Nanotechnology

The electron density and charge transport studies of organic field effect transistors (OFETs) based 2-phenyl-3Hpyrrole molecule have been calculated from the quantum chemical and DFT methods. Density functional theory calculations with B3LYP/aug-cc-PVDZ basis sets was used to determine ground state gas space molecular geometries (bond lengths and bond angles), electron density and bonding features of this molecule. The electron densities at the bond critical point (BCP) of aromatic Car–Car bonds are much stronger than the other bonds in the molecule. The calculated HOMO and LUMO energies is ~5.50 eV [B3LYP/aug-cc-PVDZ], this shows that charge transfer occurs within the molecule. The HOMO–LUMO gap calculated from quantum chemical calculations has been compared with the value calculated from the density of states. The negative electrostatic potential (ESP) is concentrated solely around the N atoms, whereas in the rest of the region a positive ESP to dominate.

Silver nanoparticles dispersed in water in presence of trisodium citrate have been prepared and characterised. Aqueous solutions of silver nitrate and trisodium citrate were mixed in various proportions and heated at 30oC for 3 hours. The nanoparticles of silver dispersed in water in presence trisodium citrate were characterised by UV-visible absorption spectra, X-ray diffraction, EDX, and SEM. Nano-silver dispersed in water based nanofluids may used to increase thermal conductivity of fluids.

In this paper, we present the concept demonstrating some of the possibilities of nanotechnologies might enable in the future communication devices. Nanotechnology aloows control of physical problem of nanostructures and devices with single molecule precision. The device is build by numerous nano-transistors. This device is used for sensing toxicity of the materials. The devices constructed by nanotechnology can be stretched and folded to desired length since it has the strength of spider silk. As the transistors are temperature dependent, the devices are auto-chargeable when exposed to sunlight (solar energy). Nanoscale electronics are invisible to human eye, the devices are transparent.

 In this research to estimate of the forming energy of Zn-Ferrite were used of the isothermal reaction by using Avrami equation and Avrami Ozawa for Non-Isothermal reaction in use Flow Injection Synthesis reactor, whether as Isothermal or non-isothermal. According the methods above can be obtainedthe formation energy of Zn-Ferrite. In this research have be done four time isothermal experiments at the temperature 60 0C,70 0C and 80 0C respectively. The sampling of experiment data have be done effectively using pH data logger where both pH and temperature were written in SD card memory automaticallyin form Excel format. As a result the formation enthalpy (?H) 4.2 kcal / mol with entropy (S) 12.6 cal / mol deg and 3:14 density gr / cc,respectively

In this study, we have demonstrated that haemoglobin can be coupled to acid-treated multiwall carbon nanotubes in the presence of 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide (EDC) and assembled as haemoglobin–carbon nanotube (Hb–CNT) composites. Our observations of the electrochemical studies demonstrate that the electrochemical response of Hb–CNT assembled in the presence of EDC is much higher than that in the absence of EDC. It is evident that the direct electron transfer of haemoglobin could be effectively accelerated in the Hb–CNT assembly by using EDC on a glassy carbon electrode (GCE), and the relative electron transfer rate constant Ks is found to be 1.02 ± 0.05 s?1. The results of our studies illustrate that the assembly of haemoglobin–multiwall carbon nanotubes using EDC could provide a novel strategy to effectively facilitate the direct electrochemistry of heme-containing proteins, which could be further utilized as a promising biosensor for some specific biological substrate and related biological process.

