Materials Literature
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This article describes the preparation of several new porphyrins bearing chelating peripheral groups fully conjugated with the macrocyclic pi-system. Treatment of a 2-nitro-meso-tetraarylporphyrin with phosphite gave a cyclic enamine, whose formylation gave an enaminoaldehyde. The thio analogue was obtained on treatme…
Three novel phosphorus-containing analogues of H(5)DTPA (DTPA = diethylenetriaminepentaacetate) were synthesised (H6L1, H5L2, H5L3). These compounds have a -CH2-P(O)(OH)-R function (R = OH, Ph, CH2NBn2) attached to the central nitrogen atom of the diethylenetriamine backbone. An NMR study reveals that these ligands bi…
We study the energetics of various point defects in silicon using ab initio density-functional methods. The formation free energies are calculated from the harmonic phonon frequencies, which are determined from ab initio density-functional perturbation theory calculations. We deduce the concentrations of defects as a…
Thin films of dodecanethiol-passivated Au and Ag nanocrystals drop cast from different solvents were examined by high-resolution scanning electron microscopy (HRSEM). C12-coated Au and Ag nanocrystals, 5-7 nm in diameter, form face-centered cubic (fcc) superlattices oriented with the (111)s planes (subscript s denotin…
Abstract Poly(trimethylene terephthalate) (PTT) was systematically studied as an engineering thermoplastics material. Crystallization rates, crystalline degrees, and mechanical properties of two commercial PTT polymers and one glass fiber–reinforced PTT compound were investigated and compared with those of poly(butyle…
Abstract Poly(lactic acid) (PLA) and poly(lactic‐ co ‐GA) (PLGA) with low molecular weights were synthesized by a one‐step polycondensation of lactic acid (LA) with glycolic acid (GA) molecules using stannous octoate as a catalyst at 160°C. A high yield (>80%) of all the polymers was obtained in the study. The PLA…
This Letter investigates the defect structures that arise between two colloidal spheres immersed in a nematic liquid crystal. Molecular simulations and a dynamic field theory are employed to arrive at molecular-level and mesoscopic descriptions of the systems of interest. At large separations, each sphere is surrounde…
The uptake of the three species of the drug model fluorescein (fluorescein sodium salt (FNa), fluorescein free acid (F), and fluorescein diacetate (FDA)) by zeolite NaX and the mesoporous zeotype MCM-41 was investigated as well as their release rates into solutions at pH 7 and pH 4.5. UV/Vis analysis was carried out a…
Abstract The surface of polydimethylsiloxane rubber (PDMS) was irradiated by a CO 2 ‐pulsed laser. The irradiated surfaces were grafted by hydroxyethylmethacrylate phosphatidylcholine (HEMAPC) by using the preirradiation method. The laser‐treated surfaces and HEMAPC‐grafted PDMS surfaces were characterized by using a…
Abstract The degradation of different polyethylenes—low‐density polyethylene (LDPE), linear low‐density polyethylene (LLDPE), and high‐density polyethylene (HDPE)—with and without antioxidants and at different oxygen concentrations in the polymer granulates, have been studied in extrusion coating processing. The degra…
The self consistent version of the density functional theory is presented, which allows to calculate the ground state and dynamic properties of finite multi-electron systems. An exact functional equation for the effective interaction, from which one can construct the action functional, density functional, the response…
A cubic structure of polymer colloid complexes is studied. The technique of the research includes i) an analysis of well-known literature SAXS data; on this base, at some assumptions, ii) constructing a simple model to estimate geometric structure parameters and to receive a simulated scattering curve, iii) calculatio…
Organic layer capped Ge nanocrystals (NCs) were synthesized by an arrested-growth method within supercritical octanol. Electrogenerated chemiluminescence (ECL) from the Ge NCs dispersed in N, N ‘ -dimethylformamide (DMF) containing 0.1 M tetra- n -butylammonium perchlorate (TBAP) was observed during potential scans or…
Reduced activation ferritic/martensitic (RAFM) steels are the reference structural materials for future fusion reactors. They have proven to be a good alternative to austenitic steels for their higher swelling resistance, lower damage accumulation and improved thermal properties. However, irradiated RAFM steels exhibi…
We use geometric considerations to study transport properties, such as the conductivity and Hall coefficient, near the onset of a nesting-driven spin density wave in a simple metal. In particular, motivated by recent experiments on vanadium-doped chromium, we study the variation of transport coefficients with the onse…
We present a density functional theory (DFT) calculation in the generalized gradient approximation to study the possibility for the existence of Jahn-Teller (JT) or pseudo Jahn-Teller (PJT) type local distortions in the La-Ba-Cu-O superconducting system. We performed the calculation and correspondingly group theory cl…
We propose a simple phenomenological model to analyze vibrational characteristics of quasicrystals (QCs). The interpretation of the obtained recently data is based on the existence of almost dispersionless optical modes most probably related to the specific clusters which constitute the characteristic building blocks…
Solid oxide fuel cells (SOFCs) using yttria-stabilized zirconia (YSZ) electrolytes, lanthanum strontium manganate cathodes, and anodes (where Cr, and Ti) were fabricated. The sulfur tolerance of the various perovskite-based anodes was examined at 1273 K in a fuel. The (50/50 wt %) anode showed no degradation in the pr…
We apply the ab initio spin density functional theory to study magnetism in all-carbon nanostructures. We find that particular systems, which are related to schwarzite and contain no undercoordinated carbon atoms, carry a net magnetic moment in the ground state. We postulate that, in this and other nonalternant aromat…
Analogous to the synthesis of CMK-3, ordered mesoporous carbons (OMC) containing nitrogen groups were synthesized using mesoporous silica SBA-15 as a template, polyacrylonitrile (PAN) as a carbon source, and 2,2‘-azobisisobutyronitrile as an initiator. Before carbonization, PAN/SBA-15 composites were treated in air at…