Nanochemistry Research
Volume:3 Issue: 2, Summer-Autumn 2018

The objective of this study is determination the volatile compounds of Matricaria chamomilla of an inorganic–organic hybrid material based on ZnO nanoparticles anchored to a composite made from polythiophene and hexagonally ordered silica (ZnO/PT/SBA-15) as a solid-phase fiber microextraction (SPME). Microextraction techniques with nanoparticles ZnO/PT/SBA-15 resulted in a more efficient analyte enrichment, faster sample preparation, and lower solvent consumption. Furthermore, they are simple, inexpensive, environmentally friendly, and compatible with many analytical instruments. Using ZnO/PT/SBA-15 followed by GC–MS, 37 compounds were separated and identified in Matricaria chamomilla, which mainly included α-bisabolol(17.51%), Cis-trans-farneso(8.72%), β-bisabolene(8.37%), E-β–Farnesene(5.48%) Guaiazulene(4.36%), α-Pinene(3.68%) and Limonene(3.24%). The presented experimental results clearly demonstrate that prepared fibers are suitable for SPME analyses of volatile oils. For optimization of the microextraction conditions by the ZnO/PT/SBA-15 SPME fiber, a one at the time optimization strategy was used. The optimized parameters were sample state and its amount, extraction temperature and time and finally desorption conditions.

ZnO nanorods have been prepared through chemical deposition of Zn(OAc)2.2H2O by employing different capping agents, (PEG, MW=2000 and PEG, MW=5000). The fabricated catalyst was characterized by scanning electron microscope (SEM) images and XRD pattern. The results show the one dimensional growth of ZnO nano-rods. The results show that capping agents can control the shape and growth of nano-sized crystals. The vertically aligned ZnO was fabricated by PEG 2000, but PEG 5000 changes the ZnO nano-rods to elbow shape. The synthesized nano-rodes have been utilized as highly efficient catalyst to promote some one-pot multicomponent reactions (MCRs) of indoles consist of symmetrical and unsymmetrical 3,3-di(indolyl)indoline-2-ones and tris(indolyl)methanes synthesis under mild reaction conditions, respectively. Comparison of the catalytic power of these two kinds of synthetic ZnO NRs (2000 & 5000) has also been investigated. Importantly, the catalysts can be recovered from the reaction media and reused for four runs without any activity loss

The principal aim of this research is the application of Fe3O4 (MNPs) in the synthesis of some indole derivatives. Fe3O4 MNPs were prepared by Co-Precipitation method from the reaction of FeCl2.4H2O and FeCl3.6H2O in ammonia solution. Morphology and structure of Fe3O4 MNPs were determined by FT-IR, X-Ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Fe3O4 (MNPs) has been used as a highly efficient catalyst for the synthesis of some Indole derivatives like 6H-Indole [2,3-b] quinoxaline, 3-methyl–6H-Indole [2,3-b] quinoxaline and (z)-3-(pyridine-2-yl-imino)-Indole-2-one. The reaction was carried out using various amounts of Fe3O4 nanoparticles in various solvents and solvent-free conditions. The optimum amount of nano-Fe3O4 was 5 mol% in THF under reflux conditions. The structures of indole derivatives were further established by NMR, and FT-IR spectra. In view of excellent catalytic capacity, the exceedingly simple workup procedure, environmentally friendly reaction and good yield, Fe3O4 (MNPs) was proved to be the good catalyst for this reaction.

A magnetic NG@CoFe2O4 photocatalyst was developed via a facile hydrothermal method and characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and vibrating sample magnetometry (VSM) techniques. The CoFe2O4 nanoparticles were found to have a size between 100-150 nm and were uniformly dispersed on the nitrogen doped graphene. Magnetic studies showed that the NG@CoFe2O4 photocatalyst can be easily separated from the solution by the simple bar magnet. The photocatalytic degradation of methylene blue dye (MB) was studied under visible irradiation. The photocatalytic performance of NG@CoFe2O4 photocatalyst was found to be influenced by structural and optical properties as well as the surface area of the samples. The NG@CoFe2O4 photocatalyst exhibited improved photodegradation performance when compared with pure CoFe2O4. The as synthesized NG@CoFe2O4 can be a probable candidate used as a visible-light active magnetically separable photocatalyst and so could be used as a potent separation tool in waste water treatment.

