Synthesis of zinc oxide nanocomposites using poly (ionic liquids) based on quaternary ammonium acrylamidomethyl propane sulfonate for water treatment

Ionic liquid based composites: A versatile materials for remediation of aqueous environmental contaminants

Water pollution is one of the most aggravated problems threatening the sustainability of human race and other life forms due to the rapid pace of civilization and industrialization. A long history exists of release of hazardous pollutants into the water bodies due to selfish human activities since the Industrial Revolution, but no effort has been completely successful in curbing the activities that result in the degradation of our environment. These pollutants are harmful, carcinogenic and have adverse health effects to all forms of life. Thus, remarkable efforts have been geared up to obtain clean water by exploiting science and technology. The application of Ionic liquids (ILs) as sustainable materials have received widespread attention since the last decade. Their interesting properties, simplicity in operation and satisfactory binding capacities in elimination of the contaminants makes them a valuable prospect to be utilized in wastewater treatment. Immobilizing and grafting the solid supports with ILs have fetched efficient results to exploit their potential in the adsorptive removal processes. This review provides an understanding of the recent developments and outlines the possible utility of IL based nano adsorbents in the removal of organic compounds, dyes and heavy metal ions from aqueous medium. Effect of several parameters such as sorbent dosage, pH and temperature on the removal efficiency has also been discussed. Moreover, the adsorption isotherms, thermodynamics and mechanism are comprehensively studied. It is envisioned that the literature gathered in this article will guide the budding scientists to put their interest in this area of research in the days to come.

Batch Preparation of CuO/ZnO-Loaded Nanofiber Membranes for Photocatalytic Degradation of Organic Dyes

Composite nanofiber membranes (CNFMs) loaded with CuO/ZnO (CZCNFMs) have important applications in a series of organic and industrial catalytic reactions because of nanoeffects of the nanofibers and the peculiar performances of semiconductor oxides. In this work, CZCNFMs with different mass ratios of Cu to Zn were successfully fabricated in batches using modified bubble electrospinning (MBE), a heat treatment method, and a hydrothermal method. The influences of the mass ratio of Cu to Zn on the morphologies, structures, and properties of the CNFMs were studied, and the obtained CNFMs with different mass ratios of Cu to Zn were applied to the photodegradation of methyl orange (MO) and methylene blue (MB). The results showed that when the mass ratio of Cu to Zn was 5:5, the fabricated CNFM had better morphology, structure, and mechanical properties and had the best degradation effects on MO and MB. In addition, the principal active substances produced during the photodegradation of MO were defined by free radical capture experiments, and the influences of the pH value of the MO solution on the photocatalytic activity of the CNFMs with the optimal mass ratio of 5:5 were discussed.

Preparation, characterization and photocatalytic performance of heterostructured CuO-ZnO-loaded composite nanofiber membranes

Inorganic semiconductor oxides loaded on composite nanofibers (CNFs) have been widely applied in environmental monitoring, industry, aviation, and transportation. In this paper, heterostructured CuO-ZnO-loaded CNF membranes (CNFMs) were prepared successfully by a combination of electrospinning, heat treatment, and hydrothermal synthesis. The influence of the synthesis parameters on morphology, structure, and properties of the CNFMs was investigated, and the optimal process parameters were determined. Then, the CNFMs obtained with optimal process parameters were applied for the photocatalytic degradation of methyl orange. It was found that the CNFMs could be reused to degrade methyl orange at least three times, and the degradation rate remained above 90%.

