Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
  • B01D71/06—Organic material
  • B01D71/58—Other polymers having nitrogen in the main chain, with or without oxygen or carbon only
  • B01D71/62—Polycondensates having nitrogen-containing heterocyclic rings in the main chain
  • B01D71/64—Polyimides; Polyamide-imides; Polyester-imides; Polyamide acids or similar polyimide precursors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/14—Ultrafiltration; Microfiltration
  • B01D61/147—Microfiltration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
  • B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2323/00—Details relating to membrane preparation
  • B01D2323/219—Specific solvent system
  • B01D2323/22—Specific non-solvents or non-solvent system
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2325/00—Details relating to properties of membranes
  • B01D2325/02—Details relating to pores or porosity of the membranes
  • B01D2325/021—Pore shapes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2325/00—Details relating to properties of membranes
  • B01D2325/02—Details relating to pores or porosity of the membranes
  • B01D2325/022—Asymmetric membranes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2325/00—Details relating to properties of membranes
  • B01D2325/04—Characteristic thickness
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
  • B01D67/0002—Organic membrane manufacture
  • B01D67/0009—Organic membrane manufacture by phase separation, sol-gel transition, evaporation or solvent quenching
  • B01D67/0011—Casting solutions therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
  • B01D67/0002—Organic membrane manufacture
  • B01D67/0009—Organic membrane manufacture by phase separation, sol-gel transition, evaporation or solvent quenching
  • B01D67/0016—Coagulation

Definitions

• the invention includes embodiments that relate to membranes. Particularly, the invention includes embodiments that are directed to polyamide-imide membranes, method of making such, and devices using such.
• PAI membranes and methods of making them are known. However, with microfiltration membrane characterization tests (such as bubble points, bacteria retention) and distinction between the various possible polysulfones, PAI membranes are still needed. Strong, chemically inert and heat stable polyamide-imide membranes in the microporous range for removing particles and ions from liquids and fluids are still needed.
• An embodiment of the invention provides a microporous membrane.
• the microporous membrane includes a polyamide-imide polymer, wherein the microporous membrane has a bubble point and an IPA flow-time.
• the microporous membrane has an HFE bubble point from about 25 psi to about 200 psi and an IPA flow-time from about 400 seconds to about 40,000 seconds.
• a second embodiment of the invention provides another membrane.
• the membrane includes a polyamide-imide polymer, wherein the membrane has a bubble point and an IPA flow-time.
• the membrane has an HFE bubble point from about 25 psi to about 200 psi.
• the membrane is microporous; asymmetric and has a tight layer with a thickness of ⁇ 10 microns.
• a third embodiment of the invention provides a filtration device.
• the filtration device includes a filter incorporating a microporous membrane.
• the microporous membrane includes a polyamide-imide polymer, wherein the microporous membrane has a bubble point and an IPA flow-time.
• the microporous membrane has an HFE bubble point from about 25 psi to about 200 psi and an IPA flow-time from about 400 seconds to about 40,000 seconds.
• FIG. 1 is a schematic representation of a membrane in accordance with an embodiment of the invention.
• FIG. 2A and 2B are scanning electronic microscopic (SEM) micrographs of a symmetric membrane in accordance with an embodiment of the invention
• FIG. 3 A and B are SEM micrographs of an asymmetric membrane in accordance with an embodiment of the invention.
• FIG. 4A and 4B are SEM micrographs of another asymmetric membrane in accordance with an embodiment of the invention.
• FIG. 5 A, B, and C are SEM micrographs showing the tight layer evolution in membranes as a function of water concentration in the coagulation bath in accordance with an embodiment of the invention
• FIG. 6A and B are SEM micrographs of a symmetric membrane in accordance with an embodiment of the invention.
• FIG. 7A and B are SEM micrographs of an asymmetric membrane in accordance with an embodiment of the invention.
• FIG. 8 A and B are SEM micrographs of another asymmetric membrane in accordance with an embodiment of the invention.
• FIG. 9A and B are SEM micrographs of another asymmetric membrane in accordance with an embodiment of the invention.
