Materials Literature
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To find a new strategy for designing porphyrin-based organogelators, hydrogen-bond-donating (carboxylic acid)/accepting (pyridine) substituents or electron-donating (dialkylamino)/withdrawing (pyridine) substituents were introduced into peripheral positions of a porphyrin (1cp or 1ep, respectively), and the gelation p…
The synthesis and oxygen atom transfer (OAT) photoreactivity of a diiron(III) mu-oxo meso-tripentafluorophenyl bisporphyrin appended to a dibenzofuran spacer are presented. Reaction of 4,6-diformyldibenzofuran under standard Lindsey conditions furnishes the parent cofacial porphyrin architecture in a single step. Thes…
A Ce 2 Zr 2 O 8 mixed oxide was prepared, and the influence of redox treatments on its reduction behavior was systematically analyzed. The temperature of reduction was found to change on application of redox cycles under severe conditions, with the final appearance of temperature-programmed reduction profiles dictated…
A theoretical study of the electronic structure, bonding, and properties of unligated and ligated manganese(II) porphyrins and phthalocyanines has been carried out "in detail" using a density functional theory (DFT) method. While manganese tetraphenylporphine (MnTPP) in the crystal is high spin (S = 5/2) with the Mn(I…
Well-defined Pt-nanoparticles with an average diameter of 1 nm supported on a series of zeolite Y samples containing different monovalent (H+, Na+, K+, Rb+, and Cs+) and divalent (Mg2+, Ca2+, Sr2+, and Ba2+) cations have been used as model systems to investigate the effect of promotor elements in the oxidation of CO i…
Abstract This study examined the effects of accelerated freeze–thaw actions on the durability of wood fiber‐plastic composites. Rigid PVC formulations filled with various concentrations of wood flour (both pine and maple) were processed in a counterrotating twin‐screw extruder and exposed to cyclic freeze–thaw actions…
We have calculated light absorption spectra of planar metal structures containing a two-dimensional (2D) lattice of spherical nanocavities. Two types of porous metal structures are considered: (i) unsupported planar metal films containing a lattice of voids and (ii) planar metal films with a lattice of voids supported…
The mechanooptical behavior of melt-cast amorphous poly( l -lactic acid) (PLA) films in the rubbery state was investigated using an apparatus that allows for direct measurement of true stress, true strain, and birefringence in real time under well-controlled temperature over a wide range of stretching rates. Three dis…
The mechanical properties of polymer composites, reinforced with silica-coated multiwall carbon nanotubes (MWNTs), have been studied using the nanoindentation technique. The hardness and the Young's modulus have been found to increase strongly with the increasing content of these nanotubes in the polymer matrix. Simil…
In the absence of large, plasmon-supporting nanoparticles, biocompatible dendrimer- and peptide-encapsulated few-atom Ag nanoclusters produce scaffold-specific single molecule (SM) Stokes and anti-Stokes Raman scattering. The strong SM vibrational signatures are enhanced by the Agn transitions in nanoparticle-free sam…
There are two types of isotropic disordered nonergodic states in colloidal suspensions: colloidal glasses and gels. In a recent paper [H. Tanaka, J. Meunier, and D. Bonn, Phys. Rev. E 69, 031404 (2004)], we discussed the static aspect of the differences and the similarities between the two. In this paper, we focus on…
A series of micelle-templated mesoporous nickel hydroxide films were prepared by electrochemical deposition from dilute surfactant solutions by using different types of template and by varying plating solvent composition. Lamellar mesostructured Ni(OH)2 films are obtained with only anionic surfactant sodium dodecyl su…
Zirconia, $\mathrm{Zr}{\mathrm{O}}_{2}$, is one of the most important ceramic materials in modern technology. Its versatility is closely related to phase transformations. Although the transformations have been repeatedly investigated by experiments, fundamental aspects of the transformations are still under debate. In…
We present the improvement of carbon nanotube field effects transistors (CNTFETs) performances by chemical tuning of the nanotube/substrate and nanotube/electrode interfaces. Our work is based on a method of selective placement of individual single walled carbon nanotubes (SWNTs) by patterned aminosilane monolayer and…
Four new isostructural one-dimensional dodecaniobate Keggin materials, Na12[Ti2O2][TNb12O40] x xH2O and Na10[Nb2O2][TNb12O40] x xH2O with T = (Si or Ge), have been synthesized hydrothermally using a Lindqvist-ion salt, Na7[Nb6O19H] x 15H2O, as the precursor. Their structure, consisting of chains of Keggin ions [TNb12O…
A new sensor for hydrazine detection is reported using conventional polyaniline thin films processed from hexafluoroisopropanol. This and other fluorinated alcohols are shown to react with hydrazine to produce a strong acid. The hydrofluoric acid (HF) protonates the emeraldine base form of polyaniline leading to large…
Recent experiments on the silicon terminated $3\times 2$ SiC(100) surface indicated an unexpected metallic character upon hydrogen adsorption. This effect was attributed to the bonding of hydrogen to a row of Si atoms and to the stabilization of a neighboring dangling bond row. Here, on the basis of Density-Functional…
We study the step bunching kinetic instability in a growing crystal surface characterized by anisotropic diffusion. The instability is due to the interplay between the elastic interactions and the alternation of step parameters. This instability is predicted to occur on a vicinal semiconductor surface Si(001) or Ge(00…
We present a new interpretation of measured Raman frequencies of a high-pressure structure of Silicon which was assigned previously to the beta-tin phase. Our results show that the beta-tin->Imma->sh phase transitions have been already indicated in this experiment which was performed before the discovery of the Imma p…
In view of the recent experimental reports of unexpected ferromagnetism in HfO$_{2}$ thin films, we carried out first principles investigations looking for magnetic order possibly brought about by the presence of small concentrations of intrinsic point defects. {\it Ab initio} electronic structure calculations using d…