Materials Literature
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On the basis of suggestive X-ray data, 14 aroyl l -cystine derivatives were designed, synthesized, and examined for their ability to gelate water. Several members of this amino acid family are remarkably effective aqueous gelators (the best being one that can rigidify aqueous solutions at 0.25 mM, ca. 0.01%, in less t…
A new class of half-metallic ferromagnets has been found in the zinc-blende crystal structure. The previously nonexistent zinc-blende CrAs thin films have been synthesized on GaAs (001) substrates by molecular-beam epitaxy, and show a ferromagnetic behavior at room temperature. The zinc-blende CrAs has been designed b…
A new work-hardening model for homogeneous and heterogeneous cell-forming alloys is introduced. It distinguishes three internal state variables in terms of three categories of dislocations: mobile dislocations, immobile dislocations in the cell interiors and immobile dislocations in the cell walls. For each dislocatio…
An enzyme, horseradish peroxidase (HRP), was adsorbed in the manner of the single immersion method on the silica mesoporous materials FSM-16, MCM-41, and SBA-15 with various pore diameters from 27 to 92 Å, and their enzymatic activities in an organic solvent and the thermal stabilities were studied. FSM-16 and MCM-41…
The phase behavior of three N -alkyl-substituted perylene diimide derivatives is examined by differential scanning calorimetry and polarized optical microscopy. The occurrence of multiple phase transitions indicates several crystalline and several liquid crystalline phases. X-ray diffraction measurements show that the…
An oxide single-crystalline whisker with high thermoelectric properties at temperatures ( T ) higher than 600 K in air has been discovered. This whisker is assigned to Ca 2 Co 2 O 5 phase (abbreviated to Co-225 whiskers) and has a layered structure in which Co–O layers of two different kinds alternate in the direction…
Polyamidoamine dendrimers having poly(ethylene glycol) grafts were designed as a novel drug carrier which possesses an interior for the encapsulation of drugs and a biocompatible surface. Poly(ethylene glycol) monomethyl ether with the average molecular weight of 550 or 2000 was combined to essentially every chain end…
Starting with the history of the fundamental science of the relation of structure to composition delineated completely by Goldschmidt, we use the perovskite structure to illustrate the enormous power of crystal chemistry-based intelligent synthesis in creating new materials.The perovskite structure is shown to be the…
Two series of polyurethanes were prepared to investigate the effect of comacrodiol structure on properties and morphology of polyurethanes based on the siloxane macrodiol, α,ω-bis(6-hydroxyethoxypropyl) polydimethylsiloxane (PDMS). All polyurethanes contained a 40 wt % hard segment derived from 4,4′-methylenediphenyl…
Colloidal silica spheres (diameter 88 nm) with a thick steric stabilization layer of polystyrene (PS; M w = 26 600 g mol -1 ) were prepared. In cyclohexane, a marginal solvent for PS, particle aggregation and gelation were observed on lowering the temperature. Near the gelation temperature and at particle concentratio…
The electronic structure of the layered ternary carbides Ti 2 SnC and Ti 2 GeC has been investigated by means of ab initio linear combination of atomic orbital calculations. The calculated band structure shows that the electrical conductivity for both Ti 2 SnC and Ti 2 GeC is metallic and anisotropic with a high densi…
The dependence of the nanotribological properties of ultrathin amorphous carbon (a-C) films, deposited on Si(100) substrates by radio frequency sputtering, on their nanomechanical properties was investigated using surface force microscopy. The thickness and nanohardness of the a-C films were found to be in the range o…
Drops containing a hydrocarbon, the anionic surfactant Aerosol-OT (AOT), and water were injected into water at 30 °C, and the resulting behavior was observed by videomicroscopy. Spontaneous emulsification of most of the injected oil yielding droplets a few microns in diameter was seen when n -octane was the hydrocarbo…
The structure of liquid GeSe 2 at T = 1373 K has been investigated by first-principles molecular dynamics. The calculated total neutron structure factor is in good agreement with recent experimental data. We found that the disappearance with increasing temperature of the first sharp diffraction peak (FSDP) in the tota…
Styrenes with pendant lithium perfluoroalkyl ether sulfonate or sulfonimide groups readily homopolymerized and copolymerized with olefinic monomers to provide moderate to high molecular weight ionomers. Comonomers included styrene, methyl methacrylate, acrylonitrile, and acrylates. In addition, soluble polymers contai…
We report on the estimation of the compressibility of Na 0.5 Bi 0.5 TiO 3 and its constituent polyhedra through two different approaches: the so-called polyhedral approach and that based on the pressure dependence of particular Raman-active modes. In order to investigate the reliability of the results obtained for Na…
A comprehensive review is given of recent advances in the study of metastable phases in rare-earth permanent magnets. The relations between the structures of the metastable and equilibrium phases and the transformations from the former to the latter are discussed. The formation of the phases is found to depend on the…
Neutron irradiation of the polygranular graphites used in reactor moderators results in an initial bulk shrinkage at low neutron fluence followed by expansion at higher neutron fluence. Recent work carried out to investigate the effects of simultaneous radiolytic oxidation on the dimensional-change behaviour of the Gi…
Thin films of yttrium sesquioxide, Y 2 O 3 , have been deposited on Si by ion beam sputtering at room temperature and 700 °C under an oxygen pressure of 4 × 10 -3 Pa or by oxygen ion beam assisted deposition. The stoichiometry of these films was analysed by Rutherford backscattering spectrometry. The thickness and ref…
Magnetization of compound La(Fe 0.98 Co 0.02 ) 11.7 Al 1.3 was measured carefully as functions of temperature and applied field around its Curie temperature of ~198 K. Magnetic entropy change |Δ S |, allowing estimation of the magnetocaloric effect (MCE), was determined based on thermodynamic Maxwell's relation. The a…