Materials Literature
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Growth of and hydrogen production by wild-type (WT) Rhodovulum sulfidophilum were compared with those by one of its mutants lacking the poly(3-hydroxybutyrate) (PHB) biosynthesis ability (PNM2). During phototrophic growth under aerobic conditions with fixed illumination, changes in the extinction coefficient and PHB c…
Abstract New cholesterol-based gelators bearing a 4-, 3-, or 2-pyridyl group (1, 2, or 3, respectively) have been designed. Compound 1 gelled 16 of the 19 solvents tested, indicating that 1 acts as a very versatile gelator. The gelation ability of compound 2 was significantly improved by added AgOTf, owing to an Ag(I)…
Spectroscopic studies involving dielectric, submillimeter, infrared, and Raman measurements were performed on a ${\mathrm{CaTiO}}_{3}$ single crystal, covering a broad spectral range (static to 10 THz) at temperatures from 6 to 300 K. The results show mode softening characteristic of an incipient ferroelectric with ${…
A family of polymers based on alternating bi‐EDOT and pyridine units is reported. Poly(BEDOT‐PyrPyr‐Ph 2 ), with a bandgap of 1.2 eV, has four electrochemically accessible colors (dark gray, burgundy, lime green, and light gray) each corresponding to a distinct redox state. In‐situ conductance measurements illustrate…
We describe recent developments in the synthesis of semiconductor nanoparticles, which lead to a substantial improvement of the luminescence quantum efficiency. Concerning a theoretical model for the growth of an ensemble of nanoparticles, the highest quantum efficiencies are achieved in particles that grow under cond…
Single wall carbon nanotubes (SWCNTs) synthesized by the recently developed HiPco® method differ from those obtained by other techniques because their diameter distribution is broader and is centered at a smaller value. Therefore, HiPco® samples contain an unusual wide selection of different nanotubes. Combining this…
Iron containing nanoparticles are found to spontaneously form on hydroxylated SiO 2 substrates when immersed in a freshly mixed aqueous solution of FeCl 3 and hydroxylamine. Upon calcination, a submonolayer of uniformly distributed iron oxide nanoparticles can be derived and used to catalyze the growth of single-walle…
The size-selective photoetching technique was used to control the size of a CdS nanoparticle inside a silica shell. With monochromatic light irradiation, the diffuse reflectance spectra of silica-coated CdS nanoparticles were blue-shifted, and the size of the resulting CdS nanoparticles incorporated in the silica shel…
Abstract Crystalline Si nanoparticles with diameters between 2.5 and 20 nm are prepared by CO 2 ‐laser‐induced decomposition of silane in a gas flow reactor. A small portion of the products created in the reaction zone is extracted through a nozzle into a high‐acuum apparatus to form a freely propagating molecular bea…
A rigorous method to engineer the electronic structure of carbon nanotubes from metallic to semiconducting is reported (see inside front cover). An intramolecular junction in carbon nanotube is fabricated, where half of the nanotube is masked by a silicon oxide thin film. Functionalization of the nanotube by atomic hy…
Nanocomposite thin films (see Figure) that are prepared by sputtering and heat treatment demonstrate exchange coupling and remanence enhancement. A high remanence of J r = 1.31 T and a maximum energy product of ( B H ) max = 203 kJ m –3 are achieved. These multilayer films consist of magnetically hard Nd 2 Fe 14 B‐typ…
Exfoliation behavior of clay layers in epoxy−clay nanocomposites was studied with the electronegativities of aromatic diamine curing agents and curing temperatures. While faster gelation in the extragallery region accelerated by much more reactive aromatic diamine curing agents (1, 3-phenylendiamine (PDA) and 4, 4‘-me…
Abstract A fine‐tuning of the emission chromaticity from red to green is reported for organic–inorganic nanostructured hybrids co‐doped with Eu 3+ , Tb 3+ , and Tm 3+ . Raising the temperature from 200 to 300 K changes the color coordinates smoothly from the yellowish–green region of the chromaticity diagram towards t…
Abstract The water‐induced crystallization of alkylbenzenesulfonate‐coated amorphous calcium carbonate (ACC) nanoparticles in water‐in‐isooctane sodium bis(2‐ethylhexyl)sulfosuccinate (NaAOT) microemulsions at a [H 2 O]/[NaAOT] molar ratio ( w ) of 10:1 produces a range of organized hybrid surfactant–vaterite nanostru…
Arrays of bismuth telluride (Bi 2 Te 3 ) nanowires with diameters of ∼25, ∼50, and ∼75 nm have been produced by electrochemical deposition into porous anodic alumina templates. Scanning electron microscopy confirms that the nanowire arrays are dense with a narrow distribution of nanowire diameters. The structure of th…
A cyclic cylindrical 3d-4f tetranuclear structure, in which the 3d and 4f magnetic ions are arrayed alternately, has been found to be a suitable molecular design to produce a large magnetic moment and large magnetic anisotropy. Complexes 3-10 with the chemical formula [MLLn(hfac)2]2 ((MII, LnIII) = (Cu, Eu) (3), (Cu,…
The synthesis and characterization of several co-oligomers, 5,5‘-bis(4,4‘-dialkyl-2,2‘-bithiazol-5-yl)-(3,4,3‘,4‘-bis(ethylenedioxy)-2,2‘-dithienyl) (AT 2 A), 5,5‘-bis(3,4-ethylenedioxythien-2-yl)-4,4‘-dibutyl-2,2‘-bithiazole (TBT), and 5,5‘-bis(3,4,3‘,4‘-bis(ethylenedioxy)-2,2‘-dithien-5-yl)-4,4‘-dibutyl-2,2‘-bithiaz…
Abstract Although three forms of lithium phosphate are known, a complete structural description of the highest temperature polymorph has not yet been given. In the present work, the phase transitions of lithium phosphate were investigated at high temperatures using Raman microscopy and x‐ray powder diffraction. Both t…
Macroemulsions stabilized solely by nanoparticles of modified silica are used to prepare porous silica solid materials (see Figure), following slow evaporation of the two liquids. Both oil‐in‐water and water‐in‐oil emulsions can be employed, and the average pore size is close to the original emulsion drop diameter. Sp…
While LDA+U method is well established for strongly correlated materials with well localized orbitals, its application to weakly correlated metals is questionable. By extending the LDA Stoner approach onto LDA+U, we show that LDA+U enhances the Stoner factor, while reducing the density of states. Arguably the most imp…