Nanochemistry Research
Volume:1 Issue: 2, Summer and Autumn 2016

Here we present our experimental results in synthesizing Au-Cu nano-particles with tunable localized surface plasmon resonance frequency through wet-chemical at temperature room. The reaction is performed in the presence of ascorbic acid as a reducing agent and polyvinyl pyrrolidone as capping agent via four different procedures: (1) mixture of 90% HAuCl4 and 10% CuSO4.5H2O precursors, (2) mixture of 75% HAuCl4 and 25% CuSO4.5H2O precursors, (3) mixture of 50% HAuCl4 and 50% CuSO4.5H2O precursors (4) mixture of 25% HAuCl4 and 75% CuSO4.5H2O precursors. Effect of different percentages of Cu on Au nanoparticles has been analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM with EDAX analysis), DRS UV-Vis, and Fourier transform IR spectra (FTIR) analysis. X-ray diffraction (XRD) analysis revealed that the nanoparticles are of cubic structure without an impure phase. The successful doping of the Cu into the Au host was evident by XRD line shiftings. The increasing percentage of copper leads to the decreasing grain size. With the increase of Cu2+ to Au3+ ratio in the Cu2+/Au3+ mixed solution (> 50% Cu), XRD lines show no shifting. The average crystal sizes of the particles at room temperature were less than 9.9 nm. The surface plasmon resonance peak shifts from 380 to 340 nm, party due to the change in particle size. SEM images show a spherical shape and the size of nanoparticles becomes smaller with increasing the percentage of copper. Moreover, in the molar ratio of Cu2+/Au3+ = 75/25 (>50% Cu), mixture of spherical and trigonal nanoparticles were prepared. Fourier transform infrared spectroscopy (FT-IR) showed the coordination and conjugation nanoparticles with N and O atoms of C-N and C=O bonds.

Our primary objective was to measure root canal penetrations of aqueous antibacterial nano-chitosan (Nano-CS), for the first time. The second objective was to compare and contrast such penetrations to those of chitosan (CS) itself, as well as sodium hypochlorite (NaOCl), chlorhexidine (CHX) and ethylenediamintetraacetic acid (EDTA), at the routinely used concentrations. Molar roots were split longitudinally by a rotary diamond saw. Nano-CS was made by dissolving CS in acetic acid and adding tripolyphosphate (TPP), followed by a freeze-drying process. Dentin penetrations are estimated through measurements of sessile contact angles. Penetrations of the probed irrigants were assessed as inverse functions of their sessile contact angles. Accordingly, all Nano-CS solutions showed smaller sessile angles compared to those of NaOCl, CS, and EDTA samples. Hence, Nano-CS appeared to be a superior irrigant for demonstrating a higher penetration than the latter three. It fell only behind CHX, yet, the superb chelating ability of Nano-CS enabled it to remove smear layer to a larger extend than all of our other irrigants including CHX. Nano-CS could be considered as a new irrigant. Higher penetration was its main advantage over CS, and commercial NaOCl, and EDTA. This was verified by  the smaller sessile contact angle of Nano-CS. Anticipated chelating effect of Nano-CS could anchor more efficient removal of smear layer. This was another advantage of Nano-CS over other irrigants including CHX. Other advantages of Nano-CS included its reported biocompatibility, biodegradability and antibacterial effects. Commercialization of Nano-CS was deemed in the near horizon.

A novel rice-husk-silica supported n-propyl bipyridinium chloride (RHPrBPCl) has been prepared. Due to the basicity of RHPrBPCl, it was decided to evaluate its catalytic activity in the one-pot preparation of tetrahydrobenzo[b]pyran, dihydropyrano[3,2-c]chromene and dihydropyrano[4,3-b]pyran derivatives. The catalyst was characterized by FT-IR, SEM and TGA analyses. This methodology offers several advantages including easy work-up procedure, high yields of the products, short reaction times, recyclable catalyst and green reaction medium.

