Articles including homogenous pore membranes disposed on porous substrates and methods of making same

Abstract

The invention relates to an article comprising a homo-porous membrane disposed on a porous substrate and a method of making the same. In particular, the present disclosure provides an article comprising a homo-porous membrane disposed on a porous substrate. The homo-porous membrane comprises a triblock copolymer or a penta-block copolymer. The homo-porous membrane has a thickness and is homo-porous throughout its thickness. Also provided is a method of making an article that does not require a solvent exchange process. The method includes depositing the composition on a porous substrate, thereby forming a film, and removing at least a portion of the solvent from the film, thereby forming a homo-porous film having a plurality of pores. The composition comprises a solvent and a solid, the solid comprising a triblock copolymer or a penta-block copolymer. The article can advantageously be hydrophilic and provide a sharp molecular weight cutoff and high throughput.

Description

[0001] This patent application is a continuation-in-part of patent application number PCT / IB2020 / 061634, international filing date December 8, 2020, entering the Chinese national phase as application number 202080086953.8, having the invention title “Article Including an Isotropic Membrane Disposed on a Porous Substrate and Methods of Making the Same”. TECHNICAL FIELD

[0002] The present invention relates to an article including an isotropic membrane disposed on a porous substrate and methods of making the same. In particular, the present disclosure provides an article including an isotropic membrane disposed on a porous substrate. The isotropic membrane comprises a triblock copolymer or a pentablock copolymer. The isotropic membrane has a thickness and is isotropic throughout its thickness. Also provided is a method of making the article that does not require a solvent exchange process. The method includes depositing a composition on a porous substrate, thereby forming a membrane, and removing at least a portion of the solvent from the membrane, thereby forming an isotropic membrane having a plurality of pores. The composition comprises a solvent and a solid, the solid comprising a triblock copolymer or a pentablock copolymer. The article advantageously can be hydrophilic and provides a sharp molecular weight cutoff and high flux. BACKGROUND

[0003] Porous materials are materials having a porous structure that enables fluids to readily pass through them. Porous membranes are suitable for use in a wide range of applications, including use in the filtration of fluids to remove solid particulates, use in ultrafiltration to remove colloidal material from fluids, use as diffusion barriers or separators in electrochemical cells, and use in gas separation and pervaporation. Porous membranes have also been used to filter antibiotics, beer, oil, bacterial fermentation broth, and for analyzing air, microbiological samples, intravenous fluids, and vaccines. Further advances in porous membranes would be desirable. SUMMARY

[0004] The present disclosure provides an article including an isotropic membrane and a method of making the article.

[0005] In a first aspect, an article is provided. The article includes an isotropic membrane disposed on a porous substrate. The isotropic membrane comprises a triblock copolymer or a pentablock copolymer. The isotropic membrane has a thickness and is isotropic throughout its thickness.

[0006] In a second aspect, a method of making an article is provided. The method includes a) depositing a composition on a porous substrate, thereby forming a membrane; and b) removing at least a portion of the solvent from the membrane, thereby forming an isotropic membrane having a plurality of pores. The composition comprises a solvent and a solid, the solid comprising a triblock copolymer or a pentablock copolymer. The isotropic membrane has a thickness and is isotropic throughout its thickness.

[0007] Specifically, due to the uniform porosity of the uniform pore membranes, the articles have the potential to show flux and size exclusion improvements at a given pore size, in contrast to porous membranes having a broad pore size distribution. In addition, some methods advantageously do not require the use of solvent exchange phase inversion steps, such as used in solvent induced phase separation (SIPS). Additional features and advantages of the present disclosure will be further understood by consideration of the detailed description and appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1A Scanning electron microscope (SEM) image of a surface of the article of Example 77 at 30,000x magnification.

[0009] Figure 1B SEM image of a cross-section of the article of Example 77 at 70,000x magnification.

[0010] Figure 2A Atomic force microscope (AFM) topography image of a surface of the article of Example 90.

[0011] Figure 2B AFM topography image of a surface of the article of Example 93.

[0012] Figure 3A AFM topography image of a surface of the article of Example 96.

[0013] Figure 3B AFM topography image of a surface of the article of Example 100.

[0014] Figure 4A AFM phase image of a surface of the article of Example 102.

[0015] Figure 4B SEM image of a surface of the article of Example 102 at 70,000x magnification.

[0016] Figure 5A AFM height image of a surface of the article of Example 150.

[0017] Figure 5B AFM height image of a surface of the article of Example 151.

[0018] Figure 6 AFM height image of a surface of the article of Example 154.

[0019] Figure 7 SEM image of a surface of the article of Example 155 at 70,000x magnification.

[0020] Figure 8 AFM height image of a surface of the article of Example 156.

[0021] Figure 9 AFM height image of the surface of the article of Example 157.

[0022] Figure 10 SEM image of the surface of the article of Example 158 at 30,000x magnification.

[0023] While the above drawings set forth embodiments of the disclosure, other embodiments are also contemplated, as noted in the description. The drawings are not necessarily to scale, as can be apparent from the detailed description. Not all features of each illustration are necessary for understanding the present disclosure. In all cases, the present disclosure is introduced by way of example only. DETAILED DESCRIPTION

[0024] The present disclosure generally provides thin film composite articles comprising a uniform pore membrane disposed on a porous support substrate. The articles exhibit one or more advantageous properties of flexibility, durability, hydrophilicity, and / or a selectively uniform pore active layer. The more uniform the uniform pores of the membrane, the sharper the molecular weight cutoff curve will be when filtering solutes through the article.

[0025] In a first aspect, an article is provided, the article comprising: a uniform pore membrane disposed on a porous substrate, the uniform pore membrane comprising a triblock copolymer or a pentablock copolymer, wherein the uniform pore membrane has a thickness and is uniform-pored throughout the thickness.

