scholarly journals Combined Layer-by-Layer/Hydrothermal Synthesis of Fe3O4@MIL-100(Fe) for Ofloxacin Adsorption from Environmental Waters

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3275
Author(s):  
Michela Sturini ◽  
Constantin Puscalau ◽  
Giulia Guerra ◽  
Federica Maraschi ◽  
Giovanna Bruni ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Magnetic Behavior ◽  
Layer By Layer ◽  
Adsorption Efficiency ◽  
Environmental Waters ◽  
River Waters ◽  
Time Consumption ◽  
Magnetite Fe3o4 ◽  
Excellent Candidate

A simple not solvent and time consuming Fe3O4@MIL-100(Fe), synthesized in the presence of a small amount of magnetite (Fe3O4) nanoparticles (27.3 wt%), is here presented and discussed. Layer-by-layer alone (20 shell), and combined layer-by-layer (5 shell)/reflux or /hydrothermal synthetic procedures were compared. The last approach (Fe3O4@MIL-100_H sample) is suitable (i) to obtain rounded-shaped nanoparticles (200–400 nm diameter) of magnetite core and MIL-100(Fe) shell; (ii) to reduce the solvent and time consumption (the layer-by-layer procedure is applied only 5 times); (iii) to give the highest MIL-100(Fe) amount in the composite (72.7 vs. 18.5 wt% in the layer-by-layer alone); (iv) to obtain a high surface area of 3546 m2 g−1. The MIL-100(Fe) sample was also synthesized and both materials were tested for the absorption of Ofloxacin antibiotic (OFL). Langmuir model well describes OFL adsorption on Fe3O4@MIL-100_H, indicating an even higher adsorption capacity (218 ± 7 mg g−1) with respect to MIL-100 (123 ± 5 mg g−1). Chemisorption regulates the kinetic process on both the composite materials. Fe3O4@MIL-100_H performance was then verified for OFL removal at µg per liter in tap and river waters, and compared with MIL-100. Its relevant and higher adsorption efficiency and the magnetic behavior make it an excellent candidate for environmental depollution.

Hydrogels Containing Prussian Blue Nanoparticles Toward Removal of Radioactive Cesium Ions

2016 ◽  
Vol 16 (4) ◽  
pp. 4200-4204 ◽  
Author(s):  
Yuichiro Kamachi ◽  
Mohamed B Zakaria ◽  
Nagy L Torad ◽  
Teruyuki Nakato ◽  
Tansir Ahamad ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Prussian Blue ◽  
High Surface ◽  
High Surface Area ◽  
Radioactive Cesium ◽  
Practical Application ◽  
Cesium Ions ◽  
Prussian Blue Nanoparticles ◽  
Excellent Candidate ◽  
Cs Ions

Recent reports have demonstrated the practical application of Prussian blue (PB) nanoparticles toward environmental clean-up of radionuclide 137Cs. Herein, we prepared a large amount of PB nanoparticles by mixing both iron(III) chloride and sodium ferrocyanide hydrate as starting precursors. The obtained PB nanoparticles show a high surface area (440 m2 g−1) and consequently an excellent uptake ability of Cs ions from aqueous solutions. The uptake ability of Cs ions into poly(N- isopropylacrylamide (PNIPA) hydrogel is drastically increased up to 156.7 m2 ·g−1 after incorporating our PB nanoparticles, compared to 30.2 m2 g−1 after using commercially available PB. Thus, our PB-containing PNIPA hydrogel can be considered as an excellent candidate for the removal of Cs ions from aqueous solutions, which will be useful for the remediation of the nuclear waste.

scholarly journals Application of Nano particles by Layer-by-Layer (LBL) Deposition Technique to Improve the Functionality of Textiles

2020 ◽  
Vol 06 (9S) ◽  
pp. 183-191
Author(s):  
Dr. Chet Ram Meena
Keyword(s):  
Textile Industry ◽  
High Surface ◽  
High Surface Area ◽  
Ultra Violet ◽  
Nano Particles ◽  
Layer By Layer ◽  
Molecular Weights ◽  
Coating Method ◽  
Textile Polymers ◽  
Fabric Surface

