International Journal Of Bio-Inorganic Hybrid Nanomaterials
Volume:5 Issue: 1, Spring 2016

Spectrometric techniques for the analysis of trace lead have developed rapidly due to the increasing need for accurate measurements at extremely low levels of this element in diverse matrices. This review covers separation and preconcentration procedures, and considers the features of the application with several spectrometric techniques. The use of an appropriate sample handling technique is a must in an analysis of trace lead in water. The efforts to use a solid phase for the recovery of analytes from a water matrix prior to their detection have a long history. The initial experimental applications of SPE resulted in widespread use of this technique in current water analysis and also to adoption of SPE into standardized analytical methods. Lead is recognized worldwide as a poisonous metal. Thus, the determination of this element is often required in environmental, biological, food and geological samples. However, these analyses are difficult because such samples contain relatively low concentrations of lead, which fall below the detection limit of conventional analytical techniques such as flame atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry. Several preconcentration procedures to determine lead have therefore been devised, involving separation techniques such as liquid–liquid extraction, solid phase extraction, coprecipitation and cloud point extraction. Review of preconcentration procedures for determining lead using spectroanalytical techniques. A brief overview of the history of the use of SPE in trace lead analysis of water is given in presented paper.

The aim of this work was to investigate the effect of silica coating on bioactivity and biodegradability of hydroxyapatite. In this purpose, we firstly attempted to synthesis hydroxyapatite (HA) nanoparticles and its silica coated (Si-HA) sample in collagen matrix using calcium chloride, sodium phosphate and sodium silicate. Characterization of the sample was carried out using Fourier transform infrared spectroscopy (FTIR), Scanning and transmission electron microscopy (SEM & TEM) and XRD patterns. The great decrease in HA’s crystallinity observed in XRD pattern and grain size growth and morphological change of HA in silica coated samples after 72 hrs immersion in SBF solution was attributed to the bioactivity and bio-degradability of HA in silica coated samples.

Sr6Nb10O30–Nb2O5 nanocomposite was synthesized in 2M NaOH aqueous solution. A stoichiometric 1:1 Sr:Nb molar ratio hydrothermal method at 120°C was used to synthesize this nanocomposite. Sr(NO3)2 and Nb2O5 were used as raw materials. The synthesized nanomaterials were characterized by powder X-ray diffraction (PXRD) technique. It was found that Sr6Nb10O30 was crystallized in tetragonal crystal structure with space group P4/mbm and cell parameters of a = b = 12.3548 and c = 3.896 Å. Nb2O5 crystals were also found in orthorhombic and monoclinic crystal structures. Nb2O5 lattice parameters were found as a= 6.175 Å, b= 29.175 Å, c= 3.93 Å and a= 12.73 Å, b= 5.56 Å, c= 4.88 Å with γ= 105.1°, respectively for the orthorhombic and monoclinic crystal structures. The morphologies of the synthesized materials were studied by field emission scanning electron microscope (FESEM). The FESEM images showed that the synthesized nanocomposite had flower and sponge-like morphologies. Ultraviolet–Visible (UV-Vis) spectra showed that the synthesized nanocomposite had strong light absorption in the ultraviolet light region. FTIR spectrum of the obtained nanomaterial was also studied.

Biomedical applications of superparamagnetic iron oxide nanoparticles (SPIONs) requiring precise control over their physical and magnetic properties, and proper surface treatment. Here we report a practical and effective electrochemical strategy for preparation of the polymer coated SPIONs. In this strategy, in situ polymer coating on the surface of SPIONs was achieved through electrodeposition process. The evaluation by XRD analysis confirmed that the electrodeposited sample has pure phase of iron oxide i.e. magnetite (Fe3O4). The PEG/PVC coating of SPIONs was confirmed by FTIR, DLS and DSC-TG analyses. The FE-SEM observation and DLS analysis revealed that the prepared polymer coated SPIONs have proper dispersion and nanosize about 20 nm. The magnetic measurement by VSM revealed that the prepared SPIONs exhibit excellent superparamagnetic behavior, showing high magnetization value (Ms= 32 emu/g), and negligible coercivity (Ce= 0.42 emu/g) and remanence (Mr= 1.1 Oe) values. Based on the obtained results, it was concluded that this electrochemical strategy is facile and effective method for preparation of polymer coated Fe3O4 nanoparticles for biomedical applications.