A mild, green and highly efficient route for regio-selective amination of oxiranes was developed via incorporation of Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) cations onto the surface of hydroxyapatite-encapsulated γ-Fe2O3 nanoparticles (γ-Fe2O3@HAp). Among six magnetically recoverable catalytic systems denoted as [γ-Fe2O3@HAp-MII], the catalyst in which M designated as Fe(II) showed the best efficiency as well as regio-selectivity in amination of oxiranes under an ambient reaction condition. A wide variety of aromatic and aliphatic amines were reacted with epoxides using magnetically separable iron catalyst to give the corresponding amino alcohols in excellent yields and selectivities in water as solvent at room temperature. In addition, recovery of the catalyst was successfully carried out in subsequent runs without any decrease in activity even after 5 runs. High regio-selectivity toward terminal ring-opening, efficient catalyst reusability using simple magnetic separation, high yields, simplicity in operation and diversity for various substrates are of advantages of this study.

In the present study, a simple, efficient and fast synthetic strategy was reported for the green biosynthesis of silver nanostructures (i.e. nanoroads and nanoparticles) by the extract of Suaeda Acuminata plant, without any catalyst, template or surfactant. Aqueous extracts were obtained by maceration and microwave assisted extraction (MAE) methods. In MAE procedure, the effect of microwave power on the extracted compounds was studied at 90, 270 and 450 W. Colloidal nano-scaled silver samples were synthesized by reacting aqueous silver nitrate with Suaeda Acuminata leaf extract at non-photomediated conditions. Comparative characterizations of the prepared Ag nanostructures were carried out by different techniques including UV-Vis absorption spectroscopy, scanning electron microscopy, X-ray diffraction, and FT-IR spectroscopy. The SEM images showed that it can be synthesized Ag nanoroads and nanoparticles with the average size of 132 nm and 73 nm, by maceration and MAE methods, respectively. According to UV-Vis absorption spectra, a broad absorption peak around 400 nm was observed for all prepared Ag nanostructure samples synthesized by maceration and MAE methods, at different reaction times and irradiation microwave powers. The band can be corresponded to the plasmon absorbance of nano-scaled silver samples.

Nanotechnology has opened up new opportunities for the design of nanoscale electronic devices suitable for developing high-performance biofuel cells. Glucose-based biofuel cells as green energy sources can be a powerful tool in the service of small-scale power source technology as it provides a latent potential to supply power for various implantable medical electronic devices. By using physiologically produced glucose as a fuel, the living battery can recharge for continuous production of electricity. This review article presents how nanoscience, engineering and medicine are combined to assist in the development of renewable glucose-based biofuel cell systems. Here, we review recent advances and applications in both abiotic and enzymatic glucose biofuel cells with emphasis on their “implantable” and “implanted” types. Also the challenges facing the design and application of glucose-based biofuel cells to convert them to promising replacement candidates for non-rechargeable lithium-ion batteries are discussed. Nanotechnology could make glucose-based biofuel cells cheaper, lighter and more efficient and hence it can be a part of the solutions to these challenges.

Natural clinoptilolite zeolite (CLP) in its original or metal ion- exchanged form (Ni2+) is a weak adsorbent for relatively large thiophene derivative molecules like benzothiophene (BT) and di-benzothiophene (DBT), due to its rather restricted micro-channel structure. A novelty of this work is that upon desilication treatments, it is possible to enhance the adsorption behavior of Ni2+-exchanged CLP for such large sulfur- containing molecules. A natural CLP zeolite has been desilicated using NaOH solutions in a concentration range of 0.2-2.0 M. The resulting powders have been subjected to XRF, XRD, FTIR, nitrogen adsorption/desorption, TEM and TGA analyses. The adsorption isotherms for the removal of thiophene (TP), BT, DBT and iso-propyl mercaptan (IPM) have been obtained experimentally at 20 °C from simulated liquid fuels using iso-octane as solvent. The sample treated with 1.5 M NaOH solution showed the most significant enhancement in adsorptive properties. The selectivity order is IPM > TP > BT > DBT. Regenerability tests show a quasi constant adsorption capacity after the first cycle. The observed phenomena have been thoroughly discussed based on the physico-chemical analyses of the samples.

