Graphene domain boundaries on Pt(111) as nucleation sites for Pt nanocluster formation

The growth of Pt nanoclusters on a graphene layer on Pt(111) was studied with ultra high vacuum scanning tunneling microscopy. Different periodicities in the moiré patterns of the graphene layer are observed corresponding to different orientations with respect to the Pt(111) lattice. Various graphene orientations are possible because of a relatively weak graphene–Pt interaction. Following Pt deposition onto the graphene-covered surface, small Pt nanoclusters are observed to preferentially form along the moiré domain boundaries. The weak interaction of graphene with Pt(111) leads to a weak corrugation in the superlattice compared to other transition metals, such as Ru, but it is found even this weak corrugation is sufficient to serve as a template for the formation of mono-dispersed one-dimensional Pt nanocluster chains. These Pt nanoclusters are relatively stable and only undergo agglomeration at annealing temperatures above 600 K.     

Preparation of Polycarbonate-ZnO Nanocomposite Films: Surface Investigation after UV Irradiation

Polycarbonate (PC)-ZnO films with different percentages of ZnO were prepared by a solution stirring technique and subjected to ultraviolet (UV; λ = 254 nm) irradiation. Structural parameters of the samples and the effects of UV irradiation on the surface properties of the PC and PC-ZnO nanocomposites were evaluated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), water contact angle (WCA) measurements, and a Vickers microhardness (H_V) tester. The XRD patterns of the nanocomposite films were found to show an increase in crystallinity with the increasing ZnO nanoparticles percentage. The WCA was found to be reduced from 90° to 17° after 15 h of UV irradiation, which could be ascribed to the oxidation of the surface of the samples during the irradiation and exposure of the ZnO nanoparticles, a result that is also supported by the obtained XPS data. The microhardness value of the PC-ZnO films including 30 wt.% ZnO enhanced considerably after UV radiation, which can also be attributed to the exposition of the ZnO nanoparticles after photodegradation of the PC superficial layer of the nanocomposite films.     

Nickel/nickel oxide coatings for fiber batteries

A Nickel–Cadmium fiber micro–battery design consisting of a nickel/nickel oxide coated glass capillary tube, cadmium micro–wire, and polyimide micro–tube was evaluated in this paper. The nickel/nickel oxide thin films were deposited via electrolysis and the quality was evaluated via the effect of the sulfate concentration, plating temperature, plating solution pH, and heat treatment. The maximum voltage range of the fiber batteries ranged from 0.68–1.2 V, while the maximum current supplied by battery ranged from 0.6–1.0 mA. The results of this work demonstrate the feasibility of fiber batteries that can be readily adapted to random or ordered hole fibers and readily integrated into all-fiber optoelectronic devices.     

Cyclopentadienylthallium(I) compounds with bulky cyclopentadienyl ligands

Interaction of TlOC₂H₅ with C₅Ph₄H₂, C₅Ph₅H, C₅Ph₄(^tBuPh)H or C₅Bz₅H gives the new cyclopentadienylthallium(I) compounds C₅Ph₄HTl, C₅Ph₅Tl, C₅Ph₄(^tBuPh)Tl, and C₅Bz₅Tl. The compounds have been characterized by IR, NMR and mass spectroscopy.     

Surface thermodynamics of binary mixtures of ethylene glycol + cyclohexanol or cyclopentanol

Surface tension data of binary mixtures of ethylene glycol + cyclohexanol and ethylene glycol + cyclopentanol was measured over the entire concentration range at various temperatures. The experimental values were correlated with temperature and with mole fraction. The values of the surface entropy, surface enthalpy and excess surface tension for these mixtures were also calculated.     

Synthesis of novel spiro-[3H-indole-3,3′-[1,2,4]triazolidine]-2-ones via azomethine imines

Novel spiroindoles 5 are prepared easily via a one-pot, 1,3-dipolar cycloaddition reaction of azomethine imines with isatin imines under thermal conditions.     

Highly functionalized dihydrofuran derivatives: Synthesis by diastereoselective intramolecular Wittig reaction

3a,8a‐Dihydroxy‐1,3,3a,8a‐tetrahydro‐ indeno[1,2‐d]imidazole‐2,8‐dione 3 reacts with dialkyl acetylenedicarboxylates in the presence of triphenylphosphine to produce some novel interesting dihydrofuran derivatives diastereoselectively. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:277–279, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20202     

Microwave-Induced One - Pot Synthesis of some new Spiro [Indoline-3,2′-Thiazolidine]-2,4′(1H)-Diones and Bis [Spiro [Indoline -3,2′-Thiazolidine]-2,4′(1H)-Diones]

The title compounds have been obtained thermally and under microwave irradiation by condensation of isatin, aromatic amines and mercaptoacetic acid in good to excellent yields without isolating the imine intermediates.     

Intrinsically thermochromic fluorans

A Suzuki coupling strategy has been employed to access a series of novel fluorans substituted with a phenolic moiety. These fluorans display good thermochromism in methyl stearate and obviate the need for traditional complex formulations containing acidic colour developers.