Materials Literature
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The synthetic and functional versatility of dendrimers and their well-defined shapes make them attractive molecules for surface modification. We synthesized six structurally very similar surface-bound dendrons and used them as building blocks for the preparation of self-assembled monolayers (SAMs) on a gold surface. W…
Abstract Correlations among the degree of crosslinking of ethylene vinyl acetate copolymer (EVA), the grafting yield of maleic anhydride (MAH) onto EVA, and the mechanical properties of the blends of poly(butylene terephtalate) (PBT) with EVA‐g‐MAH were investigated. The EVA was functionalized by melt grafting reactio…
The new oxyfluoride silicate glasses of Er 3+ -doped 50SiO 2 -(50- x )PbO- x PbF 2 were prepared. With increasing PbF 2 content in the glass composition, the fluorescence full width at half maximum and lifetimes of the 4 I 13/2 level of Er 3+ increase, while the refractive indices and densities decrease. Er 3+ -doped…
Abstract The magnetic properties of nanocrystalline hard magnetic and soft magnetic are summarized. When the grain size becomes of the order f the magnetic exchange length exchange coupling occurs. The different concepts of exchange coupling in these materials are discussed. Exchange coupling leads in isotropic hard m…
Abstract This study describes the synthesis, characterization, and thermal behavior of copolymers of methyl methacrylate (MMA) and N ‐ p ‐tolyl itaconimide (PTI)/ N ‐phenyl itaconimide (I). Homopolymerization and copolymerization of N ‐(phenyl/ p ‐tolyl) itaconimide with MMA was carried out by use of various mole frac…
The predicted polypeptide product of open reading frame sso2387 from the archaeon Sulfolobus solfataricus, SsoPK2, displayed several of the sequence features conserved among the members of the "eukaryotic" protein kinase superfamily. sso2387 was cloned, and its polypeptide product was expressed in Escherichia coli. Th…
A family of Haeckelite nanotubes is generated by rolling up a two-dimensional threefold coordinated carbon network composed of pentagon-heptagon pairs and hexagons in proportion 2:3. The corresponding two-dimensional network is highly strained due to the presence of adjacent pentagons and heptagons. When the sheet is…
Modified octaphyrins with 34pi electrons have been synthesized and characterized following a simple synthetic methodology. An acid-catalyzed alpha,alpha coupling of tetrapyrranes containing furan, thiophene and selenophene rings resulted in the formation of the respective octaphyrins in relatively good yield. Solution…
The effect of diameter on the properties of nanotubes has come a step closer to experimental verification with the CVD synthesis described here of large‐diameter single‐walled carbon nanotubes (SWNTs). The SWNTs (see Figure) have a preferential orientation, good purity, and average diameter greater than 3 nm. They exi…
A photochromic polymer film is prepared by the oxidation polymerization of a diarylethene. The photoreactive conformation is maintained. A pattern can be written on the film using visible light, and upon irradiation with IR light, a non‐destructive read‐out of the patterned image is carried out. The structural changes…
Abstract The unsymmetrical binuclear phthalocyanine 4a and the symmetrical binuclear phthalocyanine 4b with two different metals (Ni and Cu), as well as the correspondent binuclear phthalocyanines with two Ni atoms ( 4c and 4d ) were synthesized from the benzoannulated dicyano‐substituted Ni phthalocyanine 2 . Atomic…
Abstract Large scale atomistic simulations of model nanocrystalline materials are used to investigate the plastic deformation mechnisms active in interface dominated materials, with the view to understanding the origin of the related high strength seen in experiment. Results are presented detailing both inter‐ and int…
Abstract Processing by severe plastic deformation (SPD) leads to very significant grain refinement in metallic alloys. Furthermore, if these ultrafine grains are reasonably stable at elevated temperatures, there is a potential for achieving high tensile ductilities, and superplastic elongations, in alloys that are gen…
Abstract We prepared polyaniline doped with LiPF 6 and HCl, respectively, using chemical methods. The electrode composite was attached to both sides of Al mesh, while the polymer electrolyte mixture was spread on a glass plate. Then, the polyaniline‐based redox supercapacitor was fabricated using two electrodes and a…
The osmotic virial coefficient B2 of globular protein solutions is calculated as a function of added salt concentration at fixed pH by computer simulations of the "primitive model." The salt and counterions as well as a discrete charge pattern on the protein surface are explicitly incorporated. For parameters roughly…
Abstract Based on the static and dynamic mechanical properties of the corresponding blends, the compatibility of six thermoplastic elastomers with polyvinyl chloride (PVC) was investigated. A terpolymer of ethylene, vinyl acetate and carbon monoxide (EVACO) was shown to give the optimal properties for the processing o…
It has been suggested by several authors that SrTiO3 layers in SrTiO3 –BaTiO3 superlattices should be tetragonal and ferroelectric at ambient temperatures, like the BaTiO3 layers, rather than cubic, as in bulk SrTiO3, and that free-energy minimization requires continuity of the polarization direction. A recent ab init…
A canopy-shaped pyrrole derivative 2 was prepared, in which a sterically demanding pendant group is juxtaposed to the pyrrole fragment to minimize interstrand pi-pi stacking interactions in the resulting polymer. Anodic polymerization of 2 afforded highly conductive poly(2), the electronic structure of which was probe…
Lead zinc niobate–lead titanate (PZN–PT) single crystals show very large piezoelectric strains for electric fields applied along the unit cell edges e.g. [001] R . It has been widely reported that this effect is caused by an electric field induced phase transition from rhombohedral ( R 3 m ) to monoclinic ( Cm or Pm )…
Both positive and negative replicas of copolymer arrays are produced using crosslinked poly(dimethylsiloxane). Negative replicas of the nanoscopic features are manufactued by entrapping air within the microdomains. Positive replicas are produced with ∼ 1:1 aspect ratios by the PDMS filling the nanoscopic, cylincrical…