Materials Literature
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An MCM-48 membrane was prepared on a porous α-alumina support by hydrothermal synthesis. The silylation with trimethylsilane and triethylsilane was used to enhance hydrothermal stability and hydrophobicity of the MCM-48 membrane. The studies of X-ray diffraction, Fourier transform infrared (FTIR), nitrogen adsorption,…
The segmental relaxation properties of a low molecular weight (4.6 kg/mol), cyclic polystyrene (PS) were characterized. The sample was obtained by fractionation using HPLC at the chromatographic critical condition, which yields a ring uncontaminated by its linear precursor. Both the glass temperature and the temperatu…
The conformational change of isotactic polypropylene (iPP) during the crystallization process has been carefully studied by Fourier transform infrared (FTIR) spectroscopy. The experimental measurements show that the iPP melt system is stable when the persistence length of helical sequences is less than 12 monomer unit…
PMMA/Na-MMT nanocomposites were synthesized through a soap-free emulsion polymerization of methyl methacrylate (MMA) using 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). A conventional anionic surfactant, dodecylbenzenesulfonic acid sodium salt (DBS-Na), was also used to compare with AMPS in the interaction with…
A general set of methods is presented for calculating chemical potentials in solid and liquid mixtures using {\em ab initio} techniques based on density functional theory (DFT). The methods are designed to give an {\em ab initio} approach to treating chemical equilibrium between coexisting solid and liquid solutions,…
High-spin systems with orbital degeneracy are studied in the large spin limit. In the absence of Hund's coupling, the classical spin model is mapped onto disconnected orbital systems with spins up and down, respectively. The ground state of the isotropic model is an orbital valence bond state where each bond is an orb…
Dissipative effects on the nonadiabatic transition for the two and three level systems are studied. When the system is affected by a strong dissipation through the diabatic states, the exact transition probability is enumerated making use of the effective master equation. In the two-level system, we consider the case…
A range of monodomain nematic liquid crystal elastomers containing differing proportions of photo-isomerisable mesogenic moieties, which turn from a rod-like to a kinked shape upon ultraviolet (UV) irradiation, was studied. Depending on the proportion and positional role of the photo-sensitive groups in the crosslinke…
We studied the mechanical properties of dragline threads of the edible golden silk spider Nephila edulis that are produced under spinning speeds ranging from 0.1 to 400 mm s(-1) and temperatures ranging from 5 to 40 degrees C. These conditions affected the silk in all of the mechanical traits we tested (strain at brea…
Single-wall carbon nanotubes pack into crystalline ropes that aggregate into tangled networks due to strong van der Waals attraction. Aggregation acts as an obstacle to most applications, and diminishes the special properties of the individual tubes. We describe a simple procedure for dispersing as-produced nanotubes…
A variety of spectroscopy and sample preparation techniques are described that allow chemical composition changes to be followed for isolated clearcoat samples, clearcoats in complete paint systems, and all coating layers in complete paint systems as a function of exposure. The analysis techniques provide photooxidati…
Abstract Polyurethane dispersions were prepared and urethane/acrylic composite latices were synthesized with polyurethane dispersions as the seed, and core‐shell emulsion polymerization. Fourier‐transform infrared spectroscopy coupled with attenuated total reflectance (FTIR‐ATR) analyses showed that the films obtained…
Abstract The synthesis and characterization of a new series of chiral poly(ester‐amide)s are reported. They were prepared by the simple reaction of diacid chlorides with biphenolic azo chromophores and optically active dihydroxy compound (isosorbide) in dimethyl acetamide at 100 °C. The polymers containing isosorbide…
I. Introduction In this paper, we will consider, first, the fundamentals of the measurement of corrosion protection of organic coatings. This first portion will emphasize electrochemical characterization methods for the corrosion protective properties of organic coatings, especially electrochemical methods, and the in…
A straightforward procedure for engineering porosity in thin silicate films has been demonstrated. Macroporous silicate films were fabricated by doping a silica sol prepared from the acid-catalyzed condensation of tetramethoxysilane with polystyrene latex spheres of diameter ranging from 0.3 to 1 μm. After film format…
Abstract The solution properties of hydroxyl terminated hyperbranched aliphatic polyesters and their acetyl derivatives have been studied by measuring viscosity parameters. The polarity of terminated groups of molecules is the most important factor affecting their properties. The intrinsic viscosity [η] cannot reflect…
The recently developed technique of maximum-likelihood density modification [Terwilliger (2000), Acta Cryst. D56, 965-972] allows a calculation of phase probabilities based on the likelihood of the electron-density map to be carried out separately from the calculation of any prior phase probabilities. Here, it is show…
Abstract A series of low‐density polyethylene (LDPE) blends with varying proportions of plasticized tapioca starch have been used for the study of their mechanical properties. A functionalized epoxy resin, namely, poly(ethylene‐ co ‐glycidyl methacrylate) has been used as the compatibilizer. The impact and tensile pro…
The binding of N-acetylglucosamine (NAG) to chicken egg lysozyme (E.C. 3.2.1.17) was investigated by high-resolution X-ray powder diffraction at room temperature. NAG was found to bind to lysozyme in a rapid precipitation preparation with 0.05 M NaCl buffer pH 6.0, but not 0.05 M NaCl buffer pH 5.0. Binding was indica…
Nonlinear behaviour of power piezoceramic materials has to be studied under strong electric fields. A bridge designed for measuring it at low frequency is described. It consists basically of a capacitance comparison bridge that can be used in two different modes: balanced and unbalanced. The nonlinear electric displac…