Alcan International Limited

North West Water Group Plc

Alexander P Davidson

Michael P Thomas

Robin C Furneaux

Steven W Summers

Melville D Ball

William R Rigby

Peter John Williams

David R Cowieson

A composite membrane comprises an inorganic support having interstices and porous inorganic films of sintered non-metallic particles carried by the support and bridging the interstices thereof. The support is preferably a woven metal mesh, with the films substantially coplanar with the support. The films may be formed by applying a suspension of refractory particles in a polymer solution to bridge the interstices of the support, and heating the films to partly sinter the particles. Since the films are in compression at ambient temperature, any cracks that may be formed by damage to the composite membrane tend not to propagate.

Composite membranes

A composite membrane comprises an inorganic support having interstices and porous inorganic films of sintered non-metallic particles carried by the support and bridging the interstices thereof. The support is preferably a woven metal mesh, with the films substantially coplanar with the support. The films may be formed by applying a suspenion of refractory particles in a polymer solution to bridge the interstices of the support, and heating the films to partly sinter the particles. Since the films are in compression at ambient temperature, any cracks that may be formed by damage to the composite membrane tend not to propagate.

A composite membrane comprises a porous metal support and at least one porous inorganic film of sintered non-metallic particles carried by the support and overlying a surface thereof. The film is in longitudinal compression at ambient temperature, such that any cracks tend not to propagate. The composite membranes are mechanically robust and chemically inert and useful as filters e.g. in the food industry. They may be made by applying a sol or suspension of particles to form a layer on the porous metal support and heating the coated support to partly sinter the particles of the layer.

A catalyst device comprises a porous catalytically active inorganic membrane, means for presenting a fluid reactant to a first surface of the membrane and means for recovering a fluid reaction product from the second surface of the membrane. The membrane is preferably an anodic aluminum oxide membrane with a deposit of catalytically active material present within the pores, preferably concentrated in the ends of the pores adjacent the second surface of the membrane.

Porous anodic aluminium oxide membrane catalyst support

An anodic aluminum oxide film (12) has a system of larger pores (14) extending in from one face (16) and interconnecting with a system of smaller pores (24) extending in from the other face (26). The film is made by anodizing an aluminum metal substrate, then reducing the applied voltage at a rate to permit partial or complete recovery of the oxide film, either continuously or incrementally in small steps down to a level preferably below 3 V, and separating the oxide film from the substrate.

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Shipston-on-Stour, United Kingdom

Alexander P Davidson