Facile Chemical Synthesis and Characterization of Copper Tungstate Nanoparticles

Copper tungstate nanoparticles were synthesized by a chemical precipitation reaction in aqueous ambient involving direct addition of copper ion solution to the solution of tungstate reagent. Optimization of the synthesis procedure was carried out using Taguchi robust design as a statistical method. In order to controllable, simple and fast synthesis of copper tungstate nanoparticles, effects of some synthesis conditions such as reagents concentrations (i.e., copper and tungstate ions), flow rate of copper feeding and temperature of the reactor on the particle size of synthesized copper tungstate were investigated by the aid of an orthogonal array. The results of optimization process showed that copper tungstate nanoparticles could be prepared by controlling the effective parameters and at optimum conditions of synthesis procedure, the size of prepared copper tungstate particles was about 56 nm. Chemical composition and microstructure of the prepared copper tungstate nanoparticles were characterized by means of X-ray diffraction, scanning electron microscopy, UV–Vis spectrophotometry, FT-IR spectroscopy and Photoluminescence.     

Synthesis and Solution Properties of Carbohydrate‐Modified Polysiloxane Bola Surfactants

Three carbohydrate‐modified polysiloxane bola surfactants (ATPS‐GA) were synthesized using a two‐step method. Their chemical structures were characterized by infrared spectroscopy (FT‐IR) and proton nuclear magnetic resonance spectroscopy (¹H NMR). Their surface properties and aggregation properties in aqueous solution were determined using surface tension measurements and transmission electron microscopy (TEM). Surface tension measurement results indicated that the three bola surfactants are under 25 mN m^?1, and much lower than those of conventional hydrocarbon bola surfactants due to the siloxane moiety at the end of the hydrophobic chains. TEM analysis results indicated that the ATPS‐GA can self‐assemble into spherical micelles with a wide range of average diameters from 100 nm to above 600 nm.     

Synthesis and Characterization of Cationic Surfactants Based on N‐Hexamethylenetetramine as Active Microfouling Agents

Four cationic surfactants of quaternary hexammonium silane chloride based on hexamethylenetetramine and alkyl chloride were synthesized. The chemical structures of the prepared cationic surfactants were elucidated using Fourier transform infrared (FT‐IR) spectroscopy and mass spectrometry analysis. The surface and thermodynamic properties of the prepared surfactants were also studied. The performance of these cationic surfactants as microfouling agents against two strains of Gram‐negative bacteria, namely, Pseudomonas aeruginosa and Escherichia coli, and two strains of Gram‐positive bacteria, namely, Staphylococcus aureus and Bacillus subtilis, were evaluated as antimicrobial agents. The results showed that the maximum antimicrobial activity was detected for N‐hexamethylenetetramine‐N‐ethyl silane ammonium trichloride (Ah). The maximum and minimum antimicrobial activities were 73 and 60 % against S. aureus and E. coli, respectively, at a concentration of 5 mg/l, pH 7, and 37 °C.     

Synthesis and Characterization of Cadmium Selenide (CdSe) Nanoparticles Using Trigonal Selenium (t-Se) Nanorods as Selenium Source

Cadmium selenide (CdSe) nanoparticles were synthesized through colloidal method in aqueous medium using the reaction intermediates selenium nanorods as selenium source. Trigonal selenium nanorods (t-Se) were synthesized in water by the reduction method in the presence of sodium borohydride at 60?°C using sodium selenite (Na₂SeO₃) as selenium source. These selenium nanorods were further utilized to synthesis cadmium selenide nanoparticles at 100?°C in water. The synthesized nanorods and nanoparticles were characterized using XRD, SEM, TEM and XPS analysis. X-ray diffraction (XRD) analysis shown that the nanorods possess trigonal phase while the nanoparticles possess a cubic zinc blende structure. Scanning electron microscope (SEM) analysis of the prepared hexagonal shaped nanorods reveals the diameter of the nanorods are about 150 nm. Transmission electron microscopy (TEM) analysis shows the size of the synthesized CdSe nanoparticles are about 4–8 nm. X-ray photoelectron spectroscopy (XPS) analysis illustrates the presence of respective elements Cd, Se with its corresponding oxidation states. The activity of nano selenium rods in aqueous solution during the conversion of cadmium selenide nanoparticles was discussed.     

