A facile approach to the fabrication of graphene-based nanocomposites by latex mixing and in situ reduction

Graphene-based polystyrene (PS) nanocomposites were prepared by latex mixing, co-coagulation, and in situ reduction process. In the process, aqueous dispersion of graphene oxide (GO) was mixed with PS latex, which was then co-coagulated with sodium chloride to form stabilized particle suspension; subsequently, hydrazine hydrate was added to reduce GO in situ. This process could avoid the use of additional surfactant or ultrasonic power to stabilize graphene during reduction, thus is facile and energy saving. The preparation process and the resulting nanocomposites were characterized in detail. The results show that, after co-coagulation, GO nanosheets are isolated by PS nanospheres through π–π interaction, which prevents the restacking of graphene in the subsequent reduction process. Thus, a molecular-level dispersion of the graphene nanosheets in the PS matrix is achieved, which greatly improves the electrical conductivity and the mechanical properties of the nanocomposites.     

A facile and green synthetic approach toward fabrication of starch-stabilized magnetite nanoparticles

A facile and green synthetic approach for fabrication of starch-stabilized magnetite nanoparticles was implemented at moderate temperature. This synthesis involved the use of iron salts, potato starch,sodium hydroxide and deionized water as iron precursors, stabilizer, reducing agent and solvent respectively. The nanoparticles(NPs) were characterized by UV-vis, PXRD, HR-TEM, FESEM, EDX, VSM and FT-IR spectroscopy. The ultrasonic assisted co-precipitation technique provides well formation of highly distributed starch/Fe_3O_4-NPs. Based on UV–vis analysis, the sample showed the characteristic of surface plasmon resonance in the presence of Fe_3O_4-NPs. The PXRD pattern depicted the characteristic of the cubic lattice structure of Fe_3O_4-NPs. HR-TEM analysis showed the good dispersion of NPs with a mean diameter and standard deviation of 10.68 4.207 nm. The d spacing measured from the lattice images were found to be around 0.30 nm and 0.52 nm attributed to the Fe3O4 and starch, respectively. FESEM analysis confirmed the formation of spherical starch/Fe_3O_4-NPs with the emission of elements of C, O and Fe by EDX analysis. The magnetic properties illustrated by VSM analysis indicated that the as synthesized sample has a saturation magnetization and coercivity of 5.30 emu/g and 22.898 G respectively.Additionally, the FTIR analysis confirmed the binding of starch with Fe_3O_4-NPs. This method was cost effective, facile and eco-friendly alternative for preparation of NPs.     

A facile approach to prepare hybrid nanoparticles with morphology controlled by the thickness of glyco-shell

Herein, we designed a novel amphiphilic triblock glycopolymer poly(oligo(ethyleneglycol) methacrylate)-block-poly(maltopyranoside methacrylate)-block-polystyrene(POMA-b-PMal-b-PS) via the combination of reversible addition-fragmentation chain transfer(RAFT) polymerization and postpolymerization modification. The micelles with core–shell–corona structures were prepared by direct self-assembly of this glycopolymer in water. We found that these micelles can be used in in situ formation and stabilization of Au NPs. By controlling the thickness of glyco-shell, we successfully obtained Janus particles and raspberry-like particles with Au NPs in the sugar shell.     

Surfactant-assistant and facile synthesis of hollow ZnS nanospheres

Small and monodisperse ZnS hollow nanospheres with outer diameter ranging from 60 to 70 nm and wall thickness of 15-20 nm were fabricated in a large scale by a simple surfactant polyethylene glycol (PEG) assisted method. The diameter and the wall thickness of the hollow nanospheres could be controlled by manipulating the amount of PEG and the aging time, respectively. Moreover, the wall of these hollow nanospheres is very compact. The product was characterized by X-ray power diffraction (XRD), transmission electron microscopy (TEM), UV-vis spectrum and fluorescence spectroscopy. The photocatalytic activity of as-prepared ZnS hollow nanospheres was also evaluated by using methyl orange (MO) as a model organic compound and the result revealed that their photocatalytic activity is a little lower than that of Degussa P25 TiO(2) but better than that of ZnS nanocrystals prepared by literature method. Furthermore, a rational mechanism to the formation and evolution of the products is proposed.     

