Materials Literature
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[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…
Polarization modulation infrared reflection−absorption spectroscopy and surface-enhanced Raman spectroscopy are used to interrogate the behavior of the Keggin-type polyoxometalate α-[SiW 12 O 40 ] 4- on Ag and Au electrode surfaces. Assignment of specific vibrational modes and their behavior as a function of potential…
RuO(2)-based catalysts are much more active in the oxidation of CO than related metallic Ru catalysts. This high catalytic activity (or low activation barrier) is attributed to the weak oxygen surface bonding of bridging O atoms on RuO(2)(110) in comparison with the strongly chemisorbed oxygen on Ru(0001). Since the R…
Summary 1. Two types of artificial neural networks procedures were used to define and predict diatom assemblage structures in Luxembourg streams using environmental data. 2. Self‐organising maps (SOM) were used to classify samples according to their diatom composition, and multilayer perceptron with a backpropagation…
[structure: see text] Carbaporphyrinoid systems with semiquinone, cycloheptatriene, or indene subunits react under mild conditions with silver(I) acetate to give stable silver(III) organometallic derivatives.
A technique that uses a non‐static patterning method has been employed for rational design toward macrocellular silica scaffolds (see Figure). The technique allows complete control over the width, length, and curvature of the plateau borders of the silica foam. Furthermore, this macroscale void space structuration is…
Abstract An improved method of preparing water soluble chitosan was studied by N ‐acetylation with acetic anhydride. Its merits were a simple processing technique, very short reaction time, little agent, high molecular weight of the product, and good water solubility. This article not only discusses the effect of seve…
The fluorescence of a novel dyad with spiropyran and perylene diimide units can be significantly enhanced only under the combined actions of UV light, protons, and ferric ions (see Figure). This behavior corresponds to a new “AND” gate with three inputs.
Local segregation in melts of copolymers with composition gradients along their backbones is analyzed. The transition to a lamellar periodic structure as the effective degree of incompatibility χ N increases is studied for symmetric copolymers with various composition gradients. A numerical self-consistent mean-field…