Materials Literature
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The whisker of polyoxymethylene produced in the cationic polymerization process of trioxane is a single crystal of extended chain crystal morphology. Since it has a quite small size of several microns in radius and several tens of microns in length, the crystal structure analysis of POM whisker had been tried by using…
<div class="htmlview paragraph">Contrary to gasoline cars only few of the new diesel vehicles are equipped with exhaust gas after treatment devices. Diesel engine producers have managed so far to meet the emission limits by improving the engine and its control. The new emission standards are worldwide forcing pr…
The humidity-voltaic effect, i.e. generation of open-circuit voltage ( V oc ), in Au–porous silicon (PS) interface in humid atmosphere (up to 450 mV at 95% relative humidity) in dark and daylight illumination is discovered. The humidity-stimulated voltage generation is attributed to the splitting of water and hydrogen…
To gain more insight into the process of formation of adsorbed layers of diblock copolymers, ellipsometry was used to monitor in situ the thickness and adsorbed amount of a series of polystyrene- b -poly(2-vinylpyridine) diblock copolymers adsorbed on silicon from toluene. First, it is demonstrated that ellipsometry c…
Anionic phosphodiester surfactants, possessing either two fluorinated chains (F/F) or one hydrocarbon chain and one fluorinated chain (H/F), were synthesized and evaluated for solubility and self-assembly in liquid and supercritical carbon dioxide. Several surfactants, of both F/F and H/F types and having varied count…
Directly linked bisporphyrin, Zn(II)2 5,10,15,20-tetrakis(2,4,6-trimethylphenyl)-2-(10,15,20-tris(3,5-di-tert-butylphenyl)porphyrin-5-yl)porphyrin, was investigated on the basis of the magnetic property of its bis(pi-radical cation). A stable triplet state of the bis(pi-radical cation) of the bisporphyrin, which obeys…
Abstract Electrospinning is a process that employs a high static electrical potential to produce polymeric fibers of nanoscale diameter. The process has been utilized to achieve color change by electrospinning black polymer solutions to produce white fiber mats. When subsequently heated, the electrospun mats undergo a…
Monolayers of lead selenide nanocrystals of a few nanometers in height have been made by electrodeposition on a Au(111) substrate. These layers show a thickness-dependent dielectric function, which was determined using spectroscopic ellipsometry. The experimental results are compared with electronic structure calculat…
We demonstrate the electrical and optical control of ferromagnetism in semiconductor heterostructures at high temperatures of 100–117 K. The heterostructures consist of Mn delta (δ)-doped GaAs and p -type AlGaAs. We are able to isothermally change the paramagnetic state to the ferromagnetic state and vice versa , by a…
Abstract EPICLON [3a,4,5,7a‐Tetrahydro‐7‐methyl‐5‐(tetrahydro‐2,5‐dioxo‐3‐furanyl)‐1,3‐isobenzofurandione] or [5‐(2,5‐dioxotetrahydrofurfuryl)‐3‐methyl‐3‐cyclohexyl‐1,2‐dicarboxylic acid anhydride] ( 1 ) was reacted with L ‐phenylalanine ( 2 ) in acetic acid, and the resulting amic acid was refluxed under a Dean‐Stark…
The high frequency dynamics of glassy selenium has been studied by inelastic x-ray scattering at beam line BL35XU (SPring-8). The high quality of the data allows one to pinpoint the existence of a dispersing acoustic mode for wave vectors ($Q$) of $1.5<Q<12.5\text{ }{\mathrm{n}\mathrm{m}}^{\ensuremath{-}1}$, hel…
In this work, the inter-relationship between the microstructure, the grain boundary electronic structure, and the high- and low-field electrical properties of the positive temperature coefficient of resistivity BaTiO 3 ceramic thermistors was explored. At high temperatures, the resistance of the material is strongly d…
Abstract Water‐soluble sulfonated acetone–formaldehyde (SAF) resins were synthesized by the reaction among acetone, formaldehyde, and sodium bisulfite. The factors affecting the properties of SAF resins and optimum conditions of preparation were investigated. The SAF resins prepared under proper conditions have good w…
Abstract Syndiotactic polypropylene (sPP) sheets of various crystallinities were subjected to accelerated ultraviolet (UV) aging. The chemical modification of the polymer was followed by FTIR spectroscopy measuring the carbonyl index in transmittance (film) and diffuse reflectance (powder) modes. Both the tensile stre…
Isolated single-walled carbon nanotubes (SWNTs), SWNT bundles, and ropes (or strands) show a structural self-similar characteristic. By calculating the Hausdorff dimension, it was found that their self-similar organization leads to surface fractality and the value of the surface dimension ${(D}_{s})$ depends on self-s…
Dielectric relaxation in disordered dielectric mixtures is presented by emphasizing the interfacial polarization. The obtained results coincide with and cause confusion with those of the low frequency dispersion behaviour. The considered systems are composed of two phases on two-dimensional square and triangular topol…
We demonstrate a tunable-focus microlens array using polymer network liquid crystals (PNLCs). PNLCs were prepared by ultraviolet (UV) light exposure through a patterned photomask. The UV-curable monomer in each of the exposed spots forms an inhomogeneous centro-symmetrical polymer network that functions as a lens when…
Abstract In this work, the shear‐induced crystalline layers of isotactic polypropylene (i‐PP), developed in a slit die, were characterized by different techniques. Rheological studies made in a strain‐controlled rheometer, at different crystallization temperatures, T c , allowed us to observe that the induction time f…
New thermally responsive fluorescent polymers conjugated with poly( N -isopropylacrylamide) (polyNIPA) have been synthesized. A nonionic water-soluble poly(phenylene−ethynylene) (PPE) was end-capped with a di- tert -butylnitroxide derivative, and subsequent nitroxide-mediated radical polymerization of NIPA afforded PP…
Abstract An aqueous dispersible polyurethane was prepared by the reaction of hydroxyl‐terminated poly(ethylene adipate), dimethylol propionic acid, 4,4′‐diphenylmethane diisocyanate, and ethylene glycol. Formation of the dispersion was achieved by phase inversion of an acetone solution of the polyurethane with water,…