[0026] In a second aspect, a method of making an article is provided, the method comprising: a) depositing a composition on a porous substrate, thereby forming a membrane, the composition comprising a solvent and a solid, the solid comprising a triblock copolymer or a pentablock copolymer; and b) removing at least a portion of the solvent from the membrane, thereby forming a uniform pore membrane comprising a plurality of pores, wherein the uniform pore membrane has a thickness and is uniform-pored throughout the thickness.

[0027] The following disclosure relates to both the first aspect and the second aspect.

[0028] As used herein, the term "isoporous" means having substantially the same pore size. It has been found that isoporous membranes can be formed on porous substrates, where the isoporous membranes are isoporous throughout the thickness of the deposited membrane. In contrast, previous isoporous membranes formed on porous substrates have been isoporous at one major surface and possibly partially through the thickness of the membrane, but a portion of the thickness disposed on the porous substrate is not isoporous. For example, Yu et al. in "Asymmetric block copolymer membranes with ultrahigh porosity and hierarchical pore structure by plain solvent evaporation" (Chem. Commun. 2016, 52, 12064-12067) describe the formation of flexible membranes having "a thin top layer with highly ordered... and uniform pores on top of a sponge-like microporous layer." Similarly, patent application publication DE102012207344A1 (Volkan et al.) discloses the formation of membranes having an isoporous layer that directly transitions into a sponge-like structure produced by immersion in a precipitation bath. Hahn et al. also disclose in "Thin Isoporous Block Copolymer Membranes: It is All about the Process" (ACS Appl. Mater. Interfaces 2015, 7, 21130-21137) that "to fully exploit the potential of the narrow pore size distribution and high porosity on the surface layer of block copolymer membranes, we should reduce the thickness and density of the substructure." Hahn et al. report the formation of membranes having an average thickness of 1-3 micrometers. A method of forming a block copolymer (BCP) membrane having nanochannels throughout formed from diblock copolymers is described by Ma et al. in "Block copolymer ultrafiltration membranes by spray coating coupled with selective swelling" (Journal of Membrane Science (2019), doi: https: / / doi.org / 10.1016 / j.memsci.2019.117656).Ma et al. disclose "The BCP-coated support is then soaked in hot ethanol to create nanoporosity in the BCP layer in compliance with the mechanism of pore generation induced by selective swelling."

[0029] However, it was unexpectedly discovered that the method according to the present disclosure forms a uniform-porosity membrane across its thickness, rather than a uniform-porosity having (e.g., sponge-like) substructure. More specifically, it has been discovered that capillary action can be utilized to help form a thin uniform-porosity membrane on a porous support substrate, where the uniform-porosity membrane lacks substructure that is not uniform-porosity. By quickly removing the solvent through wicking into the porous substrate, it helps to cause rapid concentration of the block copolymer particles at the surface of the porous substrate and formation of a uniform-porosity membrane across its thickness. It was discovered that thin coatings of compositions (e.g., dispersions) from tri- or pentablock copolymers would exhibit this phenomenon, while thicker coatings would not. It was also shown that when an equivalent solution was coated onto a dense substrate that could not wick, the uniform-porosity structure seen when coated on a porous substrate could not be obtained. Without wishing to be bound by theory, it is believed that each support substrate has its own fluid capacity limit, once that limit is reached it will slow the wicking of the solvent, and for higher thicknesses, capillary action cannot affect the solvent system at the top surface of the thick coating. It is also possible that an amount of solvent is removed via evaporation from the composition, but it appears that wicking occurs so quickly that the wicking effect dominates the formation of the membrane. The uniform-porosity in the structure formed due to capillary removal of the solvent was not found to be adversely affected by the presence of solvent present in the pores of the support substrate and remained intact as the residence time was short using solvents with low boiling points, high vapor pressure (e.g., exhibiting rapid evaporation) or if a high boiling point solvent was used (e.g., exhibiting slow evaporation) was quickly immersed in water. In some embodiments, the method can further include washing the high boiling point residual solvent from the uniform-porosity membrane and the porous substrate using a non-solvent (e.g., water). This can be useful as certain solvents can begin to rearrange the block copolymer orientation and / or degrade the structure of the uniform-porosity membrane if allowed to remain in the article.

[0030] Accordingly, the method of the present disclosure preferably includes removing the solvent by wicking the solvent into the porous substrate. In any method of the present disclosure, removing the solvent from the composition deposited on the porous substrate includes wicking, and further includes optionally evaporating at least a portion of the solvent for a time of 1 second or more, 5 seconds or more, 10 seconds or more, 15 seconds or more, 20 seconds or more, 25 seconds or more, or 30 seconds or more; and for a time of 600 seconds or less, 500 seconds or less, 400 seconds or less, 300 seconds or less, 200 seconds or less, 100 seconds or less, 80 seconds or less, 60 seconds or less, 50 seconds or less, or 40 seconds or less. It should be noted that complete drying (e.g., evaporation) of the solvent from the article can take more than 24 hours.

[0031] In any of the methods of the present disclosure, the solids of the composition are present in an amount of 0.1 percent by weight (wt%) or greater, 0.2 wt% or greater, 0.3 wt% or greater, 0.4 wt% or greater, 0.5 wt% or greater, 1.0 wt% or greater, 1.5 wt% or greater, or 2.0 wt% or greater of the total composition; and 7 wt% or less, 6 wt% or less, 5 wt% or less, 4 wt% or less, or 3 wt% or less of the total composition.

[0032] Optionally, the solids further comprise at least one additive, which is present in the block copolymer solution or intentionally added to the composition. For example, such additives can comprise, for example, but not limited to, one or more of a homopolymer, a two-block polymer, or a three-block polymer, in an amount ranging from 1 wt% to 49 wt% of the total solids, inclusive.

[0033] In any of the methods of the present disclosure, the composition containing the three- block copolymer or the five-block copolymer is cast onto the porous substrate using a bar gap height of 1 micron or greater, 12.5 microns or greater, 15 microns or greater, 25 microns or greater, 35 microns or greater, 50 microns or greater, or 60 microns or greater; and a bar gap height of 100 microns or less, 88 microns or less, 85 microns or less, 75 microns or less, or 65 microns or less.

