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Cu-8 wt-%SmCo5 alloys were obtained through mechanical milling for novel industrial applications. Copper and SmCo5 powder mixtures were mechanically alloyed in a planetary ball mill to disperse SmCo5 fine particles in the copper matrix with the aim to modify the structural, mechanical, electrical and magnetic properties. The resulting alloyed powders were characterised as a function of milling time. Under the magnetic field, SmCo5 particles achieved Ms to improve the soft magnetic properties of copper-8 wt-%SmCo5 to be used in dielectromagnetic components. The magnetic properties of Cu-8 wt-%SmCo5 powders reached their optimum values after milling time ranging from 10 to 15 h. The consolidation of milled alloy powders was performed by uniaxial hot pressing at 923 K for 2 h under argon atmosphere to obtain dense compacts. The consolidation process resulted in good dense metal matrix composite materials with adequate properties of compression strength >900 MPa, 95 HRB in hardness, electrical conductivity up to 43% of that of the International Annealed Copper Standard (IACS) and magnetic properties such as coercive field, saturation and remanent magnetisation obtained at 218 Oe, 70·23 emu g-1 and 6·09 emu g-1 respectively at 300 K. The existence of a coercive field and a little magnetic memory of the consolidated system is a typical behaviour of magnetically soft materials. The variation of electric and magnetic properties and its dependence on structure strength change with milling time were discussed. [ABSTRACT FROM AUTHOR]

Single phase yttria nanopowders for transparent ceramics were successfully prepared by using a novel approach called microwave-flash combustion technique. This technique involves the reaction of yttrium nitrate and urea in microwave oven for few minutes. The as-prepared precursor powder was later calcined at 1100 °C for 4h to form cubic crystalline yttria nanopowders. The as-prepared and calcined powders were analysed by such methods as thermogravimetry, Brunauer--Emmett--Teller surface area measurement, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results confirmed that the yttria powder synthesized by microwave-flash combustion was homogenanus and the particles size was in the range of 50-120 nm for calcined powders. [ABSTRACT FROM AUTHOR]

La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 − δ (LSCF) perovskite nanostructures were synthesised using a 42 kHz ultrasound assisted synthesis technique for the fabrication of electrodes in the intermediate and/or low temperature solid oxide fuel and electrolysis cells (SOFCs/SOECs). The obtained nanomaterials were dried at 110 °C followed by calcination in a normal atmosphere at various temperatures from 400 to 1000 °C for 2 h. Powder characteristics such as crystal structure, thermal decomposition, particle size and morphology were analysed. The transmission electron microscopy (TEM) study revealed the uniform equi-axial shape and growth of the obtained nanostructures with respect to the calcination temperature till 800 °C. The structural and chemical analyses confirmed the existence of LSCF and CoFe 2 O 4 phases. [ABSTRACT FROM AUTHOR]

In this investigation, an ecofriendly method for the synthesis of silver nanoparticles (AgNPs) using biodegradable gelatin as a stabilizing agent is reported. Here, we prepared thermosensitive silver nanocomposite hydrogels composed of gelatin and N-isopropylacrylamide. In this green process AgNPs were formed from Ag(+) ions and reduced with leaf [Azadirachta indica (neem leaf)] extracts, resulting in a hydrogel network. The Ag(0) nanoparticles affect the hydrogel strength and improved the biological activity (inactivation effect of bacteria) of the biodegradable hydrogels. The resulted hydrogel structure, morphology, thermal, swelling behavior, degradation, and antibacterial properties were systematically investigated. The biodegradable thermosensitive silver nanocomposite hydrogels developed were tested for antibacterial activities. The results indicate that these biodegradable silver nanocomposite hydrogels are suitable potential candidates for antibacterial applications., (Copyright © 2013 Wiley Periodicals, Inc.)

The present scientific research resulted in the development of novel microbial resistant inorganic nanocomposite hydrogels, which can be used as antibacterial agents. They are promising candidates for advanced antimicrobial applications in the field of biomedical science. Novel inorganic nanocomposite hydrogels were developed from Carbopol® 980 NF and acrylamide. Dual-metallic (Ag 0 -Au 0 ) nanoparticles were prepared (via a green process) by the nucleation of silver and gold salts with mint leaf extract to form a hydrogel network. The Carbopol nanocomposite hydrogels contain (Ag 0 -Au 0 ) nanoparticles ∼5 ± 3 nm in size, which was confirmed by transmission electron microscopy. The developed hydrogels were characterized using Fourier transform infrared (FTIR) spectroscopy, thermo-gravimetric analysis (TGA), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and transmission electron microscopy (TEM). The pure and inorganic nanocomposite hydrogels developed were tested against Bacillus and E. coli, for their antibacterial properties. The results indicate that the inorganic nanocomposites show significantly greater antimicrobial activity than the pure hydrogels. Therefore, novel microbial resistant Carbopol nanocomposite hydrogels can be used as potential candidates for antibacterial applications.