We have performed a density functional theory investigation on the structural and electronic properties of pristine and Nitrogen-doped TiO2 anatase nanoparticles as the adsorbents for removal and degradation of hydrazine molecules in the environment. We have presented the most stable adsorption configurations and examined the interaction of hydrazine molecule with these doped and undoped nanoparticles. Two nitrogen atoms of hydrazine molecule are more reactive than the hydrogen atoms and tend to be adsorbed on the TiO2 nanoparticle. It turns out that the hydrazine molecule is preferentially adsorbed on the active fivefold coordinated titanium atom site of nanoparticle. The insights of the computations include the structural and electronic analyses such as bond lengths/ angles, adsorption energies, density of states (DOSs) and molecular orbitals. It is found that the adsorption of N2H4 on the N-doped nanoparticle is energetically more favorable than the adsorption on the undoped one, representing the higher reactivity of N-doped nanoparticle with hydrazine molecule. It means that the adsorption on the N-doped nanoparticle provides the most stable configurations and consequently the most efficient adsorption processes. Nevertheless, our computational study on the TiO2 anatase nanostructures suggests that the N-doped nanoparticles are highly sensitive than the undoped ones when utilized as detectors or sensors for hydrazine detection.

In the present work, the structural and electronic properties, and conductivity of (5,5) and (6,6) Single Walled Carbon Nanotubes in the ground state have done by using the Hartree-Fock and density functional theory DFT-B3LYP/6-31G* level. Delocalization of charge density between the bonding or lone pair and antibonding orbitals calculated by NBO (natural bond orbital) analysis. These methods are used as a tool to determine structural characterization CNTs in the gas phase. The total electronic energy, dipole moment, natural atomic orbital energies, charge density, density of state (DOS), highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energies, HOMO-LUMO energy bond gaps, the global index includes hardness (η), electronegativity (χ), electrophilicity index (w), chemical softness (S) and electronic chemical potential (μ) were calculated. We have reported our investigation on the conductivity and electronic structures of pure (5,5) and (6,6) SWCNTs. The calculated HOMO-LUMO energy bond gap show that charge density transfer occurs within the molecule and the results indicate that the conductivity of the CNTs, and also the semi conductivity could be justified.

In this research, the adsorption destructive process of chlorpyrifos (CP,O,O-Diethyl-O-3,5,6-trichloro-2-pyridinyl phosphorothioate) as a noticeable organophosphate pesticide using in agriculture on the nickel tungstate (NiWO4) nanoparticles catalyst was investigated and monitored via the 31P nuclear magnetic resonance (31PNMR). The effects of various experimental parameters such as catalyst dosage, contact time, initial chlorpyrifos concentration and temperature on the elimination efficiency of chlorpyrifos were surveyed. Nickel tungstate (NiWO4) nanoparticles were synthesized by hydrothermal method using NiCl2 and Na2WO4 as the precursors and source of Ni and W, respectively. The structural, morphological, crystal size and elemental composition of the pre-prepared nanoparticles powder were identified using Scanning electron microscopy-energy dispersive micro-analysis (SEM-EDAX), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques. 31PNMR results indicated that chlorpyrifos was successfully eliminated by the catalyst with a yield 100% under optimized conditions. The parameters including: contact time (300 min), catalyst dose (0.3 g/L), initial pesticide concentration (5 mg/L) and temperature (298°K) were considered as optimized conditions for this process. Besides, the reaction kinetic information was studied by applying first order model. The values of the rate constant (k) and half-life (t1/2) were determined as 0.0037 1/min and 187.2972 min, respectively. The main product resulted from destruction reaction between chlorpyrifos and NiWO4 is diethyl phosphorothioic acid (DEPA) which is less toxic than primary pesticide.

In this study, Bio-based carbon nanotubes (CNTs) have received considerable research attention due to their comparative advantages of high level stability, simplistic use, low toxicity and overall environmental friendliness. New potentials for improvement in heat transfer applications are presented due to their high aspect ratio, high thermal conductivity and special surface area. Phonons have been identified as being responsible for thermal conductivities in carbon nanotubes. Therefore, understanding the mechanism of heat conduction in CNTs involves investigating the difference between the varieties of phonon modes and knowing the kinds of phonon modes that play the dominant role. In this review, a reference to a different number of studies is made and in addition, the role of phonon relaxation rate mainly controlled by boundary scattering and three-phonon Umklapp scattering process was investigated. Results show that the phonon modes are sensitive to a number of nanotube conditions such as: diameter, length, temperature, defects and axial strain. At a low temperature (