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Aquatic pteridophyte ( Azolla sp.) was taken to assess its potential to synthesize the metal (Au) nanoparticles. The synthesized particles were characterized using X-ray, UV-visible, scanning and transmission electron microscopy analyses. Nanoparticles almost spherical in shape having the sizes of 5-17nm are found. UV-visible study revealed the surface plasmon resonance at 538nm. Responsible phytochemicals for the transformation were principally phenolics, tannins, anthraquinone glycosides and sugars present abundantly in the plant thereby bestowing it adaptive prodigality. Also, the use of Azolla sp. for the synthesis of gold nanoparticles offers the benefit of eco-friendliness. [ABSTRACT FROM AUTHOR]

Single phase silver aluminum titanate (Ag1/2Al1/2)TiO3, later called AAT, nanoceramic powder (particle size 2 to 7.5 nm) was synthesized by a low-cost, green and reproducible tartaric acid gel process. X-ray, FT-IR, energy dispersive X-ray and high resolution transmission electron microscopy analyses were performed to ascertain the formation of AAT nanoceramics. X-ray diffraction data analysis indicated the formation of monoclinic structure having the space group P2/m(10). UV-Vis study revealed the surface plasmon resonance at 296 nm. Dielectric study revealed that AAT nanoceramics could be a suitable candidate for capacitor applications and meets the specifications for 'Z7R' of Class I dielectrics of Electronic Industries Association. Complex impedance analyses suggested the dielectric relaxation to be of non-Debye type. To find a correlation between the response of the real system and idealized model circuit composed of discrete electrical components, the model fittings were performed using the impedance data. Electric modulus studies supported the hopping type of conduction in AAT. The correlated barrier hopping model was employed to successfully explain the mechanism of charge transport in AAT. The ac conductivity data were used to evaluate the density of states at Fermi level and minimum hopping length of the compound. [ABSTRACT FROM AUTHOR]

A rapid way of synthesizing silver nanoparticles by treating silver ions with a green Capsicum annum L. alcoholic fruit extract containing principally polyphenols, pigments, capsaicin and ascorbic acid is reported. The reaction protocol was monitored using UVvisible spectroscopy. Accordingly, the entire span of experimentation has been proposed in the form of a mathematical model in the light optical dependence of maturing Ag nanoparticles. The crystalline morphology and phase of the nanoparticles were determined with the help of transmission electron microscopy, selected area electron diffraction and X-ray diffraction studies. Nanoparticles almost spherical in shape having a size of 2-6 nm are found. The results indicated that the extract, which has capsaicin containing amine groups along with other candidate polyphenols and ascorbic acid, played a reducing and controlling role during the formation of silver nanoparticles in the solutions of green Capsicum annuum L. fruit. [ABSTRACT FROM AUTHOR]

A low-cost, green, and highly reproducible microbe (Lactobacillus sp.)-mediated biosynthesis of Gd2O3 nanoparticles is reported. X-ray and transmission electron microscopy analyses were performed to ascertain the formation of Gd2O3 nanoparticles. X-ray analysis indicated that Gd2O3 nanoparticles have a body-centered cubic (BCC) unit cell structure. Individual nanoparticles almost spherical in shape of 10-20 nm were found. An effort has been made to understand the possible involved mechanism for the biosynthesis of Gd2O3 nanoparticles. The present procedure offers the benefit of eco-friendliness and amenability for large-scale production through scaling up. [ABSTRACT FROM AUTHOR]

Abstract: A new low-cost, green and reproducible Lactobacillus sp. assisted biosynthesis of BaTiO3 nanoparticles is reported. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of BaTiO3 nanoparticles. The apparent crystallite size and lattice strain are estimated from Williamson–Hall approach. XRD analysis of the compound indicated the formation of a single-phase tetragonal structure. Individual nanoparticles as well as a few aggregate having the size of 20–80nm are found. A possible involved mechanism for the biosynthesis of nano-BaTiO3 has also been proposed in which ROS as well as partial pressure of gaseous hydrogen (rH2) of the culture solution seems to play an important role in the process. Remarkable enhancement in dielectric properties was observed in BaTiO3/polyvinylidene fluoride (PVDF) nanocomposite. [Copyright &y& Elsevier]

Abstract: A low-cost green and reproducible microbes (Lactobacillus sp. and Sachharomyces cerevisae) mediated biosynthesis of TiO2 nanoparticles is reported. The synthesis is performed akin to room temperature in the laboratory ambience. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of TiO2 nanoparticles. Individual nanoparticles as well as a few aggregate having the size of 8–35nm are found. Concentric Scherrer rings in the selected area electron diffraction pattern indicated that the nanoparticles are having all possible orientations. A possible involved mechanism for the biosynthesis of nano-TiO2 has also been proposed in which pH as well as partial pressure of gaseous hydrogen (rH2) or redox potential of the culture solution seems to play an important role in the process. [Copyright &y& Elsevier]

Abstract: A green low-cost and reproducible yeast (Saccharomyces cerevisiae) mediated biosynthesis of Sb2O3 nanoparticles is reported. The synthesis is performed akin to room temperature in the laboratory ambience. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of Sb2O3 nanoparticles. Rietveld analysis indicated that Sb2O3 nanoparticles have face centered cubic (FCC) unit cell structure. Individual nanoparticles as well as a few number of aggregate almost spherical in shape having a size of 2–10nm are found. Possible involved mechanism for the synthesis of nano-Sb2O3 has also been proposed. [Copyright &y& Elsevier]