The potential applications, in the biomedical fields, of curcumin loaded silver nanocomposite were studied by using bovine serum albumin (protein) and acrylamide. The design and development of silver nanoparticles with small size and adequate stability are very important, in addition to their applicability, particularly in bio-medicine. In this study, silver nanoparticles were prepared by chemical reduction method, employing sodium borohydride as the reducing agent for silver nanoparticles. The properties of the protein hydrogels formed were characterized via Fourier transform infrared spectroscopy and X-ray diffraction analyses. The size and its distribution, and formation of metal nanoparticles were confirmed by transmission electron microscopy indicating the diameter of the silver nanoparticles in the range of 3-8 nm. The thermal study of curcumin-silver nanocomposite hydrogels was determined by thermo-gravimetric analysis. In order to increase the antibacterial activity of theses inorganic nanomaterials, natural biological curcumin was incorporated into the protein hydrogel. The main emphasis in this investigation is to increase the antibacterial activity of the hydrogels by loading curcumin, for advanced medical application and as a model drug., (Copyright © 2013 Elsevier B.V. All rights reserved.)

In this paper, we report the synthesis and characterization of Iota-Carrageenan based on a novel biodegradable silver nanocomposite hydrogels. The aim of study was to investigate whether these hydrogels have the potential to be used in bacterial inactivation applications. Biodegradable silver nanocomposite hydrogels were prepared by a green process using acrylamide (AM) with I-Carrageenan (IC). The silver nanoparticles were prepared as silver colloid by reducing AgNO3 with leaf extracts of Azadirachta indica (neem leaf) that (Ag(0)) formed the hydrogel network. The formation of biodegradable silver nanoparticles in the hydrogels was characterized using UV-vis spectroscopy, thermo gravimetrical analysis, X-ray diffractometry studies, scanning electron microscopy and transmission electron microscopy studies. In addition, swelling behavior and degradation properties were systematically investigated. Furthermore, the biodegradable silver nanoparticle composite hydrogels developed were tested for antibacterial activities. The antibacterial activity of the biodegradable silver nanocomposite hydrogels was studied by inhibition zone method against Bacillus and Escherichia coli, which suggested that the silver nanocomposite hydrogels developed were effective as potential candidates for antimicrobial applications. Therefore, the inorganic biodegradable hydrogels developed can be used effectively for biomedical application., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Nanoparticles (NPs), grown in liquid media, stand out over other classes of inorganic nanomaterials due to the high degree of control with which their crystal structure, size, shape, and surface functionalities can be engineered in the synthesis stage and to the versatility with which they can be processed and implemented into a large spectrum of devices and processes. In present work pure and Ag-doped ZnSe NPs were successfully synthesized from the solution phase chemistry and investigated with respect to their structural and optical properties. The resulting powder consists of nanocrystalline particles were characterized by X-ray diffraction (XRD), UV-Visible spectroscopy, photoluminescence spectroscopy, transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray analysis (EDX) techniques and Raman spectroscopy. A UV emission peak was observed from the excitons transition at 380 nm in the room temperature photo luminescent (PL) spectra. The blue emission band was assigned to the Zn interstitial and vacancy level transition. Even though Ag ions known to act as an efficient non-radiative loss center for near band gap emission (NBE), a decreased NBE is obtained at room temperature even for a nominal Ag concentration. XRD data analysis shows that the Ag dopant atoms are incorporated into the cubic ZnSe host lattice.

This paper reports the investigation on synthesis and magnetic characterization of Ni substituted Co0.8Zn0.2Fe2O4 nano-particles. The nano-particles of Co(0.8-x)Ni(x)Zn(0.2)Fe2)O4 (x = 0.15, 0.20, 0.35, 0.50, 0.65) were prepared by co-precipitation method. The X-ray diffraction analysis confirmed the formation of single-phase face centered cubic (fcc) spinal structure. The lattice parameter decreased as Ni concentration increased from x = 0 (a = 8.388 A) to x = 0.65 (a = 8.3612 A). The morphology of the particles examined through high-resolution TEM showed a well-isolated and less agglomerated homogeneous distribution of nano-particles which suggests that co-precipitation method is beneficial for magnetic nano-materials synthesis and their characterization. The influence of Ni on magnetic behavior (saturation magnetization and 4piMs) of Co(0.8-x)Ni(x)Zn(0.2)Fe2O4 nano-materials have been evaluated and discussed.