Biocompatible polymers as a tool for the synthesis of silver nanoparticles: size tuning and in vitro cytotoxicity studies

Silver nanoparticles have attracted great attention in the biomedical research field, especially in cancer theranostics. In this study, we developed a synthesis method for silver nanoparticles in the solid state using high‐speed vibration milling, in which biocompatible polymers such as poly(vinylpyrrolidone), poly(ethylene glycol) and chitosan were used for the reduction of the silver salt. The synthesis of the size‐tunable silver nanoparticles was performed at room temperature and no surfactants to direct the anisotropic growth of the nanoparticles were required. The formation of the nanoparticles was studied using UV‐visible and Fourier transform infrared spectroscopy as well as transmission electron microscopy. The synthesized nanoparticles showed an average diameter ranging from 3.1 ± 1.4 to 22.8 ± 5.8 nm. In addition, the anticancer activity of these silver nanoparticles was assessed using cytotoxicity studies with human breast adenocarcinoma (MCF‐7), human lung adenocarcinoma (NCI‐H358) and mouse embryonic fibroblast (NIH‐3T3) cell lines. Accordingly, an effective suppression of the proliferation of cell growth was found. © 2016 Society of Chemical Industry     

Size-Controlled Synthesis of Colloidal Gold Nanoparticles at Room Temperature Under the Influence of Glow Discharge

Highly dispersed colloidal gold (Au) nanoparticles were synthesized at room temperature using glow discharge plasma within only 5 min. The prepared Au colloids were characterized with UV–visible absorption spectra (UV–vis), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) equipped with an energy dispersion X-ray spectrometer (EDX). UV–vis, XPS and EDX results confirmed that Au³⁺ ions in HAuCl₄ solution could be effectively reduced into the metallic state at room temperature with the glow discharge plasma. TEM images showed that Au nanoparticles were highly dispersed. The size of colloidal Au nanoparticles could be easily tuned in the nanometer range by adjusting the initial concentration of HAuCl₄ solution. Moreover, the as-synthesized Au colloids (d _av = 3.64 nm) exhibited good catalytic activity for glucose oxidation. The nucleation and growth of colloidal Au particles under the influence of the plasma was closely related with the high-energy electrons generated by glow discharge plasma.     

Pyrazole Derived Cationic Surfactants and their Tin and Copper Complexes: Synthesis,Surface Activity,Antibacterial and Antifungal Efficacy

Five membered heterocyclic cationic 3-pyrazolium surfactants namely: 2-[2-(alkyloxy)-2-oxoethyl]-3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-3-pyrazolium bromide (decyl-; dodecyl-) and their copper and tin complexes were synthesized, their structures were confirmed using different spectroscopic tools. The IR spectra of the metal complexes showed that these compounds exhibit a tetrahedron structure with the transition metal ion (M²⁺) at the center and the cationic ligands arranged in the apexes, while the halide ions in the center. The synthesized compounds were evaluated as biocides against different types of bacteria and fungi. The biological activity data showed that the cationic surfactants exhibit moderate to high efficacy against the tested microorganisms (either bacteria or fungi). While, complexation of these cationic surfactants with Cu (II) and Sn (II) ions the antimicrobial activity was strongly increased. The surface activity of these compounds were discussed and correlated to their chemical structure and the type of substituents on the heterocyclic moiety. Meanwhile, the antimicrobial assay was correlated to the surface activities of the synthesized compounds.     

Synthesis and characterization of nanosized polypyrrole–polystyrene composite particles

Nanosized polypyrrole–polystyrene (PPy–PS) composite particles were synthesized by the polymerization of pyrrole on PS nanoparticles in the presence of FeCl₃. The PS nanoparticles were prepared from microemulsion polymerizations using the cationic nonpolymerizable surfactant cetyltrimethylammonium bromide (CTAB), the nonionic polymerizable surfactant ω‐methoxy[poly(ethylene oxide)₄₀]undecyl α‐methacrylate (PEO–R–MA‐40), or the cationic polymerizable surfactant ω‐acryloyloxyundecyltrimethylammonium bromide (AUTMAB). For the latexes stabilized by CTAB, the resulting PPy–PS composite particles exhibited relatively poor colloidal stability and the pressed pellets exhibited relatively low electrical conductivities (～10^?7–10^?3 S cm^?1). However, for the latexes stabilized by polymerizable surfactants, the resulting PPy–PS composite particles exhibited relatively good colloidal stability and relatively high conductivities (～10^?5–10^?1 S cm^?1). The effect of polymerizable surfactants on the colloidal stability of composite particles and the conducting mechanism of the composites are discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1360–1367, 2004     

Controlled synthesis of copper nano/microstructures using ascorbic acid in aqueous CTAB solution

