The method of the present invention for separating pyrogens includes passing a pyrogen-containing liquid through a zirconium oxide membrane on a ceramic support. The membrane on ceramic support preferably includes a porous sintered zirconium oxide membrane on alpha-alumina support.

Pyrogens separations by ceramic ultrafiltration

A multilayer inorganic porous membrane consisting of a monolayer or multilayer porous support having at least one surface integrally formed thereon with a porous thin layer having an average pore size less than that of the porous support, wherein a maximum pore size in the support surface is defined to be from 1 to 250 times an average pore size of the thin layer The multilayer porous membrane is superior in preventing the occurrence of pin holes and cracks therein thereby enhancing precision of the filtration and separation

Inorganic porous membrane

This invention relates a composition useful for preparing a polyvinylidene fluoride polymer membrane containing (1) a polyvinylidene fluoride polymer, (2) glycerol monoacetate, glycerol diacetate, glycerol triacetate, or mixtures thereof, and (3) optionally glycerol, wherein the polyvinylidene fluoride polymer membrane prepared from the composition is useful for a membrane liquid separation process such as microfiltration, ultrafiltration, dialysis, or membrane stripping. In another aspect, this invention is an improved process for using the composition to prepare a polyvinylidene fluoride polymer membrane by forming a mixture of the composition, heating the mixture to a temperature at which the mixture becomes a homogeneous fluid, and extruding, molding, or casting the homogeneous fluid into a membrane. Another aspect of this invention relates to a polyvinylidene fluoride polymer membrane where the fabricated membrane contains glycerol monoacetate, glycerol diacetate, glycerol triacetate, or mixtures thereof, and optionally glycerol.

Compositions useful for making microporous polyvinylidene fluoride membranes, and process

A porous inorganic membrane for use with a membrane device having a porous support, the membrane including refractory particles bound to each other and to the support by a thermally reactive inorganic binder which reacts at a temperature below that at which the refractory particles react. Further, a method of forming a porous inorganic membrane on a support by applying a coating of a mixture of refractory particles and a thermally reactive inorganic binder to the support. The inorganic binder reacts at a first temperature lower than a second temperature at which the refractory particles sinter. The method further includes firing the support to a firing temperature at least as high as the first temperature and less than the second temperature to react the inorganic binder, and cooling the support to form the porous membrane.

Method of forming a porous inorganic membrane on a porous support using a reactive inorganic binder

A composite membrane is disclosed which operates as a filter for liquids, solids and gases and combinations thereof, having high permeability for the filtrate, e.g., nitrogen passing therethrough, and high selectivity for matter retained thereby, e.g., volatile organic compounds, so that the N 2 /VOC selectivity is at least about 50/1 or greater; prepared by a low pressure chemical vapor deposition process comprising: (a) providing as a first component thereof, a mesoporous membrane substrate having pore diameters greater than about 20 Å; (b) contacting surfaces, including pore surfaces, of the membrane with at least two reactant gas streams in an opposing reactant geometry, wherein the smallest reactant gas molecule has a kinetic diameter intermediate in size between that of the matter retained by said filter and the filtrate passing therethrough; the reactant gases are capable upon reaction of depositing thereon as a second component thereof, a reaction product which by coating the surfaces, including pore surfaces of said mesoporous substrate, substantially reduces the pore diameters thereof, resulting in a substantially uniform microporous film having pore diameters in the range of from about 4 Å to about 8 Å; the reaction product comprises predominantly silicon oxide, --Si--O--, and may optionally include for the purpose of optimizing the stress, and other mechanical, chemical and thermal properties of said film, minor amounts of one or more members, in any combination thereof, selected from the group consisting of polysilicon, --Si--Si--, silicon carbide, --Si--C--, and silicon nitride, --Si--N--; and wherein said reactant gas streams comprise: (1) as the source of silicon and optionally carbide, a di-alkylsilane of the formula R 1 (R 2 )SiH 2 .

Subnanoscale composite, N2-permselective membrane for the separation of volatile organic compounds

The invention relates to a process for the production of porous, permeable, mineral membranes According to this process, on a porous, permeable substrate is formed a thin layer of at least one mineral compound chosen from among the simple or mixed metal oxides, except aluminum oxide and mixed aluminium oxides, simple or mixed metal hydroxides, except aluminium hydroxide and mixed aluminium hydroxides and mixtures thereof on the basis of a suspension in a liquid of colloidal or non-colloidal particles, said compound or a precursor thereof having particle sizes below 10 μm The suspension is kept in the finely divided state by the continuous application of energy to the reaction medium The thus obtained membrane is dried and then annealed at a temperature between 400° and 1100° C The use of a suspension of ultrafine colloidal or non-colloidal particles makes it possible to obviate the compression stage and obtain microporous layers with very small pore radii