Novel Magnetic Silica-Ionic Liquid Nanocomposites for Wastewater Treatment

In this work, new imidazolium silica-ionic liquids doped with magnetite nanocomposites are prepared for use in the field of water purification owing to their unique properties, which can be manipulated by an external magnetic field. A silane precursor based on aminopropyltriethoxysilane (APTS) condensed with p-hydroxybenzaldehyde and glyoxal in an acetic acid solution is used to prepare disiloxyimidazolium ionic liquid (SIMIL). The silica composite (Si-IL) and silica-coated magnetite (Fe₃O₄-Si-IL) composites are prepared using the sol-gel technique. The chemical structures, morphologies, crystalline lattice structures, thermal stabilities, surface charges, surface areas, particle sizes, and magnetic characteristics of Fe₃O₄-Si-IL and Si-IL are investigated. The Fe₃O₄-Si-IL and Si-IL nanocomposites show excellent chemical adsorption capacities as 653 and 472 mg g^-1, respectively, during times ranging 90 to 110 min when they are used as adsorbents to remove Congo red (CR) dye as a water pollutant.

Hybrid Ionic Silver and Magnetite Microgels Nanocomposites for Efficient Removal of Methylene Blue

The ionic crosslinked 2-acrylamido-2-methylpropane sulfonic acid-co-acrylic acid hydrogel, AMPS/AA and its Ag and Fe₃O₄ composites were synthesized using an in situ technique. The surface charge, particle sizes, morphology, and thermal stability of the prepared AMPS/AA-Ag and AMPS/AA-Fe₃O₄ composites were evaluated using different analytical techniques and their adsorption characteristics were evaluated to remove the methylene blue cationic dye, MB, from their aqueous solutions at optimum conditions. Also, the same monomers were used to synthesize AMPS/AA microgel and its Ag and Fe₃O₄ nanocomposites, which were synthesized using the same technique. The AMPS/AA-Fe₃O₄ nanocomposite was selected as conventional iron-supported catalyst due to the presence of both Fe(II) and Fe(III) species besides its magnetic properties that allow their easy, fast, and inexpensive separation from the aqueous solution. It was then evaluated as a heterogeneous catalyst for complete MB degradation from aqueous solution by heterogeneous Fenton oxidation. It achieved a high rate of degradation, degrading 100 mg L^-1 of MB during a short time of 35 min as compared with the reported literature.

Preparation and Characterization of CuO/ZnO/PVDF/PAN Nanofiber Composites by Bubble-electrospinning

BACKGROUND

Nanocomposites loaded with metal oxides, such as CuO and ZnO, have excellent optical, electrical, mechanical and chemical properties, which result in their great potential applications in optoelectronic devices, sensors, photocatalysts and other fields. Especially, electrospun metal- oxide-loaded nanofibers have attracted much attention in many fields. However, the single-needle Electrospinning (ES) inhibits the industrial application of these electrospun nanofiber composites. Bubble-Electrospinning (BE) is an effective free surface ES for mass production of nanofiber membranes loaded with metal oxide. Few relevant patents to the topic have been reviewed and introduced.

METHODS

The BE was used to prepare mass production of Cu(Ac)2 /Zn(Ac)2/ PVDF/ PAN Composite Nanofiber Membranes (CNFMs). Then PVDF/PAN CNFMs containing CuO and ZnO nanocrystals were obtained by heat-treatment. Finally, CuO nanosheets and ZnO nanorods were successfully grown on the surface of PVDF/PAN CNFMs using hydrothermal method. In addition, the morphology and crystal structure of CNFMs were investigated by scanning electron microscopy (SEM) and X-Ray Powder Diffractometer (XRD).

RESULTS

The morphology and crystal structure of the samples were characterized by SEM and XRD. The results showed the heat treatment temperature of 150oC and the hydrothermal temperature of 150oC were the optimal process parameters for the fabrication of PVDF/PAN CNFMs loaded with CuO and ZnO nanocrystals, and a higher heat treatment temperature results in higher crystallinity of ZnO and CuO.

CONCLUSION

CuO/ZnO/PVDF/PAN CNFMs were successfully prepared by a combination of BE, heattreatment and hydrothermal method. The ZnO/CuO beads obtained by heat treatment is the key point of growing ZnO/CuO nanocrystals, and the growth temperature has great effect on the morphology of ZnO/CuO nanocrystals.