• FIG. 10 is a graph showing retention performance of membranes as a function of monolayer concentration in accordance with an embodiment of the invention.
• FIG. 11 are graphs showing tensile stress and tensile strain of membranes at break of membranes at break in accordance with embodiments of the invention.
• FIG. 12A-D are graphs showing tensile strength of membranes in accordance with embodiments of the invention.
• FIG. 13 is a flow chart of a method of making a membrane in accordance with embodiments of the invention.
• the microporous membrane 100 includes one or more polyamide-imide polymers wherein the microporous membrane 100 has a bubble point and an IPA flow-time. More specifically, the microporous membrane 100 has an HFE bubble point from about 25 psi to about 200 psi and an IPA flow-time from about 400 seconds to about 40,000 seconds.
• the microporous membrane 100 has an open pore 12 structure and the pores 12 are interconnected allowing liquid or gas filtration.
• Test methods described herein may be used to characterize the bubble point and flow time of the membranes as well as the test conditions for these values.
• the bubble point used to characterize the membranes 100 refers to a mean bubble point using an air flow porisometer.
• ASTM F316 - 03(2011 ) Standard Test Methods for Pore Size Characteristics of Membrane Filters by Bubble Point and Mean Flow Pore Test were used to calculate bubble point.
• microporous membrane bubble points refer to a mean bubble point measured by an HFE-7200 (available from 3MTM, St. Paul, MN).
• HFE-7200 bubble points can be converted into IPA bubble point values by multiplying the HFE-7200 value measured bubble point by 1.5.
• HFE-7200 by 3MTM is ethoxy-nonafluorobutane and has a reported surface tension of 13.6 mN/m at 25°C.
• IPA flow time is the time to flow 500 milliliters of isopropyl alcohol, at a temperature of 21°C and pressure of 97,900 Pa (about 0.1 MPa, or about 1 bar, or about 14.2 psid), through a 47 millimeter disk of the microporous membrane with an area of 12.5 cm .
• embodiments of the inventions include microporous membranes 100 with varying HFE bubble points.
• the HFE bubble point ranges from about 25 pounds per square inch pressure to about 150 pounds per square inch pressure.
• the HFE bubble point ranges from about 53 pounds per square inch pressure to about 99 pounds per square inch pressure.
• the HFE bubble point ranges from about 38 pounds per square inch pressure to about 75 pounds per square inch pressure.
• the HFE bubble point ranges from about 32 pounds per square inch pressure to about 38 pounds per square inch pressure.
• Embodiments of the invention include microporous membranes 100 with various ranges of IP A flow times.
• the IP A flow time ranges from about 4225 seconds to about 7535 seconds.
• the IPA flow time ranges from about 4090 seconds to about 5580 seconds.
• the IPA flow time ranges from about 3445 seconds to about 4225 seconds.
• the IPA flow time ranges from about 2860 seconds to about 3445 seconds.
• NMP stands for N-methyl-2-pyrrolidone
• EG for ethylene glycol
• TEG for tri-ethylene glycol
• Another embodiment includes a microporous membrane 100 with an HFE bubble point between 25 psi and 32 psi and an IPA flow time between 2860 seconds and 3445 seconds.
• Another embodiment of the microporous membrane 100 includes an HFE bubble point between 32 psi and 38 psi and an IPA flow time of between 3445 seconds and 4245 seconds.
• Yet another embodiment of the microporous membrane 100 includes an HFE Bubble point between 38 psi and 75 psi and an IPA flow time between 4245 seconds and 5580 seconds.
• Another embodiment includes a microporous membrane 100 with an HFE bubble point between 53 psi and 99 psi and an IPA flow time between 4090 seconds and 7535 seconds.
• microporous membranes 100 that are symmetric as in FIG. 2A or asymmetric as in FIG. 3A.
• Symmetric membranes refer to porous membranes where the pore 12 size and/or structure are
• asymmetric refers to a porous membrane in which the pore 12 size and/or structure are not the same from one side of the membrane to the other side as in FIGs. 3-4.
