Materials Literature
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We investigate the phonon dispersion of graphite within a generalized bond-charge model with emphasis on the microscopic origin of the infrared active mode. The resulting dispersion is in good agreement with experiments, particularly with the full optical spectra obtained by the recent x-ray scattering experiment. The…
Proton uptake in undoped and Y-doped BaPrO3 has been measured by cold neutron prompt-gamma activation analysis, and compared to the proton uptake in Gd-doped BaCeO3, as determined by the same technique. The conventional proton incorporation model of perovskites in which oxygen ion vacancies, generated by the introduct…
The dynamic properties of the cyclic hexanuclear iron(III) complex ${\mathrm{Fe}}_{6}{(\text{triethanolaminate}\phantom{\rule{0.3em}{0ex}}3\text{\ensuremath{-}})}_{6}$ are studied by electron spin (ESR) and $^{1}\mathrm{H}$ nuclear magnetic resonance. We analyze the angular and temperature dependence of the ESR absorp…
The quantum dot is a novel fluorescent platform that has the potential to become an alternative to conventional organic dyes used to label biological probes such as antibodies or ligands. Compared to typical fluorescent organic dyes, cadmium selenide/zinc sulfide core-shell nanocrystals, or quantum dots, have greater…
The insulating layers used for the alignment of ferroelectric liquid crystals (FLC) in electro-optical cells usually have non-negligible thickness and their capacitance determines the type of the director switching caused by a triangular-form external voltage U(tr) . With decreasing frequency of U(tr) , the hysteresis…
Abstract Summary: Differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis and polarized light microscopy were used to study the curing reaction of diglycidyl ether of 4, 4′‐bisphenol P epoxy resin with an aromatic amine, 3‐nitro‐1,2‐phenylenediamine. Because of different reactivity o…
Abstract Crystals of the 4‐halo‐1,2,3,5‐dithiadiazolyl radicals (X = F, Cl, Br) were obtained by sublimation at 80 °C and 10 −2 Torr, and the structures were determined by X‐ray diffraction. The fluoro derivative crystallizes as a cisoid dimer in the space group P 2 1 / n , whereas the chloro and bromo derivatives cry…
Thin films deposited on wafers show, in some cases, large variations in stress. The local curvature is often used in the Stoney equation [G. G. Stoney, Proc. R. Soc. London, Ser. A 82, 172 (1909)] to calculate the local stress. This practice leads to false stress results. A general method for the calculation of the fi…
Al 2 O 3 :Ce 3+ :Mn 2+ films deposited by the spray pyrolysis technique show blue and red emissions under ultraviolet light excitation. The blue emission is due to the de-excitation of Ce 3+ ions from their excited state 5d to the split ground state 2 F. The usually weak red emission attributed to 3d 3d de-excitation…
In this chapter, we outline protocols for assembling and characterizing peptide-gold nanoparticle conjugates. We describe two strategies for attaching peptides to gold nanoparticles. One involves the covalent coupling of cysteine-terminated peptides directly to a particle surface via a sulfur-gold bond. Alternatively,…
Si nanocrystals (Si nc) were formed by the implantation of Si+ into a SiO2 film on (100) Si, followed by high-temperature annealing. High-resolution transmission electron microscopy has been used to examine the microstructure of the Si nc produced by a high-dose (3×1017cm−2) implantation. It is shown that there are on…
New metal complexes with pentagonal-bipyramidal geometry have been synthesized with the chiral, pentadentate bis(oxazoline) ligand (R,R)-1, including the metal ions magnesium(II), iron(II), and cadmium(II). In the solid state, a complete transfer of chirality from the ligand is observed to exclusively yield enantiomer…
For the synthesis of well-defined star-shaped aromatic polyamides, triphenyl benzene-1,3,5-tricarboxylate ( 2a ), tetraphenyl benzene-1,2,4,5-tetracarboxylate ( 2b ), and 1,3,5-tris(4-phenyloxycarbonylbenzyloxy)benzene ( 3 ) were synthesized and then employed as multifunctional initiators for the chain-growth polymeri…
Equilibrium swelling behavior of uniaxially oriented nematic networks in nematogenic solvents has been studied in the temperature ( T ) range covering the two independent nematic−isotropic transition temperatures for the swollen network ( T NI G ) and the surrounding solvent ( T NI S; T NI G > T NI S ). The swollen is…
Abstract Starting from the first organic spin ladder reported, a dithiophene‐tetrathiafulvalene salt ((DT‐TTF) 2 [Au(mnt) 2 ]) (mnt = maleonitriledithiolate), two different approaches to enlarge the family of organic spin‐ladder systems are described. The first approach consists of a molecular variation of the donor;…
Molecular dynamics simulations of binary colloidal monolayers, i.e., monolayers consisting of mixtures of two different particle sizes, are presented. In the simulations, the colloid particles are located at an oil-water interface and interact via an effective dipole-dipole potential. In particular, the influence of t…
Centimeter-long strands of well-aligned single-walled carbon nanotubes (SWNT) synthesized by a hydrogen–argon arc discharge method were employed for the investigation of their field emission properties. These macroscopically long aligned SWNT strands showed advantages of low turn on electric field, high current densit…
This chapter summarizes the properties of fluorescent semiconductor nanocrystals (quantum dots), and their relationship to performance in biological assays. The properties of quantum dots (optical, structural, compositional, etc.) are described. Recent work employing these entities in biological studies (immunofluores…
Abstract Semi1 and semi2 interpenetrating polymer networks (IPNs) of PVC and in situ formed PMMA have been synthesized using diallyl phthalate and ethylene glycol dimethacrylate as the crosslinkers of PVC and PMMA, respectively. These two types of IPNs have been compared w.r.t their physical, mechanical, and thermal p…
Complex electrical-conductivity experimental data sets for the interfacial amorphous phase in copper-core-copper-oxide-shell nanostructured composites have been analyzed using two Kohlrausch-related frequency response models recently developed for analysis of the dispersive electrical response of conductive materials.…