Process for the production of porous, permeable mineral membranes

L'invention a pour objet un procede de fabrication de membranes minerales, poreuses et permeables. The invention relates to a method for manufacturing inorganic membranes, porous and permeable. Selon ce procede, on forme sur un substrat poreux et permeable une couche mince d'au moins un compose mineral choisi parmi les oxydes metalliques simples ou mixtes, sauf l'oxyde d'aluminium et les oxydes mixtes d'aluminium, les hydroxydes metalliques simples ou mixtes, sauf l'hydroxyde d'aluminium et les hydroxydes mixtes d'aluminium, According to this method, is formed on a porous, permeable substrate a thin layer of at least one inorganic compound selected from single or mixed metal oxides, except aluminum oxide and mixed aluminum oxides, single metal hydroxides or mixed, except aluminum hydroxide and mixed aluminum hydroxides, et leurs melanges a partir d'une suspension dans un liquide de particules colloidales ou non colloidales dudit compose ou d'un precurseur dudit compose ayant des dimensions de grains inferieures a 10 um, on seche la membrane ainsi obtenue puis on la soumet a une cuisson a une temperature comprise entre 400 °C et 1100°C. and mixtures thereof from a suspension in a liquid of colloidal particles or colloidal non of said compound or a precursor of said compound having lower particle sizes to 10 microns, drying the membrane thus obtained is then subjected to baking at a temperature between 400 ° C and 1100 ° C. L'emploi d'une suspension de particules collidales ou non colloidales ultra fines permet d'eviter l'etape de compression et d'obtenir des couches microporeuses de rayons de pores tres faibles. The use of a collidales particle suspension or non ultra fine colloidal avoids the compression step and get microporous layers of very small pore radii.

Process for the production of porous and permeable inorganic membranes

The invention relates to semipermeable organomineral membranes usable in reverse osmosis. This organomineral semipermeable membrane comprises a porous inorganic material support coated with a vinylidene fluoride polymer or copolymer-based organic layer incorporating functional groups giving the membrane a permeability to water or other solvents. The porous inorganic material support is preferably constituted by a macroporous substrate coated with a microporous layer, e.g. produced from a single or mixed metal oxide or hydroxide. The organic layer can be constituted by polyvinylidene fluoride grafted by an appropriate monomer, such as styrene incorporating functional groups giving it selective permeability, e.g. hydrophilic groups, such as sulphonic groups.

Organomineral semipermeable membrane and its production process

The process consists: a) - in immersing a polyvinylidene fluoride powder or film in a solution of the said monomer to impregnate the polyvinylidene fluoride powder or film with said monomer, b) - in irradiating the impregnated powder or film with ionising radiations in the absence of oxygen, and c) - then subjecting the graft copolymer obtained to a chemical reaction to impart an ionic character to it when the grafted monomer is not ionic in character. The monomer may be in particular dimethylaminoethyl methacrylate. The membranes obtained by this process can have a thickness of 50 to 100 mu m and an electrical resistivity markedly lower than 5 OMEGA cm .

Process for the production of graft copolymers of polyvinylidene fluoride, and membranes thereof obtained by this process

L'invention a pour objet des membranes organominerales, semi-permeables, utilisables en osmose inverse. The invention relates to organomineral membranes, semi-permeable, can be used in reverse osmosis. Cette membrane semi-permeable organominerale comprend un support poreux en materiau inorganique revetu d'une couche organique a base de polymere ou copolymere de fluorure de vinylidene comportant des groupements fonctionnels conferant a la membrane une permeabilite a l'eau ou a d'autres solvants. This organomineral semipermeable membrane comprises a porous support of inorganic material coated with an organic layer based on a polymer or copolymer of vinylidene fluoride having functional groups giving the membrane permeability to water or other solvents. Le support poreux en materiau inorganique est de preference constitue par un substrat macroporeux revetu d'une couche microporeuse, realisee par exemple en oxyde ou hydroxyde metallique, simple ou mixte. The inorganic porous support material is preferably constituted by a macroporous substrate coated with a microporous layer, made for example of metal oxide or hydroxide, simple or mixed. La couche organique peut etre constituee par du polyfluorure de vinylidene greffe par un monomere approprie tel que le styrene comportant des groupements fonctionnels lui conferant la permeabilite selective, par exemple des groupements hydrophiles comme les groupements sulfoniques. The organic layer may be constituted by polyvinylidene fluoride grafted with an appropriate monomer such as styrene containing functional groups conferring selective permeability, for example, hydrophilic groups such as sulfonic groups.

Jean-Marie Martinet

Papers

Process for the production of porous, permeable mineral membranes

Process for the production of porous and permeable inorganic membranes

Organomineral semipermeable membrane and its production process

Process for the production of graft copolymers of polyvinylidene fluoride, and membranes thereof obtained by this process

Semi-permeable organo-mineral membrane, and processes for its preparation