MgO nanoparticles

The results obtained by Kuila et al. and Acharya et al. [63,64] from the EVA elastomer blended with lamellar-like Mg-Al layered double hydroxide (LDH) nanoparticles demonstrate that MH nanocrystals possess higher flame-retardant efficiency and mechanical reinforcing effect by comparison with common micrometer grade MH particles. Kar and Bhowmick [65] have developed MgO nanoparticles and have investigated their effect as cure activator for halogenated mbber. The results as shown in Table 4.2 are promising. 

MgO nanoparticles have proven to be very effective chemical reagents in the Claisen-Schmidt condensation, which is a very valuable C—C bond-formation reaction commonly employed in the pharmaceutical and fine chemical industries [295]. When MgO(lll) nanosheets were employed for the Claisen-Schmidt condensation of benzaldehyde and acetophenone, they were found to exhibit activity superior to other systems, such as AICI3, BE3, POCI3, alumina and other reported nano-crystaUine MgO samples [296]. This development is particularly noteworthy as it represents a potential heterogenization of the Claisen-Schmidt catalytic process, which offers numerous advantages including easier product recovery and catalyst recycling. 

The electrospinning process was capable of incorporating the nanoparticles on the surface of the nanowebs. This is clearly evident from the regular pattern of the nodes in the transmission emission micrograph (Figure 8.8) and from the individual MgO nanoparticle embedded on the surface of a PEO nanoflber (Figure 8.9). 

FIGURE 8.8 High-resolution TEM image of a single MgO nanoparticle embedded on the surface of a PEO nanofiber. (Hussain, M.M. and Ramkumar, S.S., 2006, Functionalized nanofibers for advanced applications, Indian J. Fiber Text. Res., 31, 41-51.)... 

Fig. 2 IR spectra of H2 chemisorption complexes obtained after H2 addition (lmbar

Fig. 6 UV diffuse reflectance spectra of MgO nanoparticles (a) before and after exposition to UV light in the presence of (b) 1 mbar H2 and (c) 100 mbar H2. For comparison (d) the spectrum related to the reaction of 1 mbar H2 in the dark (formation of H2 chemisorption complex I) is also shown. In order to avoid interference of luminescence in the reflectance measurements, 10 mbar O2 were added in all experiments (a-d).

The airborne diameter of MgO nanoparticles was 15,000 nm, similar to an urban aerosol (57b). At that size, less than 5% of the mass and less than 35% of the surface area would enter the deep lung, evade phagocytosis, and be available to the interstitial space. Moreover, that which was available to the lung s interstitial space would not persist (24b, 25), irritate, or injure the lung tissue. Likewise if MgO nanopaiticles were spilled in the environment, conventional sodium bicarbonate would facilitate their rapid dissolution into aqueous magnesium salts. In the human body, excess magnesium is used for many biochemical reactions, and is cleared within a short time (57c). 

MgO nanoparticle B1 Blocking of viral attachment to host cell... 

Another example is the synthesis of MgO nanoparticles firom hydroxide precipitation in aqueous solutions [156]. The precipitation was conducted at a controlled temperature, while MgCl2 solution at a concentration of 1 mol L was mixed with NaOH solution with a concentration of 2 mol LT. The two solutions... 

It should be noted that the authors [1] supposed, that the oxygen vacancies are the sources of magnetization, while the authors [13] concluded, that the ferromagnetism in MgO nanoparticles originated possibly from Mg vacancies near the surface. Magnetization via percolation can appear due to large concentration of vacancies near the surface [13]. 

FIGURE 4.15 The comparison of gas permeability for pure Matrimid and nanocomposite membranes with different loadings of MgO nanoparticles (a) permeability of helium, hydrogen, and carbon dioxide (b) permeability of oxygen, nitrogen, and methane). (Adapted from Hosseini, S.S., et al., /. Membrane Sci., 302, 207-217, 2007.)... 

The most eco-fiiendly approach when it comes to solvent choices would be not to employ any solvents. Analogs of 3-alkylindole, for example, could be prepared in solvent-free conditions, using MgO nanoparticles as catalyst [35]. Bis(indol-3-yl)methanes could be synthesized in solvent-free grinding conditions, emplo3dng a reusable catalyst, phosphate-impregnated... 