Few decades back, a Nano word with big promising has been precipitously implying itself into the world's realization and associates with everyday life, economics and globally consequences. Functionalization of textile polymers has been practiced by different techniques to confer new properties on to the fibre so as to enable their application in fields other than textile industry. Nanotechnology may deliver the better performances and functionality to the textile materials due to the high surface area and energy. Further, Nanoparticles can apply on the fabrics by coating method without affecting the comfort and feel of the fabrics. It has improved the various properties like ultra violet protection, antibacterial and stain proof etc. LBL techniques is used to produce a thin polymeric film in a controlled manner on a surface of fabrics by using of different size of molecular weights and charges of polyelectrolytes. The unique feature of this technique is that it forms a very thin layer on fabric surface (1-10 nm) as compared to other available techniques; thus, no deterioration of surface properties of the substrate on which they are deposited. Nano TiO2 and ZnO particles along with polyelectrolytes and produce PEM on the Nylon 66 substrate by using LBL technique to get the antimicrobial and Ultraviolet protection property.

scholarly journals Nanoscale Copper II Oxide An Efficient and Reusable Adsorbent for Removal of Nickel II from Contaminated Water

2021 ◽  
Vol 6 (2) ◽  
pp. 146-154
Author(s):  
Prasanta K. Raul ◽  
Bodhaditya Das ◽  
Rashmi R. Devi ◽  
Sanjai K. Dwivedi
Keyword(s):  
Room Temperature ◽  
High Surface ◽  
High Surface Area ◽  
Field Application ◽  
Real Field ◽  
Contaminated Water ◽  
Adsorption Efficiency ◽  
Cuo Nps ◽  
Wide Range ◽  
Competing Ions

The present work describes the synthesis of copper(II) oxide nanoparticles (NPs) with high surface area (52.11 m2/g) and its Ni(II) adsorption efficiency from contaminated water at room temperature. Copper (II) oxide NPs are able to remove Ni(II) as 93.6 per cent and 93.7 per cent using 500 ppb & 1000 ppb initial concentration of nickel at near-neutral pH respectively. CuO NPs is very much effective to remove more than 75 per cent nickel over a wide range of pH even in presence of other competing ions like Cd2+, Pb2+, Cr6+, SO42-. Prepared CuO NPs can be used to remove Ni(II) from aqueous solution in real field application.

Nanosize Nickel Ferrite Particles Synthesized by Combustion Reaction: Evaluation of Two Synthesization Routes

2006 ◽  
Vol 530-531 ◽  
pp. 637-642 ◽  
Author(s):  
M.A.F. Ramalho ◽  
Ana Cristina Figueiredo de Melo Costa ◽  
Lucianna Gama ◽  
Ruth Herta Goldsmith Aliaga Kiminami ◽  
E.P. Hernandez ◽  
...  
Keyword(s):  
Nickel Ferrite ◽  
High Surface ◽  
High Surface Area ◽  
Magnetic Behavior ◽  
Nitrogen Adsorption ◽  
Vitreous Silica ◽  
Combustion Reaction ◽  
Magnetic Characteristics ◽  
Magnetic Recording Media ◽  
X Ray Diffraction

Ultrafine magnetic nickel ferrite particles have a significant potential for use in many applications such as magnetic recording media, ferrofluids, microwaves, catalysis and radar-absorbing coatings [1, 2]. Nickel ferrite powders with a nominal NiFe2O4 composition were synthesized by combustion reaction and an evaluation was made of the effect of two different conditions of synthesis on the nanostructural and magnetic characteristics of the resulting powders. Two synthesization routes were studied. The first, NFB, involved the preparation of the powder using a Pyrex beaker heated directly on a hot plate at 480°C until self-ignition occurred. By the second route, NFC, the powder was obtained under the same synthesization condition as the NFB route, but a vitreous silica basin was used. The resulting powders were characterized by X-ray diffraction (XRD), nitrogen adsorption by BET and scanning electron microscopy (SEM). The first route, NFB, proved more favorable to obtain powders with high surface area and, hence, smaller crystalline sizes (5.70 nm) and a superparamagnetic behavior. The NFC route confirmed the feasibility of obtaining powders with a crystalline size of 18.00 nm and a magnetic behavior. Saturation magnetization was 33.18 emu/g and the coercivity field was 25.63 Oe for powders obtained by the NFC route.