A graphene oxide-terpyridine conjugate (GOTC) based colorimetric and fluorescent nano-chemosensor was synthesized. It showed high selectivity and sensitivity for Fe2+ and Fe3+ ions in neutral aqueous solution over other metal ions such as Li+, Na+, Ba2+, Ca2+, Al3+, Cd2+, Co2+, Cu2+, Hg2+, Mn2+, Ni2+, Pb2+, Zn2+, Cr3+ and Ag+. In absorption spectra, upon addition of Fe2+ or Fe3+, the sensor displayed a peak at 568 nm, by changing the color of the solution from light pink for GOTC to light magenta and deep magenta for Fe3+ and Fe2+, respectively. Also, the fluorescence studies revealed that, Fe2+, Fe3+ and Co2+ quench the emission of GOTC at 473 nm, while other metal ions do not quench the fluorescence of GOTC in solution. Colorimetric and fluorescence techniques could be used for detection of Fe2+ ion concentration at least about 6-10 μM in water solution. The sensing on test paper was also investigated for the naked-eye detection of Fe2+.

Here, we report the synthesis of a Schiff-base mixed-ligand complex of cadmium(ІІ) in bulk and nano-scales via the precipitation and sonochemical methods, respectively. The complex formula is [Cd(3-bpdh)(3-bpdb)Cl2]n (1), where the ligands are 3-bpdh = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene and 3-bpdb = 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene. The structure of mixed-ligand complex (1) was characterized by IR, 1H NMR and elemental analyses. Cadmium(ІІ) oxide nanoparticles were prepared by direct thermolysis from nanosheet of complex (1). The cadmium(ІІ) oxide structure was characterized by X-ray Diffraction (XRD) and Energy Dispersive X-ray  analyses (EDAX). Size, morphology and structural dispersion of all obtained nanostructures were characterized by Scanning Electron Microscopy (SEM). The Schiff-base ligands, bulk and nano-scales of complex (1) and cadmium(ІІ) oxide nanoparticles were analyzed for antibacterial activities against Bacillus alvei (bacteria causing the honey bee European foulbrood disease). The Minimum Inhibitory Concentrations (MIC) has been shown moderate antibacterial activities compared with some other standard drugs. Known antibiotics like penicillin and SXT (Trimethoprim/sulfamethoxazole) were used as positive control.

Polydimethylsiloxane (PDMS) has been synthesized by ring-opening polymerization of octamethylcyclotetrasiloxane (D4) in microemulsion with acidic catalyst. The structure and properties of microemulsion were characterized by Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FT-IR), Photo Correlation Spectroscopy (PCS). The effect of the variation in pH value, amount of catalyst, emulsifier and monomer dropping rate on the properties of microemulsion were investigated and discussed. The results showed that the particle size of the latex becomes smaller, and the distribution size becomes wider with increasing the content of catalyst and emulsifier. When pH value changed, the reaction rate of ring-opening of D4 was faster with strong acid than that under the weak acid condition. The emulsification of 2 % OP-10 (Alkylphenol polyoxyethylene ether) and 3.0% DBSA (Dodecyl benzenesulfonic acid) reached to equilibrium in microemulsion. As the amount of OP-10 increases, the size of particles lowered and their corresponding  distribution widened. It is observed that emulsifier (OP-10) does not affect the transparency of the microemulsion in the case of the application of DBSA. As the monomer dropping time increased, the grain size diminished and the size distribution widened. PCS results showed that the smallest particle size was around 20nm. Taking into account of the stability of the microemulsions, the dropping time of the monomer was around 30 min.

