Abstract: A method of making a porous polymeric material by heating a mixture of a thermoplastic polymer and a cationic or non-ionic surfactant having a hydrophilic-lipophilic balance range of 4.0 to 6.0 to a temperature and for a time sufficient for the polymer and surfactant to mutually dissolve. The mixture is then cooled to a temperature so that non-equilibrium liquid-liquid phase separation takes place to form a bi-continuous matrix of the polymer and surfactant so that the polymer and surfactant form two intermingled separate phases of large interfacial surface area. The surfactant is then removed from the polymer. The porous polymeric material produced by the above method has a lacey or filamentous structure consisting of a plurality of polymer strands connected together at spaced apart locations along each strand.

Abstract: Polyphenolic substances such as food dyes, tannins, fruit juices and wine colorings are removed from a solution by adsorption onto a regeneratable adsorbent polyamide of extended surface and controlled porosity. The surface chemistry of the polyamide may be modified by a glutaraldehyde/resorcinol treatment. The polyphenolic substances are recovered by elution with water or other protonic solvent.

Abstract: A method of concentrating solids in a liquid suspension using a filter having a plurality of hollow, microporous, elastic fibres with a shell or housing, comprising applying the suspension to an outer surface of the fibres whereby a portion of the suspension passes through the fibre walls and at least a portion of the solids is retained on or in the fibres; and discharging the retained solids by stretching the fibre pores and washing out solids retained in the pores by application of gas under pressure.

Abstract: A process for producing a support capable of reaction with antibodies or enzymes, said process comprising the steps of:(i) reacting an aliphatic polyamide with a solution consisting essentially of sulphuryl chloride and a paraffin or cycloparaffin to produce a sulphuryl chloride modified polyamide reactive intermediate product;(ii) reacting the product of step (i) with a compound that binds to said product to provide a covalent chemical link to which antibodies or enzymes may be bound.

Abstract: A method of concentrating solids in a liquid suspension using a filter having a plurality of hollow, microporous, elastic fibres with a shell or housing, comprising applying the suspension to an outer surface of the fibres whereby a portion of the suspension passes through the fibre walls and at least a portion of the solids is retained on or in the fibres; and discharging the retained solids by stretching the fibre pores and washing out solids retained in the pores by application of gas under pressure.

Abstract: In the cleaning and removal of solids from microporous hollow fibre filters by a series of chemical cleaning cycles, the optimum time and pattern of the cleaning cycles is calculated from the rate of diminution in filtrate flow rate and the time and filtrate lost in each cycle.

Abstract: A porous membrane characterized by a morphology that is the reversed phase analogue of another porous membrane. The material which forms the reversed phase porous membrane can be a thermosetting resin, zirconia or silica. The other membrane can be polypropylene or polyamide.

Abstract: A filtration system for treating an emulsion containing water, an oil or a fat, an emulsifying agent and insoluble solid material (such as a maritime oil emulsion containing an anionic detergent and the solid, greasy calcium salt of the detergent) has a first hydrophobic microfilter (126) and a second hydrophobic microfilter (147).Both microfilters (126, 147) have a plurality of hollow porous fibers as the separating medium with the feed to the first filter (126) being applied to the outside of the fibers and the feed to the second filter (which is the permeate from the first filter) being applied down the lumens of the fibers. The first filter (126) removes the solid material and the second filter separates the oil or fat from the solid-free emulsion.

Abstract: Aliphatic polyamides are reacted on their surfaces with sulphuryl chloride, either neat or in solution in paraffins or cycloparaffins to give reactive intermediate whcih may convert into a support capable of reaction with antibodies or enzymes by providing covalent chemical links to which the antibodies or enzymes may be bound.

Abstract: A method of treating a heated liquid suspension, which entails:(a) applying a liquid suspension to elastic, microporous, hollow fibres within a shell or housing, and(b) discharging solids retained on or in the fibres by applying to the fibre lumens a pressurized reverse flow of gas, and wherein the hollow fibres are cooled prior to applying the reverse flow of gas.

Abstract: Pores that are smaller than or larger than a predetermined range of pore sizes in a porous membrane barrier are blocked with a controlled porosity blocking agent. The pores are first filled with a liquid so as to remove any air therein and then subjected to a transmembrane gas blow at a pressure which will clear the larger pores of the liquid. The larger gas filled pores or the smaller liquid filled pores are then blocked by a blocking agent using a polymer-forming chemical reaction, a precipitate-forming chemical reaction or the physical deposition of solids.