Visible light responsive Graphene oxide (GO) nanotitania composite was synthesized and its photocatalytic activity was investigated for the degradation of Eosin Yellow (EY). The nanocomposite was synthesized by organic solvent free-controlled hydrolysis of titanium tetrachloride (TiCl4) exfoliated with 10 wt. % (0.5 g) of the as prepared GO particles under ultrasonication through in-situ addition of the aqueous GO solution. The synthesized nanocomposite has been characterized using X-Ray Diffraction (XRD), UV-Visible Diffuse Reflectance Spectral (UV-Vis DRS) and Field emission scanning electron microscope (FESEM) techniques. In the presence of visible light, its photocatalytic activity was enhanced on contrast with the synthesized bare nanotitania particles. The aqueous solution of EY has degraded in 80 minutes (95.5 %). It was also supported with the increase in the rate constant with the composite (7.05 x 10-2 min-1) as compared with that of the nanotitania (1.41 x 10-2 min-1). Through the chemical oxygen demand (COD) studies, effective mineralization of the dye was observed with the nanocomposite.

[2,2'-Bipyridine]-1,1'-diium tricyanomethanide {[2,2'-BPyH][C(CN)3]2} as a bifunctional nanostructured ionic liquid catalyst (0.5 mol%) was used for the synthesis of 3,4-dihydropyrano[c]chromenes (14 examples) under solvent-free condition at room temperature in high yield (82-91%) and short reaction time. In addition, the described ionic liquid catalyst was also applied for the synthesis of biscoumarins (8 examples) under the same reaction condition in good yield (87-91%) and short reaction time. The {[2,2'-BPyH][C(CN)3]2} was attained by the reaction of 2,2'-Bipyridine (5 mmol) and 5 mL an aqueous solution of tricyanomethane (5 mmol) at room temperature for 3 hours. The {[2,2'-BPyH][C(CN)3]2} was obtained with high purity that was approved by FTIR, 1H NMR, 13C NMR, mass, TG, DTA, XRD, SEM, TEM analysis and melting-point determination. The catalyst was recovered in excellent yield and was used in the revealed reaction 5 times without the need of additional catalyst. The major advantages of the presented procedure are efficient catalysis and good cost efficiency.

In this study, Eu-doped CdSe nanoparticles with variable Eu3+ content were synthesized by a simple sonochemical method. Eu3+ substitution into the structure of CdSe resulted in a material with new physical properties, composition and morphology. The synthesized nanoparticles were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) and UV-Vis diffuse reflectance spectroscopy techniques. The sonocatalytic efficiency of pure and EuxCd1-xSe samples was evaluated by monitoring the decolorization of RRed 43 in aqueous solution under visible light irradiation. The BET specific surface area and pore volume of mesoporous europium doped CdSe greatly exceeds in comparison to undoped CdSe samples. Among the different amounts of dopant, 8% Eu-doped CdSe showed the highest catalytic activity. The effects of various parameters such as initial dye concentration, catalyst loading, ultrasonic power, and the presence of radical scavengers were investigated. Superoxide radicals and photogenerated holes were detected as the main oxidative spices.

Cerium orthovanadate nanoparticles (CeVO4 NPs) were fabricated using urea-assisted facile sol-gel auto combustion method. X-ray diffraction (XRD) pattern revealed the crystal planes and size of synthesized CeVO4 NPs. The morphological shape and the crystalline nature of the NPs were examined by field emission scanning electron microscopy (FESEM). Energy-dispersive X-ray spectroscopy (EDX) affirmed the presence of elemental composition and purity of the fabriacated NPs. Fourier transform Infrared spectroscopy (FT-IR) confirmed the conceivable stretching frequency on the surface of CeVO4 NPs. UV–visible diffuse reflectance spectroscopy (DRS) absorption spectrum indicates the band gap is about 3.2 eV and the synthesized tetragonal CeVO4 NPs exhibited a broad photoluminescence in the UV–visible region. Besides, these CeVO4 NPs evinced antifungal activity against Candida albicans, Aspergillus niger, Aspergillus clavatus, Trichophyton rubrum, Trichophyton mentographytes, Epidermophyton floccosum and Microsporum gypseum. The studies describing the synthesis of CeVO4 NPs by simple sol-gel auto combustion method followed by the investigation of antifungal activities may be useful for research opening a new horizon in the field of nanotechnology.

