Abstract:
Polyamide porous spherical particles having a number-average particle diameter of 2 to 30 μm, a BET specific surface area of 100 to 80,000 m2/kg, and a ratio of a volume-average particle diameter to the number-average particle diameter in the range of 1.52 to 2.50 is reduced in luminous reflectance.
Abstract:
The present invention provides a process for producing porous polymer materials. In the present invention, a polymer material and a soluble material are mixed in their solid states. The surface of the polymer material is partially dissolved and fused by introducing a solvent. The present invention makes use of a pressure difference while introducing a non-solvent into the polymer material to solidify and resolve the solved polymer material. Then, a substantial amount of water is used to wash the inside soluble material out. Therefore, the porous polymer materials with high porosity and interconnecting pores inside the materials are produced massively and rapidly.
Abstract:
This invention relates to a novel composition useful for preparing a semi-permeable cellulose ester gas separation membrane, which composition includes a mixture of a cellulose ester, a solvent selected from the group consisting essentially of glycerol acetate, glycerol diacetate, glycerol triacetate, and mixtures thereof, and optionally the non-solvent glycerol. This invention also relates to a process of fabricating a cellulose ester gas separation membrane from said composition.
Abstract:
There is disclosed a substantially skinless microporous polypropylene membrane characterized by having(a) a bubble point of about 25 to about 50 psi;(b) a thickness of about 3 to about 7 mils;(c) a nitrogen flow rate of at least 0.5 liters per square centimeter-minute;(d) a burst strength of at least 10 psi; and(e) an S value of about 15, or less.There is also disclosed a method of preparing a microporous polypropylene membrane comprising heating a mixture of about 30 percent polypropylene and about 70 percent, N,N-bis(2-hydroxyethyl)tallowamine, by weight, to a temperature and for a time sufficient to form a homogeneous solution, casting or extruding said solution at a thickness of about 3 to about 7 mils, onto a chill roll maintained at a temperature of from about 50.degree. to about 80.degree. C., allowing said solution to solidify on said chill roll to form a solid sheet, removing said solid sheet from said chill roll and removing at least a substantial portion of the liquid from said sheet to form the microporous polypropylene membrane.
Abstract:
1. A PROCESS FOR PREPARING AN ENGINE EXHAUST CATALYST COMPRISING THE FOLLOWING STEPS: A. HOMOGENEOUSLY BLENDING A COMPOSITION CONSISTING ESSENTIALLY OF 15-80 VOLUME PERCENT OF A POLYOLEFIN HAING A MOLECULAR WEIGHT OF AT LEAST 150,000 AND A STANDARD LOAD MELT INDEX OF SUBSTANTIALLY ZERO, 5-67 VOLUME PERCENT OF A CERAMIC FILLER, SELECTED FROM THE GROUP CONSISTING OF ALUMINUM, MULLITE, ZIRCON MULLITE, MAGNESIUM ALUMINATE SPINEL AND CORDIERITE AND 15-80 VOLUME PERCENT OF A PLASTICIZER; SELECTED FROM THE GROUP CONSISTING OF MINERAL OILS DETHYLENE GLYCOL, PROPYLENE GLYCOL, DIPROPYLENE GLYCOL GLYCERINE, AND A GLYCEROL MONOACETATE, TRIMERTHYLENE GLYCOL, TETRAMETHYLENE GLYCOL, 2,3BUTYLENE GLYCOL, TRIETHYL PHOSPHATE, POLYVINYL ALCOHOL, AND POLYVINYL PYRROLIDONE, B. HEATING SAID COMPOSITION TO AOUT 125* TO 175*C., MOLDING TO FORM A PLASTIC SHEET AND IMPRESSING RIBS THEREON, C. ROLLING SAID PLASTIC SHEET SO THAT SAID RIBS CONTACT SAID SHEET, HEAATING TO ABOUT 150*CC. TO JUST BELOW THE BURN OFF POINT TO FUSE THE CONTACTING AREAS TOGETHER THERMOPLASTICALLY, D. EXTRACTING SAID PLASTICIZER WITH WATER OR AN ORGANIC SOLVENT, E. REMOVING SAAID POLYOLEFIN BY HEATING TO 240* TO 700*C. TO FORM A POROUS CERAMIC STRUCTURE, AND TO BURN OFF THE POLYOLEFIN AND, F. FIRING SAID POROUS CERAMIC STRUCTURE AT A TEMPERATURE OF 1,300* TO 1,450*C. (FOR ABOUT 2 HOURS) FOR A TIME SUFFICIENT TO SINTER SAID POROUS CERAMIC STRUCTURE, G. IMPREGNATING THE POROUS CERAMIC STRUCTURE WITH SOLUTIONS OF SOLUBLE SATS OF METALS EXHIBITING CATALYTIC ACTIVITY FOR CONVERTING ENGINE EXHAUST GASES AND HEATING TO CONVERT THE METALS TO THE ACTIVE FORM.
Abstract:
Method of preparing temperature resistant exhaust oxidation catalysts suitable for use in land vehicle exhaust systems comprising a porous ceramic base impregnated with suitable oxidizing agents and the resulting catalysts. The porous ceramic base is prepared from a ceramic powder filled, plasticized polyolefin.
Abstract:
Asymmetric organic-inorganic films and methods for forming and using such films. For example, the films are used as membranes for selective separation applications. The methods combine co-assembly of block copolymer (BCP) and inorganic nanoparticles (NPs), such as, for example, titanium dioxide (TiO2), with non-solvent induced phase separation. The resulting films exhibit structural asymmetry. For example, the films have a thin nanoporous surface layer on top of a macroporous finger-like support layer. Parameters that may dictate membrane morphology include the fraction of inorganic nanoparticles used and the length of time allowed for surface layer development. In filtration tests, the resulting membranes show both desirable selectivity and permeability. The synthesis methods for hybrid membranes provide a new self-assembly platform upon which multi-functional and high-performance organic-inorganic membranes can be formed.
Abstract:
The objective of the present invention is to provide a porous ultra-thin polymer film, and a method for producing said porous ultra-thin polymer film. The present invention provides a porous ultra-thin polymer film with a film thickness of 10 nm-1000 nm. In addition, the present invention provides a method for producing a porous ultra-thin polymer film, comprising the steps of: dissolving two types of mutually-immiscible polymers in a first solvent in an arbitrary proportion to obtain a solution; applying the solution onto a substrate and then removing the first solvent from the solution applied onto the substrate to obtain a phase-separated ultra-thin polymer film that has been phase-separated into a sea-island structure; and immersing the ultra-thin polymer film in a second solvent which is a good solvent for the polymer of the island parts but a poor solvent for a polymer other than the island parts to remove the island parts, thereby obtaining a porous ultra-thin polymer film.
Abstract:
A porous polybenzimidazole (PBI) particulate resin is disclosed. This resin is easily dissolved at ambient temperatures and pressures. The resin is made by: dissolving a virgin PBI resin in a highly polar solvent; precipitating the dissolved PBI in a bath; and drying the precipitated PBI, the dried precipitated PBI being porous. The porous PBI resin may be dissolved by: mixing a porous PBI resin with a highly polar solvent at ambient temperatures and pressures to form a solution.