Materials Literature
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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,…
Abstract A series of heterocyclically conjugated polymer–clay nanocomposite (PCN) materials that consisted of organic poly(3‐hexylthiophene) (P3HT) and inorganic montmorillonite (MMT) clay platelets were prepared by in situ oxidative polymerization with FeCl 3 as an oxidant. The as‐synthesized PCN materials were chara…
Coherently-grown heteroepitaxial oxide thin films on single crystal substrates are always under elastic strain. This strain causes changes in the physical properties of thin films. We have studied the behavior of anisotropic magnetic properties of SrRuO 3 films grown directly on SrTiO 3 and on Ba 1- x Sr x TiO 3 /BaTi…
[structure: see text] Snowflake-shaped dendrimers were prepared via site-selective synthesis of dendrons, where an attachment of encapsulating dendritic branches and an extension of phenylacetylenic units were alternatively manipulated on the structure of AB(2) (diethyltriazeno for A and bromo for B) substituted diphe…
A crystalline graphitic structure—uniform diameter, thin‐walled carbon microtubes (see Figure)—has been prepared via a thermal reaction between ZnS and activated carbon. The microtubes have outer diameters of ∼ 1–2 μm, wall thicknesses of 10–20 nm, and lengths from several hundreds of micrometers to millimeters. The f…
Abstract A series of nanocomposite materials consisting of water‐soluble polyacrylamide (PAA) and layered montmorillonite (MMT) clay platelets were prepared by the effective dispersion of the inorganic nanolayers of the MMT clay in the organic PAA matrix via in situ ultraviolet‐radiation polymerization. The acrylamide…
Magnetically driven self‐assembly of colloidal particles into highly ordered structures on a substrate is demonstrated. This process allows for programming of specific geometrical patterns of colloidal particles. It also permits assembly of well‐defined colloidal patterns of many different particle types, possibly car…
The propagation and manipulation of magneto-inductive waves is studied under conditions when there is reflection due to lack of matching, when power is coupled from one waveguide to another, when coupling causes directional properties and when tunnelling occurs between two waveguides. The relationships obtained are co…
Abstract Sulfur‐crosslinked nitrile butadiene rubber (s‐NBR) was found to be devulcanized when it was heated with nitrobenzene at 200°C for 3 h. The tetrahydrofuran (THF)‐soluble fraction from s‐NBR heated with nitrobenzene was purified by reprecipitation with THF/ n ‐hexane, chloroform/ n ‐hexane, and THF/ n ‐hexane…
Pure phases of several di-octahedral (muscovite, Ca and Na-montmorillonites) and tri-octahedral (phlogopite, vermiculite and hectorite) T-O-T phyllosilicates have been studied by FT-Raman spectroscopy to determine whetherthere are characteristic vibrations for each family of minerals. The samples were first characteri…
The dynamics of crystalline and amorphous samples of poly( l -lactide) and three l -lactide/ meso -lactide random copolymers were investigated in the frequency domain using broadband dielectric spectroscopy (DRS). Two relaxations, the segmental (α) and subglass (β) processes, were observed in the temperature range bet…
Abstract The investigation of the economical use of lignocellulose waste, which is one of the environmental problems facing third‐world nations, is ongoing. In this study, we intended to increase the use of newsprint fibers in the rubber industry. For this reason, we treated newsprint fibers with sodium silicate and m…
Abstract The deterioration behavior of cellulose acetate (CA) films (degree of substitution = 2.5) was examined in hydrochloric acid (HCl) and sodium hydroxide (NaOH) solutions of various concentrations to determine acid and base catalytic effects in heterogeneous systems at room temperature. With concentrations of 0.…
Abstract The phase behaviors for the blends of poly(3‐hydroxypropionate) (PHP), poly( L ‐lactide) (PLLA), poly( D ‐lactide) (PDLA), and poly( D,L ‐lactide) (PDLLA) with catechin were investigated by differential scanning calorimetry. In PLLA/catechin, PDLA/catechin, and PDLLA/catechin blends, two glass transitions wer…
The YjgF/YER057c/UK114 family is a highly conserved class of proteins that is represented in the three domains of life. Thus far, a biochemical function demonstrated for these proteins in vivo or in vitro has yet to be defined. In several organisms, strains lacking a YjgF homolog have a defect in branched-chain amino…