A facile route to hollow nanospheres of mesoporous silica with tunable size

Hollow mesoporous silica nanospheres (HMSNs) with tunable sizes of both sphere diameter (around 100 nm) and shell thickness have been successfully fabricated.     

A facile route to the fabrication of morphology-controlled Sb2O3 nanostructures

We report in this paper a facile hydrothermal route for the preparation of Sb₂O₃ nanoribbons assembly with different aspect ratio and Sb₂O₃ polyhedral nanoparticles. Study indicates that the ratio of water and ethanol affects the morphology, size and crystal phase of Sb₂O₃ assembly building blocks. In a mixed alcohol and water solution, the orthorhombic Sb₂O₃ nanoribbons with a length of ～4 μm and a width of 400 nm were assembled into rod-like structures, while a length of ～3 μm and a width of 300 nm Sb₂O₃ nanoribbons were assembled into quadrangle structures with the increase of the water ratio. In the absolute alcohol solution, the cubic Sb₂O₃ particles with polyhedral morphology were formed. PL spectra indicate that the morphology strongly affects the luminescence property. The possible formation mechanisms involving the surfactant-assisted self-assembly and the confined growth were also proposed for the formation of the bundled nanoribbons and polyhedral granules, respectively.     

A new route to self-assembled tin dioxide nanospheres: fabrication and characterization

Nearly monodispersed self-assembled tin dioxide (SnO2) nanospheres with intense photoluminescence (PL) were synthesized using a new wet chemistry technique. Instead of coprecipitating stannous salts, bulk tin (Sn) metal was oxidized at room temperature in a solution of hydrogen peroxide and deionized water containing polyvinylpyrrolidone (PVP) and ethylenediamine (EDA). SnO2 nanocrystals were produced with diameters of approximately 3.8 nm that spontaneously self-assembled into uniform SnO2 nanospheres with diameters of approximately 30 nm. Analysis was performed by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, selected area electron diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, UV-vis absorption spectroscopy, PL spectroscopy, and fluorescence lifetime measurements. The SnO2 nanospheres displayed room-temperature purple luminescence with an intense band at 394 nm (approximately 3.15 eV) and a high quantum yield of approximately 15%, likely as a result of emission from the surface states of SnO2/PVP complexes. The present study could open a new avenue to large-scale synthesis of self-assembled functional oxide nanostructures with technological applications as purple emitters, biological labels, gas sensors, lithium batteries, and dye-sensitized solar cells.     

Controllable fabrication of platinum nanospheres with a polyoxometalate-assisted process

Pt nanospheres with an average diameter of 60±10 nm have been successfully synthesized at room temperature through a facile polyoxometalate(POM)-assisted process. Characterization by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) clearly showed that these Pt nanospheres consisted of 2-7 nm Pt nanodots. During the formation of such unique nanostructures, POMs were found to serve as both catalyst and stabilizer. The size of the as-synthesized Pt nanospheres could be controlled solely by adjusting the molar ratio of POMs to H₂PtCl₆. A possible formation mechanism based on POMs-mediated electron transfer from ascorbic acid (AA) to PtCl₆²⁻ and AA-assisted aggregation was tentatively proposed to rationalize the formation of such nanostructures. Importantly, these specific Pt nanospheres exhibited good electrocatalytic activity towards the oxidation of methanol, making them promising for applications in direct methanol fuel cells.     

A facile route to fabrication of inorganic-small organic molecule cable-like nanocomposite arrays

A novel and facile method is reported for the preparation of silver iodide-small organic molecule (SOM) cable-like nanocomposites arrays, which involved first the fabrication of SOM nanotubes inside an anodic aluminium oxide (AAO) membrane, and then using the SOM nanotubes in AAO as secondary template to prepare the AgI nanowires in aqueous solution at room temperature.     

