Materials Literature
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The effect of electric field on the electronic structure of a spherical quantum dot is studied in the framework of the effective-mass envelope-function theory. The dependence of the energy of electron states and hole states on the applied electric field and on the quantum dot size is investigated; the mixing of heavy…
The usefulness of the zinc salts of five different amino acids or amino acid derivatives as polymerization catalyst of L-lactide was studied and compared. The five amino acid (derivatives) were: N-acetyl-glycine, N-tosylglycine, L-proline, L-pyroglutamic acid and N-acetyl-4-aminobenzoic acid. All polymerizations were…
ASTM (American Society for Testing and Materials) Method F739-96 specifies a test-cell design and procedures for measuring the permeation resistance of chemical protective clothing. Among the specifications are open-loop collection stream flow rates of 0.050 to 0.150 L/min for a gaseous medium. At elevated temperature…
We describe electrochemical quartz crystal microbalance measurements on poly( o ‐toluidine) (PoT) films exposed to aqueous perchloric acid solutions (pH 0 to 2). Crystal impedance measurements show the films to behave rigidly. PC redox switching occurs in two stages and is accompanied by nonmonotonic mass changes that…
Two polyacid-modified composite resins, Dyract and Compoglass, have been studied for water-uptake on storage in three aqueous media, namely pure water, 0.9% NaCl and 1 M NaCl at 37 degrees C, and the results compared with those of a conventional composite resin, Pekafill. The equilibrium water-uptake of Dyract and Com…
We develop an analytical method, using a real-space renormalization-group technique, for calculating the trace maps of quasiperiodic or aperiodic substitutional sequences. This method is quite different from the standard method of calculating the trace map from the recursion relation of the transfer matrices. The stan…
The Scanning Vibrating Electrode Technique ( SVET ) has been applied to the study of the degradation of coil-coatings at edges. From the results it is shown that the amount of chromate and its availability in the polymer matrix will be important factors for the initiation of corrosion at edges. It is also shown that t…
An in situ study of the microstructure and mechanical properties of polystyrene−poly(ethylene−butylene)−poly styrene (SEBS) triblock copolymer gels was performed. Simultaneous time-resolved synchrotron radiation X-ray scattering and stress−strain measurements at extensions up to λ = 2 indicate that the macroscopic def…
To prepare conducting polymer composites, porous polymethyl methacrylate (PMMA) particles with different specific surface areas were prepared by seeded emulsion polymerization and solvent extraction. The dried porous particles were imbibed with the oxidant solution and adsorbed pyrrole from a solution. The incorporati…
The graft copolymerization of sodium carboxymethylcellulose (NaCMC) with acrylamide (AM) and dimethylaminoethyl methylacrylate (DMAEMA) was conducted in an aqueous solution using ammonium persulfate (APS) and N,N,N′,N′-tetramethylethylene diamine (TMEDA) as the initiator. The effects of various factors on grafting, su…
Temperature-programmed desorption (TPD) and isothermal desorption were used to investigate the desorption of methanol from Al 2 O 3 (0001) in ultrahigh vacuum. At low coverages, TPD traces for methanol displayed one broad peak that was attributed to monolayer desorption. A second, multilayer peak was observed at a low…
We present a novel method to obtain bistable azimuthal anchoring conditions for nematic liquid crystals. The fine control of the anchoring strengths of two independent planar surface anchoring attractors, perpendicular to each other, induces controlled surface transitions that give bistability. The independent anchori…
The thermotropic liquid crystalline properties of a variety of chiral and racemic dodecyloxy substituted polyols derived from carbohydrates were investigated as a function of the number of hydroxyl groups associated with the polyol unit. It was found that all of the materials exhibited smectic A* phases, and that the…
The growth kinetics of porous alumina films formed by anodic oxidation of aluminum in phosphoric acid under galvanostatic conditions was studied. Scanning electron microscope measurements, Faraday's law, and oxide film mass measurements was used to analyze the growth kinetics and obtain film growth rates, pore density…
Apparatus for measuring a reflected light signal on crystalline or powder samples of thermochromic materials, such as `spin-crossover' materials, has been developed in conjunction with a helium cryostat enabling measurements from cryogenic to ambient temperatures. Depending on the intensity and wavelength of the incid…
The charge density of oxalic acid dihydrate has been redetermined from 100 K X-ray diffraction data using a SMART CCD diffractometer. The quality of the data has been carefully analyzed and shown to be at least as good as that obtained using a point detector. The positional and thermal parameters obtained from least-s…
The quantitative development of the nonergodic mobile order thermodynamics involving the new interpretation of the hydrophobic effect leads to a general solubility equation. This equation is applied to predict the aqueous and alcohol solubility of chemicals ranging from nonpolar or slightly polar with no H-bonding cap…
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTHelicity Induction of Poly(3-carboxyphenyl isocyanate) by Chiral Acid−Base InteractionKatsuhiro Maeda, Norikazu Yamamoto, and Yoshio OkamotoView Author Information Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, J…
Effects of the natural degradation of protective organic coatings after exposure for some years in an industrial atmosphere (Turin, Italy) and the consequences of artificial weathering in an ultraviolet (UV) chamber (ASTM G 53) and salt spray test chamber (ASTM B 117) were compared using electrochemical, infrared, and…
Conductivity and dielectric constant of a three-component 0-3 composite of epoxy resin–barium titanate–carbon black (0-3 composites are systems in which the filler is in the form of 0-dimensional (point-like, disperse) particles in a three-dimensional polymeric matrix1) have been investigated both at DC and the freque…