A comprehensive review of applications of magnetic graphene oxide based nanocomposites for sustainable water purification

Lingamdinne, Lakshmi Prasanna,Koduru, Janardhan Reddy,Karri, Rama Rao Elsevier 2019 Journal of Environmental Management Vol.231 No.-

<P><B>Abstract</B></P> <P>With the rapid growth of industrialization, water bodies are polluted with heavy metals and toxic pollutants. In pursuit of removal of toxic pollutants from the aqueous environment, researchers have been developed many techniques. Among these techniques, magnetic separation has caught research attention, as this approach has shown excellent performance in the removal of toxic pollutants from aqueous solutions. However, magnetic graphene oxide based nanocomposites (MGO) possess unique physicochemical properties including excellent magnetic characteristics, high specific surface area, surface active sites, high chemical stability, tunable shape and size, and the ease with which they can be modified or functionalized. As results of their multi-functional properties, affordability, and magnetic separation capability, MGO's have been widely used in the removal of heavy metals, radionuclides and organic dyes from the aqueous environment, and are currently attracting much attention. This paper provides insights into preparation strategies and approaches of MGO's utilization for the removal of pollutants for sustainable water purification. It also reviews the preparation of magnetic graphene oxide nanocomposites and primary characterization instruments required for the evaluation of structural, chemical and physical functionalities of synthesized magnetic graphene oxide nanocomposites. Finally, we summarized some research challenges to accelerate the synthesized MGO's as adsorbents for the treatment of water pollutants such as toxic and radioactive metal ions and organic and agricultural pollutants.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Recent status of the synthetic magnetic adsorbents applications for water-purification. </LI> <LI> Preparation strategies of magnetic graphene oxide (MGO) nanocomposites. </LI> <LI> MGO's nanocomposites characterization strategies are well reviewed. </LI> <LI> Extensively reviews the status and approaches of MGO's for the removal of pollutants. </LI> <LI> Highlighted the future prospective and advantages of the MGO's at conclusions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Block Copolymer-Based Nanocomposites with Exotic Self-Assembled Structures Induced by a Magnetic Field

Hiroaki Wakayama,Hirotaka Yonekura 한국고분자학회 2017 Macromolecular Research Vol.25 No.3

Structural control of polymer nanocomposites is important for their applications in organic semiconductors, lithographic nanopatterning, separation membranes, and nanofabrication templates. However, manufacturing nanocomposite materials with novel structures in a highly efficient yet precise manner remains a great challenge. To create nanocomposite structures, we combined self-assembly processing of block copolymer (BCP)-metal complex nanocomposites with an applied magnetic field. Here, we describe in detail the mechanism of magnetic alignment of block copolymers doped with metal complexes; specifically, we investigated the effect of the applied magnetic field on the phase behavior of the assembled block copolymer-metal complex nanocomposites with various molecular weights and with different molecular structures. We show that our combination of self-assembly processing and application of a magnetic field yielded lamellar structures of alternating multilayers with different layer thicknesses. This self-assembled structure is not included in phase diagrams of BCPs. The influence of the block copolymers’ molecular structures on the nanocomposites’ phase transformation behavior is also discussed. Our results provide a route to manufacturing nanocomposite materials in a highly efficient yet precise manner, which could lead to improvement in the material properties of nanocomposites.

Multifunctional Magnetic Gold Nanocomposites: Human Epithelial Cancer Detection via Magnetic Resonance Imaging and Localized Synchronous Therapy

Lee, J.,Yang, J.,Ko, H.,Oh, S.,Kang, J.,Son, J.,Lee, K.,Lee, S.-W.,Yoon, H.-G.,Suh, J.-S.,Huh, Y.-M.,Haam, S. WILEY-VCH Verlag 2008 Advanced Functional Materials Vol.18 No.2

