Materials Literature
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Dilute solutions of strongly charged polymer electrolytes undergo, upon addition of multivaltent salt to the solutions, a phase transition from extended conformations to collapsed or bundled ones. Upon further addition of salt they experience a second transition, a redissolution back into extended conformations. This…
Raspberrylike hybrid organic−inorganic materials consisting of spherical silica beads supporting smaller polystyrene particles were prepared through a heterophase polymerization process. In a first step, micrometer-sized silica particles were synthesized according to procedures inspired from the literature. In a secon…
The fluorescence of the water-soluble anionic conjugated polymer, poly[lithium 5-methoxy-2-(4-sulfobutoxy)-1,4-phenylenevinylene] (MBL-PPV), is quenched in dilute aqueous solution by cytochrome c, a small, naturally occurring electron-transfer protein. The large value obtained for the Stern-Volmer constant (K(sv) = 3.…
We report here on the structural characterization of polyelectrolytes multilayer films formed by poly( l -glutamic acid) and poly( l -lysine) (PGA/PLL). The growth of this system is compared to that of poly(styrenesulfonate)/poly(allylamine hydrochloride) (PSS/PAH) multilayers by means of in situ atomic force microsco…
The low temperature alloying of copper and nickel nanoparticles synthesized in a fatty acid film by a novel ion-entrapment process is described. Nanoparticles of copper and nickel were grown in thermally evaporated stearic acid films by immersion of the film sequentially in solutions containing Cu2+ ions and Ni2+ ions…
Starch and urea are used as fillers, owing to their good mechanical and degradable properties, in linear low density polyethylene matrix. Composites of varying amount of starch and urea composition are prepared. Various properties like tensile strength, elongation at break, Young's modulus, shore-D hardness, and water…
The enzyme L-rhamnulose-1-phosphate aldolase catalyzes the reversible cleavage of L-rhamnulose-1-phosphate to dihydroxyacetone phosphate and L-lactaldehyde. It is a homotetramer with an M(r) of 30 000 per subunit and crystallized in space group P3(2)21. The enzyme shows a low sequence identity of 18% with the structur…
A new route to a pentaerythritol-based tetraamine is delineated and subsequently contrasted to a previous report. Access to the pure tetraamine is facilitated by the smooth reduction of its tetraazide precusor. Characterization includes the preparation of a 4:1 Zn-tetraphenylporphyrin/tetraamine complex.
Hong et al. (1) reported that they had successfully produced arrays of single-crystal silver nanowires (of diameter 0.4 nm) formed in an ambient solution phase inside the pores of self-assembled calix[4]hydroquinone (CHQ) nanotubes. These nanowires, it was suggested, existed as coherently oriented three-dimensional ar…
The structures of Bacillus intermedius ribonuclease (binase), an extracellular 109-residue enzyme, and its complexes with 3'GMP and sulfate ions were solved at 1.65 and 2.0 A, respectively. The structures were refined using REFMAC. The crystal of free binase belongs to the space group C2, whereas the crystals of compl…
A structure of native concanavalin A (ConA), a hardy perennial of structural biology, has been determined in a dimeric crystal form at a resolution of 1.56 A (space group C222(1); unit-cell parameters a = 118.70, b = 101.38, c = 111.97 A; two molecules in the asymmetric unit). The structure has been refined to an R(fr…
The collagen model peptide T1-892 includes a C-terminal nucleation domain, (Gly-Pro-Hyp)(4), and an N-terminal (Gly-X-Y)(6) sequence taken from type I collagen. In osteogenesis imperfecta (OI) and other collagen diseases, single base mutations often convert one Gly to a larger residue, and T1-892 homologues modeling s…
The interaction-site-density-fluctuation correlators, the dipole-relaxation functions, and the mean-squared displacements of a system of symmetric dumbbells of fused hard spheres are calculated for two representative elongations of the molecules within the mode-coupling theory for the evolution of glassy dynamics. For…
Heteropoly acid H3PW12O40 is a very efficient and environmentally benign catalyst for the Fries rearrangement of phenyl acetate in homogeneous or heterogeneous liquid-phase systems at 100-150 degrees C.
ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionORIGINAL ARTICLEThis notice is a correctionThermodynamics of Pure-Silica Molecular Sieve SynthesisSanyuan Yang, Alexandra Navrotsky, and Mark E. DavisCite this: J. Phys. Chem. B 2002, 106, 20, 5312Publication Date (Web):April 26, 2002Publication History Published onl…
This paper reports on an electrochemical technique for the detection of oxidizing radical species, produced as the result of cavitation induced by ultrasound. A study of two example reactions is reported: the Weissler reaction and the Fricke reaction. In both cases, redox-active materials trap oxidative radicals. Elec…
Electric fields are used to control the layer-by-layer deposition of positively charged poly(diallyldimethylammonium chloride) (PDDA) and negatively charged CdTe nanocrystals on Au substrates following the method of ‘Electric Field Directed Layer-by-layer Assembly’ (EFDLA) described in . Experimental results demonstra…
Abstract Because silica has strong filler‐filler interactions and adsorbs polar materials, a silica‐filled rubber compound exhibits poor dispersion of the filler and poor cure characteristics in comparison with those of a carbon black‐filled rubber compound. Acrylonitrile‐butadiene rubber (NBR) improves filler dispers…
Lead sulfide, PbS, nanoparticles with the average size of 3.2 ± 0.4 nm have been synthesized by exposing self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid adsorbed Pb 2+ ions on Au(111) substrate into a H 2 S atmosphere. The preparation process of the PbS nanoparticles consists of the formation of the SAM…
The magnetic-field, temperature, and angular dependence of the interlayer magnetoresistance of two different quasi-two-dimensional (2D) organic superconductors is reported. For $\ensuremath{\kappa}\ensuremath{-}(\mathrm{BEDT}\ensuremath{-}\mathrm{TTF}{)}_{2}{\mathrm{I}}_{3},$ where BEDT-TTF is bisethylenedithio-tetrat…