Materials Literature
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Metamaterials are so-named to recognize and emphasize their purpose, which is to achieve material performance beyond the limitations of conventional composites. The holy grail of conventional composite design is to achieve an optimum combination of the constituent's properties without requiring that they react. Succes…
Abstract Polyfluorenes are an important class of electroactive and photoactive materials. In the last three years this research field has literally exploded because of polyfluorenes' exceptional electrooptical properties for applications in light‐emitting diodes. This is the only family of conjugated polymers that emi…
The configurations of oligomers of polyimide and polyetherketone polycyclic polymers in the melt are predicted by a new hybrid pivot Monte Carlo (PMC)/molecular dynamics (MD) single-chain sampling technique restricted to a limited number of near-neighbor interactions. These are then compared to configurations obtained…
Fully relativistic density functional calculations have been performed for group 8 tetroxides MO4, where M=Ru, Os, and element 108, Hs. The electronic structure analysis has shown HsO4 to be very similar to OsO4, with the covalence and stability increasing from OsO4 to HsO4. Using models of atom-slab interactions, ads…
The energetics and the electronic structure of AlnC clusters (n=3, 4, 5; 11, 12, 13) have been studied by a global optimization of their geometry without any symmetry constraint. The total energies of these clusters both in neutral and charged states are calculated using an all-electron basis and the generalized gradi…
We report high-pressure liquid chromatography (HPLC) and transmission electron microscopy studies of the size-dependent absorbance properties of Au and Ag nanoclusters dispersed in organic solvents. These nanosize metal clusters are synthesized by an inverse micelle synthetic technique at room temperature in inert oil…
Sonochemistry involves focusing acoustic energy through cavitation bubbles to increase chemical activity. The violent bubble collapses lead to temperatures of several thousand kelvin, which drive chemical reactions. In previous work, we gave a detailed computational model of a single bubble collapse, taking into accou…
Resonance Raman intensities of p-nitroaniline, a prototypical “push–pull” chromophore with a large first hyperpolarizability (β), have been measured in dilute solution in five solvents having a wide range of polarities (cyclohexane, 1,4-dioxane, dichloromethane, acetonitrile, and methanol) at excitation wavelengths sp…
We present a comparative study of the structural parameters characterizing thin macromolecular adsorbed films that are obtained from two optical techniques: optical waveguide lightmode spectroscopy (OWLS) and scanning angle reflectometry (SAR). We use polyelectrolyte multilayers and polyelectrolyte multilayers/protein…
CaRuO_3 is perovskite with an orthorhombic distortion and is believed to be close to magnetic ordering. Magnetic studies of single crystal and polycrystalline CaRu_{1-x}Cu_xO_3 (0\le x \le 15 at.%Cu) reveal that spin-glass-like transition develops for x\le 7 at.%Cu and obtained value for effective magnetic moment p_{e…
We consider mesoscopic thermal transport between two bulk dielectrics joined by a narrow wire or weak mechanical link. In the ``tunneling'' regime where the phonon transmission probability through the link is small and the thermal conductance is much less than the value for a single channel, the thermal current is det…
Single molecule confocal microscopy is used to investigate the detailed kinetics of fluorescence intermittency in colloidal II–VI (CdSe) semiconductor quantum dots. Two distinct modes of behavior are observed corresponding to (i) sustained “on” episodes (τon) of rapid laser absorption/fluorescence cycling, followed by…
Platinum chloride−graphite intercalated compounds (PtCl 4 −GICs) with a stage three structure were produced by mixing platinum tetrachloride and graphite at 723 K under 0.3 MPa of chlorine atmosphere. Two-dimensional platinum nanosheets with a thickness of 2−3 nm and a width of 5−300 nm were formed between graphite la…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA Conformationally Programmable LigandYong S. Chong, Mark D. Smith, and Ken D. ShimizuView Author Information University of South Carolina Department of Chemistry and Biochemistry Columbia, South Carolina 29208 Cite this: J. Am. Chem. Soc. 2001, 123, 30, 7463–7464Publi…
The MacDonald [2 + 2]-type condensation of readily available 5-aryl-substituted dipyrromethanes with acenaphthenequinone leads to the trans-syn- and anti-porphodimethenes, which in turn can be converted to the alpha,alpha- and alpha,beta-porphyrin atropisomers, respectively. Treatment of the metalated or unmetalated p…
A range of europium-activated titania phosphors with the formula Ti 1 - 3 x Eu 4 x O 2 ( x varying between 0.000397 and 0.00794) have been prepared, and the effects of europium content and titania phase on the luminescent properties have been investigated. It has been demonstrated that the crystallization temperature…
The crystallization behavior and crystalline morphologies of poly[(S)-lactide] (P[(S)-LA]) in thin films crystallized isothermally at over 160 degrees C were characterized by transmission electron microscopy and atomic force microscopy (AFM). The dendritic crystal and hexagonal crystal were formed in thin film with th…
A series of novel manganese α,ω-dicarboxylates, Mn 2 (H 2 O)[O 2 C(CH 2 ) n CO 2 ] 2 ( n = 3−12), were synthesized as single crystals or polycrystallines by the hydrothermal reaction of MnCl 2 with the corresponding dicarboxylic acid in the presence of base. Mn 2 (H 2 O)[O 2 C(CH 2 ) 3 CO 2 ] 2 and Mn 2 (H 2 O)[O 2 C(…
The preparation and electrochemical properties of four new dendrimers, compounds 1, 2, 3, and 4, containing eight, seven, four, and four ferrocene residues, respectively, are described. These small dendrimers were prepared with the building block bis(ferrocenylmethyl)alkylamine, which contains the tether −CH 2 −N(R)−C…
Microstructured honeycomb catalysts made of rhodium were manufactured and tested in the partial oxidation of methane under different experimental conditions. Even at operating pressures of up to 1.2 MPa with oxygen and up to 2.0 MPa with air, the catalyst was not found to be adversely affected by the reaction heat cau…