Advanced Materials Research Vol. 678

Abstract: In the present work we report, synthesis, structural, thermal and optical properties of ZnO incorporated PVP films. To prepare Polyvinylpyrolidone (PVP) capped ZnO films, simple room temperature sol gel method was adopted. Prepared PVP capped ZnO films were annealed at 800 C for 15 min and 30 min. X ray diffraction pattern shows prepared particles are in hexagonal wurtzite structure. Optical absorption measurements show an exciton absorption peak around ~ 370 nm. Emission spectra shows strong peaks around 329 and 333 nm are attributed to the band edge emission and broad peak found at 432 nm is attributed to the defect related emission. Thermal properties of the prepared films were studied by thermo gravimetric analysis. Interaction between the ZnO nanoparticles and PVP were investigated by Fourier Transform Infrared Spectroscopy (FTIR), it shows band at 441 cm-1 is attributed to Zn-O bond.

Abstract: Aniline was polymerized with mmt (Montmorrillonite) by chemical oxidation method using potassium perdisulphate. The solubility of the chemically prepared polymer–clay nanocomposite was ascertained and it showed good solubility in DMSO and DMF. The Pani–mmt nanocomposites were characterized by UV–Vis, FTIR spectral studies. Amine vibration peak observed at 1593 cm-1 was shifted to lower wave numbers when the polymer–clay nanocomposites were formed. The X-ray diffraction studies revealed the formation of nano sized (26 nm) crystalline nanocomposite. SEM analysis showed mixed granular nature of the polymer–clay nanocomposite in which polymer was intercalated with the clay. EDAX analysis shows the presence of Na, Mg Al, Si, C and N. Cyclic Voltammetric studies exhibit good adherent behaviour on electrode surface at pH 1.0. It exhibited two oxidation peaks at 0.360V and 0.638V and two reduction peaks at 0.431V & 0.103V. Chronoamperometric and chronocoulometric studies were also carried out at inert as well as oxidation atmosphere.

Abstract: Aniline was polymerized with TiO2 by chemical oxidation method using Potassium perdisulphate. The solubility of the chemically prepared polymer–ceramic nanocomposite was ascertained and it showed good solubility in DMSO and DMF. The Pani–TiO2 nanocomposite was characterized by UV–Vis, FTIR spectral studies. Amine vibration observed at 1593 cm-1 was shifted to lower wave numbers when the polymer–ceramic nanocomposites were formed. The X-ray diffraction studies revealed the formation of nano sized (26 nm) crystalline polymer. SEM analysis showed mixed granular nature of the polymer–ceramic nanocomposite. EDAX analysis shows the presence of Ti, C and N. Cyclic Voltammetric studies exhibit good adherent behaviour on electrode surface at pH 1.0. It showed the presence of oxidation peaks at 0.271V and 0.623V and reduction peaks at 0.832 and 0.493V. CV, Chronoamperometric and chronocoulometric studies were also carried out at inert as well as oxidation atmosphere.

Abstract: Abstract Methyl ester of fatty acids, derived from vegetable oils or animal fats are known as biodiesel. The most common method of biodiesel production is transesterification (alcoholysis) of oil (triglycerides) with methanol in the presence of a catalyst which gives biodiesel (fatty acid methyl esters, FAME) and glycerol (by product). In this work, an environmentally benign process for the methanolysis of neem oil to methyl esters using Mg–Al nano hydrotalcites as solid base catalysts in a heterogeneous manner was developed. The effect of the reaction temperature, reaction time, catalyst amount, and methanol /oil molar ratio on the Mg-Al nano hydrotalcite was analyzed. The nano catalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM). Biodiesel produced from the neem oil by using Mg-Al nano hydrotalcite catalyst was analyzed by gas chromatography.

Abstract: Nano particles of Copper oxide and Poly(3,4-ethylenedioxythiophene)-Copper oxide nanocomposite were prepared by chemical oxidation method. The formed metal oxide nanoparticle and polymer metal oxide nanocomposites were characterized by UV–VIS, XRD, SEM and EIS studies. The UV-VIS studies of nanoparticles and nanocomposites exhibited four peaks, two peaks are sharp and centered at 280nm and 360 nm while the other two were broaden waves obtained at 780nm and 985nm. SEM image of copper oxide nanoparticles and nanocomposite exhibits sponge-like morphologies, in addition to nanospheres, nanowires, and nanotube shapes. The grain size of the metal oxide nanoparticle and polymer metaloxide nanocomposites was calculated using Scherrer’s formula. Electrochemical impedance spectroscopy (EIS) studies revealed the high conductivity nature due to the increased surface area of the nanocomposites.