<P>Novel multifunctional magnetic gold nanocomposites (MGNCs) were synthesized for synchronous cancer therapy and diagnosis via magnetic resonance imaging (MRI). The MGNCs consist of magnetic kernels (aggregates of ultra-sensitive MnFe<SUB>2</SUB>O<SUB>4</SUB> magnetic nanocrystals wrapped in polymer) as effective MR contrast agents and silica–gold nanocomposites as hyperthermal therapeutic agents. A therapeutic antibody, Erbitux (ERB), was conjugated for specific tumor cell targeting both to localize the near-IR laser beam and to image their events through MRI. ERB-conjugated MGNCs selectively recognize the target cancer cell lines. Fluorescence images and MRI analysis show that the MGNCs are effectively taken up by the cells. ERB-conjugated MGNCs have an excellent synchronous therapeutic efficacy as a result of the therapeutic antibody and near-IR laser-induced surface plasmon resonance. Consequently, MGNCs clearly demonstrate selective imaging and treatment of human epithelial cancer simultaneously.</P> <B>Graphic Abstract</B> <P>Multifunctional magnetic gold nanocomposites (MGNCs) were synthesized from aggregates of magnetic nanoparticles wrapped in a polymer as the magnetic resonance contrast agent and a silica–gold nanocomposite shell (see figure) as an effective hyperthermal therapeutic agent. Therapeutic antibody-conjugated MGNCs have an excellent synchronous therapeutic efficacy stemming from the antibodies and NIR-laser-induced hyperthermia, which implies the potential of the MGNCs for simultaneous diagnosis and treatment of cancer. <img src='wiley_img/1616301X-2008-18-2-ADFM200700482-content.gif' alt='wiley_img/1616301X-2008-18-2-ADFM200700482-content'> </P>

Hydrothermal synthesis of different morphologies of MgFe2O4 and magnetic cellulose acetate nanocomposite

Davood Ghanbari,Masoud Salavati-Niasari 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.5

MgFe2O4 nanostructures were synthesized via a facile hydrothermal reaction. The effect of various surfactants such as cationic, anionic and polymeric on the morphology of the product was investigated. Magnetic nanoparticles were added to cellulose acetate (CA) to make magnetic nanocomposite. Nanoparticles appropriately enhanced flame retardant property of the CA matrix. Application of the most conventional flame retardants is limited with respect to the environmental requirements. The most important novelty of this work is the preparation of a nontoxic magnetic and flame retardant cellulose acetate nanocomposite. Dispersed nanoparticles play the role of a magnetic barrier layer, which slows down product volatilization and prevents flame and oxygen from reaching the sample during decomposition of the polymer. In the presence of flame, magnetic nanoparticles remain together (show resistance to drop falling) and build a barrier. Also, distribution of the magnetic nanoparticles into cellulose acetate matrix increases the coercivity.

ONE-STEP SYNTHESIS OF BIOCOMPATIBLE CHITOSAN/NaGdF 4 :Eu 3 þ NANOCOMPOSITE WITH FLUORESCENT AND MAGNETIC PROPERTIES FOR BIOIMAGING

HUI LI,QUAN LIN,CHUANXI WANG,YINGNAN JIANG,ZHANCHEN CUI 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.1

Lanthanide-doped luminescent nanoscale materials have great potential applications in biologicalresearches. Herein, we reported a novel and mild method for one-step synthesis of chitosan/NaGdF 4 :Eu 3 þnanocomposites. The luminescent Eu 3 þions and magnetic resonance imaging(MRI) contrast agent Gd 3 þions were incorporated to these biocompatible nanocomposites. Theresultant nanocomposites exhibited strong °uorescence and attractive magnetic features. Thenanocomposites also have pure hexagonal phase with uniform size of about 65 nm. FT-IR spectrarevealed that these nanocomposites were successfully coated by hydrophilic chitosan, whoseamine groups conferred the nanocomposites excellent dispensability in aqueous solution. Besides,the MTT assay and laser confocal microscopy images have con¯rmed the good biocompatibilityof the nanocomposites. These results indicated that the as-prepared nanocomposites could beused as an excellent targeted imaging agent in biological felds.

