POROUS MEMBRANES CONTAINING EXCHANGE RESINS
Articles that include two or more exchange resins in one or more microporous membranes, where the membranes remove oppositely charged impurities from a fluid in contact with the membranes, are disclosed. Methods for using such devices to remove charged impurities from fluid in contact with the membrane are provided.
1 An article comprising:
two or more exchange resins, the exchange resins in one or more porous membranes, the exchange resins remove material of different signed charge from a fluid that contacts the porous membranes.
2 . The article of claim 1 where two or more exchange resins are in separate layers.
3 . The article of claim 1 where the two or more two or more exchange resins are in separate porous membranes.
4 . The article of claim 1 where the material of different signed charge comprises charged ions, charged colloids, charged particles, or combinations including these in the fluid that contact with the porous membranes.
5 . The article of claim 1 where the membrane further removes particles from the fluid by sieving filtration.
6 . The article of claim 1 wherein the membranes are characterized by providing a treated fluid containing a lower concentration of ionic impurities at a temperature of 80° C. or less than a feed fluid.
7 . The article of claim 1 where the membrane is a cast membrane.
8 . The article of claim 1 further including a flow distributor that is a microporous membrane.
9 . The article of claim 1 further comprising a housing, the membranes fixtured to the housing, the housing has an inlet that provides a fluid to the membranes and an outlet for removing fluid from the housing treated by the membranes.
10 . An apparatus for treating substrates comprising the article of claim 1 .
11 . A substrate treated by the apparatus of claim 10 .
12 . A process fluid treated by the article of claim 1 having less than 1000 ppb (v/v) of ionically charged impurity.
13 . The process fluid of claim 12 wherein the ionic impurity comprises iron, aluminum, calcium, copper, or any combination of these.
14 . The article of claim 1 having a third porous membrane.
15 . A method for purifying a fluid comprising:
flowing the fluid through one or more porous membranes, the membranes comprising two or more exchange resins that removes material of different sign from the fluid.
16 . The method of claim 15 where the resin in the porous membranes is a porous ion exchange resin.
17 . The method of claim 15 further comprising flowing the fluid through a third porous membrane.
18 . An article comprising two or more porous membranes, each porous membrane comprising one or more types of porous resin particles that remove charged impurities of different signed charge.
19 . An article comprising:
one or more porous membranes, the membrane comprising a resin that removes material of different sign from a fluid in contact with the membranes.
20 . The article of claim 19 where the material of different sign comprises charged ions, charged colloids, charged particles, or combinations including these in the fluid in contact with the membranes.
21 . The article of claim 19 where the membrane further removes particles from the fluid by sieving filtration.
22 . The article of claim 19 wherein the membranes are characterized by providing a fluid containing less than 1000 ppb of charged impurities at a temperature of 80° C. or less.
23 . The article of claim 19 where the porous membrane is a cast membrane.