Materials Literature
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In this work, we review, extend and discuss low-temperature specific-heat experiments, that we have conducted on different molecular (hydrogen-bonded) solids both in crystalline and glassy (either amorphous or orientationally disordered) phases. In particular, we have measured the low-temperature specific heat C p for…
RTV siloxane rubbers have been thermally aged in inert gas atmospheres and in the presence of moisture at temperatures up to 190°C. Toluene extractable matter measurements showed an increase in the levels of non-network fragments with age for those samples aged in sealed containers. Samples aged open to air did not sh…
Linear and Fourier-transform rheology were used to study the influence of the oscillatory shear amplitude, γ 0 , on the isothermal crystallization at 140 ° C of three commercial isotactic polypropylenes. The development of the crystallization was monitored through the time dependence of the dynamic storage modulus, G…
The dynamical behaviours of glass-forming liquids have been analysed extensively via computer simulations of model liquids, among which the Kob–Andersen binary Lennard-Jones mixture has been a widely studied system. Typically, studies of this model have been restricted to temperatures above the mode coupling temperatu…
The ageing of various glass forming materials (polycarbonate, polystyrene, polyvinyl acetate and triphenylethene) has been studied by differential scanning calorimetry. The variation of the relaxation enthalpy Δ H with the ageing time measured in a large domain of time is compared to the variation of volume Δ V report…
Newtonian viscosities of 19 multicomponent natural and synthetic silicate liquids, with variable contents of SiO 2 (41–79 wt%), Al 2 O 3 (10–19 wt%), TiO 2 (0–3 wt%), FeO tot (0–11 wt%); alkali oxides (5–17 wt%), alkaline-earth oxides (0–35 wt%), and minor oxides, obtained at ambient pressure using the high-temperatur…
Superconducting ${\mathrm{LaGe}}_{5}$ was synthesized by the reaction of La and Ge mixtures under a pressure of 5 GPa at 1200 \ifmmode^\circ\else\textdegree\fi{}C. It crystallized in the orthorhombic space group Immm (No. 71) with $a=4.0290(6),$ $b=6.307(1),$ and $c=9.978(2)\AA{},$ $V=253.54(6){\AA{}}^{3},$ and $Z=2.$…
Gold nanoparticles have been precipitated in the presence of a stiff polyphenylene dendrimer template with 16 thiomethyl groups on the outside. Powder X-ray diffraction analysis shows an average particle size of ∼3.7 nm; surprisingly, transmission electron microscopy (TEM) reveals a bimodal particle size distribution.…
Durch chemisches „Entkernen“ eines dendritischen Metalloporphyrin-Koordinationspolymers können organische Nanoröhren erzeugt werden (siehe schematische Formel). Zuvor wird die Peripherie des Oligomers durch Ringschlussmetathese intramolekular vernetzt.
The two-dimensional coordination polymer spin-crossover compound Fe(pyridine)2[Ni(CN)4] (1) and its isotope substituted analogues Fe(pyridine-D5)2[Ni(CN)4] (2) and Fe(pyridine-15N)2[Ni(CN)4] (3) have been synthesised and the isotope effect on the thermal spin-crossover behaviour has been studied using magnetic suscept…
We investigate the slow dynamics of strongly aggregated particle gels by diffusing wave spectroscopy (DWS) using a charge coupled device (CCD) camera as a multispeckle detector. The evolution of the slow dynamics after the gel-point is followed using two different techniques, the multispeckle method and a novel correl…
As a fundamental building block of a conductive magnetic macromolecule, a series of pyrrole derivatives carrying a nitronyl nitroxide (NN) group was prepared. Some of these derivatives afforded ground-state triplet diradical cations upon one-electron oxidation, and the difference in the spin multiplicities of the sing…
Degrading films: Surface-component-dependent and time-controlled degradation of a layer-by-layer (LbL) assembly comprising DNA and a cationic synthetic polymer is demonstrated through enzymatic hydrolysis by DNase I (see picture). The negatively charged enzyme is preserved on the cationic polymer surface in an inactiv…
Abstract Chelating agents are materials that are used to control undesirable reactions of metal ions. In oilfield chemical treatments, chelating agents are frequently added to stimulation acids to prevent precipitation of solids as the acid spends on the formation being treated. These precipitates include iron hydroxi…
We study the influence of the system size on various static and dynamic properties of a supercooled binary Lennard-Jones liquid via computer simulations. In this way, we demonstrate that the treatment of systems as small as N = 65 particles yields results relevant for the understanding of bulk properties. In particula…
Incorporating films: An ultrathin polymer film that is molecularly porous and conformationally regular is prepared by the selective solvent extraction of one component from a layer-by-layer stereocomplex assembly. The resulting host film can reincorporate the extracted polymer (see picture; PMMA: poly(methyl methacryl…
In variable-range-hopping theories for the dc conductivity, the extension of sites where the charges are located and the energy dependence of the density of states (DOS) are usually neglected. We show that these dependences are the dominant factors for understanding the strong doping dependence, and present an analyti…
In this communication we present the facile preparation and characterisation of thermotropic liquid-crystalline materials from the ionic self-assembly of a charged perylenediimide derivative and oppositely charged surfactants.
Carbon hollow spheres (400-600 nm) and vessels (400 nm x 3000 nm) have been synthesized from sp3-CCl4 at 190 and 230 degrees C, respectively. The HRTEM images and Raman spectra reveal the sp2 nature of the as-obtained products, indicating that the transformation from carbon sp3 to sp2 occurs in the reactions. The poss…
Silicones have become established in a wide variety of applications ranging from electronics to personal care products. It has been estimated recently that there are approximately 3000 commercial silicone products. These are made up from silicone fluids, elastomers and resins. Many hybrid materials also exist whereby…