This paper describes a low-temperature green chemical synthesis of various morphologies of copper nano/microstructures. These syntheses achieved high yields in aqueous solution using ascorbic acid as a reductant and the cationic surfactant cetyltrimethylammonium bromide (CTAB) as a capping agent. The resulting copper particles were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and UV-Vis. absorption spectroscopy techniques. From the SEM analysis, it was found that different morphologies of copper particles, including submicron polyhedrons, micrometer rods, spherical nanoparticles, and nanowires were obtained by varying factors such as the molar ratio of reactants (ascorbic acid and CuSO₄·5H₂O), pH, reaction time, and temperature. Increasing the molar ratio of ascorbic acid to precursor salt and increasing the pH led to a decrease in the size of copper particles formed. At short reaction times, spherical copper nanoparticles with an average diameter of 90 nm are obtained. When the reaction time was prolonged, the nanoparticles transformed into nanowires with diameters in the range of 100-250 nm, and lengths of up to 6-8 μm. When the reaction temperature was decreased, Cu mixed with Cu₂O particles were obtained instead of Cu particles. The resultant copper particles were confirmed by EDX and XRD to be pure Cu, with face-centred cubic (fcc) structures.     

A Two-Step Hydrothermal Synthesis Approach to Monodispersed Colloidal Carbon Spheres

This work reports a newly developed two-step hydrothermal method for the synthesis of monodispersed colloidal carbon spheres (CCS) under mild conditions. Using this approach, monodispersed CCS with diameters ranging from 160 to 400 nm were synthesized with a standard deviation around 8%. The monomer concentration ranging from 0.1 to 0.4 M is in favor of generation of narrower size distribution of CCS. The particle characteristics (e.g., shape, size, and distribution) and chemical stability were then characterized by using various techniques, including scanning electron microscopy (SEM), FT-IR spectrum analysis, and thermalgravity analysis (TGA). The possible nucleation and growth mechanism of colloidal carbon spheres were also discussed. The findings would be useful for the synthesis of more monodispersed nanoparticles and for the functional assembly.     

Surface Parameters and Biological Activity of <Emphasis Type="Italic">N</Emphasis>-(3-(Dimethyl Benzyl Ammonio) Propyl) Alkanamide Chloride Cationic Surfactants

Three cationic surfactants containing amide groups were prepared by quaternization of dimethylaminopropylamine with benzyl chloride. FTIR and ¹H-NMR spectroscopy were used to confirm the chemical structure of the prepared cationic surfactants. The surface parameters were estimated using surface tension measurements at three different temperatures. The prepared cationic surfactant showed a lower CMC than conventional cationic surfactants. Thermodynamic parameters of adsorption and micellization depend mainly of alkyl chain length and temperature. The adsorption process is more favorable than micellization. The biological activity of the three surfactants was estimated using inhibition zone showing that amidoamine cationic surfactants have good activity and the surfactants C12Bn is the most effective one.     

Preparation and characterization of UV‐curable ZnO/polymer nanocomposite films

A series of novel nano‐ZnO/polymer composite films with different ZnO contents was prepared through incorporation of pre‐made colloidal ZnO particles into monomer mixtures of urethane‐methacrylate oligomer and 2‐hydroxyethyl methacrylate, followed by ultraviolet (UV) radiation‐initiated polymerization. The colloidal ZnO nanoparticles with a diameter of 3–5 nm were synthesized from zinc acetate and lithium hydroxide in ethanol via a wet chemical method. In order to stabilize and immobilize the ZnO particles into the polymer matrix, the ZnO nanoparticles were further capped using 3‐(trimethoxysilyl)propyl methacrylate. Thermogravimetric analyses show that the ZnO nanoparticles were successfully incorporated into the polymer matrix and these ZnO/polymer composites have a good thermal stability. Transmission electron microscopy studies indicate the ZnO nanoparticles were uniformly dispersed in the polymer and they remained at the original size (3–5 nm) before immobilization. All nanocomposite films with ZnO particle contents from 1 to 15 wt% show good transparency in the visible region and luminescent properties. In addition, composite films with high ZnO content (>7 wt%) are able to absorb UV irradiation below 350 nm, indicating that these composite films exhibit good UV screening effects. Copyright © 2006 Society of Chemical Industry     

