Materials Literature
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Change of crosslink density of natural rubber (NR) vulcanizates by thermal ageing at 60 °C has been studied under swollen conditions in solvents to investigate the influence of internal strain applied to the vulcanizate on the crosslink density change. The internal strain was controlled by swelling with various solven…
The non-thickness-limited (NTL) growth phenomenon reported by Melody et al. in which anodic oxide films on tantalum continue to grow in dry glycerol solutions of dibasic potassium phosphate to large thicknesses (tens of micrometers) at low applied voltages (tens of volts) was investigated using mostly constant current…
Isotropic liquid phthalocyanine compounds with peripheral polydimethylsiloxane oligomer substitution were synthesized and found to have a unique combination of thermorefractive and nonlinear optical properties along with unusual metal substitution reactivity and aggregation behavior.
High-purity single crystalline B4C, several cm in size, has been prepared by a Floating Zone method. The electrical conductivity, Hall mobility, Seebeck coefficient and thermal conductivity are measured from room temperature to 1023 K . The electrical conductivity is about four times higher than that of sintered B4C .…
To study the mechanism of electronic transduction along (poly)phenylene chains, a series of aromatic donors with general formula D–B–D has been synthesized [where D = 2,5-dimethoxy-4-methylphenyl donor and B = (poly)phenylene bridge]; and the corresponding cation–radical salts D–B–D+˙ SbCl6− have been isolated for X-r…
Logarithm of electrical conductivity of poly( o -phenylenediamine)/poly(vinyl alcohol) composite is known to be proportional to relative humidity covering more than five orders of magnitude. Such a humidity-sensing system has been analyzed by ac impedance spectroscopy. Two different equivalent circuits for the humidit…
The reaction between N,N-dimethylaminoethanol (dmaeH) and nickel(II) acetylacetonate, [Ni(acac)2]3 or Ni(II) acetate tetrahydrate, [Ni(CH3CO2)2(H2O)4] yields the new complexes [Ni(acac)2(dmaeH)] (1) and [Ni(CH3CO2)2(dmaeH)2] (2). Complexes (1) and (2) are mononuclear, containing six-coordinate Ni(II) atoms in slightly…
Corrosion at cut edges is the most important failure mechanism of organic-coated, profiled galvanized steel architectural claddings. Currently, edge corrosion is generally controlled by the addition of strontium chromate in the paint primers; however, there is substantial interest in chromate replacements due to envir…
A diffusion ame system was used to generate an aerosol of soot and iron oxide.The primary fuel was ethylene.Iron was introduced by passing ethylene over liquid iron pentacarbonyl.The aerosol emission from the ame was diluted by secondary air to a level that could be used in animal exposure studies.The system was desig…
The hydriding/dehydriding (H/D) rates and pressure-composition isotherms (PCTs) of Mg–Pd, Mg–Nd and Mg–Pd–Nd alloys with ∼ 90 at% Mg have been measured, and the characteristics of these hydrogen-storage properties have been discussed in relation with the phase structures and microstructures of the alloys studied by X-…
This article presents a broad class of materials made by copolymerization of a family of telechelic free radically polymerizable siloxanes with various acrylate monomers that polymerize to form high Tg polymers. Films with properties ranging from strong elastomers to plastics have been obtained by UV-initiated bulk co…
Fiber reinforced polymer composites have been used in many applications, such as in automobile, aerospace and naval industries, due basically to their high strength-to-weight and modulus-to-weight, among other properties. Even though particles are usually not able to lead to the level of reinforcement of fibers, parti…
The crystal structure at 293 K of the new pyridinium compound, (C5H5NH)BiCl4, has been determined by X-ray diffraction as monoclinic, space group Cc, Z = 4. The crystal is built up of one-dimensional (BiCl4−)n chains and pyridinium C5H5NH+ cations. A structural phase transition of first-order type is detected by diffe…
Sonolysis is one of the techniques to destroy various organic contaminants in dilute aqueous solutions. The purpose of this study was to examine the effect of alumina particles on the enhancement of sonolysis. Chlorobenzene was chosen as the model organic compound and batch experiments were carried out with 20 kHz ult…
A suite of zwitterionic pyridylidene-based merocyanines that contain no interconnecting π-bridge between the donor and acceptor rings has been synthesised and their second-order NLO properties evaluated largely by semi-empirical computational methods (MOPAC 97/AM1). Contrary to expectation, increasing the degree of in…
The synthesis of the first alkynyl core-modified porphyrin building block, 5,10,15,20-tetrakis(4-ethynylphenyl)-21,23-dithiaporphyrin (N2S2 core), is reported. The building block was used to construct donor-appended dithiaporphyrin systems under mild palladium-coupling conditions. The porphyrin building block appended…
Multilevel diffractive optical elements are necessary for achieving high-efficiency performance. Here the diffraction efficiency of a multilevel phase-only diffractive lens is analyzed. Approximate, as well as more accurate, approaches are presented. Both plane-wave and Gaussian illumination are discussed. It is shown…
Abstract Hybrid density functional theory (DFT) and post‐Hartree–Fock methods are compared by depicting potential energy curves of the O–O dissociation of hydroperoxide and the M–O dissociation of transition‐metal oxides. The former approach includes BLYP, B2LYP, B3LYP, and more general hybrid DFT methods, while the u…
A FTIR spectroscopy study on the surface reactivity of calcined layered double hydroxides (LDH), with different cations in the interlayer space (namely, carbonate, nitrate, silicate, and borate), for isopropanol oxidation is reported. The LDHs were previously calcined at 600°C and then their surface acidity was quanti…
Comparative solid state structural studies of three lanthanide macrocyclic complexes derived from 1,4,7,10-tetraazacyclododecane with pendant arms bearing amide co-ordinating groups have been performed in order to evaluate the parameters influencing the co-ordination polyhedron and to assess the importance of the geom…