Materials Literature
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Carbon nanotubes (CNTs)−magnetite nanocomposite with 20−30-nm magnetite particles attached onto CNTs has been successfully prepared for the first time by in situ solvothermal synthesis from the precursor of Fe−urea coordination complex (Fe[(NH 2 ) 2 CO] 6 (NO 3 ) 3 ) and CNTs. The effects of CNTs and various processin…
Morphological instability of the solid-liquid interface occuring in a crystal growing from an undercooled thin liquid being bounded on one side by a free surface and flowing down inclined plane is investigated by a linear stability analysis under shear flow. It is found that restoring forces due to gravity and surface…
The thermal conductivity of nanometric objects or nanostructured materials can be determined using non equilibrium molecular dynamics (NEMD) simulations. The technique is simple in its principle, and resembles a numerical guarded hot plate experiment. The 'sample' is placed between a hot source and a cold source consi…
CMK-5 ordered mesoporous carbons that consist of two-dimensional (2-D) hexagonal arrays of pipes were synthesized using furfuryl alcohol as a carbon source and SBA-15 aluminosilicate of 2-D hexagonal structure as a template. External and internal pipe diameters were varied concomitantly by using SBA-15 templates with…
Boron, chromium, molybdenum, and selenium often occur in high concentrations in fly ash leachates. During the leaching of fly ash in alkaline environments, hydrocalumite (Ca4Al2(OH)12(OH)2 x 6H2O) and ettringite (Ca6Al2(OH)12(SO4)3 x 26H20) form as secondary precipitates. In this study, the removal of B, Cr, Mo, and S…
Abstract The molecular orientation of an aromatic polycarbonate containing fluorene side chains was investigated by polarized infrared spectroscopy and birefringence analyses. The copolymers were synthesized from 2,2‐bis(4‐hydroxyphenyl)propane (BPA), 9,9‐bis(4‐hydroxy‐3‐methylpheny)fluorene (BMPF), and phosgene by in…
Abstract Surlyn®/silicate hybrid materials were produced via diffusion‐controlled polymer in situ sol–gel reactions for tetraethylorthosilicate. The heterogeneous morphologies of these materials were inspected with transmission electron (TEM), atomic force (AFM), and environmental scanning electron microscopic methods…
We develop a model to describe the competition between gelation and crystallization in colloidal suspensions where particle interactions are represented by square well attractions. The competition is discussed locally in terms of the tendencies of individual particles to attain amorphous or crystalline configurations…
Decomposable microcapsules with tunable permeability, loading, and release properties—with potential applications as chemical reservoirs and for controlled drug release—have been fabricated by assembly of weak polyelectrolytes on melamine formaldehyde templates followed by removal of the cores at low pH by precise con…
Owing to light confinement , naturally shaped needle‐like organic semiconductor single crystals of an end‐capped fluorene/phenylene co‐oligomer provide low‐threshold unidimensional stimulated emission. The Figure shows a photograph of the ∼1.5 mm long crystals, and gain‐narrowed normalized emission spectra from a poly…
Multi‐walled carbon nanotubes are used for the templated assembly of HErPc 2 nanowires via the phase‐separation method. When the solvent is evaporated gradually, HErPc 2 nanoparticles and nanowires are found to self‐assemble on the exterior walls of CNTs, as shown in the Figure. The CNT–HErPc 2 hybrid materials exhibi…
Unusual narrow transmission bands are found in the Bragg reflective region of a multi-layered structure consisting of alternate right-handed material (RHM) and left-handed material (LHM). These unusual narrow transmission bands may exist no matter whether the optical length of a LHM layer completely cancels that of a…
CdS films were prepared by chemical bath deposition (CBD) at 60 °C without stirring. The crystallographic structure of the films and the size of the crystallites in the films were studied by x-ray diffraction. The energy gap of the films was found to decrease by annealing. The best annealing temperature for CBD grown…
Double helical and single‐chain arrays of Au and Pd metal nanoclusters have been achieved by assembling the corresponding metal nanoparticles on peptide nanofibril templates at different pH values. The assembled metal nanoparticles are useful for studying the superstructures of the peptide nanofibrils. Pd nanowires of…
High degree of electron spin polarization is of crucial importance in operation of spintronic devices. We study the propagation of spin-polarized electrons through a boundary between two n-type semiconductor regions with different doping levels. We assume that inhomogeneous spin polarization is created/injected locall…
The spin relaxation time of electrons in GaAs and GaN are determined with a model that includes momentum scattering by phonons and ionized impurities, and spin scattering by the Elliot-Yafet, D'yakonov-Perel, and Bir-Aronov-Pikus mechanisms. Accurate bands generated using a long-range tight-binding Hamiltonian obtaine…
We report a novel method for depositing patterned dielectric layers with sub-micron features using atomic layer deposition (ALD). The patterned films are superior to sputtered or evaporated films in continuity, smoothness, conformality, and minimum feature size. Films were deposited at 100-150C using several different…
In $R{\mathrm{B}\mathrm{a}\mathrm{C}\mathrm{o}}_{2}{\mathrm{O}}_{5+x}$ compounds ($R$ is rare earth), a ferromagnetic-antiferromagnetic competition is accompanied by a giant magnetoresistance. We study the magnetization of detwinned ${\mathrm{G}\mathrm{d}\mathrm{B}\mathrm{a}\mathrm{C}\mathrm{o}}_{2}{\mathrm{O}}_{5.5}$…
Ultralong Bi 2 S 3 nanoribbons have been synthesized by a solvothermal process, using a mixture of aqueous NaOH solution and glycerol as the solvent. These nanoribbons (see Figure) are 50–300 nm wide, 20–80 nm thick, and up to several millimeters long, and the initial formation of the precursor polycrystalline NaBiS 2…
Acidic proteins play a major role in the biomineralization process. These proteins are generally thought to control mineral formation and growth. Thus, characterization of individual acidic proteins is important as a first step toward linking function to individual proteins, which is our ultimate goal. In order to cha…