Synthesis of heterocyclic compounds by catalysts supported on nano-magnetite (Fe3O4)-an update

2020 ◽  
Vol 17 ◽  
Author(s):  
Soheil Sayyahi ◽  
Mehdi Fallah-Mehrjardi ◽  
Seyyed Jafar Saghanezhad
Keyword(s):  
Metal Organic Framework ◽  
High Surface ◽  
High Surface Area ◽  
Point Of View ◽  
Heterocyclic Synthesis ◽  
Magnetite Fe3o4 ◽  
Recoverable Catalyst ◽  
Metal Organic ◽  
Magnetically Recoverable Catalyst ◽  
Surface Modified

: Magnetic nanoparticles have attracted a great deal of attention from both academic and industrial stand point of view, owing to their unique properties including high surface area, and superparamagnetism, which enable them to be suitable for modification with many compounds and employing them as catalyst in organic reactions. In this mini review, we have summarized the application of surface modified magnetite nanoparticles as magnetically recoverable catalyst in heterocyclic synthesis. These catalysts include silica, biopolymer, acid, amine, transition metal, ionic liquid and metal organic framework supported magnetite catalysts.

Engineered 2D Materials for Efficient Biosensors

2015 ◽  
Vol 1725 ◽  
Author(s):  
Tharangattu Narayanan Narayanan ◽  
Pulickel Madhavapanicker Ajayan ◽  
Sowmya Viswanathan ◽  
Gurusaran Manickam ◽  
Venkatesan Renugopalakrishnan
Keyword(s):  
Electron Transfer ◽  
Surface Area ◽  
2D Materials ◽  
Point Of Care ◽  
High Surface ◽  
High Surface Area ◽  
Thin Layers ◽  
Layer By Layer ◽  
Electrode Geometry ◽  
Surface Charges

ABSTRACTThe emergence of 2-dimensional (2D) materials could herald numerous advanced scientific methodologies for both fundamental and applied research. These ultrathin materials can be functionalized and, thus, have the potential to make new devices and sensors that are both highly efficient and sensitive. In addition to being mechanically robust, the 2D materials can be engineered to provide sensor architectures that further increase their inherent high surface area by creating 3D geometries using layer by layer assembly to make stacked devices that could potentially be transparent. The increased sensor surface area would deliver increased signal-to-noise and sensitivity. Here highly sensitive and selective electrochemical detection of bio-analytes using some of engineered 2D materials such as graphene nano-ribbons, fluorinated graphene, and molybdenum disulfide is presented. It is found that surface moieties, defects and surface charges in these ultra-thin layers result in enhanced electron transfer kinetics between the electrodes and biomolecules. This in turn results in an oxidation or reduction of biomolecules with a high peak current, indicating the possible uses of 2D materials for various point-of-care devices. A novel stable 3D electrode geometry has been found to have enhanced heterogeneous electron transfer properties compared to 2D electrodes and provides evidence that electrode geometry and surface area could significantly impact the performance of biosensors.

scholarly journals Spirobifluorene-based polymers of intrinsic microporosity for the adsorption of methylene blue from wastewater: effect of surfactants

2020 ◽  
Vol 7 (9) ◽  
pp. 200741
Author(s):  
Entesar Al-Hetlani ◽  
Mohamed O. Amin ◽  
C. Grazia Bezzu ◽  
Mariolino Carta
Keyword(s):  
Methylene Blue ◽  
Surface Area ◽  
Organic Contaminants ◽  
High Surface ◽  
Sodium Dodecyl ◽  
High Surface Area ◽  
Adsorption Efficiency ◽  
Hydrophobic Polymers ◽  
Polymers Of Intrinsic Microporosity ◽  
Intrinsic Microporosity