A facile approach to phosphonic acid diesters

The symmetric H‐phosphonates of carbohydrate and other compounds were conveniently prepared by direct transesterification of the corresponding monohydroxylic compounds with diphenyl phosphite. The approach has the merits of mild reaction conditions and high yields. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:208–210, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10130     

A facile two synthon approach to the camptothecin skeleton

A synthesis of deethyldesoxycamptothecin via the reaction of two readily accessible synthons is described. One of the synthons constitutes the ABC ring system of camptothecin, while the second provides all the C atoms of the rings D and E. The synthetic approach is suited for the total synthesis of camptothecin analogues.     

A facile one-pot synthesis of uniform core-shell silver nanoparticle@mesoporous silica nanospheres

The uniform core-shell silver nanoparticle@mesoporous silica nanospheres have been prepared by a simple one-pot synchronous method, which combines several steps into one, including the generation of silver nanocrystals and mesoporous silica, transfer and aggregation of silver nanoparticles in an incompact silica framework.     

Facile fabrication of AgCl@polypyrrole-chitosan core-shell nanoparticles and polymeric hollow nanospheres

A one-step sequential method for preparing AgCl@polypyrrole-chitosan core-shell nanoparticles and subsequently the formation of polypyrrole-chitosan hollow nanospheres is reported. The formation of the core and the shell is performed in one reaction medium almost simultaneously. Transmission electron microscopy (TEM) images show the presence of core-shell nanoparticles and hollow nanospheres. Ultraviolet-visible (UV-vis) studies reveal that AgCl was formed first followed by polypyrrole. X-ray diffration (XRD) and UV-vis studies show that AgCl was present in the core-shell nanoparticles and could be removed completely from the core.     

A facile approach to hexagonal ZnO nanorod assembly

Nanocrystalline ZnO nanorods were successfully grown by ultrasonication using an acidic ethanolic zinc acetate precursor solution followed by a flow coating process and annealing at 600 °C. The ZnO nanorods obtained were hexagonal in shape and showed a high degree of uniformity in size and distribution. These samples were characterized by X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and Raman spectrophotometry and the results are discussed. This approach appears to be the easiest way to fabricate bulk ZnO nanorods.     

A facile approach to the synthesis of chiral 2-substituted benzofurans

An effective route to chiral optically active 2-substituted benzofurans directly from carboxylic acids is reported. This procedure, which allows the preparation of alpha-alkyl-2-benzofuranmethanamines from N-protected alpha-amino acids without sensible racemization phenomena, proceeds in good yields under mild conditions with the help of microwave irradiation.     

A novel approach to polymeric hollow nanospheres with stabilized structure

Polymeric hollow nanospheres with stabilized structure have been realized by self-assembly of crosslinkable rigid poly(amic acid) ester (PAE) oligomer and coil-like poly(4-vinylpyridine) (PVPy) via hydrogen bonding in their common solvent and subsequent photo-crosslinking of the PAE.     

A facile and environment-friendly method for fabrication of polymer brush

A novel environment-friendly system is proposed tofabricate polymer brush, which has the advantages including non-toxic and inexpensive initiator(eosin Y), visible-light exposure(λ= 515 nm), water medium and ambient environment. The experimental results from UV-Vis spectroscopy, AFM-based single molecule force spectroscopy(SMFS) and other measurements indicate thata polymer brush with a living nature is fabricated via free radical polymerization. This polymer brush may find applications incoatings, bio-interfaces and so forth.     

A facile template free synthesis of porous carbon nanospheres with high capacitive performance

Porous carbon nanospheres have been widely used in different fields such as electric devices, catalysts, and water treatment. Here we will introduce a template-free process for the preparation of porous carbon nanospheres starting from a direct 3-aminophenol formaldehyde polymerization in a mixed solution. We identify that the addition of different alcohols, particularly ethanol and n-butanol, is able to change the growth habit of the polymer nanospheres and introduce a favorable inner compositional homogeneity for the preparation of porous structure. After the carbonization of the polymer nanospheres, the obtained porous carbon exhibits promising electrochemical performance when used as electrode material in super capacitor.