Synthesis characterizationA facile and fast approach for the synthesis of doped nanoparticles using a microfluidic device
The microfluidic approach emerges as a new and promising technology for the synthesis of nanomaterials. A microreactor allows a variety of reaction conditions to be quickly scanned without consuming large amounts of raw material. In this study, we investigated the synthesis of water soluble 1-thioglycerol-capped Mn-doped ZnS nanocrystalline semiconductor nanoparticles (TG-capped ZnS:Mn) via a microfluidic approach.
Highly stable Ag nanoparticles in agar-agar matrix as inorganic–organic hybrid
A novel synthesis of inorganic–organic hybrid films containing well dispersed and almost uniform size Ag nanoparticles in agar-agar matrix has been reported. The films are found to be highly stable for more than a year. The colloidal particles of Ag can be obtained in large quantities in the form of a film or in the gel form when dispersed in agar-agar or by dissolving in a suitable solvent as solution. Characterization has been done by UV–visible spectroscopy and TEM.
ZnO and ZnCdO nanocrystallites obtained by oxidation of precursor Langmuir-Blodgett multilayers.
ZnO and Zn1−xCdxO nanocrystallites were prepared by oxidation of zinc arachidate–arachidic acid and zinc arachidate–cadmium arachidate–arachidic acid LB multilayers, respectively. The metal content of the multilayers was controlled by manipulation of subphase composition and pH. Precursor multilayers were oxidized in the temperature range of 400 °C–700 °C. The formation of ZnO and Zn1−xCdxO was confirmed by UV–Visible spectroscopy.
Synthesis and characterisation of controllably functionalised polyaniline nanofibres
A novel method for functionalising solution based polyaniline (PAni) nanofibres is reported whereby the degree of side-chain attachment can be controllably altered. The covalent attachment of functional sidegroups to the surface of PAni nanostructures is achieved by post-polymerisation reflux in the presence of a nucleophile and the functionalised nanomaterial can be purified by simple centrifugation. The technique is therefore easily scalable.
Synthesis and aggregation study of tin nanoparticles and colloids obtained by chemical liquid deposition
Tin colloids (Sn-Colls) and nanoparticles were synthesized by a chemical liquid deposition method (CLD). Sn0 was evaporated and codeposited with acetone, 2-propanol, and tetrahydrofurane vapors at 77 K to obtain colloidal dispersions. Sn-Coll were characterized by UV spectroscopy, transmission electron microscopy (TEM), high resolution transmission electron microscopy, selected area electron diffraction, thermal analysis, infrared spectroscopy [Fourier transform infrared (FTIR)], and light scattering.
Facile preparation of monodispersed core/shell zinc oxide@ polystyrene (ZnO@ PS) nanoparticles via soapless seeded microemulsion polymerization
Monodispersed core/shell zinc oxide@polystyrene (ZnO@PS) nanoparticles with chemical bonds between the inorganic core and the polymer shell were prepared successfully by the facile soapless microemulsion polymerization of styrene (St) with the oleic acid modified zinc oxide (OA-ZnO) nanoparticles as seeds, and potassium persulphate (KPS) as initiator in water. The products were characterized by elemental analysis (EA),
Living biomembrane bitemplate route for simultaneous synthesis of different morphologies of CdSe and ZnSe nanomaterials
In this paper, CdSe (nanotubes, nanorods) and ZnSe (nanorods, nanoslats) were simultaneously synthesized through a biomineralization process through biomembrane bitemplates of mungbean sprouts at room temperature. The XRD patterns indicated that these nanocrystals were crystallized in the hexagonal structure and cubic structure with lattice constants a = 0.423 and c = 0.701 nm (CdSe) and a = 0.567 nm (ZnSe), respectively.
Keggin Ion Mediated Synthesis of Hydrophobized Pd Nanoparticles for Multifunctional Catalysis
Development of simple and reliable protocols for the synthesis of organically soluble catalytically active metal nanoparticles is an important aspect of research in nanomaterials. We demonstrate herein the formation of Pd nanoparticles by reduction of aqueous Pd(NO3)2 by photoexcited Keggin ions (phosphotungstate anions). This results in the formation of Pd nanoparticles capped with with Keggin ions that render the particles negatively charged.
Adsorption of transition-metal ions in ethanol solution by a nanomaterial based on modified silsesquioxane
The material octakis[3-(3-amino-1,2,4-triazole)propyl]octasilsesquioxane (ATZ-SSQ) was synthesized and its potential was assessed for Cu(II), Ni(II), Co(II), Zn(II) and Fe(III) from their ethanol solutions and compared with related 3-amino-1,2,4-triazole-propyl modified silica gel (ATZSG). The adsorption was performed using a batchwise process and both organofunctionalized surfaces showed the ability to adsorb the metal ions from ethanol solution.
