Materials Literature
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Abstract A hinged, photoresponsive polypeptide (PAzP) was prepared and the effect of the photochromic hinge on the dielectric and photoisomerization behavior of the polymer in solution was probed. Polymerization of N ‐carboxyanhydride of γ‐benzyl‐ L ‐glutamate was carried out with two different bifunctional photochrom…
Pt-containing nanocomposite catalysts were synthesized by deposition of [Pt(NH3)4]2+ complex ions on several samples of Al pillared clays, differing in the nature of the parent clay and in the pillaring procedure. In particular, we compared classical Keggin-Al13 pillared clays, with a rather open microporous network,…
The effect of a magnetic field ${B}_{\ensuremath{\perp}}$ on the resonant tunneling between different magnetic states of the molecular clusters ${\mathrm{Fe}}_{8}$ and ${\mathrm{Mn}}_{12}$ has been studied by measuring the magnetic specific heat of these compounds between $0.1 \mathrm{K}$ and $6 \mathrm{K}.$ At zero f…
We present electron diffraction and high-resolution electron microscopy measurements characterizing the structure of a Bi-based layered manganite. The crystal structure of ${\mathrm{Bi}}_{0.75}{\mathrm{Ca}}_{3.25}{\mathrm{Mn}}_{3}{\mathrm{O}}_{10}$ is orthorhombic and A centered (space group ${A2}_{1}22),$ with lattic…
Abstract Dendritic polyarylether 2‐bromoisobutyrates with different generations (Gn‐Br, n = 1–3) were prepared by reaction of the Fréchet‐type hydroxyl‐terminated polyarylether with 2‐bromoisobutyryl bromide and triethylamine. Gn‐Br as a macroinitiator for the controlled free‐radical polymerization of N ‐phenylmaleimi…
A series of dinuclear (phosphine)gold(I) complexes of the ambidentate 1,3,4-thiadiazoledithiolate ligand (SSS) were prepared in high yield from the corresponding (phosphine)gold(I) chlorides and K(2)(SSS) in methanol. While mononuclear components (R(3)P)AuCl with R(3) = Ph(3), Ph(2)Py, or Me(3) (1-3) gave open-chain c…
Two open-framework ammonium−iron borophosphates, black colored (NH 4 ) 0.4 Fe II 0.55 Fe III 0.5 (H 2 O) 2 [BP 2 O 8 ]·0.6H 2 O ( 1a ) (pale gray colored 1b with a powder X-ray diffraction pattern indicating an isotype relationship was also observed) and pale pink colored NH 4 Fe III [BP 2 O 8 (OH)] ( 2 ), were synthe…
ZrO 2 nanoparticles (10−400 nm) were produced by laser ablation deposition and studied by transmission electron microscopy. The particles were predominantly tetragonal (t-) phase with spherical shape. Relatively large t-ZrO 2 particles, however, showed {111} and {100} faces and tended to attach over well-developed {11…
Abstract A new fracture behaviour is described for acrylonitrile–butadiene rubber/clay nanocomposite. The nanocomposite is prepared by melt mixing the organo‐treated montmorillonite into the rubber matrix, together with a peroxide curative, and crosslinked by conventional compression moulding for typical rubbers. A co…
Pt nanoparticles supported in nanoporous Al 2 O 3 catalyst are prepared by reduction of K 2 PtCl 4 solution using H 2 in the presence of Al 2 O 3 and poly(acrylic acid) as capping material. After thorough washing with water to remove Pt nanoparticles located on the external surface of the Al 2 O 3 and drying at 70 °C…
A series of novel azo polyelectrolytes have been synthesized based on an extremely reactive precursor polymer, poly(acryloyl chloride) (PAC), prepared from acryloyl chloride by radical polymerization. The precursor polymer was post-functionalized by the Schotten-Baumann reaction of PAC and several aromatic azo reactan…
We introduce a first-principles scheme for calculating a core-hole potential for core-electron excitations. The scheme incorporates atomic and solid-state screening in the description of core excitations in several materials. We compare the results calculated using our scheme to experimental x-ray absorption and inela…
Abstract A series of terpolymers were synthesized by the chemical oxidative polymerization of m ‐phenylenediamine (MPD), o ‐anisidine (AS), and 2,3‐xylidine (XY) in hydrochloride aqueous medium. The yield, intrinsic viscosity, and solubility of the terpolymers were studied by changing the MPD/AS/XY molar ratio from 10…
Crowded solutions of densely branched polymers with starlike architecture undergo a reversible gelation upon heating. This phenomenon is characterized by slow kinetics and is attributed to the formation of clusters causing a partial dynamic arrest of the swollen interpenetrating spheres at high temperatures. A kinetic…
The crystallization, dissolution, and associated pseudo-polymorphic behavior of citric acid crystals from aqueous solution is investigated using temperature-programmed and isothermal batch experiments. Quantitative attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy is used to measure in s…
Sol−gel nanocasting is used to imprint the soft-matter structures of lyotropic phases of nonionic n -alkyl−poly(ethylene oxide) amphiphiles (“C x E y ”) into solid porous silica. Small angle X-ray scattering (SAXS), nitrogen sorption, and transmission electron microscopy (TEM) are used to investigate the dependence of…
The optical absorption of point-defect-free SiO(2) glass in the vacuum ultraviolet region is primarily controlled by the concentrations of three- and four-membered ring structures composed of heavily strained Si-O-Si bonds. The main channel of color center formation by F(2) excimer laser (7.9 eV) irradiation is not Fr…
Semiconductor nanoparticles, NPs, exhibit fluorescence properties that are closely related to the nature of their surface. CdSe NPs that range in size from 2 to 15 nm in diameter fluoresce with both near-band-edge emission and deep-trap emission, depending on the quality of the surface. When butylamine is added to col…
Deformation properties of multi-wall gold nanowires under compressive loading are studied. Nanowires are simulated using a realistic many-body potential. Simulations start from cylindrical fcc(111) structures at T=0 K. After annealing cycles axial compression is applied on multi-shell nanowires for a number of radii a…
We study the geometrical characteristic of quasi-static fractures in disordered media, using iterated conformal maps to determine the evolution of the fracture pattern. This method allows an efficient and accurate solution of the Lamé equations without resorting to lattice models. Typical fracture patterns exhibit inc…