• the asymmetric microporous membranes 100 have a tight layer 10 (bottom) and an open layer 20 (top).
• the polyamide-imide (PAI) polymer dope formulation includes one or more polyamide-imide (PAI) polymers, one or more solvents, and one or more non-solvents.
• PAI polyamide-imide
• a particular embodiment of the PAI polymer dope formulation includes N- methylpyrrolidone (NMP) as the solvent, ethylene glycol (EG) as a non-solvent, and polyamide-imide polymer.
• the membrane 100 also includes the reaction product of the one or more solvents with each other, the reaction product of the one or more non-solvents with the each other, the reaction product of the one or more PAI polymers with each other, and the reaction product of the one or more solvents, one or more non-solvents, and one or more PAI polymers with each other.
• FIG. 2A and FIG. 2B are SEM micrographs showing cross-sectional
• Torlon® was used as the polyamide-imide polymer (PAI).
• PAI polyamide-imide polymer
• FIG. 3 A and FIG. 3B. are SEM micrographs of an asymmetric membrane 100 of another embodiment of the invention, made according to Example lb of Table 1, with a tight layer 10 (located beneath the dashed white line) of about ⁇ 5 microns (NMP/water (75/25 weight %) and an open layer 20 (located above the dashed white line).
• FIG. 3B is a cross- sectional magnification of FIG. 3 A showing the asymmetrical nature of the membrane 100 with the tight layer 10 and the open layer 20.
• FIG. 4A and FIG. 4B are SEM micrographs showing cross-sectional
• FIG. 4B is a cross- sectional magnification of FIG. 4 A showing the asymmetrical nature of the membrane 100 with the tight layer 10 and the open layer 20.
• FIG. 5A-C are SEM micrographs showing the tight layer evolution in membranes 100 as a function of water concentration in the coagulation bath through Examples la-lc in Table 1.
• FIG. 5 A-C show effects of increasing the water concentration in an external coagulation bath in embodiments of the invention. As demonstrated in FIG.
• FIG. 5A-C the thickness of the tight layer 10 increases as the amount of water in the coagulation bath increases.
• FIG. 5A is a symmetric membrane in (NMP/Water (80/20) weight %).
• FIG. 5B is an asymmetric membrane with a thickness of the tight layer 10 (beneath the dashed white line) of about ⁇ 5 microns (NMP/Water (75/25 weight %); and
• FIG. 5C is an asymmetric membrane with a thickness of the tight layer 10 (beneath the dashed white line) about ⁇ 10 microns (NMP/water (70/30 weight %).
• the thickness of the tight layer 10 increases as the amount of water in the coagulation bath increases.
• Another embodiment of asymmetric membrane 100 includes a tight layer 10 with a thickness of about ⁇ 8 microns.
• Examples 2a-2d are other examples with dope formulations differing from
• FIG. 6A and 6B are SEM micrographs of an embodiment of a symmetric membrane 100 of Example 2a. The FIG. 6B magnification shows the symmetrical nature of the membrane 100 and an absence of a tight layer.
• FIG. 7A and 7B are SEM micrographs of an embodiment of an asymmetric membrane 100 of Example 2b with a tight layer 10 (above the dashed white line) having a thickness about ⁇ 5 microns.
• FIG. 7B is a cross-sectional magnification of FIG. 7A showing the asymmetrical nature of the membrane 100 with the tight layer 10 and the open layer 20.
• FIG. 8A and B are SEM micrographs of another embodiment of an
• FIG. 8B is a cross-sectional magnification of FIG. 8A showing the asymmetrical nature of the membrane 100 with the tight layer 10 and the open layer 20.
• FIG. 9A and 9B are SEM micrographs of an asymmetric membrane 100 of
• Example 2d with a tight layer 10 (above the dashed white line) having a thickness about ⁇ 10 microns.
• FIG. 9B is a cross-sectional magnification of FIG. 9A showing the asymmetrical nature of the membrane 100 with the tight layer 10 and the open layer 20.
