Carbon foam derived from various precursors

A high conductivity graphite foam developed at Oak Ridge National Laboratory (ORNL) owes its unique thermal properties to the highly aligned graphitic structure along the cell walls. The material exhibits a peak in thermal conductivity at temperatures similar to that of highly ordered natural graphite, indicating the foam has an extremely graphitic nature. This paper explores the graphitic structure of the foam and attempts to correlate the morphology of the ligaments with the bulk thermal properties, up to 182 W/m·K. First, the manufacturing process of the foam and the resulting material properties are reported. Then, several models for representing the bulk materials properties are reviewed. Examination by optical image analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) was used to examine the structure of the graphite foam. In addition, crystallographic structure determined by X-ray diffraction is reported. A simple two parameter model of the morphology was developed and then used to predict the overall thermal properties of the foam based on the assumed highly ordered ligament structure. This new model correlated (within 5%) thermal conductivity to density of several foams, provided the average ligament conductivity could be accurately represented. From the new model and the material characterization data, it was determined that the average ligament thermal conductivity of the foam is >1650 W/m·K at room temperature, and increases to more than 2300 W/m·K at liquid nitrogen temperatures.

The role of structure on the thermal properties of graphitic foams

The production of cohesive bodies with controlled porosity by blending a carbon yielding binder, a pore forming liquid, and a dispersant; casting the mixture thus formed into a desired configuration; consolidating the cast material to form a selfsupporting, physically handleable body; and heating the body to form a cohesive carbonaceous mass.

Methods of producing carbonaceous bodies and the products thereof

A low density, open-celled microcellular carbon foam is disclosed which is prepared by dissolving a carbonizable polymer or copolymer in a solvent, pouring the solution into a mold, cooling the solution, removing the solvent, and then carbonizing the polymer or copolymer in a high temperature oven to produce the foam. If desired, an additive can be introduced in order to produce a doped carbon foam, and the foams can be made isotropic by selection of a suitable solvent. The low density, microcellular foams produced by this process are particularly useful in the fabrication of inertial confinement fusion targets, but can also be used as catalysts, absorbents, and electrodes.

Low density microcellular carbon foams and method of preparation

Development of mesophase pitch derived high thermal conductivity graphite foam using a template method

Method for manufacturing foam carbon products

A process for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contacting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible compound, such as, water or a polyhydroxy compound, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of water or polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the water or polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds and the low polar or nonpolar solvent are separated by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered from recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced.

Process for removing halogenated aliphatic and aromatic compounds from petroleum products

A process for removing mercury from water to a level not greater than two parts per billion wherein an anion exchange material that is insoluble in water is contacted first with a sulfide containing compound and second with a compound containing a bivalent metal ion forming an insoluble metal sulfide. To this treated exchange material is contacted water containing mercury. The water containing not more than two parts per billion of mercury is separated from the exchange material.

Process for removing mercury from aqueous solutions

PROCEDE D'ELIMINATION DE COMPOSES ALIPHATIQUES ET AROMATIQUES HALOGENES, PAR EXEMPLE DE BIPHENYLES POLYCHLORES, DE PRODUITS PETROLIERS PAR EXTRACTION PAR LES SOLVANTS. LES COMPOSES ALIPHATIQUES ET AROMATIQUES HALOGENES SONT EXTRAITS D'UN PRODUIT PETROLIER DANS UN SOLVANT POLAIRE PAR CONTACT DU PRODUIT PETROLIER AVEC LE SOLVANT POLAIRE TEL QUE LE DIMETHYLFORMAMIDE. UN COMPOSE MISCIBLE, TEL QUE L'EAU OU UN COMPOSE POLYHYDROXYLE, EST AJOUTE AU SOLVANT D'EXTRACTION POLAIRE POUR AUGMENTER LA POLARITE DU SOLVANT D'EXTRACTION POLAIRE. LES COMPOSES ALIPHATIQUES ET AROMATIQUES HALOGENES SONT EXTRAITS DU MELANGE FORTEMENT POLARISE D'EAU OU DE COMPOSE POLYHYDROXYLE ET DE SOLVANT D'EXTRACTION POLAIRE DANS UN SOLVANT FAIBLEMENT POLAIRE OU NON POLAIRE. LES COMPOSES ALIPHATIQUES ET AROMATIQUES HALOGENES ET LE SOLVANT FAIBLEMENT POLAIRE OU NON POLAIRE SONT SEPARES PAR DES MOYENS PHYSIQUES, PAR EXEMPLE PAR EVAPORATION SOUS VIDE.

John Mathew Napier

Papers

Method for manufacturing foam carbon products

Process for removing halogenated aliphatic and aromatic compounds from petroleum products

Process for removing mercury from aqueous solutions

Procede d'elimination de composes halogenes aliphatiques et aromatiques de produits petroliers