[0034] As an alternative to casting, the composition containing the three-block copolymer or the five-block copolymer can be deposited onto the porous substrate using electrospray deposition or inkjet printing. Each of the electrospray deposition and the inkjet printing can independently deposit the composition at a thickness of 20 nanometers to 1000 nanometers, inclusive. One suitable electrospray deposition apparatus is described in Chowdhury et al., “3D Printed Polyamide Membranes for Desalination,” Science, Vol. 361, No. 6403, pp. 682-686 (2018). In general, inkjet printing provides a drop spacing of 360 drops per square inch to 1200 drops per square inch, inclusive (21.2 drops per square micrometer to 70.5 drops per square micrometer), and a drop volume of 1 picoliter to 70 picoliters (pL). One suitable inkjet printer is available under the trade designation “DIMATIX MATERIALS PRINTER” from FUJIFILM Dimatix, Inc., Santa Clara, CA.

[0035] As noted above, traditional methods for producing uniform pore membranes using SIPS have been reported. In this method, a block copolymer solution is cast into a wet film, subjected to an evaporation step in which the block copolymer concentration in the film is increased, and quenched in an aqueous non-solvent bath to precipitate the polymer and form a porous solid film. As a result of the traditional SIPS process utilizing block copolymers, the resulting film forms a uniform pore surface structure supported by a non-uniform pore sponge layer of the same material.

[0036] Traditional SIPS phase inversion methods typically use high concentrations of polymer in the casting solution, such that about 10 wt% - 30 wt% is comprised of polymer. Due to the high concentration of polymer, the viscosity of the casting solution is typically high. The coating solution is almost always formulated to yield a uniform single phase solution. "The casting solution must be viscous (equal to or greater than 10^4 cps) to maintain integrity upon immersion in the non-solvent." (Synthetic Polymer Membranes A Structural Perspective, 2nd Edition, Robert E Kesting, John Wiley and Sons, 1985).

[0037] The methods of the present disclosure differ from traditional SIPS processes. The thin film composite is produced by depositing a composition containing less than 7 wt% block copolymer onto a porous substrate. When deposited on a porous substrate, the block copolymer coalesces into a film at or near the surface of the porous substrate, as opposed to conformally coating the porous substrate. Despite the lower content of block copolymer relative to traditional SIPS, the coating composition is formulated to produce a minimal mixture of free polymer chains and a majority of colloidal block copolymer particles such as polymer micelles or polymer aggregates, with the volume of polymer free chains being substantially minimal and the volume of polymer particles being increased relative to the cast solution used for traditional SIPS with block copolymer, as determined by suitable analytical methods such as dynamic light scattering (DLS). A composition according to the present disclosure is considered to be a dispersion if it contains 20 volume percent (vol%) or more of total block copolymer present as particles, such as 25 vol% or more, 30 vol% or more, 35 vol% or more, 40 vol% or more, 45 vol% or more, 50 vol% or more, 55 vol% or more, 60 vol% or more, 65 vol% or more, 70 vol% or more, or 75 vol% or more of total block copolymer present as particles in the composition; and 100 vol% or less, 99.9 vol% or less, 99.5 vol% or less, 99 vol% or less, 95 vol% or less, or 90 vol% or less of total block copolymer present as particles in the composition. Preferably, a dispersion contains greater than 50 vol% of total block copolymer as particles (i.e., a majority).

[0038] The depositing (e.g., casting) compositions useful in these methods are generally scattering of visible light and appear hazy or cloudy by visual inspection, or if the composition appears clear or transparent, will scatter light from a red laser. See, for example, page 411, Figure 13.2 and throughout Chapter 13 of Physical Properties of Colloids and Solutions, General Chemistry Principles and Structure (5thEdition, John Wiley & Sons, Inc., James E. Brady, 1990) demonstrating the Tyndall effect. Surprisingly, it was discovered that when incorporating triblock and pentablock copolymers of one or more hydrophilic blocks in low solids, low viscosity compositions for application to a porous substrate, uniform pore membranes were readily formed. This is surprising at least because the guidelines for traditional SIPS membrane generation and uniform pore formation were not followed. More specifically, when starting from a dispersion (e.g., micelles or micellar aggregates in a solvent) rather than from a block copolymer largely dissolved in solution, improved uniform pore membrane formation was discovered. In some embodiments, advantages of the methods of the present disclosure include very dilute compositions (e.g., dispersions) that do not require low boiling point solvents, do not require evaporation of solvents, do not require a delay prior to a water wash step, and can eliminate the water immersion step of traditional SIPS.

[0039] As used herein, a "block copolymer dispersion" is a mixture of polymers in which the block copolymer is dispersed microscopically as insoluble or partially soluble particles uniformly suspended in the entire solvent. It should be understood that the term "solvent" refers to a single solvent and combinations of two or more solvents unless otherwise specified. The block copolymer dispersion is preferably not sedimented. Dynamic light scattering (DLS) can be used to determine whether the block copolymer is present as free chains, micelles, or aggregates. Preferably, the majority of the solids in the dispersion according to the present disclosure are present in the form of micelles or micellar aggregates.

[0040] Because the dispersion contains aggregates and micelles dispersed in a liquid, the particles will not diffuse through a porous substrate having a pore size smaller than the size of the particles due to size exclusion mechanisms. In contrast, for a solution, the dissolved copolymer molecules will more readily diffuse through the porous membrane. The larger the size of the particles, the larger the pores of the support membrane that can be used to induce rapid concentration of the block copolymer in the (e.g., cast) membrane. This rapid solvent removal by capillary action of the support substrate favors the formation of uniform pores during the coating process.