Magnetic and electrochemical properties of nickel oxide nanoparticles obtained by the reverse-micellar route
Homogeneous nanoparticles of nickel oxide (NiO) of 25 nm size with narrow size distribution have been synthesized by the reverse-micellar route using CTAB (cetyltrimethyl ammonium bromide) as the surfactant. FTIR studies show a broad absorption around 405–415 cm−1 and a weak absorption around 82 cm−1 corresponding to a surface-active mode, which is indicative of the nanocrystalline nature of the oxide.
One-step copolymerization modified magnetic nanoparticles via surface chain transfer free radical polymerization
Copolymer brushes growing onto magnetic nanoparticles were prepared by surface chain transfer free radical polymerization. Block copolymer brushes (P(PEGMA)-co-PNIPAAm) consist of poly(ethylene glycol) monomethacrylate (PEGMA) and N-isopropylacrylamide monomer. X-ray photoelectron spectroscopy (XPS) characterized the chemical composition of copolymer.
The melting behavior of aluminum nanoparticles
The melting behavior of aluminum nanoparticles having an oxide passivation layer is examined using a differential scanning calorimetry (DSC). Both broad and narrow size-distributed particles are studied, and the weight-average particle radius ranges from 8 to 50 nm. With decreasing particle size, the melting response moves towards lower temperatures and the heat of fusion decreases. The effect of the oxide coating on the particles is to apply a compressive force to the aluminum core, thereby increasing the observed melting point and the heat of fusion.
Sulfate-Functionalized Carbon/Metal-Oxide Nanocomposites from Hydrotalcite-like Compounds
As a new application of hydrotalcite-like compounds, sulfate-functionalized carbon/metal-oxide nanocomposites have been prepared at relatively low temperatures in a single step, in which interlayer sulfonated polymeric anions are catalytically converted to the nanocarbons (secondary phase) while CoAl-containing brucite-like sheets are converted to the metal oxide matrices.
Photocatalytic property of colloidal TiO2 nanoparticles prepared by sparking process
Titanium oxide nanoparticles (NPs) were successfully prepared by sparking off two titanium tips into water for 1–5 h. The nanoparticle-dispersed water was obtained for further characterization. The transmission electron microscopy result shows that the particle size is in the range of 1–5 nm. The electron diffraction patterns and Raman spectra reveal that the as-prepared and the annealed samples at 250 °C are the anatase phase.
Silver doped titanium dioxide nanomaterials for enhanced visible light photocatalysis
This paper presents a systematic study on two different preparation methods for titanium dioxide with silver. The silver can be incorporated by irradiating the reaction mixture during preparation to reduce silver ion to silver metal or by direct calcination of the sol–gel material to decompose silver nitrate to silver. Of the two methods, we found the latter produces a more effective photocatalytic material (6–50% improvement in catalytic efficiency), which is attributed to the fact that the silver is homogeneously dispersed throughout the material.
Poly (hydroethyl acrylate) grafted from ZnO nanoparticles via surface-initiated atom transfer radical polymerization
Poly(hydroethyl acrylate) (PHEA) was grafted from ZnO nanoparticles via the copper-mediated surface-initiated atom transfer radical polymerization (SI-ATRP) technique with the bromo-acetamide modified ZnO nanoparticles (BrA-ZnO) as macroinitiators with the catalysts of 1,10-phenanthroline and Cu(I)Br in water. Graft reaction was first order kinetic with respect to the polymerizing time in the low monomer conversion stage, this being typical for ATRP.
CdS/ZnS core–shell nanoparticles in arachidic acid LB films
Core–shell CdS/ZnS nanoparticles in arachidic acid film were prepared through a novel Langmuir–Blodgett (LB) approach. Post-deposition treatment of the precursor LB multilayers of cadmium arachidate with H2S gas followed by intercalation of Zn2+ ions and further sulfidation result in the formation of CdS/ZnS nanoparticles in the LB film. The formation of these nanoparticles and resulting changes in layered structures were studied by FTIR and X-ray reflection measurements.
SERS enhancement by aggregated Au colloids: effect of particle size
In this work the spectroscopic properties of a range of samples of monodisperse Au colloids with diameters ranging from 21 to 146 nm have been investigated in solution. The UV/visible absorption spectra of the colloids show complex changes as a function of aggregating salt (MgSO4) concentration which diminish when the colloid is fully aggregated. Under these conditions, the relative RAMAN SERS enhancements provided by the variously sized colloids vary very significantly across the size range.
Preparation and characterization of ZnO nanoparticles coated paper and its antibacterial activity study
Coating of ZnO nanoparticles on paper surface has potential technological applications. With this motivation, a simple approach of ultrasound assisted coating of paper with ZnO nanoparticles (
20 nm) without the aid of binder is reported for the first time in this work. The ultrasound assisted coating approach concurs with 
green
chemistry as it is simple and environmentally friendly. Scanning electron microscope is used to characterize the surface morphology showing ZnO nanoparticles bound to cellulose fibers.