硅烷改性氟代聚丙烯酸酯乳液的合成及其应用

在阳/非离子表面活性剂及引发剂作用下,将甲基丙烯酸十二氟庚酯、甲基丙烯酸十二醇酯、丙烯酸羟丙酯、甲基丙烯酸二甲氨乙酯、乙烯基三乙氧基硅烷进行乳液共聚,制得了硅烷改性的阳离子氟代聚丙烯酸酯乳液(FL-HDV)。用红外光谱(FT-IR)和核磁共振氢谱(1H NMR)对FLHDV主组分的结构进行了表征,用X射线光电子能谱仪(XPS)对乳液的成膜表面成分进行分析和表征,并讨论了硅烷改性前后及不同的整理工艺对其在涤纶织物上应用性能的影响。结果表明,与未用硅烷改性的氟代聚丙烯酸酯乳液(FLDH)对比,硅烷改性可以提高含氟聚合物的交联度,进而增加织物的拒水拒油性。XPS分析和接触角测定结果表明,在涤纶纤维表面明显存在有FLHDV膜,使得纤维与空气的界面上富集着疏水的含氟链段,而硅氧基团与纤维表面结合,从而赋予涤纶良好的拒水拒油性。在不同的工艺条件下,一浸一轧工艺处理的织物具有更高的拒水拒油等级,且弯曲刚度略低,柔软度较好。     

Facile preparation of cationic P (St-BA-METAC) copolymer nanoparticles and the investigation of their interaction with bovine serum albumin

Cationic copolymer nanoparticles were prepared by emulsifier-free emulsion polymerization of styrene and n-butyl acrylate, using [2-(methacryoyloxy ethyl] trimethylammonium chloride as the cationic functional comonomer and 2,2′-azobis (2-methypropionamidine) as the cationic initiator. FTIR spectroscopy, ¹H-NMR spectroscopy, and GPC were applied to characterize the chemical structure and molecular weight of the obtained copolymer. The size and size distribution of the nanoparticles were characterized through photon correlation spectroscopy. The interaction of nanoparticles with bovine serum albumin (BSA) was investigated by the means of transmission electron microscopy and fluorescence spectroscopy. It was found that the copolymer nanoparticles were monodisperse spheres with the diameter less than 90 nm and can complex well with BSA through electrostatic interaction. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Application of Novel Zeolite Y Nanoparticles in Catalytic Cracking Reactions

The cracking activity of a fluid catalytic cracking (FCC) catalyst containing novel zeolite Y nanoparticles fabricated using mesoporous silica (average particle size of 150 nm) was examined and compared with the performance of other catalysts. The activity experiments were carried out in a fluidized bench-scale batch riser simulator reactor. The bulky probing compound of 1,3,5-triisopropylbenzene (TIPB) was cracked to lighter compounds over a catalyst containing 25% of the developed zeolite. The synthesized sodium-type zeolite nanoparticles were subjected to two cycles of ion-exchange treatment using ammonium sulfate and lanthanum chloride and then to calcination. To investigate the effects of particle size on the activity, three additional catalysts were prepared with the mean particle size of the supported zeolites ranging from 450 to 1800 nm. The preparation of the FCC catalysts was conducted by mixing the highly aqueous dispersed zeolite Y nanoparticles with colloidal silica–alumina as a matrix and silica sol as a binder. The results of the catalytic cracking of TIPB demonstrated the significant effect of the size reduction of the synthesized zeolite Y nanoparticles on the catalytic performance of the catalyst. The FCC catalyst that contained zeolite Y nanoparticles (150 nm) showed superior conversion and selectivity percentages for the main products. The results of this study have a direct implication on the preparation of colloidal catalysts containing zeolite Y nanoparticles, which form stable emulsion with petroleum products. These emulsions can be utilized for slurry and ebullated bed reactors in heavy oil upgrading applications.     

油性介质中组装二氧化硅胶体晶体薄膜

报道厂一种由粒径大于700nm的SiO2微球组装胶体晶体薄膜的方法。以一种密度较大的疏水性有机物替代水或醇类为分散剂,通过对SiO2微球表面进行疏水性处理改善其在油性介质中的分散性,采用改进的垂直沉积法在油性分散剂中制备SiO2胶体晶体。用扫描电子显微镜、红外光谱仪和紫外－可见光谱仪对SiO2胶体晶体薄膜的形貌、结构和光学性能进行了观察测试。结果表明;较大密度的分散剂能有效降低SiO2微球的沉降速度,组装成直径在700～2000nm范围的SiO2微球的胶体晶体。获得的SiO2光子晶体具有长程有序结构,并在近红外区具有显著的光子频率带隙。     

In situ preparation of magnetite/cuprous oxide/poly(AMPS/NIPAm) for removal of methylene blue from waste water

