α-Fe2O3 Nanoparticles: An Efficient, Inexpensive Catalyst for the one-pot Preparation of 3,4-dihydropyrano[c]chromenes

This paper describes the combustion synthesis of α-Fe2O3 nanopowder at much lower temperature and its catalytic activity for the one-pot preparation of 3,4-dihydropyrano[c]chromenes. The combustion derived α-Fe2O3 nanopowder was characterized by powder X-ray diffraction (PXRD), Braunauer, Emmett and Teller (BET) surface area, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Highly efficient, three-component condensation of aromatic aldehyde, malanonitrile and 4-hydroxycoumarin catalyzed by α-Fe2O3 nanoparticles at room temperature is described. The method offers an excellent alternative to the synthesis of 3,4-dihydropyrano[c]chromenes. The reactions are rapid, clean, and the products with good yield and high purity

Nano ZnO and its Perspective in Anti-Cancer Activities

Several methods are used to counter the deadly disease cancer. Zinc oxide nanoparticles (ZnO NPs) is one of the metal oxide nanoparticles which had been used in anti-cancer activities due to its large bandwidth and high exciting binding energy and it has potential applications like antibacterial, antifungal, anti-diabetic, anti-inflammatory, wound healing, antioxidant, optic properties and also which holds promise to treat cancer effectively. Studies have shown that Zinc metal oxide nano particles induce cytotoxicity in cancer cells. The mechanism for antitumor could work through apoptosis or the generation of reactive oxygen species or and necrosis, among other possibilities. This review is on some of the most significant antitumor results obtained with zinc oxide nanoparticles depending on their size, surface morphology, methods of preparation and also cytotoxicity result

Ion beam-induced luminescence and photoluminescence of 100 MeV Si8+ ion irradiated kyanite single crystals

lonoluminescence (IL) of kyanite single crystals during 100 MeV Si8+ ion irradiation has been studied in the fluence range 1.87-7.50 x 10(11) ions/cm(2). Photoluminescence (PL) of similar dimensional crystals was recorded with same ions and energy in the fluence range 1 x 10(11) -5 x 10(13) ions/cm(2) with an excitation of 442 non He-Cd laser beam. A sharp IL and broad PL peaks at similar to 689 and 706 run were recorded. This is attributed to luminescence centers activated by Fe2+ and Fe3+ ions. It is observed that up to a given fluence, the IL and PL peak intensities increase with increase of Si8+ ion fluence. The stability of the chemical species was Studied on with and without irradiated samples by means of FT-IR spectroscopy. The results confirm that the O-Si-H type bonds covering on the surface of the sample. This layer might be acting as a protective layer and there by reducing the number of non-radiative recombination centers. (c) 2008 Elsevier Ltd. All rights reserved

Synthesis, Characterization of Nano MnO2 and its Adsorption Characteristics Over an Azo Dye

ABSTRACT Nano MnO2 powder was synthesized by low temperature solution combustion method using oxalyl dihydrazide (ODH) fuel. The final product was well characterized by Powder X-ray diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning electron microscopy (SEM) for crystallographic purity, phase formation and surface morphology respectively. PXRD results show that pure MnO2 was synthesized at 300 0 C with no other impurities. SEM micrograph shows the product has highly porous structure with large voids, typical of combustion derived material. An adsorption characteristic of the porous MnO2 was studied over direct green dye (DG). The optimum dose of MnO2 for removal of 10 ppm DG azo dye was found to be 0.4 g L -1

Effect of flux on thermoluminescence studies of Sr2SiO 4:Eu0.01 nanophosphor

Eu3+ doped (0.01 mol %) nanocrystalline Sr2SiO 4 phosphor was prepared by solution combustion method using citric acid as fuel and NaF as flux. The crystallization and particle size of Sr 2SiO4 have been investigated by using Powder X-ray diffarction. Thermoluminescence of Sr2SiO4:Eu 0.01 nanophosphor exposed to γ-irradiation in the dose range 10-100 Gy has been investigated. Two glow peaks recorded at 156°C and 220°C respectively. The kinetic order, activation energy and frequency factor were estimated by Chen's peak shape method

Effect of flux on thermoluminescence studies of Sr2SiO 4:Eu0.01 nanophosphor

Eu3+ doped (0.01 mol %) nanocrystalline Sr2SiO 4 phosphor was prepared by solution combustion method using citric acid as fuel and NaF as flux. The crystallization and particle size of Sr 2SiO4 have been investigated by using Powder X-ray diffarction. Thermoluminescence of Sr2SiO4:Eu 0.01 nanophosphor exposed to γ-irradiation in the dose range 10-100 Gy has been investigated. Two glow peaks recorded at 156°C and 220°C respectively. The kinetic order, activation energy and frequency factor were estimated by Chen's peak shape method