[0041] The processes described herein allow films to be formed from materials that are not amenable to SIPS. For example, block copolymer materials containing hydrophilic blocks (e.g., polyethylene oxide) that would be soluble in water as homopolymers can undergo gelation rather than precipitation and thus would not form films by traditional SIPS methods. However, by forming thin film composites from solvents that can be readily removed by evaporation, precipitation is no longer a necessary step to organize the film structure and a uniform pore structure can be formed. The exact mechanism is not known, but coalescence and packing of the block copolymer occurs during one or more of the steps of concentration, (optional) residual solvent washing, or drying, forming a uniform pore film.

[0042] Another situation where the process can be more beneficial than traditional SIPS is for polymer systems that begin to gel at solution concentrations (typically greater than 10 wt%) required to form a bulk film material by SIPS. The processes according to the present disclosure avoid this problem as they can utilize much lower solution concentrations (less than 7 wt%).

[0043] The nature and composition of the solvent that makes up the (e.g., cast) composition with the block copolymer is not particularly critical, so long as a mixture of free polymer chains, polymer micelles, and polymer aggregates is obtained, with the population of polymer free chains being substantially minor (e.g., is a dispersion). Solvents can be broadly classified as neutral, selective, and non-solvents. A neutral solvent for a given block copolymer will dissolve the block copolymer to produce a clear solution of free chains. A selective solvent for a given block copolymer will dissolve homopolymers that make up the blocks of at least one block copolymer with similar molecular weight and composition, while showing limited solubility or no solubility for at least another block copolymer that makes up the blocks. Such a selective solvent for a given block copolymer will tend to swell the block copolymer or form a dispersion of micelles and / or aggregates. A non-solvent for a given block copolymer shows limited solubility for homopolymers that make up the blocks of all block copolymers. The methods of the present disclosure typically use a solvent combination, with at least one selective solvent being used. Multiple selective solvents can be combined to form the desired composition (typically a dispersion).

[0044] The solvent composition can be modified to form the desired composition (e.g., dispersion) by judicious selection of neutral, selective, and non-solvents. For example, Hansen solubility parameters can be used to determine useful solvent compositions. It should be recognized that in some cases, a non-solvent can be identified as a pore former or pore forming agent. It can be advantageous to select a (e.g., cast) volatile solvent such that the process is purely evaporative, eliminating the need for a wash bath to remove residual solvent that enters the porous substrate by capillary action.

[0045] The amount of solvent present is not particularly limited and can include 65 percent by weight (wt%) solvent or more, 70 wt% solvent or more, 75 wt% solvent or more, 80 wt% solvent or more, or 85 wt% solvent or more; and 99.9 wt% solvent or less, 99.8 wt% solvent or less, 99.7 wt% solvent or less, 99.6 wt% solvent or less, 99.5 wt% solvent or less, 99 wt% solvent or less, 98.5 wt% solvent or less, 98 wt% solvent or less, 97.5 wt% solvent or less, 97 wt% solvent or less, 96 wt% solvent or less, 95 wt% solvent or less, 90 wt% solvent or less, or 85 wt% solvent or less. The weight percent of solvent is based on the total weight of the solution. In other words, the solvent can be present in an amount ranging from 65 wt% to 99.9 wt% of the total solution, including the endpoints, from 65 wt% to 95 wt% of the total solution, including the endpoints, or from 85 wt% to 99.9 wt% of the total solution, including the endpoints.

[0046] Some exemplary solvents for use in the method include dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, 1,4-dioxane, 1,3-dioxane, 1,1-dioxotetrahydrothiophene, methyl ethyl ketone, tetrahydrofuran, sulfolane, acetone, hexane, methyl THF, and combinations thereof. In some embodiments, the solvent includes a blend of N-methylpyrrolidone and methyl ethyl ketone, or a blend of tetrahydrofuran with one of dimethylacetamide, N-methylpyrrolidone, acetone, or dimethylformamide. In certain embodiments, a single solvent is used instead of a combination of two or more solvents.

[0047] Because the coating compositions suitable for use in the methods of the present application are composed of particles dispersed in a liquid, solid particles will not diffuse through a porous substrate having a pore size smaller than the colloidal size due to size exclusion mechanisms. Additionally, particles smaller than the pore size can not readily diffuse through the pores because the dispersed particles accumulate in the pores and block the pores (e.g., form a bottleneck) and cannot rapidly concentrate at the surface of the support substrate. In contrast, for a molecular solution of block copolymer chains, the dissolved copolymer molecules will more readily diffuse through a porous membrane. The larger the size of the particles, the larger the pores of the support membrane, the more useful for causing rapid concentration of the block copolymer particles. Higher concentrations of the dispersed particles also aid in the concentration of the particles at the surface of the support substrate. This rapid solvent removal by capillary action of the support substrate favors the formation of uniform pores during the coating process.

[0048] If the pores of the porous substrate are too large, or if the (suspended particle) micelles or free chains of the triblock copolymer or pentablock copolymer in the composition are too small, the copolymer can penetrate the pores of the porous substrate and will typically form an undesirable conformal coating on the surface and pore walls of the support substrate. In some embodiments, the porous substrate comprises pores having an average pore diameter of 500 nm or less, 450 nm or less, 400 nm or less, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, or 100 nm or less; and 1 nm or more, 5 nm or more, 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, 50 nm or more, 55 nm or more, 60 nm or more, 65 nm or more, 70 nm or more, 75 nm or more, 80 nm or more, 85 nm or more, 90 nm or more, or 95 nm or more at the surface of the porous substrate.

[0049] Suitable porous support substrates include, for example, but are not limited to, polymeric membranes, nonwoven substrates, or combinations thereof. Suitable polymeric membranes can be symmetric or asymmetric, for example, depending on the desired application. In some embodiments, the porous substrate comprises a microfiltration membrane or an ultrafiltration membrane. The porous support substrate can have one or more layers and can be made of different materials throughout its thickness. Suitable nonwoven substrates include electrospun substrates, blown microfiber substrates, wet-laid substrates, spunbond substrates, air-laid substrates, and any combinations thereof. If desired, the porous support substrate can be calendered to reduce its thickness and pore size. Preferably, the porous substrate is sufficiently hydrophilic such that it can be wetted by water spontaneously or under a pressure of 210 kiloPascals (kPa) or less, 180 kPa or less, 150 kPa or less, 120 kPa or less, or 90 kPa or less.