In situ techniques have attracted great attention for the formation of nanomaterials with controlled sizes, shapes and dispersion within supramolecular hydrogels. In the present work, the doping of copper oxides onto magnetite nanoparticles into hydrogels based on sodium 2‐acylamido‐2‐methylpropanesulfonate (AMPS) and N‐isopropylacrylamide NIPAm copolymers was investigated. The contents, morphology and thermal stability of magnetite, cupreous oxide and doped copper oxides onto the magnetite nanoparticles were evaluated. The optimum conditions for removal the cationic dye methylene blue (MB), such as solution pH, concentration of adsorbents, contact time and stirring time, were determined to investigate the effect of MB concentrations on the removal efficiencies of the prepared adsorbents. The recyclability of the prepared AMPS/NIPAm composites for the removal of MB was examined for up to six cycles without changes in removal effectiveness. © 2018 Society of Chemical Industry     

Influence of surfactants on properties of electrochemically synthesized pyrrole/1-dimethylaminopyrrole copolymer

The electrochemical copolymerization of pyrrole (Py) and 1-dimethylaminopyrrole (DMAPy) was successfully carried out in the presence of three different types of surfactant (anionic, cationic and non-ionic) by cyclic voltammetric method. The influence of anionic (sodium dodecylbenzenesulfonate) (NaDBS), cationic (tetradecyltrimethylammonium bromide) and non-ionic poly(ethylene oxide)(10) iso-octylphenyl ether (Tween 20) surfactants on the properties of copolymer was investigated. The copolymer has been characterized by the cyclic voltammetry, fourier transform infrared spectroscopy, UV–Vis spectroscopy, scanning electron microscopy, thermogravimetric analysis and conductivity measurements. The results confirmed that the electrochemical reaction of Py and DMAPy in the presence of surfactants generated copolymers. The type of surfactant had an effect on the structural, morphological, thermal and conductivity properties of the copolymers in different ways. According to the initial decomposition temperatures, the thermal stability of the copolymers improved in the presence of surfactants. Py/DMAPy copolymer synthesized in the presence of anionic surfactant NaDBS had the highest initial decomposition temperature (320 °C). The copolymer prepared using various surfactants exhibited different morphologies. The electrical conductivity of pyrrole/1-dimethylaminopyrrole copolymer (8.39 × 10^?3 Scm^?1) was improved using surfactants, especially with anionic surfactant (3.75 × 10^?2 Scm^?1) due to the incorporation of NaDBS into the PPy polymer chain that resulted in a more compact morphology and reduced size of PPy globules.     

Synthesis and Evaluation of Bis-quaternary-Based Surfactants as Additives for Water-Based Mud

Two series of cationic gemini surfactants, alkanediyl-α,ω-bis[N,N-dimethyl alkyl (octyl or dodecyl)ammonium] dibromide (R-s-R; s = 6, 10, 12 and R = 8 and 12) were prepared and evaluated as additives for water-based mud. The chemical structures of the prepared surfactants were confirmed using FTIR and mass spectroscopy. Surface activity of these compounds has been studied and their surface properties including surface tension, emulsification power, critical micelle concentration, effectiveness, maximum surface excess and minimum surface area were determined. The results showed that the prepared compounds have significant surface activity, especially those of longer hydrophobic chain length. The prepared cationic gemini surfactants were evaluated as viscosifiers and filter loss additives for water-based mud formulated from local Na-montmorillonite clay. XRD analysis was carried out to the Na-montmorillonite clay to determine the interaction of the surfactants with inter layers of the clay structure. Rheological properties, gel strength, thixotropy, filtration properties and the effect of temperature on rheological properties of the water-based mud were studied. The results indicated that the gemini surfactants have a positive effect on the rheological and filtration properties of the Na-montmorillonite clay according to American Petroleum Institute specifications.     

Metal nanoparticles stabilized by cubic silsesquioxanes for catalytic hydrogenations

Octa(diacetic aminophenyl) silsesquioxanes (OAAPS) were synthesized and used as stabilizers for preparing metal (Pt, Pd and Ru) nanoparticles using NaBH₄ as a reducing agent. The synthesized catalysts were characterized by UV-vis, XRD, and TEM. The average diameters of Pt (0), Pd (0) and Ru (0) nanoparticles are 1.6 ± 0.3, 1.4 ± 0.2 and 1.3 ± 0.2 nm, respectively. The metal colloids show excellent stability since OAAPS offer stronger bonding of the cubic linker to the metal nanoparticles through the chelating effect. All colloids prepared are stable and show no precipitation at room temperature for several months. The catalytic hydrogenations of phenyl aldehydes using the metal colloids as catalysts demonstrate that catalytic activities depend on the variety of the metal colloids and the substrates. The colloidal catalysts stabilized by OAAPS can be recycled by simply adjusting the pH of the solution.