Owing to their high surface area and superior adsorption properties, spirobifluorene polymers of intrinsic microporosity (PIMs), namely PIM-SBF-Me (methyl) and PIM-SBF-tBu ( tert -butyl), were used for the first time, to our knowledge, for the removal of methylene blue (MB) dye from wastewater. Spirobifluorene PIMs are known to have large surface area (can be up to 1100 m 2 g −1 ) and have been previously used mainly for gas storage applications. Dispersion of the polymers in aqueous solution was challenging owing to their extreme hydrophobic nature leading to poor adsorption efficiency of MB. For this reason, cationic (cetyl-pyridinium chloride), anionic (sodium dodecyl sulfate; SDS) and non-ionic (Brij-35) surfactants were used and tested with the aim of enhancing the dispersion of the hydrophobic polymers in water and hence improving the adsorption efficiencies of the polymers. The effect of surfactant type and concentration were investigated. All surfactants offered a homogeneous dispersion of the polymers in the aqueous dye solution; however, the highest adsorption efficiency was obtained using an anionic surfactant (SDS) and this seems owing to the predominance of electrostatic interaction between its molecules and the positively charges dye molecules. Furthermore, the effect of polymer dosage and initial dye concentration on MB adsorption were also considered. The kinetic data for both polymers were well described by a pseudo-second-order model, while the Langmuir model better simulated the adsorption process of MB dye on PIM-SBF-Me and the Freundlich model was more suitable for PIM-SBF-tBu. Moreover, the maximum adsorption capacities recorded were 84.0 and 101.0 mg g −1 for PIM-SBF-Me and PIM-SBF-tBu, respectively. Reusability of both polymers was tested by performing three adsorption cycles and the results substantiate that both polymers can be effectively re-used with insignificant loss of their adsorption efficiency (%AE). These preliminary results suggested that incorporation of a surfactant to enhance the dispersion of hydrophobic polymers and adsorption of organic contaminants from wastewater is a simple and cost-effective approach that can be adapted for many other environmental applications.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

Electron holography of catalysts

1995 ◽  
Vol 53 ◽  
pp. 416-417
Author(s):  
A. K. Datye ◽  
D. S. Kalakkad ◽  
L. F. Allard ◽  
E. Völkl
Keyword(s):  
Heterogeneous Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Atomic Scale ◽  
Nano Particles ◽  
Phase Image ◽  
Electron Holography ◽  
Specimen Thickness ◽  
Phase Information ◽  
Particle Structure

The active phase in heterogeneous catalysts consists of nanometer-sized metal or oxide particles dispersed within the tortuous pore structure of a high surface area matrix. Such catalysts are extensively used for controlling emissions from automobile exhausts or in industrial processes such as the refining of crude oil to produce gasoline. The morphology of these nano-particles is of great interest to catalytic chemists since it affects the activity and selectivity for a class of reactions known as structure-sensitive reactions. In this paper, we describe some of the challenges in the study of heterogeneous catalysts, and provide examples of how electron holography can help in extracting details of particle structure and morphology on an atomic scale.Conventional high-resolution TEM imaging methods permit the image intensity to be recorded, but the phase information in the complex image wave is lost. However, it is the phase information which is sensitive at the atomic scale to changes in specimen thickness and composition, and thus analysis of the phase image can yield important information on morphological details at the nanometer level.

Structure and composition of metal particles in Pt-Sn/Al2O3 bimetallic catalysts

1990 ◽  
Vol 48 (4) ◽  
pp. 278-279
Author(s):  
A. Sachdev ◽  
J. Schwank
Keyword(s):  
Bimetallic Catalysts ◽  
Bimetallic Catalyst ◽  
Size Structure ◽  
High Surface ◽  
High Surface Area ◽  
Metal Particles ◽  
Alloy Formation ◽  
Particle Size Range ◽  
Oxide Supports ◽  
Petroleum Fractions

Platinum - tin bimetallic catalysts have been primarily utilized in the chemical industry in the catalytic reforming of petroleum fractions. In this process the naphtha feedstock is converted to hydrocarbons with higher octane numbers and high anti-knock qualities. Most of these catalysts contain small metal particles or crystallites supported on high surface area insulating oxide supports. The determination of the structure and composition of these particles is crucial to the understanding of the catalytic behavior. In a bimetallic catalyst it is important to know how the two metals are distributed within the particle size range and in what way the addition of a second metal affects the size, structure and composition of the metal particles. An added complication in the Pt-Sn system is the possibility of alloy formation between the two elements for all atomic ratios.

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