Two new nano particles of copper (II) and nickel (II) complexes, [Cu(cd5Clsalen)] (1) and [Ni(cd5Clsalen)] (2) with unsymmetrical tetradentate Schiff base ligand cd5Clsalen={methyl-2-[N-[2-(2-hydroxy-5-choloro-2phenyl) methylidynetrilo]ethyl}amino-1-cyclopentenedithiocarboxylate, were synthesized by hydrothermal method. These compounds were characterized by a variety of physic-chemical techniques via. scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (IR) and elemental analysis. The complexes (in bulk) have a NNOS coordination sphere, with the two nitrogens coordinated in a cis configuration. The coordination around nickel center is essentially square-planar with a small tetrahedral distortion and the geometry around the copper center is square planar. Nano-particles of Copper (II) and Nickel (II) oxides have been prepared by calcination of two different Copper (II) and Nickel (II) complexes at 450 ºC that were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and IR spectroscopy. The average size of the particles was estimated from the Sherrer formula. This study demonstrates the Schiff base complexes may be suitable precursors for the preparation of nanoscale materials with different and interesting morphologies.

In this study, quantitative structure-retention relationship (QSRR) methodology employed for modeling of the retention times of 16 banned pesticides in nano-liquid chromatography (nano-LC) column. Genetic algorithm-multiple linear regression (GA-MLR) method employed for developing global and consensus QSRR models. The best global GA-MLR model was established by adjusting GA parameters. Three descriptors of SpMax2_Bhp, Mor31u and, MATS6c appeared in this model. Consensus QSRR models developed as an average consensus model (ACM) and weighted consensus model (WCM) by a combination of a subset of the GA-MLR models. Comparison of statistical parameters of developed models indicated that an ACM which is combining of the best global QSRR model with four-descriptor sub-model can be selected as the best consensus QSRR model. CrippenLogP, RDF070m, Lop, and HASA1 descriptors appeared in four-descriptor sub-model. In ACM, the square of correlation coefficients (R2) was 0.973 and 0.939, and the SE was 0.49 and 0.40, for the training and test sets, respectively. The ACM was assessed by leave one out cross-validation ("Q2 cv" = 0.935) as well as internal validation. Descriptors which appeared in this model suggest electrostatic, steric and hydrophobic interactions play the main role in the chromatographic retention of studied pesticides in nano-LC conditions.

Nitrogen oxides (NOx) released in atmosphere by fuels combustion lead to photochemical smog and acidic rains and have negative effects on human`s nervous system. In this research nanocomposite membranes of Poly Vinylidene Fluoride (PVDF)/ Poly Dimethylsiloxane (PDMS) and Titanium Dioxide nanoparticles (TiO2) with different weight percentage of TiO2 (0.5 and 1) for adsorption of NOx were prepared using electrospinning. To investigate the properties of prepared fibers, scanning electron microscopy (SEM) and Attenuated Total Reflectance spectroscopy (ATR) were used. The fibers morphology and particles distribution in polymer were determined by SEM pictures. The composite fibers with 0.5 wt% TiO2 removed 50% nitrogen oxides and fibers with 1 wt% TiO2 removed 100% of nitrogen oxides. Generally, the presence of Titanium Dioxide nanoparticle (anatase phase) in fibers, vapor and ultraviolet ray have removed toxic NOx gas by contribution in photocatalysis. The ATR spectrum of fibers confirmed NOx adsorption by composite nanofibers. TiO2/ polymer composite membrane showed the promising potential for application as a filter to remove Nitrogen Oxides from air.

Natural nanomaterial; Montmorillonite Clay was collected and purified and then applied in the removal of Fluoride. The Montmorillonite Clay was grounded and 150g was weighed and refluxed in 500mL 1MHCl at 1200C for one hour thirty minutes and activated Montmorillonite Clay was obtained. Flouride was determined with the aid of SPADNS Reagent (2-parasulfophenylazo)-1,8-dihydroxy-3,6-naphthalene disulfanate) using UV/Visible spectrophotometer (Model JENWAY 6300) at the wavelength of 570 nm. Adsorption parameters studied were; adsorbent dose, contact time and pH effect. Fluoride was removed with a maximum percentage of 83.5% at optimum pH of 2 with contact time of 50 minutes and adsorbent dose of 2.0 g as well as temperature of 25oC. Two most used kinetic models were employed in this research which are Pseudo-first and Pseudo-second order. The experimental data was found follow Pseud-second kinetic than Pseudo-first order. Thus, Montmorillonite clay as a natural nanoadsorbent could be use to remove fluoride which could help in the prevention of dental fluorosis.