Exxon Research and Engineering Company

Adam L Shrier

Norman N Li

Robert P Cahn

William J Asher

This invention relates to a process for the removal of dissolved species from aqueous solutions, which comprises contacting said aqueous solution with an emulsion, said emulsion comprising an exterior phase which is characterized as being immiscible with said aqueous solution and yet permeable to said dissolved species, and an interior phase which contains a reactant capable of converting said dissolved species to a nonpermeable form. The dissolved species permeate the exterior phase, into the interior phase where they are converted into nonpermeable forms and thus retained in the interior phase of said emulsion. The aqueous solution, depleted in said dissolved species, is separated from said emulsion and the emulsion cycled for reuse. In one preferred embodiment said dissolved species are ions, and an ion exchange compound is incorporated in the exterior phase of the emulsion, to promote the permeation of said ions through the exterior phase.

Water in oil emulsions useful in liquid membrane

In a liquid membrane process for removing ions from solution which comprises contacting a feed solution containing a first ion with an emulsion, said emulsion comprising an external phase which is immiscible with said solution and contains a complexing agent, said complexing agent being capable of forming a first complex with said first ion, which is soluble in said external phase, and an internal phase, the improvement which comprises providing a second ion, in the internal phase, of the emulsion, said second ion being capable of converting said first complex to a second complex by replacing said first ion in said first complex, said second complex being also soluble in said external phase, whereby the first ion diffuses from said solution into said internal phase, and said second ion diffuses from said internal phase into said solution. More particularly, the instant invention comprises maintaining the concentration of the second ion, in the feed solution, at a sufficiently low level to allow formation of the first complex at the interface of the external phase of the emulsion and the solution, and maintaining the concentration of the second ion, in the internal phase of the emulsion at a concentration, sufficiently high, to convert said first complex into a second complex. Preferably, the first ion is a metal ion--for example, copper, or a complex ion, such as H.sub.g Cl.sub.4 =comprising a metal constituent and said second ion is either hydrogen or hydroxyl ion.

Use of liquid membrane systems for selective ion transfer

This invention relates to the use of liquid membrane technology in preparing medicinals. The medicinals prepared by this invention may be ingested and may be utilized as traps for toxins present in the GI (gastrointestinal) tract, or as slow-release compositions of drugs, or as reactors. In the trap embodiment, the liquid membrane encapsulated medicinal is an emulsion comprising an exterior phase which is immiscible with the liquids present in the GI tract and permeable to the toxins therein, and an interior phase which is immiscible with the exterior phase and comprises a reagent capable of converting said toxin into a nonpermeable form. In addition, hydrophilic adsorbents, such as a hydrophilic carbon or a silica gel, may be encapsulated in the emulsions of the instant invention. When the compositions of the instant invention are utilized as slow-release drugs, the interior phase of the emulsion will comprise a drug which is slightly soluble in the exterior phase of the emulsion whereby said drug permeates through said exterior phase of the emulsion over a period of time into the GI tract. The third method for utilizing the compositions of the instant invention comprises encapsulating a catalyst for a reaction which is desired to be carried out in the GI tract. In this embodiment the reactants present in the GI tract permeate through the exterior phase of the emulsion into an interior phase wherein said catalyst, for example, an enzyme, converts the permeated reactants to reaction products. The reaction products then may permeate through the exterior phase back into the GI tract. In all cases, the liquid membrane encapsulated medicinals may be administered by either oral ingestion or injection anywhere else into the GI tract.

Detoxifying-medicinal emulsions

A process for preparing reactive products which comprise two or more relative components is described. Said process comprises emulsifying at least one reactant in a first liquid which is substantially impermeable to all of the reactants, forming droplets of said emulsion, and suspending said droplets in a second liquid which is immiscible with said first liquid and which forms an immiscible continuous liquid phase, which comprises the remaining reactants. Preferably, the emulsion and the continuous liquid phase density are adjusted to be substantially equal so that a nonsettling product is obtained. In a most preferred embodiment, the reactive product comprises a two-component adhesive system, i.e., an epoxy resin and an amine hardener, said epoxy resin and amine hardener are maintained separate from each other by the exterior phase of an emulsion, the interior phase comprising the hardener, and the continuous phase, wherein said emulsion is suspended, comprising the epoxy resin. The adhesive product is applied to the objects, which are joined, by processes known in the art, i.e., spraying, dipcoating, etc., and the emulsion broken by heat and/or pressure, whereby the epoxy and the hardener mixes and forms a reaction product consisting of a copolymer of the epoxy resin and the amine hardener.

Liquid membrane encapsulated reactive products

The instant invention relates to an improvement in the liquid membrane process for removing soluble materials from solution. More specifically, in a process wherein soluble materials are removed from solution by contacting said solution with an emulsion, the external phase of which is immiscible with said solution and permeable to said soluble materials and the internal phase contains a reactant which reacts with said soluble material and converts said soluble material to a material which is insoluble and thus trapped in the internal phase, the improvement which comprises maintaining the concentration of said reactant in the internal phase of the emulsion at a level at which the concentration of said soluble material in the internal phase of the emulsion is less than the concentration to which it is desirable to lower said soluble material in said solution. Preferably the solution is aqueous and said soluble material is a salt. In a preferred embodiment of the instant invention the concentration of fluoride ion in an aqueous solution is lowered to less than 6 ppm by contacting said solution with an emulsion containing a soluble calcium salt in the internal phase. The concentration of calcium in said internal phase is maintained at a level sufficient to provide a concentration of less than 6 ppm soluble fluoride ion in said internal phase.

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Montclair, NJ, United States of America

Adam L Shrier