China
Africa
Explore chapters and articles related to this topic
Magnetic Nanosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
What are amino-CLIO nanoparticles? CLIO (cross-linked iron oxide) nanoparticles (Haun et al. 2010) contain a superparamagnetic iron oxide core (3–5 nm-sized MION) composed of ferromagnetic magnetite (Fe3O4) and/or maghemite (γ-Fe2O3). Maghemite is structurally and functionally similar to magnetite but differs in one aspect, in that it contains cation vacancies in the sublattice.
Iron Nanoparticles for Contaminated Site Remediation and Environmental Preservation
Published in Alok Dhawan, Sanjay Singh, Ashutosh Kumar, Rishi Shanker, Nanobiotechnology, 2018
Adam Truskewycz, Sayali Patil, Andrew Ball, Ravi Shukla
Maghemite is ferrimagnetic below its Curie temperature (645K). Its structure has a meta stable cubic iron oxide spinel structure and possesses Fe3+ charged states. It is magnetic and reddish brown in appearance and is often the product of weathered magnetite. It may also be produced by heating other iron oxides (Laurenzi III 2008, Zhang and Olin 2011, Virkutyte and Varma 2013).
Nanomedicine Clinical and Preclinical Use
Published in Bertrand Henri Rihn, Biomedical Application of Nanoparticles, 2017
Roudayna Diab, Sanghoon Kim, Ileana-Alexandra Pavel, Nadia Canilho, Fernanda Bianca Haffner, Sijin Li, Alain Celzard, Mihayl Varbanov, Emmanuel Lamouroux, Andreea Pasc
Under aerobic conditions, magnetite (Fe3O4), which is not thermodynamically stable, can be transformed in maghemite (γ-Fe2O3). Another way to achieve the formation of maghemite is to use acidic media under anaerobic conditions (Equation 3.2).
A study on the preparation and characterization of maghemite (γ-Fe2O3) particles from iron-containing waste materials
Published in Journal of Asian Ceramic Societies, 2020
Lutfor Rahman, Shovon Bhattacharjee, Sydul Islam, Fauzia Zahan, Bristy Biswas, Nahid Sharmin
At present, the iron-bearing waste materials, very rich in iron (≈ 72% Fe), are produced in massive volumes and represent a potential of nearly five million tons worldwide [9]. Different forms of iron oxides can be extracted from these waste materials. Gamma phase magnetic iron oxide (ferric) is the second most stable polymorph of iron oxide, which is easier to produce and very utilitarian. The chemical name of the gamma phase magnetic iron oxide is maghemite (γ-Fe2O3). Maghemite has a spinel structure showing ferrimagnetism in contrast with antiferromagnetic hematite (α-Fe2O3) below 928 K [10,11]. Owing to the non-toxicity, high chemical and physical stability, low cost, and flabbergasting hysteric properties, it has been extensively investigated by chemists, physicists, and engineers. Consequently, it has wide potentials in the field of high density magnetic recording media and storage of information [12,13], magnetic resonance imaging [14,15], catalyst [16], magnetic fluids [17], and pigments [7,18]. It is also exploited in magnetocaloric refrigerators [19], gas sensors [20,21], biomedical and clinical uses [22–26], spintronics [27,28], and so on. There are several methods in the literature that have been reported for the preparation of maghemite particles. However, the prohibitive costs of the reagents and instrumentation is a compelling aspect to look for a new approach. Moreover, maximum techniques are not utterly utilized on a large scale [7,29–36].
Facile green synthesis of Fe3O4 nanoparticles using aqueous leaf extract of Zanthoxylum armatum DC. for efficient adsorption of methylene blue
Published in Journal of Asian Ceramic Societies, 2018
A. V. Ramesh, Dharmasoth Rama Devi, Satish Mohan Botsa, K. Basavaiah
During the past decade, there has been increasing concern about the organic pollutants, heavy metals and pathogens in an aquatic environment due to their wide distribution and potential adverse health effects [1]. Especially, the presence of toxic organic dyes in water effluent, even at parts per billion (ppb) levels, is extremely harmful and undesirable. Various treatment approaches for removing organic dyes from contaminated water are available, such as adsorption, bioremediation, precipitation, membrane filtration, reverse osmosis, and photocatalysis [2]. However, these methods have proved to be ineffective for removal of dyes from water effluents due to high chemical stability of dyes, high cost and low efficiency of these processes. Among these chemical and physical methods, the adsorption method is more versatile and efficient, and has been successfully used for removal of dyes from contaminated water due to its simplicity of design, wide adaptability, convenience and ease of operation. Especially, nano-adsorbents offer the possibility of efficient removal of organic dyes owing to smaller size and higher adsorptive surface area. From the past few years, there have been an increased investigations based on iron oxide nanoparticles such as magnetite nanoparticles (Fe3O4 NPs), maghemite (γ-Fe2O3 NPs), etc., for the removal of organic and inorganic contaminants. Among all magnetic nanoparticles, Fe3O4 NPs have emerged as potential candidate for technological applications such as magnetic fluids, high-density magnetic storage, environmental remediation, cancer therapy, MRI contrast enhancement, drug delivery, tissue repair engineering, antibacterial, catalysis, lithium-ion battery due to their small size, biocompatibility, low toxicity and high saturation magnetism [1–7].
Fe2O3-powder activated carbon/CaO2 as an efficient hybrid process to remove a reactive dye from textile wastewater
Published in Chemical Engineering Communications, 2023
Behzat Balci, M. H. Ahmed Al Dafiry, F. Elcin Erkurt, Mesut Basibuyuk, Zeynep Zaimoglu, Fuat Budak, H. Kivanc Yesiltas
Maghemite (γ-Fe2O3) is an iron oxide that may be used as a coating material on the adsorbent surface, and it also provides magnetic properties to the adsorbent. Furthermore, maghemite is widely used in the adsorption process to remove persistent compounds from industrial wastewater. It is cost-effective, easy to produce, and has high magnetic saturation (Barad et al. 2022; Liu et al. 2022; Vinayagam et al. 2022). Magnetic adsorbents can be separated from industrial wastewater by applying a magnetic field, such as magnetic drums (Liao et al. 2022; Prochazkova et al. 2022). Magnetically modified PAC possesses a high surface area adsorbent for the removal of textile dyes. Also, magnetic PAC can be effectively separated from the wastewater. The advanced oxidation process (AOP) is much more effective than other methods because it converts dyes into harmless compounds such as CO2 and H2O (Cechinel et al. 2022; Guo et al. 2022; Panwar et al. 2022). Fenton and Fenton-like processes are commonly used methods for removing dyes from textile effluents. However, the requirement of the acidic pH values and iron sludge formation after the neutralization limit the use of the Fenton and Fenton-Like processes. Recently, the UV-assisted photocatalytic process has become well-known for degrading organic pollutants. However, the main disadvantage of the UV-assisted AOP is the rise in operation costs (Louhichi et al. 2022; Zhu et al. 2022). Calcium peroxide (CaO2) is known as solid hydrogen peroxide (H2O2). CaO2 is preferred more than H2O2 due to its chemical stability. CaO2 releases H2O2 and strong oxidizing radicals such as hydroxyl radical (•OH) in aqueous media (Equations (1)–(5)). The •OH radical can oxidize dye molecules effectively due to its high reactivity. CaO2 is an eco-friendly and strong oxidant (E° = 2.01 V) and does not cause metal sludge formation as in Fenton processes (Hou et al. 2022).