Materials Literature
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Here, for the first time, we demonstrate amplified spontaneous emission (ASE) from PbSe nanocrystals (NCs) with emission energies tunable in the near-infrared (IR). We show that despite complications associated with a high, 8-fold degeneracy of the lowest quantized states and fast, nonradiative Auger recombination, op…
Carbon nanotubes show promise for a wide range of applications due to a combination of their unusual structural, mechanical, and electronic properties. However, the limited ability to process nanotubes hinders the realization of their full potential. To remove this obstacle, research has been focused on the dispersion…
We present a quantum-chemical analysis of the molecular structure and second- and third-order polarizabilities in a series of promising nonlinear optical (NLO) chromophores, the zwitterionic ammonio/borato diphenylpolyenes, R3N+Ph(C=C)nPhB-R3, whose synthesis has been reported recently. The molecular geometries are ob…
In this work we demonstrate that specific MR image contrast can be produced in the water signal that reflects endogenous cellular protein and peptide content in intracranial rat 9L gliosarcomas. Although the concentration of these mobile proteins and peptides is only in the millimolar range, a detection sensitivity of…
The combination of their electronic properties and dimensions makes carbon nanotubes ideal building blocks for molecular electronics. However, the advancement of carbon nanotube-based electronics requires assembly strategies that allow their precise localization and interconnection. Using a scheme based on recognition…
A major challenge of computational protein design is the creation of novel proteins with arbitrarily chosen three-dimensional structures. Here, we used a general computational strategy that iterates between sequence design and structure prediction to design a 93-residue alpha/beta protein called Top7 with a novel sequ…
The work function of nano Porous Silicon (PS) has been studied by the kelvin probe method as a function of the exposure to different gaseous species. Characterisation has been performed n dark and in presence of sub band and supra band gap light Surface Photovoltage (SPV)measurements. Traces of ammonia and nitrogen di…
New methods were developed to prepare silver-doped sol-gel films for surface-enhanced Raman spectroscopy (SERS) applications. First, silver ions were doped into a sol-gel matrix. The doped silver ions were reduced into corresponding silver metal particles by two reductive procedures; chemical reduction and thermal red…
The synthesis and the emission properties of colloidal YVO<sub>4</sub>:Ln nanocrystals (8nm in diameter) are investigated, where Ln = Eu, Nd, Yb, Er. The nanoparticles synthesized here are constituted of a (Y,Ln)VO<sub>4</sub> crystalline core and stabilized by a lanthanide-citrate complexing shell. Surface derivatiza…
Aluminum nitride (AN) is beginning to replace alumina as a substrate and heat sink for electronic circuits. The thermal conductivity of A1N, about 8 times that of alumina, is the primary reason for its selection in these applications. While beryllium oxide has even higher conductivity, concerns about that material's t…
Thermodynamics of polymer chains in the ϑ condition confined to a space between two parallel walls was studied by using lattice Monte Carlo simulations. The ϑ state was realized by allocating positive interaction to nearest-neighbor pairs of a polymer segment and a solvent molecule that is now explicitly included, rat…
We study, by simulation, the effect of attractive triplet interactions on the phase behaviour of suspensions of charged colloidal particles at low ionic strength, i.e. in the regime where the pair interactions are purely repulsive. We use the pair and triplet interactions that were obtained recently from a numerical,…
Abstract The present work revealed that the chemical polymerization of ortho ‐ethoxyaniline yields two types of polymers not only with different spectroscopic properties but also with different molecular weights: (1) a green form, which corresponds to the high molecular weight fraction of the polymer with a molecular…
Abstract Carbon fiber (CF) filled low‐density polyethylene (LDPE) composites were prepared by the conventional melt‐mixing method. The distribution of CF in the composite was studied by wide‐angle X‐ray diffraction (WAXD) and scanning electron microscope (SEM) observations. A phenomenological model was proposed to ill…
Abstract A detailed study of the novel melt transetherification polycondensation process, which was recently developed in our laboratory, is presented. The efficacy of different catalysts, such as p ‐toluenesulfonic acid (PTSA), camphorsulfonic acid, and their pyridinium salts, was examined. The pyridinium salts, espe…
Raman spectra of ${\mathrm{C}}_{60}$ and ${\mathrm{C}}_{70}$ encapsulated in single-wall carbon nanotubes (so-called peapods) were measured at different excitation wavelengths in the range 458--568 nm and at hydrostatic pressure up to 9 GPa. We present the excitation profiles for some intense high-frequency peaks of $…
Abstract Four kinds of polyaniline (PANI)‐coated glass fibers (GF–PANI) combined with bulk PANI particles were synthesized. GF–PANI fillers containing different PANI contents were incorporated into an epoxy–anhydride system. The best conductivity behavior of the epoxy/GF–PANI composites was obtained with a GF–PANI fil…
Depletion forces in homogeneous and inhomogeneous binary colloidal mixtures in two dimensions are accounted for by a theoretical approach based on a contraction of the description of liquid mixtures, as well as by computer simulations. We study the depletion interactions in concentrated binary mixtures of additive and…
The crystal structure of a ternary complex of the alcohol dehydrogenase from the archaeon Sulfolobus solfataricus (SsADH) has been determined at 2.3 A. The asymmetric unit contains a dimer with a NADH and a 2-ethoxyethanol molecule bound to each subunit. The comparison with the apo structure of the enzyme reveals that…
We have used a microscopic lattice dynamical model to study phonon modes in germanium (Ge) NC with size varying between 47 to 7289 atoms $(\mathrm{diameter}\ensuremath{\sim}6.8\mathrm{nm}).$ By separating these atoms into bulk and surface atoms we have found that surface modes can exist in Ge NC both at low frequencie…