Materials Literature
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A series of dodecyloxybiphenylyl and cholesteryl group containing dimers with ethers as spacers have been prepared and their liquid crystalline properties were investigated as a function of spacer length. For short spacers SmA and SmC phases were observed with monolayer ordering. This is aparent from polarization micr…
Several NiO–MgO systems were prepared from commercial nickel nitrate hexahydrate and MgO by means of different preparative paths and with two NiO/MgO weight ratios. All the samples were structurally characterized by using BET, XRD, SEM and TPR techniques. These preparative paths lead to NiO–MgO samples with different…
Periodic Hartree–Fock and DFT methods were employed to calculate the geometric and electronic properties of bulk 2H-MoS2 and of its catalytically important (100) edge structure. The core electrons of molybdenum and sulfur were represented by the effective core pseudo-potentials, developed by Hay and Wadt. For the calc…
The mechanical properties of thermoplastic polyurethanes (TPU) depend upon their composition and the complex two‐phase morphologies, which originate from microphase separation of chains segments. In the present work, poly(ether‐urethanes) were prepared with hard segment contents from 36% to 71% by weight, by systemati…
A small‐volume shear cell designed to perform in situ scattering experiments is presented. This device allows the in situ structural study of deformations in polymeric melts and their subsequent crystallization. It is designed specifically for scattering experiments where the rheometer must be held in a vertical posit…
The coordination environment of fluorine in the CaO-SiO2-CaF2-Na2O glasses has been measured by 19F MAS NMR over a wide composition range including the similar compositions to those of mould fluxes so as to determine the composition dependence of the coordination environment of F−. Most of F− are fourfold-coordinated…
The development of a fundamental understanding of the mechanisms governing the attenuation of explosives effects by a surrounding mitigant material or system would benefit many civilian and military applications. Current approaches rely almost exclusively on empirical data, few if any truly predictive models exist. Ds…
The thermal property of fabric is very important for both its thermal comfort and protection against challenging weather conditions. Although some research has reportedly been done on the dimensional and some of the mechanical properties of rib knit fabrics, no detailed study about the thermal properties of rib knit f…
Hydrothermal synthesis under basic conditions has given a new cluster compound, Ni7(OH)8(ox)3(pip)3 (ox = oxalate; pip = piperazine). This hybrid material comprises inorganic Ni7(OH)8 clusters, which have a vertex-shared dicubane structure. These units are held together in a 3-dimensional coordination network by organ…
Polybenzoxazoles (PBO) are also expected as low-K & low-CTE dielectric materials as well as polyimides. High molecular weight PBO precursors, polyhydroxyamides (PHAs), were prepared from silylated bis(3-hydroxy-4-amino)biphenyl(p-HAB) and dichlorides of terephthalic acid (TPA) or trans-1,4-cyclohexanedicarboxylic acid…
Abstract The role played by the peripheral substituent and the solvent on the aggregation and photochemical properties of copper(II) phthalocyanine and copper(II)phthalocyanine-3,4',4'',4'''-tetrasulfonic anion [Cu(tsPc) -4 ] in aqueous solution has been studied by resonance Raman spectroscopy (RRS). The vibrational m…
Based on the density functional theory, we investigate and discuss how hydrogen behaves at the edges of graphite sheets/layers, in particular the zigzag edge. Our calculation results show that the zigzag edge is very reactive. It is possible to dissociatively adsorb H2 on these surfaces without any activation barrier…
A new approach to studying the dynamic strength properties of structural materials is demonstrated with fracture of 2024-T3 aircraft aluminum alloy. The central idea of this approach is the incubation time to failure. In [1], experimental data for dynamic fracture of this alloy were analyzed in terms of the classical…
Lignocellulosic natural fibres are an excellent raw materials for production of wide range of composites. Generally, composites based on lignocellulosic particles or fibres can be divided into the following groups:conventional panel-type composites like particleboards, fibreboards, insulating boards, etc.,lignocellulo…
Full atomic position optimizations and ab initio molecular dynamics simulations at room temperature were performed in a study of the adsorption of phenoxyacetic acid herbicides on the octahedral surface of a kaolinite layer formed from hydroxyl groups. The studied molecules are bound strongly to the surface hydroxyl g…
This work investigates the thermal stability and physical and barrier properties for three species of amorphous silicon-oxycarbide (α-SiCO) dielectric barrier films, deposited by plasma-enhanced chemical vapor deposition (PECVD), to copper (Cu) diffusion using octamethylcyclotetrasiloxane precursor and helium (He) car…
Barium titanates doped with Nb5+, and Y3+, were prepared. The starting powders were synthesized from citrate solutions by the Pechini process and partial Pechini process in two steps. Sintering was performed in the range from 13100 up to 13800C for 2 hours in air atmosphere. The structural study concerning the incorpo…
A series of novel soluble conjugated regioregular copolymers (poly(2,5-dialkoxy-p-phenylene thienylenes)) was prepared via palladium-catalyzed Stille coupling reactions. The attachment of ethylene oxide chains to the phenylene rings ((OCH2CH2)nOR; n = 2, R = Me; n = 2, R = Bu; n = 3, R = Me) provided to the polymer in…
Abstract Summary: Novel polyester and copolyesters have been prepared by anionic ring‐opening polymerization of racemic 4‐alkyloxycarbonyl‐3,3‐dimethyl‐2‐oxetanones that had been synthesized in five steps from diethyl oxalpropionate used as chemical precursor. The anionic polymerizations, realized in bulk or in soluti…
Reaction of K3[Cr(CN)6] with [CuL1](ClO4)2 (L1 = 3,10-dipropyl-1,3,5,8,10,12-hexaazacyclotetradecane) leads to a novel three-dimensional (3-D) cyano-bridged bimetallic assembly [CuL1]2[Cr(CN)6]ClO4·0.5H2O (1), in which each hexacyanochromate(III) ion connects four copper(II) ions using four co-planar CN− groups, which…