Materials Literature
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We report unambiguous evidence for ferroelectricity in a chiral bent-core liquid crystal. This evidence includes (i) a single current peak in the polarization reversal current, (ii) a strong dielectric response that is suppressed by applying a bias electric field, and (iii) strong optical second-harmonic generation in…
This review summarizes data for all known tricyanomethanide and dicyanamide compounds of copper(II), nickel(II) and cobalt(II). The possible bonding modes of [C(CN)3]− and [N(CN)2]− ions and their influence on infrared spectra are demonstrated. Preparative methods are briefly described and structural data for crystall…
The convergent synthesis and surface modification of a novel family of aliphatic polyether dendrons is described. The synthesis utilizes methallyl dichloride as the monomeric building block along with peripheral benzyl ether and ketal protected hydroxy functionalities. The allylic nature of the electrophilic moieties…
Temperature dependence of the polarized reflectance spectra have been measured on single crystals of $\ensuremath{\theta}\ensuremath{-}{\mathrm{ET}}_{2}{\mathrm{MM}}^{\ensuremath{'}}{(\mathrm{SCN})}_{4}$ (abbreviated as $\ensuremath{\theta}{\ensuremath{-}MM}^{\ensuremath{'}};$ ${\mathrm{MM}}^{\ensuremath{'}}=\mathrm{R…
A detailed dielectric investigation of liquid, supercooled liquid, and glassy ethanol was performed, extending the frequency and temperature range of previous investigations. The results reveal a third relaxation process, in addition to the two processes already known. In this respect the relaxational behavior of etha…
Abstract Intermolecular Coulomb repulsion, V, of the highest occupied molecular orbitals (HOMO) of BEDT-TTF (bis(ethylenedithio)tetrathiafulvalene) is calculated for various molecular geometries. The bare V is a quantity that is easily estimated under the point charge approximation. As far as the screened V in actual…
Suspensions of sterically stabilized colloidal gibbsite platelets have recently been found to exhibit both an isotropic-nematic (I-N) and a nematic-columnar (N-C) phase transition. In the present paper we show that depletion attraction, brought about by the addition of nonadsorbing polymer, enriches the phase behavior…
Large-area mesoporous silicate thin films are reported to be formed on solid silica substrates by the simple technique of spin-coating. The mesophase of the films can be controlled to be one-dimensional hexagonal, cubic, or lamellar by adjusting the casting solution composition, i.e., mainly the ratio of surfactant to…
Epitaxial La0.7Ca0.3MnO3 (LCMO) thin films of a thickness ∼170 nm were grown on (001) LaAlO3 (LAO) and (001) SrTiO3 (STO) substrates by pulsed laser deposition. Transmission electron microscopy and associated techniques have been applied to investigate the microstructures introduced by lattice mismatch that are respon…
Spherical polystyrene latex beads of about 2.0 μm diameter were coated with islands of silver or gold metal, about 5−200 nm in diameter, by reduction of aqueous silver or gold ions in the presence of sugar-coated polystyrene latex beads. The metal islands are held on the bead surface by a polymeric sugar derivative, a…
Differential scanning calorimetry has revealed the presence of a new denaturation endotherm at 32 degrees C following UV irradiation of collagen, compared with 39 degrees C for the native triple helix. Kinetic analyses showed that the new peak was a previously unknown intermediate state in the collagen helix-coil tran…
The main properties of realistic models for manganites are studied using analytic mean-field approximations and computational numerical methods, focusing on the two-orbital model with electrons interacting through Jahn-Teller (JT) phonons and/or Coulombic repulsions. Analyzing the model including both interactions by…
A simple and general method for making ceramic laminates with porous crack‐deflecting interlayers is demonstrated. Both the strong laminae and the porous interlayers are made by tape casting suitable slurries using the same ceramic powders. Porosity is introduced into the interlayer by adding starch particles to the s…
We have investigated the interaction of Co 2+ ions (as nitrate salt) with dendrimers of the poly(propylene amine) family functionalized in the periphery with fluorescent dansyl units. Each dendrimer n D, where the generation number n goes from 1 to 5, comprises 2 ( n +1) dansyl functions in the periphery and 2 ( n +1)…
Scientific investigations have long concluded that prolonged exposure to low dose radiation can induce deleterious effects in humans. The aim of this paper is to investigate the radioactivity of gypsum and gypsum derived products as part of a bigger project aimed at establishing radiation levels in materials or/and pr…
Rhizopus oryzae, strain IMI 057412, was immobilised by inclusion in six different polymers: polyvinlformal, polysulfone, polyurethane, alginate, polyacrylamide, k-carrageenan, polyethyleneimine(PEI). It was also grown on a seventh, polyurethane. The biomass/polymer matrices were formed into equal size units (4 mm sphe…
<span class="label">1</span> <div class="htmlview paragraph">Natural and synthetic sulfides are important components in friction materials such as pads, linings and even clutch facings and are summarized under the term “Friction Stabilizers”. Their unique properties lead to a high and stable friction…
The slurry‐based Three Dimensional Printing (3DP TM ) process requires the production of an easily redispersible powder bed from a well‐dispersed slurry. Understanding and control of the interparticle potential in the dispersed state, as well as in the dry consolidated state, are important. The strength of the particl…
A new experimental model based on the geometric parameters of a woven structure's yarn linear density and fabric tightness has been developed to predict the volume porosity of woven fabrics. The experimental model is based on a factor analysis. Experiments involve fabrics made from staple yams, but the mathematical mo…
Butyric esters of (2-hydroxypropyl) cellulose (BuPC) with different degree of substitution (DS) were synthesized via control of the esterification time of butyryl chloride and (2-hydroxypropyl) cellulose. These BuPCs are thermotropic and displayed different colors at ambient temperature due to the formation of a chole…