[0050] In some embodiments, the uniform pore membrane is attached to the porous substrate. By "attached" it is meant that, in addition to complex surface entanglements, the uniform pore membrane and the porous substrate can also interact via van der Waals forces, hydrogen bonds, and / or hydrophobic bond interactions (i.e., without any covalent bonding) when the solvents partially dissolve the uniform pore membrane and the porous substrate and they are bonded together before re-solidification. The lack of reliance on covalent bonding is an advantage. When the uniform pore membrane is sufficiently adhered to the porous substrate, the uniform pore membrane tends to resist peeling and / or flaking, and tends to be flexible (e.g., can be bent without breaking up to the point of creasing the support substrate). In at least certain embodiments, the article has good stability to changes in temperature and pH.

[0051] In some embodiments, the uniform-pore membrane is integral with the porous substrate, and a majority of the thickness of the uniform-pore membrane is above (or below) a major surface of the porous substrate. When integral, a portion of the uniform-pore membrane is within the porous substrate. See, e.g., Figure 1B A scanning electron microscope (SEM) image of a cross-section of the article 1000 of Example 77 is provided (see below). The article 1000 includes a porous substrate 1100 having a uniform-pore membrane 1200 integrally formed on the porous substrate 1100 having a thickness of about 50 nm. Advantageously, articles having a uniform-pore membrane integrally attached to a porous substrate have increased toughness (e.g., reduced brittleness) compared to articles in which the uniform-pore membrane and the porous substrate are not integral with one another.

[0052] Generally, the thickness of the uniform-pore membrane (e.g., not including the uniform-pore membrane located within the pores of the porous substrate) from a major surface of the porous substrate is 1000 nanometers (nm) or less, 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 40 nm or less, or 30 nm or less; and 20 nm or more, 25 nm or more, 30 nm or more, 40 nm or more, 55 nm or more, 65 nm or more, 75 nm or more, 85 nm or more, 95 nm or more, or 105 nm or more. In certain embodiments, the desired pores of the uniform-pore membrane have a generally cylindrical shape and a depth that is approximately twice the average pore diameter at the surface of the uniform-pore membrane.

[0053] Process conditions and specific solution formulations can be selected to provide a uniform-pore membrane in which the average pore diameter of the pores at one surface (or both major surfaces) of the membrane is 1 nanometer (nm) or more, 5 nm or more, 10 nm or more, 20 nm or more, 30 nm or more, or 40 nm or more; and 500 nm or less, 450 nm or less, 400 nm or less, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, or 150 nm or less. In other words, the average pore diameter of the surface pores (e.g., pores located on at least one surface of the membrane) can be in the range of 1 nm to 500 nm, inclusive, or in the range of 5 nm to 50 nm, inclusive. Further, the uniform-pore membrane can have a pore density of 1 x 1010 14 or more pores per square meter.

[0054] For a uniform pore membrane, in some embodiments, when the average pore diameter at the surface of the membrane is in the range of 5 nm to 15 nm, the pore diameter at the surface of the membrane (e.g., the surface pore diameter) is 4 nanometers (nm) or less of the standard deviation of the average pore diameter at the surface of the membrane, when the average pore diameter at the surface of the membrane is in the range of greater than 15 nm to 25 nm, the pore diameter at the surface of the membrane is 6 nm or less of the standard deviation of the average pore diameter at the surface of the membrane, and when the average pore diameter at the surface of the membrane is in the range of greater than 25 nm to 50 nm, the standard deviation of the pore diameter at the surface of the membrane is 25% or less of the average pore diameter at the surface of the membrane. Desirable pores are typically circular or elliptical, and the average pore diameter is determined using an idealized circular shape to measure the diameter when analyzing pores from scanning electron microscope images or atomic force microscope images. The average surface pore diameter is the average diameter of the pores at the surface of the membrane, but the pores within the bulk of the membrane can have the same average diameter.

[0055] Preferably, the uniform pore membranes according to the present disclosure are spontaneously water wettable (e.g., hydrophilic). As used herein, the term "water wettable" means that the material spontaneously absorbs water or solvent, rather than merely allowing water or solvent to pass through the pores of the material under applied pressure.

[0056] Suitable triblock copolymers typically comprise an ABC block copolymer or an ACB block copolymer, where suitable pentablock copolymers typically comprise an ABCBA block copolymer or an ACBCA block copolymer. The A, B, and C blocks are described in detail below.

[0057] The "B" block of the copolymer comprises polymer units that form hard glassy domains upon polymerization, and the T g is at least 50 °C, preferably at least 70 °C, and more preferably at least 90 °C. The T g may be determined using differential scanning calorimetry. The B block polymer domains collectively comprise 30 wt% to 80 wt% of the block copolymer.

[0058] The hard B block is typically selected from vinyl aromatic monomers, and includes, for example, styrene, a-methylstyrene, p-methylstyrene, 4-methylstyrene, 3-methylstyrene, 4-ethylstyrene, 3,4-dimethylstyrene, 2,4,6-trimethylstyrene, 3-tert-butyl-styrene, 4-tert-butylstyrene, 4-methoxystyrene, 4-trimethylsilylstyrene, 2,6-dichlorostyrene, vinyl naphthalene, and vinyl anthracene.

[0059] In some embodiments, the B block comprises a polyalkyl methacrylate. Exemplary B blocks include, for example and without limitation, styrene, p-methylstyrene, a-methylstyrene, poly(tert-butylstyrene), and polymethyl methacrylate.

[0060] The nature and composition of the monomers making up the individual C blocks is not particularly important, so long as the polymerized monomers provide a phase that meets the glass temperature requirements and thus can be described as "amorphous," "soft," or "rubbery." These terms are used interchangeably throughout this specification. It is understood that "amorphous" blocks contain no or negligible amounts of crystallinity.

