Materials Literature
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A method for the synthesis of boron nitride (BN) fullerene-like nanoparticles (FNPs) and (BN) x C y nanotubes in large quantities using carbon nanotubes as templates is presented. Boron oxide vapor was reacted with nitrogen gas in the presence of carbon nanotubes (CNTs) at 1573 K in a boron nitride crucible to form BN…
Stress corrosion cracking (SCC) on the external surface of pipelines contributes to the major failure of pipelines. The great majority of SCC is intergranular and occurs in a carbonate-bicarbonate environment. Metallurgical factors affecting SCC are still vague and therefore have been studied. Uniform microstructures,…
Abstract The effects of nucleating agent, temperature of crystallization, and degree of machine direction (MD) orientation on the mechanical, optical, and thermal properties of biaxially oriented polypropylene (BOPP) films were investigated. Addition of nucleating agent improved only the initial tear resistance in the…
The technique of real-time electronic speckle pattern interferometry (ESPI) is proposed to study the diffusion process of surfactants and proteins in gels. The diffusion coefficient is simply and directly determined from the interferograms. The experiments were carried out on a series of surfactants as well as on a my…
Five silsesquioxanes (RSiO3/2)2n with R = siloxy and n = 4, 5 have been investigated by X-ray crystallography, MALDI-TOF mass spectrometry, and differential scanning calorimetry (DSC).
A comparative crystallographic analysis of the conformation of porphyrin diacids with various substituent types reveals considerable differences in the degree of nonplanarity and distortion modes. Diacids of 5,10,15,20-tetraarylporphyrins generally exhibit typical saddledistorted macrocycles with displacements of the…
The thermal stability of the powder or film forms of Eudragits L, S, and L30D and carbopol polymers was qualitatively investigated by microscopic reflectance Fourier transform infrared spectroscopy equipped with differential scanning calorimetry (FT-IR/DSC microscopic system). DSC and thermogravimetric analysis (TGA)…
A quaternary ammonium salt of poly(oxyethylene) methacrylates containing a quaternary ammonium group was designed and synthesized as a single-ionic solid polyelectrolyte. The ionic conductivity of the polymer is about 10−5 S/cm at room temperature. Furthermore, when a small amount of water or aqueous KOH solution was…
Phase change rewritable optical recording media contain a chalcogenide layer, e.g., GexSbyTez, that undergoes a transition between the amorphous and crystalline phases (by absorption of laser energy). Differences in their optical constants [n,k] result in reflectivity differences in the multilayer optical devices. We…
Electrical conductivity and dielectric relaxation studies with a wide range of compositions of lithium ion conducting glasses belonging to the ternary glass system Li2SO4-Li2O-B2-O3- have been carried out over the temperature range 150-450 K and between 10 - 10(7) Hz. DC conductivities exhibit two different activation…
Dissipative dynamics of a tunneling, methyl-like rotor, whose spatial coordinate is weakly coupled to a thermal bath, are described using the reduced density matrix (RDM) approach. It is found that, owing to selection rules imposed on thermally induced transitions by the symmetrization postulate, there are two sorts o…
Copolymers of styrene and ethyl acrylate are prepared by radical polymerization and analysed with respect to microstructure by means of nuclear magnetic resonance. Using 13C NMR, the compositional styrene- and ethyl acrylate-centered triads can be determined and compared to theoretical values. Good agreement between e…
A practical‐scale cell with a trickle‐bed electrode was developed for on‐site electrochemical production of hydrogen peroxide by the cathodic reduction of oxygen. Terminal voltage and current efficiency were affected by the dispersions of liquid and oxygen gas in the trickle‐bed cathode and by the current density. Cur…
Metalloproteins perform a wide variety of biological functions and, in doing so, in many cases exploit the redox properties and the coordination chemistry of the metal atom. The structural changes associated with the different coordination and redox changes can be quite small and can only be visualized at a very high…
The new bimetallic nickel(II) compound (PPh4)4[Ni2(2)]·6H2O (3), where H8[2] stands for N,N′,N′′,N′′′-1,2,4,5-benzene-tetrayltetrakis(oxamic acid), has been synthesized and its crystal structure determined by single-crystal X-ray diffraction. The structure of 3 consists of [Ni2(η4:η4-2)]4– anions, tetraphenylphosphoni…
Aesthetic appearance is one of the most important criteria used by consumers in judging clothing wear performance. Bagging is a kind of three-dimensional residual deformation that deteriorates garment appearance during wear and causes dissatisfaction. To understand the psychophysical mechanisms of fabric bagging perce…
Electropolymerized cobalt salen compounds on pyrolytic graphite electrodes were first tested as oxygen reduction catalysts in aqueous solutions of various pH. N,N '‐Bis(salicylidene)ethylenediaminocobalt(II) [abbreviated Co(salen)] and its analogs were polymerized on a basal plane of pyrolytic graphite electrode by el…
In x-ray diffraction spectrometry as well as in the many other scientific, engineering and medical disciplines involving photon radiation, x-ray attenuation coefficients are required as input data. Within a very few years after the discovery of x-rays by Röntgen in 1895, the transmission of a narrow (parallel) beam of…
Simulations based on Cahn-Hilliard spinodal decomposition theory for phase separation in thermally quenched polymer/solvent/nonsolvent systems are pre- sented. Two common membrane-forming systems are studied, cellulose acetate (CA)/ acetone/water, and poly(ethersulfone) (PES)/dimethylsulfoxide (DMSO)/water. The ef- fe…
Imidazole-, 2-methylimidazole- and benzimidazole-blocked hexamethylene diisocyanate and isophorone diisocyanate have been prepared and characterized by elemental analyses, IR and NMR spectroscopy. The structure–property relationship of these adducts has been established by reacting with hydroxyl-terminated polybutadie…