Materials Literature
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Ceria (CeO2) nanowires have been successfully synthesized by a sonochemical method in ambient air and alkali aqueous solution from CeO2 nanoparticles without using any templates. The results showed that both alkali concentration and ultrasonic irradiation played critical roles in the formation of the nanowires. The cr…
Lyotropic liquid crystals (LLC's) have recently been employed as polymerization templates to yield highly ordered nanostructured materials with potential applications in regulated transport, ultrafiltration, and catalysis. With the goal of understanding the reaction mechanisms ultimately determining polymer morphology…
In this communication, we illustrate a new method to modulate the chemical and mechanical properties of peptide-amphiphile nanofibers. Hydrogels containing a mixture of peptide-amphiphile and phospholipid were prepared and evaluated for their mechanical properties, peptide conformation, and nanostructure. It was found…
In this paper, we show that for aqueous phase-separated biopolymer mixtures (water-in-water emulsions) both interfacial tension and permeability of the interface are important for the relaxation process of deformed droplets. We give an expression for the characteristic relaxation time that contains both contributions.…
In this work, we have used the previously designed controlled uniaxial swelling (CUS) cell to obtain predetermined extents of swelling in montmorillonite. Using the CUS cell, a simultaneous measurement of swelling pressure is done with controlled swelling. Undisturbed clay samples at well-defined swelling (0%-75%) wer…
We have performed ultrafast absorption bleach recovery and fluorescence upconversion measurements ( approximately 100 fs time resolution) for three CdSe samples, with nanoparticle diameters of 2.7, 2.9, and 4.3 nm. The two types of experiments provide complementary information regarding the contributions of the differ…
The thermodynamic properties of solid solutions of ceria and zirconia, having the general formula Ce 1 - y Zr y O 2, were studied as a function of temperature and oxygen fugacity by measuring the oxygen content of samples equilibrated in H 2 /H 2 O mixtures between 873 and 1173 K. The thermodynamic redox properties we…
A new water-soluble polyphosphazene polyelectrolyte containing carboxylate functionalities, poly[di(sodium carboxylatoethylphenoxy)phosphazene] (PCEP) was synthesized via reaction of macromolecular substitution. The polymer was characterized using (1)H, (31)P NMR, and gel permeation chromatography with multiangle lase…
We report the fabrication and analytical functions of a biosensor based on a nanoneedle consisting of a multiwall carbon nanotube attached to the end of an etched tungsten tip. The devised electrode is the smallest needle-type biosensor reported to date. The nanoneedles prepared in this work are 30 nm in diameter and…
Block copoly(ether urea)s with uniform hard blocks consisting of two urea groups possess appealing elastomeric properties. The crystal structure of a model bisurea illustrates the formation of long stacks of hydrogen-bonded urea groups. Thermal analysis of these polymers demonstrates the reversible melting of the hard…
We revisit the problem of the spontaneous magnetization of an {\em sp} impurity atom in a simple metal host. The main features of interest are: (i) Formation of the spherical spin density/charge density wave around the impurity; (ii) Considerable decrease in the size of the pseudoatom in the spin-polarized state as co…
We present a series of ab-initio calculations of spectroscopic properties of liquid water at ambient conditions. Our results show that all available theoretical and experimental evidence is consistent with the standard model of the liquid as comprising molecules with approximately four hydrogen bonds. In particular, t…
Using the relativistic all-electron density-functional calculations on the AuN (N=2-26) in the generalized gradient approximation, combined with the guided simulated annealing, we have found that the two- to three-dimensional structural transition for AuN occurs between N=13 and 15, and the AuN (16<= N <=25) prefer al…
We present a two-band kinetic equation method to investigate the anomalous Hall effect in a Rashba two-dimensional electron system subjected to a homogeneous magnetization. The electron-impurity scattering is taken into account in the self-consistent Born approximation. It is demonstrated that the impurity-density-fre…
We propose a mechanism for 1/f-type noise in hopping insulators based on the multi-electron charge redistribution within the specific aggregates of the localized states located in the vicinity of the critical resistors. We predict that the noise with 1/f-type spectrum extends down to practically arbitrarily low freque…
Microporous and nanoporous polyelectrolyte multilayer films have been explored as ultrathin coatings for controlled drug release. Ketoprofen and cytochalasin D were successfully loaded into nanoporous films and showed zero-order release kinetics over a period of many days. In addition to homogeneous porous multilayers…
Hydrogen-bonded multilayers of a neutral polymer (poly( N -vinylpyrrolidone), PVPON) with poly(methacrylic acid) (PMAA) were used as templates to introduce cross-links between PMAA layers using carbodiimide chemistry and ethylenediamine as a cross-linking agent. Upon exposure to high pH, PVPON is completely released f…
The adsorption of CO on Al2O3- and SiO2-supported Ru catalysts has been investigated through FTIR spectroscopy. Deconvolution of the spectra obtained reveals the presence of 11 distinct bands in the case of Ru/Al2O3 and 10 bands in the case of Ru/SiO2, which were assigned to different carbonyl species adsorbed on redu…
The recent upsurge of interest in contrast agents for magnetic resonance imaging, of luminescent chemosensors for medical diagnostic, and lately, for optical imaging of cells has generated an impressive momentum for the coordination and supramolecular chemistry of trivalent lanthanide ions. We shortly review the synth…
Abstract The thermal decomposition of freeze‐dried Li‐Mn(II)‐Fe(III)‐formate precursors was investigated by means of DTA, TG and mass spectroscopy. By the thermal treatment of the prefired precursors between 400 and 1000°C, single phase solid solutions Li x Mn 1+x Fe 2–2x O 4 (0 ≤ x ≤ 1) with cubic spinel structure we…