Spherical shaped CuO nanocrystals were successfully synthesized by sol–gel technique. Triethanolamine (TEA) used as a capping agent to control the size, morphology and optical properties of the CuO nanocrystals. Evolution of structure, surface morphology and optical absorption analysis of these nanocrystals were studied using UV–Visible spectrophotometer (UV–Vis), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), Field Emission Scanning Electron Microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS). UV–Visible technique used to measure the band gap of TEA capped CuO nanocrystals having good optical property compared than uncapped CuO nanocrystals in the synthesized samples. The FT-IR study of transmittance peaks at 502 cm-1,603 cm-1 and 674 cm-1 were Cu-O stretching mode, and 677 cm-1 has been Cu-O monoclinic phase of the uncapped CuO nanocrystals. In addition the transmittance peaks at 502 cm-1, 583 cm-1 have been Cu-O Stretching mode and 784 cm-1 are Cu-O monoclinic phase of the Triethanolamine capped CuO nanocrystals.

Metal oxides play a very important role in many areas of chemistry, physics and materials science.  The metal elements are able to form a large diversity of oxide compounds.  These can adopt a vast number of structural geometries with an electronic structure that can exhibit metallic, semiconductor or insulator character. In technological applications, oxides are used in the fabrication of microelectronic circuits, sensors, Piezo-electric devices, fuel cells, coatings for the passivation of surfaces against corrosion, and as catalysts. In the emerging field of nanotechnology, a goal is to make nanostructures or nanoarrays with special properties with respect to those of bulk or single particle species.  Oxide nanoparticles can exhibit unique physical and chemical properties due to their limited size and a high density of corner or edge surface sites. Amomg the metal oxides,  Magnesium oxide (MgO) is widely used in the chemical industry as a scrubber for air pollutant gases (CO₂, NO_X, SO_X) and as a catalyst support.  It exhibits a rock salt structure like oxides of other alkaline earth metals.  The non-polar (100) face is by far the most stable surface,  and particles of MgO usually display a cubic shape. For example, when Mg metal is burned in air or oxygen, the MgO smoke particles that are formed are almost perfect cubes having (100) faces.

This research will examine synthesis of single-wall carbon nanohorns (SWCNHs) by dielectrophoresis (DEP). This will involve electrokinetic synthesis method which will produce a SWCNHs sensor. In dielectrophoresis (DEP), the carbon particles will be subjected to a non-uniform electric field and thus a force will be exerted on the particles. The materials are dielectrically polarized with electrokinetic motion in non-uniform electric fields. The region of higher electric field will attract the nanoparticles due to positive DEP force. The carbon nanoparticles are then trapped in the electrode gap and thus form an electrical connection to the external measuring circuit. This method provides a fast, simple and low cost fabrication of nanomaterial-based sensors based on a bottom-up approach.

NiO NPs and Barium doped NiO NPs calcined for different periods of time (3hr, 4hr) at 700?C were synthesized through co-precipitation method. XRD analysis confirmed that all the samples exhibit FCC cubic structure. The doping of barium and also increasing the calcinations time of Ba:NiO increases the crystallite size .Optical absorption spectra reveal that energy gap decreases from 3.75 eV to 3.35 eV due to the increase in crystallite size.PL spectral analysis shows that emission intensity decreases with decreasing grain size. . The morphology of the NiO NPs and Ba:NiO NPs has been analyzed by FESEM and SEM respectively The results of antimicrobial activity of NiO NPs and Ba:NiO (4 hrs) against E-Coli indicated that NiO NPs have excellent inhibitory activity.

Pure Nickel Oxide (NiO) nanoparticles and Lithium doped Nickel Oxide nanoparticles at two different concentrations 0.01M, 0.02M were synthesized through co-precipitation method. From XRD analysis it is observed that all the three samples exhibit FCC cubic structure and the incorporation of lithium decreases the crystallite size with increase in the Li doping concentration. Optical absorption spectra reveal that the energy gap increases from 3.8 eV to 3.98 eV with increasing lithium doping concentration. The Photoluminescence spectra show that the PL intensity increases with increase in lithium content. The SEM images clearly show an agglomeration of nanoparticles and snowflake-like morphology. Cyclic voltammetry characterization was carried out for all the three samples to study electrochemical activity. The magnetic property of the samples was studied using a vibrating sample magnetometer (VSM).