Abstract: The main aim of present study is to develop the nanocrystals as a viable drug delivery strategy for the improvement of dissolution rate and bioavailability of dexibuprofen. Dexibuprofen nanocrystals were prepared by the combination of precipitation and high shear homogenization method. Particle size and morphology of produced nanocrystals were compared with that of the pure drug. Particle size of nanocrystals is in the range of 95 to 117 nm were as 2.43µm for pure drug. Photomicrographs of phase contrast microscopy and the TEM showed the spherical shape of the nanocrystals. In-vitro drug release of dexibuprofen nanocrystals formulations was studied by dialysis bag method and observed the drug release of 92 to 100% within 6 hrs. Hence we conclude that the formulated nanocrystals may offer exciting opportunities for oral and other formulations.

Abstract: The aim of the present study was to develop a self nanoemulsifying drug delivery system (SNEDDS) for the improved oral delivery of Rosuvastatin, a lipid lowering agent. Captex 810D, based on the higher solubility of Rosuvastatin was selected as an oil phase. Mixture of permeation enhancers such as Solutol HS15 and Acconon MC8 was selected as surfactants for the formulation of SNEDDS. Formulated SNEDDS upon mixing with water, dispersed rapidly into fine droplets size ranging from 95-263nm. Further the SNEDDS was evaluated for self nanoemulsification time, precipitation, cloud point, morphology, in-vitro drug release and ex-vivo permeation. Formulation (F3) showed the globule size of 139nm, quick self nanoemulsifiation time (20 sec) and transparency (97%). Maximum drug release of 99.9% and higher drug permeation of 95% was observed with formulation F3 when compared with conventional tablet. The formulated SNEDDS can be used to improve the oral absorption and bioavailability of Rosuvastatin.

Abstract: Silver thin film of 5 nm thicknesses was evaporated on glass and stainless steel substrates and annealed at 300°C for one hour. Then these samples were characterized by using X-ray diffraction method (XRD), Scanning Electron Microscopy (SEM), UV-VIS spectroscopy, and subjected to anti-microbial resistance test. XRD analysis showed as deposited silver thin film coated on glass substrate and stainless steel substrates have amorphous nature. The annealed Ag thin film coated on glass and stainless steel substrates showed crystallinity with silver phase and their crystalline size were in the range of 30-40 nm and 17 nm respectively. SEM image indicates that formation of silver nanoparticles with spherical morphology after annealing on the glass substrate. But there is no nanoparticles formation was observed on annealed steel substrates. The anti microbial resistance test was done against E.Coli and that microbial growth was observed after 24 and 48 hrs. The results displayed a microbial resistance after 24 hrs for annealed Ag thin film coated on glass substrate due the formation of silver nanoparticles.

Abstract: Wet chemical method was applied to prepare magnesium oxide nanoparticles using magnesium nitrate and sodium hydroxide as precursors in presence of starch as stabilizing agent. The XRD analysis of MgO nanoparticles showed the average particles size of crystallite as 12nm. SEM images also proved the crystalline nature of MgO nanoparticles. Antibacterial studies were done on gram positive (S. aureus) and gram negative (E.coli) bacteria using the above prepared nanoparticles by agar diffusion method. The zone of inhibition was found to more in S.aureus compared to E.coli. Since this method of preparation produced better yield in simple and cost effective way, it can be applied for large scale preparation of magnesium oxide nanoparticles.

Abstract: Silver nanoparticles are known to have antimicrobial activity. The green synthesis method of nanoparticle synthesis is one of the most cost effective and eco friendly method. The present study is based on the synthesis of silver nanoparticles by the self reduction of silver nitrate by the leaf extracts of Vitex negundo which is one of the novel methods used in developing nanoparticles. The characterization of the particle was done by UV-Vis spectrophotometer, Fourier Transform Infra Red Spectroscopy, X-ray Diffraction analysis and the size of the synthesized nanoparticle was analyzed in the Scanning Electron Microscopy. The size of the particle was found to be 56 nm. The obtained silver nanoparticles showed anti-microbial activity against E.coli and Klebsiella pneumonia.