Materials Literature
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We report the synthesis and photophysical properties of 1,4-bis(9-ethynylanthracenyl)benzene. Results in dilute hexane solutions give a very high fluorescence quantum yield (Φ = 0.97) and a lifetime of τ = 1.8 ns. Studies at different temperatures, viscosities, and micromorphologies, as well as excited-state semiempir…
Nanostructured, mesoporous inorganic–organic hybrid xerogels were reproducibly synthesized by a sol–gel procedure. For the introduction of long alkyl chains into inorganic polymers, trifunctional n-alkyltrialkoxysilanes of the type CH3(CH2)nSi(OR)3 (n = 7, 11, 17; R = CH3, C2H5) were co-condensed with Si(OEt)4 (TEOS).…
Regioregular poly(propylene oxide), PPO, formed by simple base (KOH) and coordinate base (TPP)AlCl, (tetraphenylporphinato)aluminum chloride, ring-opening polymerization of propylene oxide, PO, has been studied by high field 13 C{ 1 H} NMR spectroscopy at various concentrations in CDCl 3 and C 6 D 6 . The original ass…
Abstract Clinoptilolite-rich materials from widespread pyroclastic and epiclastic deposits of northern Sardinia were investigated to assess their cation exchange properties and to find the most reliable experimental method to determine their cation exchange capacity (CEC). The CECs were evaluated using a cross exchang…
Heterocyclic compounds, namely 3,5-diphenyl-imino-1,2,4-dithiazolidine (DPID); 3-phenyl-imino-5-chlorophenyl-imino-1,2,4-dithiazolidine (PCID); 3-phenyl-imino-5-tolyl-imino-1,2,4-dithiazolidine (PTID); and 3-phenyl-imino-5-anisidyl-imino-1,2,4-dithiazolidine (PAID), were synthesized in the laboratory. Their influence…
Abstract Illite-smectite (I-S) minerals isolated from Upper Jurassic oil-source rock shales from Denmark and the North Sea have been investigated by X-ray diffraction, thermal analysis, infrared, Mössbauer, and solid-state nuclear magnetic resonance spectroscopies and chemical analysis. Detailed structures have been d…
This paper reports on a study of the magnetic susceptibility, x-ray photoelectron, and x-ray emission spectra of the LiCoO 2−δ and Na x CoO 2 nonstoichiometric oxides. The valence-band structure of LiCoO 2 was analyzed. The hole concentration in the oxygen 2 p band of LiNiO 2 and LiCoO 2 was derived from measurements…
This paper focuses on the dimensional, pilling, and abrasion properties of a series of plain jersey, lacoste, and two-thread fleece fabrics made from cotton ring and open-end spun yams as well as from blend yams (50/50 cotton/polyester, dyed). The results show that both structural differences and fiber type play a lar…
Abstract Poly(L‐lactic acid) sheets, prepared by melt extrusion, were treated with O 2 −, He−, and N 2 −plasmas generated in radio frequency (RF) at 13.56 MHz. Atmospheric pressure discharge at 20 kHz in helium was also applied to the modification of the sheets. The surface of the PLLA sheets was etched to form the ch…
Single domain Ni3N nitride particles are synthesized by simultaneous decomposition and nitridation in ammonia atmosphere of [Ni(NH3)6](NO3)2 complex crystals at 650 K. The Ni3N phase crystallizes in the hexagonal structure with unit cell parameters a = 4.624(4) Å and c = 4.316(4) Å, and has a crystallite size of 16 nm…
Tissue engineering has emerged as a promising alternative approach in the treatment of malfunctioning or lost organs. In this approach, a temporary scaffold is needed to serve as an adhesive substrate for the implanted cells and a physical support to guide the formation of the new organs. In addition to facilitating c…
The Handbook of Thin Film Deposition Techniques: Principles, Methods, Equipment and Applications, Second Edition explores the technology behind the spectacular growth in the silicon semiconductor industry and the continued trend in miniaturization over the last 20 years. This growth has been fueled in large part by im…
Acetyl coenzyme A (CoA) synthetase (ADP forming) (ACD) represents a novel enzyme of acetate formation and energy conservation (acetyl-CoA + ADP + P(i) right harpoon over left harpoon acetate + ATP + CoA) in Archaea and eukaryotic protists. The only characterized ACD in archaea, two isoenzymes from the hyperthermophile…
We study the structure and thermodynamics of the critical nuclei in metastable binary polymer blends using the self-consistent field method. At the mean-field level, our results are valid throughout the entire metastable region and provide a smooth crossover from the classical capillary-theory predictions near the coe…
Despite the importance of the chloride ion in magmas and the fluids that separate from them, very little is known about atomic-scale structural environments for Cl- in silicate glasses. We present here the first solid-state 35 Cl NMR data for Cl in silicate and aluminosilicate glasses, made possible by the availabilit…
A simple pictorial method using HOMO, LUMO, and LUMO+1 of azulene coupled with interaction between the electrons in the singly occupied orbitals is introduced to show how the S 2 -S 0 energy gap relative to the S 1 -S 0 gap can be changed by a choice of substituents. The result is changing the characteristic blue colo…
Molecular dynamics simulations are performed on generations 2 ( G 2) through 5 ( G 5) of poly(propylene imine) dendrimers at 400 K in order to investigate characteristics of molecular structure and morphology in the melt. As the generation increases, the dendrimers assume a more spherical shape, and the degree of dend…
Abstract Many crystalline materials show chemical short range order and relaxation of neighboring atoms. Local structural information can be obtained by analyzing the atomic pair distribution function (PDF) obtained from powder diffraction data. In this paper, we present the successful extraction of chemical short ran…
Abstract The plasticity of semicrystalline polymers is analyzed in the framework of Young's dislocation model under the assumption of nucleation of screw dislocations from the lateral surface of the crystalline lamellae. It is proposed that the driving force for the nucleation and propagation across the crystal width…
We present a stable and efficient method for the Bloch-mode computation of one-dimensional grating waveguides. The approach uses the Fourier modal method and the S-matrix algorithm to remove numerical instabilities. The use of perfectly matched layers provide a high accuracy. Numerical results obtained for different l…