Enhanced Adsorptive Removal of Cr (VI) from Plating Industry Wastewater Using CoFe2O4/CTAB Magnetic Nanocomposites

Tran Thi Tuong Van,Nguyen Duc Linh,Nguyen Chi Hieu,Bui Tan Nghia 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.4

The plating industry is one of the causes of hexavalent chromium Cr (VI) pollution in surface water, raising problems for human health and other living things. In this study, we synthesized CoFe 2 O 4 magnetic nanoparticles and coated them with cetyltrimethylammonium bromide (CTAB), a commonly used cationic surfactant, to form CTAB/CoFe 2 O 4 magnetic nanocomposite for Cr (VI) adsorptive removal application from aqueous solution. Characteristic properties of CTAB/ CoFe 2 O 4 were examined using scanning electron spectrometry, surface area apparatus, X-ray diff ractometer, Fourier transform infrared spectrometry, zeta potential analyzer, and vibrating sample magnetometer. The CTAB/CoFe 2 O 4 had superparamagnetic properties, being easily isolated from an aqueous solution and well regenerated by an external magnet. Besides, the CTAB molecules anchored onto the Co 2 FeO 4 nanoparticle surfaces could increase the positive charge and thus facilitate the electrostatic interaction with the Cr (VI) anions. Accordingly, the CTAB/CoFe 2 O 4 reached the Cr (VI) adsorption effi ciency of 89%, two times higher than the pure CoFe 2 O 4 , at an optimal pH of 2, an adsorbent dose of 1 g/L, and an initial Cr (VI) concentration of 10 mg/L. The CTAB/CoFe 2 O 4 magnetic nanocomposite would promise a high potential for Cr (VI) treatment from plating wastewater with simple separation, good adsorption capacity, and an inexpensive, nontoxic production process.

Sono-synthesized Fe3O4–GO–NH2 nanocomposite for highly efficient ultrasound-assisted magnetic dispersive solid-phase microextraction of hazardous dye Congo red from water samples

Sricharoen Phitchan,Chanthai Saksit,Lamaiphan Natthida,Sakaew Chinawooth,Limchoowong Nunticha,Nuengmatcha Prawit,오원춘 한국세라믹학회 2021 한국세라믹학회지 Vol.58 No.2

This research focuses on the preparation of amino-functionalized magnetic graphene oxide nanocomposite (Fe 3 O 4 –GO– NH 2 ), which increases the pre-concentration effi ciency of Congo red residue in water samples. Their characterizations by FT-IR, SEM, EDX, and VSM were carried out in line with the magnetic property. The magnetic adsorbent was mainly used for the pre-concentration of anionic dye under optimized conditions of ultrasound-assisted magnetic dispersive solid-phase microextraction (UA-MDSPME). Typically, pre-concentration optimization conditions such as the pH of the solution, sorbent amount, power and sonication time, type of eluting solvent and its concentration were precisely investigated before the determination by UV–visible spectrophotometry. The analytical performance of the UA-MDSPE method was validated and found to have a linear range of 1.0–25.0 mg L −1 with R 2 > 0.999. The limits of detection and quantifi cation were 4.3 μg L −1 and 14.4 μg L −1 , respectively. The precision of the method calculated from the slope of the calibration curve (%RSD, n = 3 × 3) for intra-day and inter-day analyses was 3.23 and 4.74, respectively. The extraction of Congo red dye from real water samples (drinking water, swamp water, and tap water) ranged from 90.65 to 105.8%. The enrichment factor of the developed procedure was averaged to 32.4 folds, ensuring the determination of trace amounts of residual dye in the water samples. It is, therefore, concluded that the magnetic adsorbent is an effi cient method for the pre-concentration of hazardous dye from aqueous solution.

Effect of Various Composition Ratios on the Exchange Spring Effect in SrFe12O19/CoFe2O4 Nanocomposite Magnets

Novrita Idayanti,Dedi,Dadang Mulyadi,Tony Kristiantoro,Nanang Sudrajat,Gandi Sugandi,Azwar Manaf 한국자기학회 2023 Journal of Magnetics Vol.28 No.3