[0061] In particular embodiments, each block C is independently selected from a polymerized (i) conjugated diene monomer, or (ii) silicon polymer, and (iii) mixtures of monomers in which the segment comprising the polymerized conjugated diene monomer is optionally hydrogenated. Suitable conjugated dienes include, for example, butadiene, isoprene, and the like, as well as 1,3-cyclodiene monomers such as 1,3-cyclohexadiene, 1,3-cycloheptadiene, and 1,3-cyclooctadiene, preferably 1,3-cyclohexadiene. When the C block of acyclic conjugated dienes such as butadiene or mixtures thereof is optionally hydrogenated, such blocks should have a vinyl content of 0 mol% to 40 mol% after hydrogenation. The hydrogenated C blocks include, but are not limited to, poly(ethylene-alt-propylene), poly(butylene), poly(ethylene-co-butylene), and poly(ethylene-co-propylene-co-butylene).

[0062] In addition, the C block can be a polymer block of a silicone rubber segment, i.e., a block of an organopolysiloxane having repeating units of the general formula -[Si(R 10 )2-O]-, wherein each R 10 represents an organic group, such as an alkyl group, a cycloalkyl group, or an aryl group. Such blocks of organopolysiloxanes can be prepared by anionic polymerization of a cyclic siloxane of the general formula -[Si(R 10 )2-O] r , wherein the subscript r is 3 to 7. Preferably, the cyclic siloxane is one in which the subscript r is 3 or 4 and R 10 is a methyl group. Anionic polymerization of hexamethylcyclotrisiloxane monomers is described in several papers by Y. Yamashita et al. (e.g., Polymer J. 14, 913 (1982); ACS Polymer Preprints 25 (1), 245 (1984); Makromol. Chem. 185, 9 (1984)).

[0063] In some embodiments, the C block comprises a polyacrylate and a polysiloxane. Exemplary C blocks include, for example and without limitation, polyisoprene, polybutadiene, polyisobutylene, polydimethylsiloxane, polyethylene, poly(ethylene-alt-propylene), poly(ethylene-co-butylene-co-propylene), polybutylene, and poly(ethylene-random-butylene).

[0064] The "C" blocks of the copolymer are substantially free of functional groups. Further, each of such block C can have a number average molecular weight of about 1,000 to 200,000, and can have a glass transition temperature Tg of < 20°C, preferably < 0°C. g The soft "C" blocks collectively comprise 10% to 40% by weight of the pentablock copolymer. The B blocks and C blocks together comprise 70% to 95% by weight of the pentablock copolymer.

[0065] The A block comprises a copolymer block that is immiscible with the B block and the C block. The immiscible components of the copolymer show a plurality of amorphous phases, which is determined, for example, by the presence of a plurality of amorphous glass transition temperatures as known by using differential scanning calorimetry or dynamic mechanical analysis. As used herein, "immiscibility" refers to polymer components that have a finite solubility and a non-zero interfacial tension, that is, a blend with a free energy of mixing greater than zero: ΔG ≌ ΔH m greater than 0 The miscibility of polymers is determined by both thermodynamic and kinetic factors. A commonly used miscibility predictor for non-polar polymers is the difference in solubility parameters or the difference in the Flory-Huggins interaction parameter. For polymers with non-specific interactions, such as polyolefins, the Flory-Huggins interaction parameter can be calculated by the square of the difference in solubility parameters multiplied by a factor (V / RT), where V is the molar volume of the amorphous phase of the repeat unit, R is the gas constant, and T is the absolute temperature. Thus, the Flory-Huggins interaction parameter between two non-polar polymers is always positive.

[0066] In certain embodiments, the A block comprises a poly(alkylene oxide), a polymerized substituted epoxide, a polyoxamide, a substituted polycarbonate, or a polymeric diene block hydrophilized by post-polymerization modification. Exemplary A blocks include, for example, but are not limited to, poly(D-lactide), poly(L-lactide), poly(D / L-lactide), poly(ethylene oxide), poly(propylene oxide), poly(ethyloxy ethyl glycidyl ether), poly(4-vinylpyridine), poly(2-vinylpyridine), polyhydroxystyrene, polyacrylamide, polyacrylic acid, poly(methacrylic acid), polydimethylacrylamide, poly(N-isopropylacrylamide), polyhydroxyethyl methacrylate, poly-ε-caprolactone, and poly(propylene carbonate). Examples of hydrophilized poly(diene) segments generally consist of hydrosilylation blocks where the silane used contains a hydrophilic component such as poly(ethylene oxide) and oligoethylene oxide.

[0067] In certain embodiments, the A block is derived from an anionic ring-opening polymerization of a cyclic monomer or dimer selected from alkylene oxides (epoxides) to yield polyethers, cyclic sulfides to yield polyethersulfides, lactones and lactides to yield polyesters, cyclic carbonates to yield polycarbonates, lactams to yield polyamides, and aziridines to yield polyamines. Polycarbonates can also be prepared by metal-catalyzed polymerization of carbon dioxide with the previously listed epoxides (as described in Journal of the American Chemical Society, 2005, pg. 10869).

[0068] Useful epoxides include C2-C 10 alkyl epoxides, preferably C2-C4alkyl epoxides. Specifically, ethyl ethoxy-glycidyl ether, ethylene, propylene, and butylene oxide.

[0069] Suitable lactones and lactams are those having 3 to 12 carbon atoms on the main ring and having the following general formula: wherein R 20 is an alkylene moiety, which can be straight or branched, having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, optionally substituted by a catenary (in-chain) oxygen atom, a carbonyl group, or a carboxylate; and X is -O- or NR 1 -, wherein R 1C1-C4alkyl. Cyclic lactone derivatives from hydroxy acids including 3-hydroxybutyrate, 4-hydroxybutyrate, 3-hydroxyvalerate, lactic acid, 3-hydroxypropionate, 4-hydroxyvalerate, 3-hydroxyvalerate, 3-hydroxyhexanoate, 3-hydroxyheptanoate, 3-hydroxyoctanoate, dioxanone, valerolactone, caprolactone, and glycolic acid would be acceptable. Lactam derivatives from the corresponding amino acids. Dimers of the hydroxy acids such as lactide can be used.

