Materials Literature
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In this paper a method of numerically handling boundary conditions within Brownian dynamics simulations is discussed. The usual naive treatment of identifying reflection or absorption processes by checking for boundary crossings yields O(sqrt[deltat]) discretization errors. The method we propose here yields O(deltat)…
Single crystals of R(2)Mo(5)O(18) and R(6)Mo(12)O(45) (R = Eu and Gd), which are novel compounds in the R(2)O(3)-MoO(3) system, have been obtained by thermal decomposition of [R(2)(H(2)O)(12)Mo(8)O(27)].nH(2)O in air at 750 degrees C for 2 h. TG-DTA and X-ray diffractometry showed that R(2)Mo(5)O(18) crystallizes in a…
Molecular relaxation processes following Soret band excitation of tetrakis(N-methyl-4-pyridyl)porphyrin (H2TMPyP(4)) and tetrakis(N-methyl-4-pyridyl)porphyrin-Zn(II) (ZnTMPyP(4)) have been investigated by femtosecond transient absorption measurements in the spectral range 420–600 nm. The analysis has been carried out…
Abstract The free‐radical graft polymerization of vinyl acetate onto nonporous silica particles was studied experimentally. The grafting procedure consisted of surface activation with vinyltrimethoxysilane, followed by free‐radical graft polymerization of vinyl acetate in ethyl acetate with 2,2′‐azobis(2,4‐dimethylpen…
Substitution of Cd(II) sites by Eu ions in 5.0 nm ± 0.25 nm CdSe, Cd 1 - x Eu x Se ( x = 0−0.374), can be achieved by modification of a lyothermal, single source precursor method. The Eu guest ion occupies a tetrahedral lattice site as a Eu(III) defect ion based on analysis of the XPS and XAS data. XRD and XAS measure…
The photophysics of a dendrimer containing four chromophores are investigated at the single-molecule level. First, the multichromophoric character of single dendrimers' absorption is probed by modulating the linear polarization of the excitation beam. Subsequently, using circular polarization, the same dendrimers are…
Abstract Binary composites of high‐crystalline fibrous cellulose with polypropylene (PP) or maleic anhydride‐grafted polypropylene (MAPP) were prepared by melt‐mixing with different contents of cellulose from 0 to 60 wt %. Ternary composites of cellulose with PP and MAPP were also prepared to investigate the effects o…
Mott insulator superconductor transition, via pressure and no external doping, is studied in orbitally non degenerate spin-\half systems. It is presented as another RVB route to high \tc superconductivity. We propose a `strong coupling' hypothesis which helps to view first order Mott transition as a self doping proces…
We study the equilibrium state of a superconducting film covered with a regular square array of perpendicularly magnetized magnetic dots. The dots induce vortices in the film directly under them and antivortices between the dots. We show that the symmetry of the dot array is spontaneously violated by the vortices. The…
The role that non-local short-range correlation plays at metal surfaces is investigated by analyzing the correlation surface energy into contributions from dynamical density fluctuations of various two-dimensional wave vectors. Although short-range correlation is known to yield considerable correction to the ground-st…
We present a theory of interstitial Mn in Mn-doped ferromagnetic semiconductors. Using density-functional theory, we show that under the nonequilibrium conditions of growth, interstitial Mn is easily formed near the surface by a simple low-energy adsorption pathway. In GaAs, isolated interstitial Mn is an electron don…
The recently discovered structural transition in polymerized KC60 at about 50 K results in a doubling of the unit cell volume and accompanies the metal-insulator transition. Here we show that the (a+c,b,a-c) superstructure results from small orientational charge density waves along the polymer chains and concomitant d…
Within the framework of the Landau-Lifshitz-Gilbert equation, using permalloy parameters, we study the statics and dynamics of flat circular magnetic nano-structures with an in-plane magnetic vortex configuration, putting particular emphasis on the (planar) vorticity of the magnetic state and on the (perpendicular) po…
Polyaniline (PANI) samples were synthesized by an ultrasonic irradiation synthesis method and by a magnetic stirring process. The structure of the polyanilines was investigated by using infrared and UV−vis−NIR spectral analysis, X-ray diffraction, transmission electron microscopy, electron diffraction, and elemental a…
The synthesis, characterization, and stability of porphyrin nanoparticles of 20-200 nm diameter presented herein is general for meso arylporphyrins. The elegance of the method lies in its simplicity. This work shows that the agent used to prevent agglomeration can be covalently attached to the dye forming the particle…
Nanostructured polyelectrolyte multilayer thin films electrostatically assembled alternately from such polymers as poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) were investigated for their in vitro cell interactions. Not surprisingly, NR6WT cells, a highly adhesive murine fibroblast cell line, atta…
The fabrication of Ti3SiC2 from five different starting materials was investigated. Pulse discharge sintering (PDS) was employed for a rapid synthesis in a relatively low temperature range. The highest purity of Ti3SiC2 (about 99 wt%) was achieved at the sintering temperature of 1300 °C, which is obviously lower than…
A series of novel chromogenic host compounds based on a diphenylazo core with bulky endgroups and hydrogen bonding capability has been synthesised and shown to exhibit distinct and easily detected colour changes on complexation with guests, allowing for rapid screening of host∶guest complex formation.
Viscosity tuning of preceramic polymers, in order to adapt them to various applications, has been elaborated by the authors. Thermal and photochemical crosslinking adjusts the viscosity of the polyureasilazane Ceraset in the range from 0.05 up to 20 Pas; the low viscous Ceraset can be used for the reaction molding of…
We studied the crystallization behavior in a diblock copolymer/homopolymer blend system exhibiting “dry-brush” phase behavior in the melt. A nearly symmetric poly(ethylene oxide)- block -polybutadiene (PEO- b -PB) was blended with a PB homopolymer (h-PB) having approximately the same molecular weight as that of the PB…