Materials Literature
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The anomalous signal of S atoms is easily detected at the Cu Kalpha wavelength of a non-synchrotron source with current data-collection methods. The position of sulfur and other anomalous scatterers can be located through an anomalous difference Fourier map (F+ - F-, phi(calc) - 90 degrees). It has been discovered exp…
The incorporation of chosen, non-amino acids into cyclopeptides is a promising approach to designs capable of performing specific tasks. While such hybrid cyclopeptides are common in the microbial world, there is hardly any effort by synthetic organic chemists to explore such designs for creating architecturally beaut…
A review is given of the mathematical procedures required for a molecular-replacement structure determination. These apply equally to the more frequently encountered situations where a known homologous structure can be used as a search model and to phase determination in the presence of non-crystallographic symmetry (…
Abstract Many dynamical properties of polymers, including segmental relaxation and chain diffusion, exhibit anomalies in thin‐film samples. We extend the studies of thin‐film dynamics to the case of semicrystalline polymers and present a study of the crystal growth rate for thin films of poly(ethylene oxide). We used…
Chapter 1: Introduction Chapter 2: Mechanical Aspects and Macroscopic Fracture-Surface Orientation Chapter 3: Fracture Mechanisms and Microfractographic Features Chapter 4: Fracture Modes and Macrofractographic Features Chapter 5: Failure Analysis of Composites Chapter 6: Electronic Failure Analysis Chapter 7: Case St…
We derive the gravitational and electrostatic self-energies of a particle at rest in the background of a cosmic dispiration (topological defect), finding that the particle may experience potential steps, well potentials or potential barriers depending on the nature of the interaction and also on certain properties of…
The ``14-1-11'' phase compounds based on magnetic Mn ions and typified by Ca14MnBi11 and Ba14MnBi11 show unusual magnetic behavior, but the large number (104) of atoms in the primitive cell has precluded any previous full electronic structure study. Using an efficient, local orbital based method within the local spin…
The molecular-replacement method has been extended to locate molecules and their fragments in an electron-density map. The approach is based on a new spherically averaged phased translation function. The position of the centre of mass of a search model is found prior to determination of its orientation. The orientatio…
Mesoscopic organosilicas were synthesized with bis(triethoxysilyl)ethane (BTSE) and cetyltrimethylammonium chloride (CTAC) under basic conditions. Further functionalization was achieved by co-condensation with trialkoxyorganosilanes. Surfactant extraction produced periodic mesoporous organosilicas (PMO's) functionaliz…
An account is given of the molecular replacement method as implemented in the package AMoRe. The overall strategy of the method is presented and the main functions used in the package are described. The most important features of AMoRe are the quality of the fast rotation and translation functions and the facility of…
Ab initio 6-31G* optimization of a fragment of poly(styryl sodium) and poly(α-methylstyryl sodium) composed of two monomer units in cis-configuration gives rise to low energies of the triplet state. The novel mechanism of living polymer depolymerization is proposed, involving thermal excitation into the low-lying trip…
Abstract The kinetics of the transesterification reaction between poly(ethylene terephthalate) (PET) and poly(ethylene 2,6‐naphthalate) (PEN) with and without the addition of a chain extender were studied with 1 H NMR. Different kinetic approaches were considered, and a second‐order, reversible reaction was accepted f…
PbZrO 3 (PZ) nanoparticles were synthesized through a halide- and organic-free hydrogen peroxide method at 700 °C for 2 h. Stoichiometric amounts of zirconyl nitrate and lead nitrate were dissolved in a diluted H 2 O 2 (aqueous) solution, which was slowly dropped into a solution of H 2 O 2 and NH 3 (pH = 11). The prec…
Abstract For the poly(butylene terephthalate) (PBT)/poly(ethylene terephthalate) blend system, the addition of a barium sulfate (BaSO 4 ) particle, the surface of which was modified with a titanate coupling agent, suppressed the transesterification reaction. The polyester chain ends, considered one of the main sites o…
Abstract Poly(ethylene terephthalate‐ co ‐ethylene naphthalate) (PETN)/organoclay was synthesized with the solution intercalation method. Hexadecylamine was used as an organophilic alkylamine in organoclay. Our aim was to clarify the intercalation of PETN chains to hexadecylamine–montmorillonite (C 16 –MMT) and to imp…
A concept is demonstrated for comb-shaped supramolecules based on dodecylbenzenesulfonic acid-doped polyaniline, i.e., PANI(DBSA) 0.5, by complexation with zinc dodecylbenzenesulfonate, Zn(DBS) 2 . Model studies using related protonated single crystalline bipyridine oligomers suggest that Zn(DBS) 2 molecules are bonde…
We report on the electrical and defect characterization of Au Schottky diodes formed on single-crystal ZnO, before and after irradiating with high-energy (1.8 MeV) protons. Prior to bombardment we observed that several electron traps (E1-E4), with energies between 0.10 and 0.57 eV below the conduction band, are presen…
Combined high-resolution transmission electron microscopy, selected area electron diffraction and parallel electron energy loss spectroscopy are used to characterise carbon nano-phases found embedded in fused quartz. These appear after implantation of 1 MeV carbon ions, followed by annealing in argon, oxygen and formi…
Abstract The anisotropic structures found in drawn poly(lactic acid) films are strongly correlated to their overall dimensional stability. Several aspects of this relationship can be efficiently characterized by Raman spectroscopy. We determined the degree of orientation in these drawn films by measuring the relative…
Abstract This article demonstrated the possibility of recycling PVC pipes by investigating the effect of adding PVC pipes (varying from 0 to 80 % wt) into two commercial PVC virgin grades on the rheological, morphological, mechanical, and thermal properties of the PVC blends. The results obtained showed an increase in…