Materials Literature
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Recent nuclear magnetic resonance measurements on isotope engineered double walled carbon nanotubes (DWCNTs) surprisingly suggest a uniformly metallic character of all nanotubes, which can only be explained by the interaction between the layers. Here we study the inter-shell interaction in DWCNTs by density functional…
In some semiconductors donor impurity atoms can attract additional electrons, forming negative donor impurity ions. Thus we have 3 energy levels for electrons: zero energy levels at the bottom of the conductivity band, negative energy levels of the bounded electrons of the negative donor impurity ions, and deeper nega…
We show that under appropriate conditions, mixtures of oil, water, and nanoparticles form thermodynamically stable oil-in-water emulsions with monodisperse droplet diameters in the range of 30-150 nm. This observation challenges current wisdom that so-called Pickering emulsions are at most metastable and points to a n…
Graphene has two atoms per unit cell with quasiparticles exhibiting Dirac-like behavior. These properties lead to interband in addition to intraband optical transitions and modify the $f$-sum rule on the longitudinal conductivity. The expected dependence of the corresponding spectral weight on the applied gate voltage…
The goal of this chapter is to review the importance of excitons to single-wall carbon nanotube (SWNT) optics. We have developed the presentation for both researchers in the SWNT field who want to learn more about the unusual aspects of SWNT exciton photophysics and researchers more knowledgeable about the physics of…
The synthesis of gold nanospheres via the reduction of AuCl 4 - salt by sodium citrate has been revisited, with focus on the mechanism of particle growth. In stark contrast to the widely accepted LaMer nucleation-growth model, the initially formed nanoclusters of about 5 nm diameter self-assemble to form an extensive…
We demonstrate that by utilizing displacement currents in simple dielectric resonators instead of conduction currents in metallic split-ring resonators and by additionally exciting the proper modes, left-handed properties can be observed in an array of high dielectric resonators. Theoretical analysis and experimental…
Three-dimensional covalent organic frameworks (3D COFs) were synthesized by targeting two nets based on triangular and tetrahedral nodes: ctn and bor. The respective 3D COFs were synthesized as crystalline solids by condensation reactions of tetrahedral tetra(4-dihydroxyborylphenyl) methane or tetra(4-dihydroxyborylph…
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Abstract This paper analyzes the thermal and thermo‐oxidative degradation behavior, phase separation, melting, and crystallization of blends consisting of isotactic poly(propylene) (IPP) and poly(propylene) grafted with maleic anhydride (PP‐ g ‐MA). It has been established that, depending on the blend composition and…
A liquid crystal lens with wide focus range and fast switching between negative and positive power is reported. The switching between negative and positive lens are accelerated by high voltage pulses so that only approximately 40 ms is required to cover the 10 D focus range from negative to positive lens switching and…
Magnetocaloric compound Gd5Si4 has a higher Curie temperature TC=336K than that of Gd pure metal (TC=294K). High temperature synchrotron x-ray powder diffraction experiments have been performed for Gd5Si4 from 300to400K. Rietveld fitting of the results indicate that the compound retains the orthorhombic Gd5Si4-type st…
The crystal structure of four Aurivillius phases within the pseudo-binary system Bi 4 Ti 3 O 12 —PbTiO 3 is examined using a 3 + 1D approach where these phases are treated as commensurately modulated layered structures. The structure of PbBi 4 Ti 4 O 15 , Pb 2 Bi 4 Ti 5 O 18 , Pb 3 Bi 4 Ti 6 O 21 and PbBi 8 Ti 7 O 27…
A model is developed for determining the ideal operating point, based on maximum power output, for a thermoelectric conversion (TEC) element coupled to a combustor. In the analysis, heat recirculation from the combustor exhaust is included. Results presented here are relevant to the operating characteristics of small,…
Reactions to produce graft copolymers at polymer interfaces during extruder mixing are important for controlling dispersed phase size by retarding droplet coalescence and reducing interfacial tension while reinforcing the polymer interface. Such reactions are investigated at various temperatures in a model bilayer fil…
A set of open-chain fully substituted bi-, ter-, and quaterpyrroles bearing analogous substituents in the alpha- and beta-pyrrolic positions were studied as a function of their chain length, subunit number, and size of potential conjugation pathway by means of cyclic voltammetry, EPR, and UV-vis spectroelectrochemistr…
Extended x-ray absorption fine structure (EXAFS) measurements have been performed at the K edge of iodine in (AgI) 1− y (Ag 2 MoO 4 ) y glasses, with y = 0.25 and 0.33, as a function of temperature from 25 K to the glass transition temperature T g ≃ 323 K. EXAFS monitors the short-range component of the I–Ag distance…
BACKGROUND: Over the past decade, a number of tools have emerged for the examination of homology relationships among protein sequences in a structural context. Most recent software implementations for such analysis are tied to specific molecular viewing programs, which can be problematic for collaborations involving m…
Silver nanoparticles embedded on silica nanospheres were prepared by using ion-exchangeable poly(acrylic acid) (PAAc) grafted on the silica surface as a soft template followed by chemical reduction. The prepared hybrid nanospheres were characterized using x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD)…
Abstract The existence of lignin in lignocellulosic fibers increases the loss in breaking tenacity and elongation of fibers when they are exposed to heat and light. Delignification by sulfonation helps to remove some of the lignin from the fibers without affecting the breaking tenacity. The delignified fibers have hig…