[0070] Useful lactams include 2-pyrrolidone, 2-piperidone, caprolactam, lauryl lactam, and mixtures thereof.

[0071] Useful cyclic carbonates include 5- to 7-membered cyclic carbonates. In embodiments, the cyclic component includes trimethylene carbonate, neopentyl glycol carbonate, 2,2,4-trimethyl-l- 1,3-pentanediol carbonate, 2,2-dimethyl-l,3-butanediol carbonate, 1,3-butanediol carbonate, 2-methyl-l,3-propanediol carbonate, 2,4-pentanediol carbonate, 2-methyl- butane- 1,3-diol carbonate, ethylene carbonate, and propylene carbonate.

[0072] Suitable cyclic anhydrides include, but are not limited to, aliphatic dicarboxylic anhydrides such as succinic anhydride, glutaric anhydride, maleic anhydride, and combinations thereof.

[0073] Examples of aziridine monomers include aziridine and its alkyl-substituted homologs.

[0074] Suitable cyclic ethers include 5- to 7-membered cyclic ethers.

[0075] References to suitable ring-opening polymerizable monomers can be found in Frisch, Kurt Charles; Reegan, Sidney L; Ring-opening polymerization: Kinetics and mechanisms of polymerization, Dekker Publishing, NY; 1969 and Su, Wei-Fang, Ring-Opening Polymerization in Principles of Polymer Design and Synthesis; Springer Berlin Heidelberg, pp. 267-299, 2013.

[0076] Suitable triblock or pentablock copolymers can be obtained or produced by any appropriate method for the synthesis of block copolymers well known in the art. Methods known in the art suitable for the synthesis of block copolymers, which can be used alone or in combination to synthesize the triblock or pentablock copolymers described herein, include sequential anionic polymerization, ring-opening polymerization, anionic ring-opening polymerization, ring-opening metathesis polymerization (ROMP), and controlled radical polymerization methods such as atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer polymerization (RAFT), and nitroxide-mediated polymerization (NMP).

[0077] In some embodiments, sequential anionic polymerization is used to make the triblock or pentablock copolymers. In some embodiments, sequential anionic polymerization and anionic ring-opening polymerization are used to make the triblock or pentablock copolymers.

[0078] Anionic polymerization and copolymerization include one or more polymerization initiators. Carbon-centered growing anions will often require initiators different from those used to produce oxygen-centered growing anions.

[0079] Suitable initiators include alkali metal hydrocarbons such as alkyl lithium, alkyl sodium or alkyl potassium compounds, or aryl lithium, aryl sodium or aryl potassium compounds, which contain up to 20 carbon atoms or more in the alkyl or aryl group, preferably up to 8 carbon atoms. Examples of such compounds are benzyl sodium, ethyl sodium, propyl sodium, phenyl sodium, butyl potassium, octyl potassium, benzyl potassium, benzyl lithium, methyl lithium, ethyl lithium, n-butyl lithium, sec-butyl lithium, t-butyl lithium, phenyl lithium and 2-ethylhexyl lithium. Lithium compounds are preferred as initiators.

[0080] Initiators that are particularly useful with the specific monomers are known in the art. Initiators that are compatible with the exemplary monomer systems discussed herein are summarized in Hsieh et al., Anionic Polymerization: Principles and Practical Applications, Ch. 5, and 23 (Marcel Dekker, New York, 1996), published in 1996.

[0081] Examples include, for example, alkyl lithium compounds such as sec-butyl lithium, n-butyl lithium, t-butyl lithium, amyl lithium, and the like, as well as other organolithium compounds, including di-initiators such as di-sec-butyl lithium adduct of m-diisopropenyl benzene and t-butyl lithium adduct of 1 -bis(phenyl)vinyl benzene. Further suitable difunctional initiators are disclosed in U.S. Patent 6,492,469. Of the various polymerization initiators, sec-butyl lithium is preferred. The initiator can be used in the polymerization reaction mixture (including monomer and solvent) in an amount calculated on the basis of one initiator molecule per desired polymer chain. The lithium initiator process is well known in the art and is described, for example, in U.S. Patent 4,039,593 and Re. 27,145.

[0082] The molecular weight is determined by the initiator / monomer ratio, and thus the amount of initiator can range from about 0.0001 mole to about 0.2 mole of organometallic initiator per mole of monomer. Preferably, the amount will be from about 0.002 mole to about 0.04 mole of initiator per mole of monomer. During the initiation phase of the anionic polymerization reaction centered on carbon, an inert organic solvent, preferably a non-polar organic solvent, can be utilized. Anionic polymerization to give anions centered on oxygen, cyclic monomers and lithium cations requires a strongly polar solvent such as tetrahydrofuran, dimethylsulfoxide or hexamethylphosphoramide, or a mixture of such polar solvents with non-polar aliphatic, cycloaliphatic or aromatic hydrocarbon solvents such as hexane, heptane, octane, cyclohexane or toluene.

[0083] In one embodiment, the polymerization reaction of the monomer to triblock polymer is initiated via the addition of a divalent anionic initiator known in the art to be useful in the copolymerization of diene monomers with vinyl aromatic hydrocarbons. Such initiators can be selected from organic compounds containing two lithium groups, such as represented by the formula: Li-R 30 -Li wherein R 30 is a divalent hydrocarbon group. In general, each R 30 group contains from 4 to 30 carbon atoms. Useful bifunctional initiators are described in US 7884160 (Wang et al.) and US 5750055 (Van Der Steen et al.), incorporated herein by reference.

[0084] Other bifunctional anionic initiators include, but are not limited to, 1,4- dilithiobutane, 1,5-dilithiopentane, 1,10-dilithiodecane, 1,20-dilithioeicosane, 1,4- dilithiobenzene, 1,4-dilithionaphthalene, 1,10-dilithioanthracene, 1,2-dilithio-1,2- diphenylethane, and the like, and mixtures thereof.

