informative findings could offer valuable insights into the development of effective antibiofilm agents and materials applicable in diverse sectors such as water treatment facilities, medical devices, and industrial pipelines.
In order to develop smart concrete with afterglow emission, epoxy resin (EPX) was immobilized with nanoparticles of alkaline earth aluminate (NAEA) as a photoluminescent agent and electrospun ...polypropylene nanofibers (EPN) as a reinforcement agent. Scanning electron microscope images of EPN displayed diameters of 70–90 nm, whereas transmission electron microscopic images showed that NAEA has diameters of 3–9 nm. To create a transparent sheet that glows in the dark, NAEA were physically immobilized in EPN@EPX composite. CIE Lab and photoluminescence spectrum studies demonstrated that EPN@EPX bars turned greenish upon exposure to ultraviolet (UV) rays and greenish‐yellow in a darkened box. The luminous EPN@EPX morphologies and chemical compositions were analyzed using various analytical methods. The resistance to scratching of EPN@EPX bars was monitored to considerably increase with increasing NAEA concentration. The photoluminescence spectrum demonstrated two emission peaks at 437 and 518 nm. Photoluminescent EPN@EPX hybrids with low NAEA content have shown rapid photochromism reversibility. On the contrary, NAEA‐rich EPN@EPX bars displayed slow reversibility, glowing in the dark. Superhydrophobicity and UV blockage were found to be significantly improved in the luminescent colorless EPN@EPX hybrids.
Preparation of photoluminescent transparent electrospun polypropylene nanofiber‐reinforced epoxy concrete toward afterglow emission, hydrophobicity, photostability, and ultraviolet blocking.
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