POLYCATION-POLYANION COMPLEXES: PREPARATION AND PROPERTIES OF POLY-(VINYLBENZYLTRIMETHYLAMMONIUM) POLY-(STYRENESULFONATE)
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1961.
Materials Literature
文献浏览
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Localized Magnetic States in Metals
The conditions necessary in metals for the presence or absence of localized moments on solute ions containing inner shell electrons are analyzed. A self-consistent Hartree-Fock treatment shows that there is a sharp transition between the magnetic state and the nonmagnetic state, depending on the density of states of f…
On the theory of polymer crystallization
Abstract The systematic pleating of polymer molecules in their crystallization, in segments of a length of the order of 100 A, which depends on the crystallization temperature, is interpreted in terms of the kinetics of crystal growth. The theory begins with but departs from a theory proposed by Lauritzen & Hoffma…
Ultrasonic Amplification in CdS
Radiofrequency waves at 15 and 45 Mc are transduced into pressure waves at the same frequencies, and are applied to a CdS crystal. The waves are then converted by a second transducer into a r-f output wave. The signal amplification is found as a function of the illumination intensity on the crystal, and the electric f…
Diffraction contrast of electron microscope images of crystal lattice defects - II. The development of a dynamical theory
Abstract The dynamical theory of electron diffraction is developed in a form suitable for the computation of images of crystal lattice defects such as dislocations observed by transmission electron microscopy. As shown in a previous kinematical theory, the contrast arises because the waves diffracted by atoms near the…
COMPLEXES OF IRON WITH d-TARTARIC AND meso-TARTARIC ACIDS
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCOMPLEXES OF IRON WITH d-TARTARIC AND meso-TARTARIC ACIDSR. W. Green and Gwenda M. ParkinsCite this: J. Phys. Chem. 1961, 65, 9, 1658–1659Publication Date (Print):September 1, 1961Publication History Published online1 May 2002Published inissue 1 September 1961https://doi.org…
Molecular weight distribution changes during the thermal breakdown of poly‐α‐methylstyrene
Abstract The changes in the molecular weight distribution accompanying the thermal depolymerization of poly‐α‐methylstyrene have been investigated. The original polymer, produced by anionic catalysis, had a narrow distribution of molecular weights, which facilitated measurement of the changes. The depolymerization whe…
An X-ray examination of an exceptionally well crystallized kaolinite
Summary Specimens of kaolinite have been found in inclusions in the ferruginous deposits on the Yorkshire Coast, just north of Scalby. The excellent quality of the X-ray powder pattern suggests that this kaolinite is better crystalline than kaolinites from other localities. Although the lattice constants of the Scalby…
Fundamentals of Glass‐to‐Metal Bonding: VII, Wettability of Iron by Molten Sodium Silicate Containing Iron Oxide
Contact angles, and adherence of sodium disilicate glasses with varying iron oxide additions on platinum and iron were studied at 1000°C. in vacuum. In the glass‐platinum systems the iron concentration in the glass did not affect either the contact angle or the adherence. No devitrification occurred in the glass‐plati…
Spin Resonance in Neutron-Irradiated Graphite
The carrier spin-resonance line of neutron-irradiated single crystals of graphite at 300\ifmmode^\circ\else\textdegree\fi{}K has been observed as a function of the thermal neutron flux up to a dose of 9.6\ifmmode\times\else\texttimes\fi{}${10}^{18}$ nvt. From the intensity increase and the $g$ shift for $H$ parallel t…
``Boxcar'' Integrator with Long Holding Times
The bipolar output of the rf phase detector of the receiver in a nuclear magnetic resonance pulse experiment is fed through a 4-diode sampling switch to an RC integrator, whose output is read by a recording electrometer. The switch (a ``transmission gate'') includes two type 7266 ceramic thermionic diodes, whose back…
Über Reaktionsweisen des Vanadinhexacarbonyls
Abstract Vanadinhexacarbonyl erweist sich als besonders reaktionsfähig. Reaktionen mit N‐Basen (B) in Benzol verlaufen bereits bei Raumtemperatur im Sinne einer „Basenreaktion”︁ unter Bildung von Hexacarbonylvanadaten, [VBn] [V(CO)6]2 (n = 4 oder 6). Auch schwache Basen wie Säurenitrile und O‐Basen geben Verbindungen…
Preparation and Properties of Spinel Made by Vapor Transport and Diffusion in the System MgO‐Al 2 O 3
In a hydrogen atmosphere, MgO was vaporized by heating MgO (periclase) in the range 1500° to 1900° C, and the vapor products diffused into Al 2 O 3 (sapphire) to form a uniform outer layer of spinel on all surfaces. At 1900°C. a spinel layer 48 mils thick could be obtained in 16 hours. The rates of spinel formation we…
Synthesis of Multiple Antireflection Films over a Prescribed Frequency Band
The synthesis (as opposed to analysis) of multilayer dielectric films as antireflection coatings over any specified frequency band has not been attempted before. The similarity with transmission lines, which can be synthesized as multisection quarter-wave transformers to minimize reflection over any prescribed frequen…
Initiation of graft polymerization on cellulose by hydroxyl radicals and by ceric salts
Landells and Whewell have previously reported that vinyl monomers are polymerized “within viscose filaments” by hydrogen peroxide in the presence of ferrous salts and the polymers are not extractable. Such products, obtained by polymerization of acrylonitrile and styrene in viscose, have now been acetylated. Fractiona…
The Quantity of Water in the Cell Wall and its Significance
Cell wall preparations from the leaves of Eucalyptus globulus Labill. may absorb water equal to approximately 150% of their dry weight.
Dispersion of Carbon Black in Rubber: Revised Calculation Procedure
Abstract Carbon black, the most important reinforcing filler for rubber, must be well dispersed if it is to function effectively. The state of dispersion of the carbon black can be studied effectively by microscopic examination of a thin (2µ) section of the rubber compound, using transmitted light, as described by Tid…
INFRARED SPECTRA OF XANTHATE COMPOUNDS: III. ORGANIC SOLVENT EFFECT ON THE C=S FREQUENCY
The previously made absorption-band assignment (1) for the C=S stretching mode in xanthate-type compounds, 1020–1070 cm −1 , has been confirmed by the characteristic behavior of the C=S dipole in a range of different solvents (Bellamy and Rogasch (2)).
THE MECHANISM OF HYDROGEN EMBRITTLEMENT OBSERVED IN IRON-SILICON SINGLE CRYSTALS
The technique of decorating dislocations was employed to investigate plastic deformation and fracture resulting from precipitation of H in Fe3% Si single crystals. It is shown that cracks are produced on (100) planes inside crystals quenched from H atmosphere at elevated temperatures or cathodically charged with H at…
THE PREPARATION AND PROPERTIES OF SELF-BONDED SILICON CARBIDE
Dense self-bonded silicon carbide, prepared by impregnating with silicon pressed mixtures of silicon carbide and graphite, has been improved by attention to grading and composition. Treatment at 2000°C for ½ h has given a much greater degree of self-bonding. Porous self-bonded silicon carbide with a dense surface has…