• the HFE bubble point of the membrane 100 increased as the amount of water in the coagulation bath increased as shown in Table 1. It should be appreciated that is it within the scope of invention to make microporous membranes 100 with a combination of one or more parameters such as range of IP A flow times, HFE bubble points, as well as varying the amount of water in the coagulation bath, etc.
• Another embodiment of the membrane 100 includes one or more polyamide-imide polymers, wherein the membrane 100 has an HFE bubble point from about 25 psi to about 200 psi.
• the membrane is asymmetric-and microporous and has a tight layer that has a thickness of ⁇ 10 microns.
• the membrane 100 also has an IPA flow time in a range from about 400 seconds to about 40,000 seconds.
• the microporous membrane 100 is not limited by its form or shape unless expressly stated and includes membranes of varying shape, form, and morphology unless expressly limited by the specification.
• the membrane 100 includes pleated form.
• the membrane 100 includes hollow fiber.
• the membrane 100 is in the form of flat films.
• the membrane 100 includes composite form.
• microporous membranes 100 can be incorporated in filtration or purification housings.
• An embodiment of the invention provides a filtration device 300 as shown in FIG. 1.
• the filtration device includes one or more filters 200 incorporating a microporous membrane 100.
• the microporous membrane includes polyamide-imide polymer, has an HFE bubble point, and an IPA flow-time.
• the microporous membrane has an HFE bubble point from about 25 psi to about 200 psi and has an IPA flow- time from about 400 seconds to about 40,000 seconds.
• the microporous membranes 100 can be pleated and bonded, including potting, to form integral devices that permit filtration and purification of liquids and other fluids that pass through the membrane in the housing.
• the membranes can be hollow fibers and incorporated to a housing to form integral devices that permit filtration and purification of liquids and other fluids that pass through the membrane in the housing.
• Step 1310 includes providing polyamide-imide (PAI) polymer dope formulation.
• the polyamide-imide (PAI) polymer dope formulation includes one or more polyamide-imide (PAI) polymers, one or more solvents, and one or more non-solvents.
• the polyamide-imide (PAI) polymer dope formulation includes N- methylpyrrolidone (NMP) as the solvent, ethylene glycol (EG) as a non-solvent, and polyamide-imide polymer in a ratio range of 79(NMP)/8(EG)/13(PAI) weight% to 75(NMP)/12(EG)/13(PAI) weight%.
• the dope formulation includes a plurality of polyamide- imides which differ from each other.
• the plurality of polyamide-imides may have various characteristics which are similar or vary from each other.
• the pluralities of differing polyamide-imides are in various ranges.
• the dope formulation includes a plurality of solvents which are similar or vary from each other.
• the pluralities of differing solvents are in various ranges.
• the dope formulation includes a plurality of non-solvents which are similar or vary from each other. In one embodiment, the plurality of differing non- solvents are in various ranges.
• Step 1320 includes phase separating the polyamide-imide (PAI) polymer dope formulation with a coagulant.
• the coagulant includes NMP and water in a ratio of
• FIG. 10 is a graph showing retention performance of the membranes 100 as a function of monolayer concentration.
• Ninety mm coupon membranes were challenged with an aqueous solution containing 8ppb G25 PSL particles with 0.1 % Triton X-100 surfactants. Samples of the permeate were collected at different time intervals corresponding to different monolayer coverage of the membrane surface. The permeate samples were analyzed afterwards to measure the concentration of the G25 particles in the permeate sample and the corresponding membrane retention.
• the double layer polyamide-imide polymer membrane 100 was laminated together in a configuration in which the tight layer 10 sides of the respective membranes 100 are in contact with each other.
• embodiments of the invention include a plurality of layers, and each layer in independent configuration with a given contact layer. For example: two other configurations include an open layer 20 of one membrane 100 in contact with a tight layer 10 of another membrane 100 and an open layer 20 of one membrane 100 in contact with an open layer 20 of another membrane 100.
• FIG. 11 are graphs comparing the tensile stress at break and tensile strain at break.
