Materials Literature
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A gravimetric method was used to study the sorption and diffusion of supercritical carbon dioxide in a temperature range from 40°C to 80°C and a pressure range from 8.0 to 18.0 MPa in a biodegradable polymer, namely poly(butylene adipate-co-terephthalate) (PBAT). The PBAT presented Fickian behavior and Fick's diffusio…
The environment of individual tryptophans in known protein structures and the effectiveness of four commercial robotic UV microscopes to illuminate tryptophan-containing protein crystals by either tryptophan fluorescence (epi-illumination) or absorbance (transmission) are evaluated. In agreement with other studies, tr…
The influence of polyolefin elastomer (POE) content on the fracture behavior of injection-molded polypropylene (PP)/POE blends was evaluated by means of the essential work of fracture (EWF) method. The results indicated that the EWF approach worked well for the PP/POE blends when POE content was 0∼7.5 wt% of the blend…
In a systematic approach, the ability of the Maximum Entropy Method (MEM) to reconstruct the most probable electron density of highly disordered crystal structures from X-ray powder diffraction data was evaluated. As a case study, the ambient temperature crystal structures of disordered alpha-Rb(2)[C(2)O(4)] and alpha…
We developed a microscope intended to probe, using a parallel heterodyne receiver, the fluctuation spectrum of light quasi-elastically scattered by gold nanoparticles diffusing in viscous fluids. The cutoff frequencies of the recorded spectra scale up linearly with those expected from single-scattering formalism in a…
Polycyclic aromatic monomers based on substituted dibenz[ a, h ]anthracene frameworks have been prepared in high yields. From these, several fluorescent stair-stepped conjugated polymers containing fused aromatic subunits have been synthesized via Sonogashira polycondensations and Glaser-type oxidative couplings. The…
2,6-Didodecyl-4,8-diphenyl-benzo[1,2-d;4,5-d']bisthiazole (3) and 2,6-didodecyl-4,8-dipyrrole-2-yl-benzo[1,2-d;4,5-d']bisthiazole (5) were synthesized, and their optical properties were investigated in solution and in the solid state. Compounds 3 and 5 were excited with the 325 nm He-Cd laser line to produce blue and…
An excitonic recombination line is observed in photoluminescence spectra of ZnO thin films at 3.3465 eV. The line is labeled ${\text{I}}_{12}$. Its appearance was only observed in samples grown on a MgO or heavily aluminum-doped ZnO buffer layer. The properties of the recombination mechanism were probed by photolumine…
We study the quantum Hall effect (QHE) in graphene based on the current injection model, which takes into account the finite rectangular geometry with source and drain electrodes. In our model, the presence of disorder, the edge-state picture, extended states, and localized states, which are believed to be indispensab…
Tetraphenylethene (TPE)-substitued silanes [(Ph 4 C=C) m Si(Ph) n , m = 3–1, n = 3–1] are designed and synthesized, and their optical, thermal, and electrochemical properties are studied. Whereas they are nonluminescent in solutions, they become highly emissive when aggregated in poor solvents (such as water) or fabri…
Adsorption of mixed polymer solutions in good solvent containing polymers of different chain length has been studied by applying simulation techniques on a coarse-grained bead-spring polymer model. Fully flexible polymers at varying bead-surface interaction strength and different combinations of flexible, semiflexible…
A new AB 2 monomer [3,5-bis(4-fluoro-3-trifluoromethylphenyl)phenol] has been successfully prepared by the Pd(0)-initiated coupling reaction of 4-fluoro-3-trifluoromethylphenylboronic acid and 3,5-dibromophenol. This monomer led to a high molecular weight hyperbranched polymer ( M w = 230 000 g/mol) by self-condensati…
Ga(4)B(2)O(9), an aluminium-free mullite-type compound, was prepared by a boric-acid flux method and its structure was determined using powder X-ray diffraction techniques, in combination with transmission electron microscopy, solid-state (11)B MAS-NMR and IR spectroscopies. GaO(6) octahedra share edges in a trans-man…
Carbon nanofibers (CNFs) with diameters ranging from 50 nm to 150 nm were prepared from polymer blends of polyacrylonitrile (PAN)/polymethyl methacrylate (PMMA) via a wet-spinning method and subsequent thermal treatment. The main factors that influence the diameter of the CNFs, including molecular weight of PAN, mass…
Connected through single crystalline junctions, low dimensional materials such as nanowires and nanorods form complex nanostructures. These new materials exhibit mechanical strengths and electrical conductivities superior to their constituents while maintaining comparable surface areas, an attribute ideal for energeti…
This work was supported by theMICINN, Spain, under Projects CTQ2006-15611-CO2-01, MAT2008- 06522-C02, CTQ2009-09030, and FEDER funding EU, by seventh FP-THE PEOPLE PROGRAMME, The Marie Curie Actions;ITN, No. 215884-2, and by the Gobierno de Aragón (Project PI109/09, Research Group E04).
Stacked-graphene carbon nanotubes (SG-CNTs) obtained via pyrolysis of columnar superstructures of polycyclic aromatic hydrocarbons are studied by electrical transport measurements and scanning photocurrent microscopy. The charge transport in individual SG-CNTs (see figure) is found to be dominated by variable range ho…
Abstract Red oak wood ( Quercus rubra L.) samples were submitted to an enzymatic treatment with a commercial mixture of hemicellulases aiming at the selective depolymerization and removal of the hemicelluloses. Mechanical properties of treated samples were characterized and compared with untreated samples at two hiera…
According to general relativity, the frequency of electromagnetic radiation is altered by the expansion of the universe. This effect-commonly referred to as the cosmological redshift--is of utmost importance for observations in cosmology. Here we show that this redshift can be reproduced on a much smaller scale using…
It is known that emulsions can be stabilized by the presence of particles that get trapped at fluid-fluid interfaces and prevent adjacent drops from coalescing with one another. We show here that such emulsions, or Pickering emulsions, can be destabilized by applying external electric fields. This is demonstrated expe…