This study aims to examine the effect of various composition ratios on the exchange spring effect of strontium ferrite (SrFe12O19)/cobalt ferrite (CoFe2O4) nanocomposite magnets. Nanoparticles of hexagonal hard phase SrFe12O19 and spinel soft phase CoFe2O4 were each prepared through mechanical alloying and high-power ultrasonic irradiation processes. Furthermore, the constituent of the hard-soft particles was weighed based on its ratios and the mixture was homogenized under a sonicator-type Qsonica at a frequency of 20 kHz for an hour. The bulk composite samples were obtained in cylindrical pellets form through compaction of mixture powders at 5000 kg/cm2, followed by sintering at 1200 °C. The exchange spring effect enhanced the magnetic properties, surpassing the normal limit for non-interacting magnetic particles due to enhanced grain interactions. The results showed that the degree of property enhancement depended on the various composition ratios and microstructure of the composite magnets. The magnetization of saturation (Ms) of the samples increased compared to a single SrFe12O19. Furthermore, the highest coercivity (Hc) and product energy maximum (BH)max values were observed in the sample which had mass ratios of SHF:COF of 85:15 with coded S80C20. The occurrence of exchange spring effects was observed in material characterized by a microstructure consisting of a hard-magnetic phase with elevated magnetocrystalline anisotropy and saturation magnetization values, along with a soft magnetic phase exhibiting high saturation magnetization value.

SYNTHESIS OF MAGNETIC SBA-15 AND Fe–SBA-15 MESOPOROUS NANOCOMPOSITES WITH COBALT FERRITES

HONGXIAO JIN,LIANG LI,MIN CHEN,JINGCAI XU,BO HONG,BAO HUANG,DINGFENG JIN,HONGLIANG GE,XINQING WANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2011 NANO Vol.6 No.3

A new nanocomposite based on SBA-15 mesoporous materials combined with Fe_2O_3 and CoFe_2O_4 nanoparticles was prepared via sol–gel growth. The nanostructures and magnetic properties of the SBA-15 nanocomposite were investigated by X-ray diffraction topography, high resolution transmission electron microscopy, and vibrating sample magnetometer. Results indicate that α-Fe_2O_3 nanoparticles are present in the frame or micropores of SBA-15 (denoted as Fe–SBA-15 below) and that CoFe_2O_4 nanoparticles are confined in the mesoporous channels of Fe–SBA-15. Our results also reveal that the addition of CoFe_2O_4 and α-Fe_2O_3 magnetic nanoparticles critically affects their magnetic properties. The saturation magnetization of the SBA-15 nanocomposite is attributed to ferrimagnetic CoFe_2O_4 nanoparticles and antiferromagnetic α-Fe_2O_3 nanoparticles, whereas the coercivity increases with the content of CoFe_2O_4. Moreover, the presence of the couple exchange interaction between the magnetic nanoparticles is confirmed, which can enhance the magnetic properties of the SBA-15 nanocomposite.

Magnetic properties and dye adsorption capacities of silica-hematite nanocomposites with well-defined structures prepared in surfactant solutions

You, K.E.,Park, J.H.,Kim, Y.C.,Oh, S.G. Elsevier 2014 SOLID STATE SCIENCES Vol.33 No.-

Silica-hematite (α-Fe<SUB>2</SUB>O<SUB>3</SUB>) nanocomposites were synthesized by addition of aqueous solution containing ferrous ions (Fe<SUP>2+</SUP>), cetyltrimethylammonium bromide (CTAB) as a surfactant and tert-butanol (t-butanol) as a cosurfactant into colloidal silica solution. At alkaline atmosphere, silica surface with negative charges electrostatically attracts positively-charged iron hydroxide nuclei or particles which are stabilized by cationic CTAB molecules, and then silica-iron compound composites could be formed. Finally, the silica-hematite composite particles were obtained after calcination at 800 <SUP>o</SUP>C for 4 h. Through these processes, two types of composites having ''core-shell type'' or ''decorated type'' could be achieved. Morphology, BET surface area, crystallinity and magnetic properties of samples were analyzed by using TEM, BET, XRD and VSM, respectively. The ''decorated type'' composites had larger BET surface area and better magnetization. Also, to estimate the application in water treatment, adsorption properties of composites were studied through methylene blue (MB) adsorption which was characterized by UV-vis spectroscopy, involving collection of composites with neodymium magnet.