Abstract: A concentrator for concentrating the fine solids of a liquid feed suspension has a shell within which there is a bundle of microporous fibers. Pressurized feed suspension is introduced through an inlet and passes over the external walls of the fibers with the clarified liquid being drawn from the lumens of the fibers and the concentrated feed being discharged through an outlet. The solids retained within the shell are removed by first applying a pressurized liquid and then applying a gas at a pressure sufficient to ensure that the gas will pass through the larger pores of the fibrs to remove the solids from the shell through the outlet to an external collection point. The fibers are enclosed within a variable volume diaphragm located within a diaphragm holder by spaced plugs. The volume of the diaphragm is altered by varying the pressure of a fluid introduced through the inlet to the space between the diaphragm and the diaphragm holder.

Abstract: A reversed phase analogue of at least part of a first membrane having substantially interconnected pores is formed by first filling at least some of the pores of the first membrane with a fluid that will form the analogue membrane and then forming the analogue membrane in the pores of the first membrane. The first membrane is then removed from the analogue membrane. The structure of the analogue membrane is of different morphology from that of the first membrane and the reversed phase nature arises because it is the pores of the first membrane which lead to the formation of the walls of the reversed phase membrane and it is the walls of the pores of the first membrane which lead to the formation of the pores of the reverse phase membrane.

Abstract: A method of cleaning a filter having a plurality of elastic, porous hollow fibers with lumens within a shell or housing and in which filtration is carried out by applying a liquid suspension feedstock to the outer surface of the fibers whereby a portion of feedstock passes through the walls of the fiber to be drawn from the fiber lumens as a filtrate or permeate, and a portion of the solids in the feedstock are retained on or in the pores of the fibers, with the non-retained solids being removed from the shell or housing with the remainder of the feedstock, said method entailing introducing a pressurized gas into the fiber lumens which passes through the walls of the fibers to dislodge the retained solids, the gas being applied at a pressure which is sufficient to overcome the effect of the surface tension of the continuous phase of the feedstock within the pores of the membrane.

Abstract: A method of increasing the rate the transport of volatiles through porous barriers (13) such as membranes consists of subjecting the porous barriers (13) to a vacuum for sufficient time to remove any permanent gas from the pores (V), admitting a non-wetting liquid through inlet (14) to the barrier (13) either before or during the application of the vacuum whereby the non-wetting liquid forms films or bubbles (16) which seal the pores (V) to create a low pressure region within each pore (V) which is filled with vapor of the non-wetting liquid. The invention may be used to transport volatiles such as ethanol across a membrane and to transfer heat across a membrane.

Abstract: Aliphatic thermoplastic polyamide porous membranes are reacted with an acid halide of basicity above one to provide acid radicals within the membrane. The acid halide may be derived from an aromatic carboxylic acid or an aromatic derivative of a chlorosilane. The substituted aliphatic polyamide porous membrane lend themselves to the preparation of chemical derivatives of the membrane which are not readily available by aqueous synthesis and to increased density of derivatives which otherwise may be prepared by water.

Abstract: A polymeric porous membrane having a matrix made from an aliphatic thermoplastic polyamide or from an aliphatic thermoplastic polyamide/polyimide copolymer which has both relatively non-crystalline and relatively crystalline portions. The pores in the membrane are defined by spaces between the relatively crystalline portions and at least some of the relatively crystalline portions are linked together by the reaction of a bis-aldehyde with the membrane matrix.

Abstract: Water is separated from an oil emulsion containing a surface active agent by passing the emulsion through a polymeric porous membrane cross-flow ultra-filter. Either the oil emulsion feedstock or the membrane is treated with a hydrophilic colloid so that the effective pore size of the composite membrane so formed by the colloid will be reduced as the surface tension falls in the presence of the surface active agent in the oil emulsion. The hydrophilic colloid is selected according to the chemical ionic classification of the surface active agent.

Abstract: This invention relates to a method of forming porous membranes from thermoplastic or polymeric materials and to membranes so formed.

Abstract: Aliphatic thermoplastic polyamide porous membranes are reacted with an acid halide of basicity above one to provide acid radicals within the membrane. The acid halide may be derived from an aromatic carboxylic acid or an aromatic derivative of a chlorosilane. The substituted aliphatic polyamide porous membrane lend themselves to the preparation of chemical derivatives of the membrane which are not readily available by aqueous synthesis and to increased density of derivatives which otherwise may be prepared in water.