Materials Literature
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Amorphous “diamond-like/quartz-like” composites a-(C:H/Si:O) constitute a novel class of diamond-related materials with a number of unique bulk and surface properties. Using a thermal imaging microscope we have determined the thermal conductivity (κs) of a-(C:H/Si:O) films deposited on Si(001) substrates. We have deve…
The charge ordering in , which occurs on cooling the ferromagnetic metallic ground state, is readily destroyed on application of a magnetic field of 6 T. For , for which the ground state is charge ordered, on the other hand, magnetic fields have no effect on the charge ordering. In order to understand such a marked di…
A scaling theory describing the strength of lamellar materials is developed. The theory is based on the premise that dislocation pileups are responsible for the yielding behavior of the lamellar material. The theory is developed in terms of four parameters: The pileup length, the exponent characterizing the divergence…
We study statistical properties of energy spectra of a tight-binding model on the two-dimensional quasiperiodic Ammann-Beenker tiling. Taking into account the symmetries of finite approximants, we find that the underlying universal level-spacing distribution is given by the Gaussian orthogonal random matrix ensemble,…
The surface deformation induced by a Gaussian laser beam on azobenzene polymer film reveals strong polarization dependence and establishes that an optical field component in the direction of the intensity gradient is essential for the deformation process. The experimental results allow us to infer the phase relationsh…
We show that light emission from different systems of silicon nanocrystals does behave as expected for indirect-band-gap quantum dots. Photoluminescence excited on the low energy part of the distribution of Si nanocrystals exhibits a set of narrow peaks associated with Si TA and TO momentum-conserving phonon-assisted…
We directly measure the equilibrium length scale of dynamic heterogeneities close to the glass transition by means of a new multidimensional NMR experiment. The spatial information is gained from a proton spin diffusion experiment combined with two 2D ${}^{13}\mathrm{C}$ exchange sequences via appropriate back and for…
Abstract With the development of a number of new HT/HP fields in the North Sea, for example the ETAP fields (Eastern Trough Area Project), a number of important "scale" control issues have arisen. In addition to harsh downhole conditions (T - 180 C; P - 13,000 psi), high salinity formation water chemistries indicate t…
The growth mechanisms and physical properties of the orthorhombic crystal form of beef liver catalase were investigated using in situ atomic force microscopy (AFM). It was observed that the crystals grow in the <001> direction by an unusual progression of sequential two-dimensional nuclei of half unit-cell layers corr…
Abstract This paper presents field results from two scale squeeze treatments carried out on the same sub sea horizontal well from a field in the North Sea, The initial squeeze was a bullhead application of phosphonate scale inhibitor to control a sulphate scale problem in a horizontal well. Ten months after the initia…
A novel polymer with quasi-one-dimensional structure of ethylenediamine bridged polymeric manganese phthalocyanine [PcMn(eda)]n was synthesized by complexing of manganese phthalocyanine (MnPc) and ethylenediamine (eda). The structure of the polymer was identified by infrared, ultraviolet–visible, and differential scan…
Enantiotropic liquid crystal (LC) polyurethanes were synthesized for the first time. Thermotropic LC copolyurethanes PU n T( m / p )s ( n, the number of methylene unit, 6, 8, and 11; m, meta-type unit; p, para-type unit) were synthesized by polyaddition of 4,4‘-bis(ω-hydroxyalkoxy)biphenyls (BPn) with two kinds of dii…
A novel polymer with quasi-one-dimensional structure of ethylenediamine bridged polymeric manganese phthalocyanine [PcMn(eda)]n was synthesized by complexing of manganese phthalocyanine (MnPc) and ethylenediamine (eda). The structure of the polymer was identified by infrared, ultraviolet–visible, and differential scan…
Thin films of poly(dimethylsilane) (PDMS) and permethyldodecasilane (DM12) were prepared by the vacuum-deposition method, and the molecular orientation in the films was investigated. Well-oriented films of DM12 were prepared without detectable degradation; however, degradation occurred in the films of PDMS, though wel…
A conducting polymer composite was prepared by the postpolymerization of pyrrole in a polyacrylonitrile (PAN) matrix film. To enhance the electrostatic interaction between the two phases, a small amount of a sulfonate or a carboxylate (COO−) group was incorporated into the PAN structure. The presence of electrostatic…
Fracture mechanics study of polypropylene samples of various molecular weight, obtained under different crystallizations conditions, is reported. Fracture toughness values obtained at high speed of impact as well as at low temperatures increased with increasing molecular weight and decreasing crystallization temperatu…
Blends of natural rubber (NR) and polystyrene (PS) were prepared by melt mixing in a Brabender plasticorder and by solution casting using chloroform as the casting solvent. Earlier studies have indicated that these blends are incompatible and immiscible, and their compatibility can be improved by the addition of a gra…
The solubility parameters of a BMC composite material, its polyester matrix, and its low profile additive [poly(vinyl acetate)] were determined by using several methods. For Hildebrand's solubility parameter : calculation from molar additive laws and determination from unrelaxed elastic constants, these latter being d…
Permeability to water vapor and oxygen, elastic modulus, tensile strength, and impact strength of polystyrene–polypropylene and high-impact polystyrene–polypropylene blends were determined as functions of blend composition and morphology. Three types of styrene–butadiene block copolymers were tested as compatibilizers…
The compatibilizing effect of the triblock copolymer poly(styrene-b-butadiene-b-styrene) (SBS) on the morphology and mechanical properties of immiscible polypropylene/polystyrene (PP/PS) blends were studied. Blends with three different weight ratios of PP and PS were prepared and three different concentrations of SBS…