• a control, polyamide-imide polymer membrane 100 made according to Example 2c, and similar membranes were soaked in different solvents including cyclohexanone, n-butyl ⁇ ⁇ acetate (nBA), Propylene glycol mono-methyl ether (PGME), propylene glycol mono-methyl ascetate (PGMEA), OK73 (70% PGME, 30% PGMEA), dilute (2%) hydrofluoric acid (HF) for 3 weeks.
• the sample membranes were cut in l"x4.5" dimensions and soaked in the solvents for three weeks. Later the membranes were immersed in isopropyl alcohol (IP A) for a few minutes and then dried in air. The dried samples were tested for tensile strength using an InstronTM Model 3342 Compression / Tensile instrument.
• IP A isopropyl alcohol
• FIG. 12 are also graphs showing tensile strength.
• the polyamide-imide membrane made by method explained in Example 2c was thermally cross-linked by heating at 250 ' C inside an oven for 6 hours.
• the cross-linked and non-cross linked membranes were soaked in 10% HCl solution for three weeks and then dried in air.
• the HCl treated membranes and the control membrane were tested for tensile strength using the method explained earlier.
• the membranes 100 made through embodiments of the invention also have nonsieving ion removal capability, which can be used for impurity removal from a variety of liquids, such as but not limited to, the semiconductor manufacturing field.
• the microporous polyamide-imide membrane 100 was challenged with cyclohexanone containing at least 48.8 ppb of sodium, 1.2 ppb magnesium, 0.79 ppb of aluminum, 3.7 ppb of potassium, 45.7 ppb of calcium, 0.07 ppb Titanium, 27.9 ppb chromium, 2.3 ppb of iron, and 1.38 ppb of zinc.
• the membrane 100 had a metal capacity above a control cleaned membrane of at least 31 nanograms per centimeter squared of membrane area for sodium.
• the membrane 100 had a metal capacity above the control cleaned membrane of at least 14 nanograms per centimeter squared of membrane area for magnesium.
• the membrane 100 had a metal capacity above the control cleaned membrane of at least 1.5 nanograms per centimeter squared of membrane area for aluminum. In another embodiment, the membrane 100 had a metal capacity above the control cleaned membrane of at least 8.7 nanograms per centimeter squared of membrane area for potassium. In another embodiment, the membrane 100 had a metal capacity above the control cleaned membrane of at least 95 nanograms per centimeter squared of membrane area for calcium. In another embodiment, the membrane 100 had a metal capacity above the control cleaned membrane of at least 1 nanogram per centimeter squared of membrane area for titanium. In another embodiment, the membrane 100 had a metal capacity above the control cleaned membrane of at least 2.8 nanograms per centimeter squared of membrane area for chromium. In another embodiment, the membrane 100 had a metal capacity above the control cleaned membrane of at least 1 nanogram per centimeter squared of membrane area for iron. In another embodiment,
• the membrane 100 had a metal capacity above the control cleaned membrane of at least 5.9 nanograms per centimeter squared of membrane area for zinc.
• the membrane 100 had a metal capacity above a control cleaned membrane for one or more metals, either individually or a combinations of two or more thereof when challenged with cyclohexanone containing at least 48.8 ppb of sodium, 1.2 ppb magnesium, 0.79 ppb of aluminum, 3.7 ppb of potassium, 45.7 ppb of calcium, 0.07 ppb Titanium, 27.9 ppb chromium, 2.3 ppb of iron, and 1.38 ppb of zinc.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Water Supply & Treatment (AREA)
• Separation Using Semi-Permeable Membranes (AREA)
• Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)

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• 2014
  • 2014-11-14 US US15/032,833 patent/US10532329B2/en active Active
  • 2014-11-14 WO PCT/US2014/065699 patent/WO2015073820A1/en not_active Ceased
  • 2014-11-14 JP JP2016530977A patent/JP6653649B2/ja active Active
  • 2014-11-14 TW TW103139535A patent/TWI658070B/zh active
• 2019
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