This study offers an exclusive class of magnetic nanoparticles supported hyperbranched polyglycerol (MNP/HPG) that was functionalized with citric acid (MNP/HPG-CA) as a host immobilization of palladium nanoparticles. The MNP/HPG-CA/Pd catalyst was fully characterized using some different techniques such as thermogravimetric analysis (TGA), x-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), inductively coupled plasma (ICP) and x-ray photoelectron spectroscopy (XPS). The new catalytic system showed high activity for the Suzuki–Miyaura cross-coupling and Heck reaction under mild and green conditions. Besides, the MNP/HPG-CA/Pd was found to be a convenient catalyst for copper-free Sonogashira coupling reaction in water as a green solvent at room temperature. Moreover, the catalyst could be recovered easily and reused several times without significant loss of reactivity. Ease of preparation, oxygen insensitive, phosphine-free, air- and moisture-stable, and high reusability of this immobilized palladium catalyst are the noteworthy advantages of this catalytic system.

In the present study, a new chemically modified carbon paste electrode (CPE) is constructed for rapid, accurate, simple, highly sensitive, and selective determination of Mo (VI) using differential pulse voltammetry. The electrode was prepared using magnetic nickel zinc ferrite nanocomposite (Ni0.5Zn0.5Fe2O4), as the modifier in CPE (Ni0.5Zn0.5Fe2O4/CPE). Mo (VI) was determined after preconcentration at the surface of the modified electrode at -0.7 V vs. Ag/AgCl. Under the optimal conditions, the linear dynamic range and limit of detection were 0.005-1.00 and 0.003 µgmL-1, respectively. Ten successive measurements of 0.06 and 0.70 µg mL-1 of Mo (VI) ions showed the relative standard deviation of 3.20 and 1.98 %, respectively. The reproducibility and stability of the electrode response were also studied. Investigation of the effects of different cations and anions on the determination of Mo (VI) indicated that the electrode is highly selective. Furthermore, the present method was applied to the determination of Mo (VI) in several plant foodstuff samples with satisfactory results.

In this study, the ultrasonic, photocatalytic and sonophotocatalytic degradation of organics in textile industrial effluent was studied using ZnO nano catalyst, ZnO nano catalyst was synthesized by using sol-gel method. The structure and morphology of the catalyst were investigated using scanning election microscopy (SEM), electron dispersive X-ray spectroscopy (EDS) and X-ray diffraction pattern (XRD). The percentage removal of textile influents was determined by using TOC.  The effects of various operational parameters such as, contact time, catalyst loading, and solution pH on the degradation efficiency were studied. The increase in degradation efficiency with the increase in catalyst loading, contact time. Neutral pH is suitable for degradation of textile industrial effluents, and comparative study shows that the sonophotocatalyst is effective for degradation technique than ultrasonic and photocatalytic degradation of textile industrial effluent.

Analytical chemistry has experienced, as well as other areas of science, a big change due to the needs and opportunities provided by analytical nanoscience and nanotechnology. Now, nanotechnology is increasingly proving to be a powerful ally of analytical chemistry to achieve its objectives, and to simplify analytical processes. Moreover, the information needs arising from the growing nanotechnological activity are opening an exciting new field of action for analytical chemists. Magnetic nanoparticles have been used in various fields owing to their unique properties including large specific surface area and simple separation with magnetic fields. For Analytical applications, they have been used mainly for sample preparation techniques (magnetic solid phase extraction with different advanced functional groups (layered double hydroxide, β-cyclodextrin, carbon nanotube, graphen, polymer, octadecylsilane) and automation of it, microextraction techniques) enantioseparation and chemosensors. This review summarizes the basic principles and achievements of magnetic nanoparticles in sample preparation techniques, enantioseparation and chemosensors. Also, some selected articles recently published (2010-2016) have been reviewed and discussed.