Very recently, Montero and co-workers (369) have reported the pronounced structure sensitivity of MgO-catalyzed glyceryl tributyrate transesterification. In this study, size-controlled MgO nanoparticles were prepared by thermal treatment of Mg(OH)(OCH3). Controlled calcination was employed to control surface structure and the basicity was determined by the application of Auger spectroscopy and XPS. Figure 40 demonstrates the relationship between turnover frequency and snrface polarizability (which reflects surface basicity). It was found... 

Fig. 9.3 Variation in the real part of the relative permittivity of nanocomposite systems, as a function of volume fraction of alumina (AI2O3) and magnesium oxide (MgO) nanoparticles in an epoxy resin matrix data from Andritsch (2010)...

Heitz S, Epping J-D, Aksu Y, Driess M. Molecular heterobimetaHic approach to Li-containing MgO nanoparticles with variable Li-concentrations using lithium-methylmagnesium alkoxide clusters. Chem Mater. 2010 22(16) 4563—4571. 

FIGURE 14.3 Rotated MgO nanoparticles and their relation to . The frequency of measuring a rotation 9 is f(9). 

Ganguly A, Trinh P, Ramanujachary KV, Ahmad T, Mugweiu A, Ganguli AK (2011) Reverse micellar based synthesis of ultrafine MgO nanoparticles (8-10 nm) characterization and catalytic properties. J Coll Int Sci 353 137-142... 

It was suggested that the material s abrasiveness, basic character, electrostatic attraction and oxidizing power (due to the presence of active halogen) combine to promote these biocidal properties. Subsequently, Koper and coworkers described the size effect of the antibacterial activities of MgO nanoparticles (168). More details indicated that smaller MgO nanoparticles with a diameter of 8nm had the highest activity in killing E. coli and S. aureus, while a gradual decrease in antibacterial activity was observed with increase in particle size (from 11 to 23 nm) (169). 

F e 5.17 Procedure for generating atomistic models for mesoporous materials by positioning nanoparticles at crystallographic positions. The images at the bottom are atomistic models of mesoporous MgO generated by positioning MgO nanoparticles at FCC positions. Reprinted with permission from Sayle et al. Copyright 2008 American Chemical Society. 

ZnO and MgO nanoparticles have been shown to increase bone cell functions and decrease infection (Liu et al., 2015 Weng and Webster, 2012). Nano zinc oxide (ZnO) also can induce osteogenic properties from stem cells (Liu et al., 2015). Composites incorporating ZnO nanoparticles with a diameter near 60 nm can form a scaffold for tissue regeneration. The size of laminin, collagen, and fibronectin, which are all major components of the natural ECM, is on the same order of magnitude as a ZnO nanoparticle. Moreover, the piezoelectric and antibacterial properties of ZnO particles make it a good choice for orthopedic implant applications (Sell and Webster, 2(X)8). 

Chandran A, Prakash J, Naik KK, Srivastava AK, D browski R, Czerwinski M, Biradar AM (2014) Preparation and characterization of MgO nanoparticles/ferroelectric liquid crystal composites for faster display devices with improved contrast. J Mater Chem C 2 1844-1853 Chatterjee T, Mitchell CA, Hadjiev VG, Krishnamoorti R (2012) Oriented single-walled carbon nanotubes-poly(ethylene oxide) nanocomposites. Macromolecules 45 9357-9363 Chiu JJ, Kim BJ, Kramer EJ, Pine DJ (2005) Control of nanoparticle location in block copolymers. J Am Chem Soc 127 5036-5037... 

Berger, T., et al., 2007. Lithium ion induced surface reactivity changes on MgO nanoparticles. Journal of Catalysis 247 (1), 61—67. Available at http //www.sciencedirect.com/science/ article/pii/S0021951707000243 (accessed 13.05.15.). 

Microwave-assisted synthesis of nanocrystalhne MgO and its use as a bactericide was demonstrated by Makhluf et al. (2005). The antibacterial activities of the MgO nanoparticles were tested by treating Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) cultines with 1 mg/rtiLof the nanoparticles. The effect of size, pH, and the form of the active MgO species as a bactericidal agent was also observed. The amount of eradicated bacteria was strongly dependent on the particle size. 

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