CdS/ZnS core–shell nanoparticles in arachidic acid LB films
Development of simple and reliable protocols for the synthesis of organically soluble catalytically active metal nanoparticles is an important aspect of research in nanomaterials. We demonstrate herein the formation of Pd nanoparticles by reduction of aqueous Pd(NO3)2 by photoexcited Keggin ions (phosphotungstate anions). This results in the formation of Pd nanoparticles capped with with Keggin ions that render the particles negatively charged.
Characterization of silver sulfide nanoparticles synthesized by a simple precipitation method
Silver sulfide nanoparticles with different sizes were synthesized using a simple aqueous precipitation. Particles were obtained in the presence of three stabilizing agents controlling thus particle size and agglomeration. The particles obtained were characterized using XRD, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal and spectroscopy techniques.
One-pot synthesis of monodisperse iron oxide nanoparticles for potential biomedical applications
One-pot reaction of iron(III) acetylacetonate, Fe(acac)3, [or Fe(acac)3 and M(acac)2 where M = Mn and Co], with 1,2-alkanediol, oleic acid, and oleylamine in high boiling organic solvent leads to monodisperse ferrite MFe2O4 nanoparticles. Depending on the concentration of the metal precursors, surfactant-to-metal precursor ratio and the solvent used in the reaction, the particle size from this one-pot reaction can be tuned from 4 to 15nm. The as-synthesized iron oxide nanoparticles have an inverse spinel structure, and their magnetic properties are controlled by particle size and M in the MFe2O4 structure. The hydrophobic iron oxide nanoparticles are readily transformed into hydrophilic ones by functional phospholipid addition to the as-synthesized particles and as a result, the monodisperse nanoparticles are readily functionalized with biotin, –COOH, –SH, and –NH2, facilitating their link to biomolecules for biomedical applications
Infiltrated and inverted photonic crystals with high index contrast.
Three-dimensionally ordered photonic crystals are fabricated using the self-assembly method from a colloidal solution of polymethyl methacrylate. The air voids in the crystal are filled with zinc oxide and converted to inverse photonic crystal of zinc oxide. The structural and optical characterization results of the sample are analyzed.
Copper-ion-induced photoluminescence tuning in CdSe nanoparticles
Investigations have been made on luminescence properties of copper-doped CdSe nanoparticles, synthesized via green chemical route. The nanoparticles remain stable under normal atmospheric conditions and can be redispersed in suitable solvents (water and dimethyl formamide). The photoluminescence peak positions in the copper doped CdSe nanoparticles are found to strongly depend on the copper ion concentration.
Copper-ion-induced photoluminescence tuning in CdSe nanoparticles
Investigations have been made on luminescence properties of copper-doped CdSe nanoparticles, synthesized via green chemical route. The nanoparticles remain stable under normal atmospheric conditions and can be redispersed in suitable solvents (water and dimethyl formamide). The photoluminescence peak positions in the copper doped CdSe nanoparticles are found to strongly depend on the copper ion concentration.
A novel one-pot route for the synthesis of water-soluble cadmium selenide nanoparticles
A novel, facile one-pot synthetic route to highly water dispersible and potentially biocompatible CdSe nanoparticles is reported. The monodispersed CdSe particles are passivated by cysteine, with water being the solvent. This route involves the reaction of selenium powder with sodium borohydride to produce selenide ions, followed by the addition of a cadmium salt and l-cysteine ethyl ester hydrochloride.
Synthesis, structural and optical properties of CeO2 nanoparticles synthesized by a simple polyvinyl pyrrolidone (PVP) solution route
This paper reports the synthesis and characterization of CeO2 nanoparticles by a simple polymer complex method using cerium (III)) acetate hydrate and polyvinyl pyrrolidone (PVP) as the starting chemicals. The precursor was calcined at 500 °C for 2 h to obtain CeO2 nanoparticles. The XRD, FTIR, Raman and electron diffraction analysis results indicated that the calcined CeO2 sample has the fluorite structure of CeO2. TEM revealed that the CeO2 sample consists of crystalline particles of 5–10 nm which are weakly aggregated. UV–vis spectroscopy was also performed to study the optical properties of the synthesized CeO2 sample.
Polymerization of benzylthiocyanate on silver nanoparticles and the formation of polymer coated nanoparticles
olymerization of benzylthiocyanate on silver nanoparticles produces organic shell covered nanoparticles with controllable thickness in a one-pot process. Gram scale quantities of core–shell materials have been synthesized by this method. The methodology involves the addition of the precursor into Ag–citrate solution and the shell nucleates over a period of three weeks with complete precipitation of the core–shell material which can be dispersed subsequently in organic solvents.