Materials Literature
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Gadolinium diethylenetriaminepentaacetic acid (DTPA) covalently linked to the lipophilic ethoxybenzyl moiety (Gd-EOB-DTPA) was designed for use as a contrast agent in hepatobiliary magnetic resonance imaging. With T1 relaxivity values of 8.7 L/mmol.second in plasma and 16.6 L/mmol.second in rat liver tissue and a medi…
We report a computer-simulation study of a system of ``hard cut spheres,'' oblate particles that are obtained by slicing off the top and bottom caps of a sphere at a distance L/2 from the equatorial plane. This system serves as a model for a disklike mesogen. The phase behavior of this system is found to be strongly d…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAzo polymers for reversible optical storage. 1. Poly[4'-[[2-(acryloyloxy)ethyl]ethylamino]-4-nitroazobenzene]A. Natansohn, P. Rochon, J. Gosselin, and S. XieCite this: Macromolecules 1992, 25, 8, 2268–2273Publication Date (Print):April 1, 1992Publication History Published on…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUnique behavior of dendritic macromolecules: intrinsic viscosity of polyether dendrimersT. H. Mourey, S. R. Turner, M. Rubinstein, J. M. J. Frechet, C. J. Hawker, and K. L. WooleyCite this: Macromolecules 1992, 25, 9, 2401–2406Publication Date (Print):April 27, 1992Publicati…
The detailed behavior of the phase transitions was mapped out for the series R${\mathrm{NiO}}_{3}$ as a function of the rare earth (R). A sharp insulator-metal transition is observed, which depends strongly on R.Forsmall$R it occurs at a higher temperature than the antiferromagnetic ordering (measured by muon-spin rel…
A convolution approach to X-ray powder line-profile fitting is developed in which the line shape is synthesized from the Cu Kα emission profile, the dimensions of the diffractometer and the physical variables of the specimen. In addition to the integrated intensities and 2 θ positions of the line profiles, the paramet…
This review discusses the principal physical mechanisms responsible for direct electromagneticacoustic conversion in ferromagnets. It is shown that in a wide range of frequency, magnetic field, and temperature ultrasound is generated via the inductive and magnetoelastic interactions. In the latter mechanism features a…
Fundamentals of polymers and formulations. Protective agents. Plasticizers. Inorganic additives. Impact modifiers. Speciality compound additives. Processing modifiers. Colorants. Special purpose additives. Flame retardants and smoke suppressants.
Abstract Two series of random copolymers of 10‐(pentamethyl disiloxanyl) decyl oxazoline ( Si ) with undecyl ( U ) (four copolymer compositions) and nonyl ( N ) (eight copolymer compositions) oxazolines over the whole composition range, with a total degree of polymerization of about 100, were studied by DSC and wide a…
Abstract The transamidation reaction in a polyamic acid solution has been investigated using size‐exclusion chromatography and low‐angle light scattering. Mixtures of a high‐molecular weight ( DP = 150) and a low‐molecular weight ( DP = 10) polymer and of the high‐molecular weight polymer with monomer were studied. Mi…
Abstract The plasticization by 4‐decylaniline (4DA) of a microphase‐separated poly(ethyl acrylate) ionomer containing sodium carboxylate groups is examined. Dynamic mechanical thermal analysis, supplemented by differential scanning calorimetry, shows that the matrix and cluster glass transitions ( T g 's) in the ionom…
Abstract 10‐(Pentamethyl disiloxanyl) decyl oxazoline ( Si ) was synthesized. It was copolymerized with either undecyl ( U ) or nonyl ( N ) oxazolines using methyl 4‐nitrobenzenesulfonate as initiator. Two series of random poly( N ‐acylethylenimine) copolymers, U/Si and N/Si , were synthesized over the whole compositi…
Abstract Dried gels of a linear low‐density polyethylene cast from decalin solutions are investigated with particular attention toward structural, thermal, and mechanical properties. The number‐average and weight‐average molecular weights are M n = 32,000 and M w = 160,000. In the concentration range 1.00–0.20, the sw…
Neutron spectroscopy has been applied to study the electronic ground state of NpO 2 both in the paramagnetic and in the ordered phase, below T c =25 K. The magnetic inelastic scattering cross section shows a broad peak which is split into two components and is centred at about 55 meV. This inelastic peak is shown to o…
Aluminum tantalum nitride amorphous alloy powders have been synthesized by a high energy ball mill under purified nitrogen gas (N2) flow at room temperature. The alloy powders were characterized by means of transmission electron microscopy, differential thermal analysis, and chemical analysis. An amorphous phase conta…
Recent experiments in charge-density-wave systems suggest that thermally activated phase slip is responsible for current flow. We present a quantitative theory that explains the nonlinear current-voltage relationship.
The fundamental surface chemistry underlying selectivity in copper chemical vapor deposition (CVD) from COD-Cu-hfac and Cu(hfac)2 has been determined. Both electronic and chemistry contributions strongly influence the precursor reactivity on oxide as compared to metal surfaces. These results have important implication…
Abstract The dielectric relaxation of 30% crystalline Nylon‐12 of molecular weight 20,000 has been studied at frequencies from 12 Hz to 0.1 MHz and temperatures from 77 to 375 K, and the effect of water on the relaxation spectra has been investigated. Absorbed water increases both the rate and the intensity of both it…
Abstract Wide‐angle x‐ray scattering (WAXS) and Raman spectroscopic data show that on both the crystal and molecular levels, a bimodal stress distribution exists in strained high‐performance polyethylene fibers. In part of the crystalline PE the microscopic strain level is high (ca. 70% of macroscopic strain); in the…
The formation of photoluminescent porous Si in an etchant solution made from the HF-HNO3-CH3COOH system is reported. The porous Si is characterized on the basis of its photoluminescence (PL) spectra and the degradation of the PL during exposure to laser irradiation. The surface topography as characterized by atomic fo…