Abstract: A homogeneous bulky porous ceramic material is provided, the average pore diameter D50 of which is less than 4 ?m and the closed porosity of which is less than 2 ?m, and having a bubble point that matches the pore diameter measured on the material. A hollow fiber based on the material and a module employing such fibers together with a paste constituting a precursor for the material and including a pore-forming agent are also provided.

Abstract: There are provided a sheet of filtration, separation or reaction elements, a method for preparing such a sheet, a filtration, separation or reaction module comprising at least one such sheet, and a method for preparing this module.

Abstract: A homogeneous bulky porous ceramic material is provided, the average pore diameter D50 of which is less than 4 &mgr;m and the closed porosity of which is less than 2 &mgr;m, and having a bubble point that matches the pore diameter measured on the material. A hollow fiber based on the material and a module employing such fibers together with a paste constituting a precursor for the material and including a pore-forming agent are also provided.

Abstract: A homogeneous bulky porous ceramic material is provided, the average pore diameter D50 of which is less than 4 &mgr;m and the closed porosity of which is less than 2 &mgr;m, and having a bubble point that matches the pore diameter measured on the material. A hollow fiber based on the material and a module employing such fibers together with a paste constituting a precursor for the material and including a pore-forming agent are also provided.

Abstract: The invention is directed to a method for preparing a membrane comprising a homogeneous porous carrier, on which a layer of a molecular sieve is deposited, comprising the following steps (i) preparing an inert solution and a precursor solution of the molecular sieve; (ii) impregnating the porosity of the carrier with the inert solution and/or the precursor solution; (iii) bringing the region of the ceramic carrier intended to receive the layer of a molecular sieve into contact with the precursor solution, and bringing the region of the carrier not intended to receive the layer of a molecular sieve into contact with the inert solution; and (iv) forming a molecular sieve in situ. The invention applies e.g., to filtration or gas or liquid fluid separation, reverse osmosis or catalysis.

Abstract: A multi-channel porous ceramic fiber is provided, preferably having a particular geometry, together with a filtration and/or reaction module comprising such fibers and a precursor paste for the fiber comprising a compression binder as the extrusion binder.

Abstract: Membrane apparatus for performing filtration, separation or a catalytic reaction, the apparatus including a macroporous block provided with parallel longitudinal through channels, the surface of each channel being covered with a respective membrane having finer pores than those of the block. According to the invention, the pores in both ends of said block are filled with a dense material (3) formed by a monometallic or polymetallic organic-inorganic polycondensate which has been subjected to heat treatment, this type of condensate being known under the name of ORMOSIL (organically modified silicate) or ORMOCER (organically modified ceramic).

Abstract: An organic-inorganic polycondensate characterized by the fact that it satisfies the following formula:C.sub.v H.sub.w O.sub.x Si.sub.y Me.sub.zwhere:v=4 to 48w=5 to 52x=5 to 48y=2 to 16z=1the ratio v/(y+z) being less than 7;C.sub.v H.sub.w being a carbon-containing chain carried by silicon; andMe being a metal or a mixture of metals chosen from groups IVA, VA, VIA, IIIB, and IVB of the periodic table of elements.

Abstract: A membrane for a filter device or a device for gas or liquid separation, the membrane being constituted by a porous structure made of at least one material selected from sintered ceramic, sintered metals, microporous carbon, microporous glass, and polymers, said structure including at least one microporous layer, wherein the entire outside surface and inside surface of the pores of said structure is covered by a thin and continuous film of a polyphosphazene, the thickness of said film lying in the range 0.01% to 10% of the mean diameter of the pores of said microporous layer.

Abstract: A membrane device comprising a macroporous block of sintered material with the pores at each end of the block being filled with a porous sintered material, wherein the porous sintered material comprises at least two types of grain: grains of a first type called "frame" grains having a diameter lying in the range about 1% to about 20% of the diameter of the pores in said block; and grains of a second type called "finishing"grains having a diameter lying in the range about 0.2% to about 20% of the diameter of the frame grains, with the finishing grains being received in the pores defined between the frame grains.

Abstract: A membrane for a filtration, gas or liquid separation or pervaporation apparatus comprising at least one porous layer of an inorganic material selected from sintered ceramic, sintered metal, sintered glass or carbon and a separating layer of organic material, the membrane being characterized in that said organic material is a polyphosphazene, in that the average diameter of the pores in said porous layer of inorganic material is between about 5 nm and 1 .mu.m, and in that said separating layer is continuous and only penetrates into said porous layer to a depth of less than five times the diameter of said pores in said porous inorganic layer, said layers being strongly bonded to each other.

Abstract: The fiter membrane comprises a porous structure made of a material selected from sintered ceramics, sintered metals, microporous carbon, and microporous glass, and is characterized by the fact that its entire external surface, including the inside surface of the pores in the structure, is covered with a thin and continuous film of carbon or of an oxide. In a sintered aluminum membrane, the surfaces of pores are coated with a dense and continuous thin layer of zirconia which prevents the surfaces from being degraded in service. In the figure, curve 3 shows how the throughput of a membrane without a zirconia layer falls off over time, while curve 4 shows little change in the same membrane having such a layer.

Abstract: The filter membrane comprises a porous structure made of a material selected from sintered ceramics, sintered metals, microporous carbon, and microporous glass, and is characterized by the fact that its entire external surface, including the inside surface of the pores in the structure, is covered with a thin and continuous film of carbon or of an oxide. In a sintered aluminum membrane, the surfaces of pores are coated with a dense and continuous thin layer of zirconia which prevents the surfaces from being degraded in service. In the figure, curve 3 shows how the throughput of a membrane without a zirconia layer falls off over time, while curve 4 shows little change in the same membrane having such a layer.