Materials Literature
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Abstract A single‐site ethyl aluminum complex, [2,2‐ diethyl‐1,3‐propylenebis(3,5‐di‐ tert ‐butyl‐salicylideneiminato)] ethyl aluminum (2), with a geminal diethyl substitutent on the diamino bridge was synthesized by the reaction of AlEt 3 with 1 equiv of N,N ′‐(2,2‐diethyl‐1,3‐propylene)bis(3,5‐di‐ tert ‐butylsalicyl…
Ceria-based ternary oxides are novel materials with potential use in many areas of chemistry, physics, and materials science. Synchrotron-based time-resolved X-ray diffraction (TR-XRD), X-ray absorption near-edge spectroscopy (XANES), Raman and infrared spectroscopies (RS and IR), and density-functional (DF) calculati…
A new sol-gel precursor, based on 1-methyl-3-[3-(trimethoxy-lambda(4)-silyl)propyl]imidazolium iodide (MTMSPI(+)I(-)), was synthesized and investigated as a potential novel quasi-solid-state ionic liquid redox electrolyte for dye-sensitized photoelectrochemical (DSPEC) cells of the Graetzel type. MTMSPI(+)I(-) was hyd…
Several new liquid-crystalline indene and pseudoazulene systems are reported. These molecules give rise to either columnar hexagonal mesophases and/or columnar plastic phases. The unique nature of these compounds stems from their non-classical discotic structure. Although the molecules have rigid aromatic cores, they…
Polyhedral oligomeric silsesquioxane (POSS) molecules when functionalized appropriately and dispersed in polymers show promise as monodisperse organic-inorganic hybrid nanocomposite materials characterized by superior mechanical properties. We report here molecular-simulation results for POSS-POSS radial distribution…
Straight single chains of Au nanoparticles have been synthesized using 10 nm diameter peptide nanotubes as templates (see Figure). The 6 nm Au nanoparticles grow in the gaps between the synthetic peptide coating the nanotubes which regulates the size, dispersity, interparticle distance, and crystallinity of the nanopa…
A mathematical model of a catalytic converter for automobile diesel engines that contains zeolites for adsorption of hydrocarbons has been developed. The model includes a description of mass- and heat-transfer resistance at the external surface of the monolith washcoat and internal diffusion within the catalytic washc…
We report the observation of two-dimensional melting in a monolayer film of a sphere-forming diblock copolymer. By annealing in a well-controlled temperature gradient we obtain a complete record of the transition from a low-temperature hexatic phase to a high-temperature liquid in a single experiment. We investigate t…
This paper describes the synthesis of a new series of molecules composed of a ruthenium cation liganded by a chloro or a thiocyanato, a 4,4'-(diethoxycarbonyl)-2,2'-bipyridine, and a 2,2':6',2' '-terpyridine substituted in its 4' position by a difluoroborazaindacene or a zinc phthalocyanine. A set of conditions are re…
Pressure-induced changes in the electronic and structural properties of tin monoxide are examined by means of ab initio density-functional calculations. Also, the pressure shifts of the ${A}_{1g}$ and ${E}_{g}$ zone-center phonon modes are derived. The results are compared to recent experimental high-pressure data as…
Araneoid spiders use specialized abdominal glands to manufacture up to seven different protein-based silks/glues that have diverse physical properties. The fibroin sequences that encode egg case fibers (cover silk for the egg case sac) and the secondary structure of these threads have not been previously determined. I…
Abstract Commercial grade poly(ethylene terephthalate), (PET, intrinsic viscosity = 0.80 dL/g) and poly(butylene terephthalate), (PBT, intrinsic viscosity = 1.00 dL/g) were melt blended over the entire composition range using a counterrotating twin‐screw extruder. The mechanical, thermal, electrical, and rheological p…
Free exciton and above-band-gap free carrier dynamics in ZnO nanorods have been investigated at room temperature with a femtosecond transient transmission measurement. Following the photoexcitation of above-band-gap free carriers, an extremely fast external thermalization time on the order of 200 fs can be observed. U…
Seven new 1,3,5-cyclohexyltricarboxamide-phenylalanine derivatives were synthesized in order to investigate the effect of the amino acid chirality on the gelating properties of these small molecules in water. Gelation tests have shown that enantiomerically pure homochiral 1,3,5-cyclohexyltricarboxamide-L-phenylalanine…
Magnetic and structural properties of single crystalline ${\mathrm{Gd}}_{5}{\mathrm{Si}}_{2}{\mathrm{Ge}}_{2}$ under hydrostatic pressure have been characterized by using magnetization, linear thermal expansion, and compressibility measurements. A strong dependence of Curie temperature on pressure, $d{T}_{C}∕dP=+4.8\p…
An electron-beam-sensitive zinc naphthenate resist is used to pattern ZnO. Features as small as 7 nm and with an aspect ratio of ∼ 9 can be patterned. Size reduction to ∼ 5 nm is observed when these patterns are heat treated to give crystalline ZnO (see Figure). The functionality of ZnO is confirmed via photoluminesce…
In order to investigate and optimize the electronic transport processes in carbon nanotubes doped with organic molecules, we have performed large-scale quantum electronic structure calculations coupled with a Green's function formulation for determining the quantum conductance. Our approach is based on an original sch…
We report thermal measurements on individual carbon nanotubes using a temperature sensing scanned microscope probe. An arc-grown bundle of multiwalled nanotubes (MWNTs) is mechanically attached to a thermal probe. The heat flow down individual MWNTs is recorded as a function of the temperature difference across them.…
The thermal behaviors of linear and branched polypropylene (PP) with foaming additives were investigated using a normal and a high-pressure differential scanning calorimeter (DSC). Specifically, the effects of material branching, dispersed additives, cooling rates, and dissolved blowing agents on the crystallization t…
Time-to-failure of polymers, and the actual failure mode, are influenced by stress, temperature, processing history, and molecular weight. We show that long-term ductile failure under constant load is governed by the same process as short term ductile failure at constant rate of deformation. Failure proves to originat…