[0085] Generally, the polymerization can be carried out at temperatures ranging from about -78°C to about 100°C, preferably from about 0°C to about 60°C. It is typically required to use anhydrous conditions and an inert atmosphere such as nitrogen, helium or argon.

[0086] Generally, termination of the anionic polymerization reaction is achieved via direct reaction of the active polymer anion with a protic solvent. Termination using a halogen-containing terminator, i.e., a functional chlorosilane, can produce, for example, a vinyl-terminated polymer monomer. Such terminators can be represented by the general formula X-(Y) n -Si(R) 3-m Cl m wherein m is 1, 2 or 3, and wherein X, Y, n and R have been previously defined. The preferred terminator is chlorotrimethylsilane or methacryloyloxypropyldimethylchlorosilane. The termination reaction is carried out by adding a slight excess of the terminator, relative to the amount of initiator, to the active polymer at the polymerization temperature.

[0087] It is recognized that the conversion from carbon-centered to oxygen-centered growing anions can be used as a method to terminate the anionic polymerization of vinyl aromatics or conjugated dienes. For example, the addition of an alkylene oxide such as ethylene oxide to the styrene anion produced during the polymerization of styrene can result in the polymer chain being terminated with a hydroxyl, oxygen-centered anionic functionality. The reduced nucleophilicity of the oxygen-centered anion prevents any further polymerization of the existing vinyl aromatic or conjugated diene, thus the ethylene oxide acts in a sense as a terminator, additionally forming an initiator for further ring-opening polymerization (as described by Hsieh et al., Anionic Polymerization: Principles and Practical Applications, Ch. 5, and 23 (Marcel Dekker, New York, 1996)).

[0088] Functional anionic initiators can also be used to provide end-functionalized polymers. These initiators are generally adapted to initiate the recited monomers using techniques known to those skilled in the art. This strategy can be used to incorporate a variety of functional groups at the end of the polymer chain, including one or more alcohols, one or more thiols, carboxylic acids, and one or more amines. In each of these cases, the initiator must contain a protected functional group that can be removed using post-polymerization techniques. Suitable functional initiators are known in the art and described in, for example, U.S. Patents 6,197,891 (Schwindeman et al.); 6,160,054 (Pereira et al.); 6,222,991 (Letchford et al.); 6,184,338 (Schwindeman et al.); and 5,321,148 (Schwindeman et al.); each incorporated herein by reference.

[0089] These initiators contain a tertiary alkyl or trialkylsilyl protecting group that can be removed by post-polymerization deprotection. The tertiary alkyl protecting group can also be removed by reaction of the polymer with p-toluenesulfonic acid, trifluoroacetic acid, or trimethylsilyl iodide to yield an alcohol, amino, or thiol functionality. Additional methods for deprotection of tertiary alkyl protecting groups can be found in T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, Second Edition, Wiley, New York, 1991, page 41. The tert-butyldimethylsilyl protecting group can be removed by treatment of the polymer with an acid such as hydrochloric acid, acetic acid, p-toluenesulfonic acid. Alternatively, a source of fluoride ion, for example, tetra-n-butylammonium fluoride, potassium fluoride, and 18-crown-6 or pyridine-hydrofluoric acid complex can be used for deprotection of the tert-butyldimethylsilyl protecting group. Additional methods for deprotection of the tert-butyldimethylsilyl protecting group can be found in T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, Second Edition, Wiley, New York, 1991, page 80-83.

[0090] One suitable method for preparing a pentablock copolymer includes the steps of a) anionic polymerization of a B block monomer (such as styrene) with a functional initiator, b) polymerization of a C block monomer (such as isoprene), c) coupling, deprotection of the block copolymer formed in step a) and step b) with a coupling agent, and further polymerization of the coupled polymer of step c) with a ring-opening polymerizable monomer (such as ethylene oxide).

[0091] In this method, the ends of the RO-BC-Li block copolymer are coupled using a coupling agent to produce RO-CBC-OR block copolymer such that substantially every polymer chain has an initiator residue present at substantially every polymer chain end. The coupling agent is present in the backbone of the CBC polymer chain in minimal proportions. Suitable coupling agents include, in solution, dihalogenated compounds; diacyl chlorides; diacyl bromides; dichloro compounds; dibromo silanes and dichloro silanes, and difunctional compounds: bis-epoxides, bis-aziridines, bis-isocyanates, bis-anhydrides and diesters. Preferred coupling agents include terephthaloyl chloride, dichlorodimethylsilane, dichlorodiphenylsilane, 1,4-dibromo-butene, α,α'-dibromo-xylene and m-bis(phenylvinyl)benzene (PEB).

[0092] This method can be illustrated as follows, using styrene as the "B" monomer, isoprene as the "C" monomer, and a functional initiator. Styrene is anionically polymerized, followed by anionic polymerization with isoprene to give a RO-BC-Li block copolymer intermediate having a carbon-centered lithium anion at one end and a functional initiator residue with a protected functional group at the other end. If the functional initiator is, for example, t-butyldimethylsilylpropyllithium (TBDMSPL), then the residue is t-butyldimethylsilylpropyl. This intermediate is reacted with a coupling agent such as α,α'-dibromo-xylene to produce an intermediate having protected functional groups at both ends. This intermediate can be deprotected, such as by reaction with fluoride ion. Using the TBDMSPL initiator, the deprotection reaction gives hydroxyl groups at both ends of the copolymer. This hydroxyl-functional copolymer can be reacted with A monomer, via ring-opening polymerization to provide A blocks.

[0093]

[0094] In another embodiment, the functional initiator can be reacted with B monomer, followed by reaction with C monomer to produce the same Li-[C block]-[B block]-FG intermediate as described previously. This intermediate can then be reacted with a second amount of B monomer, followed by reaction with an amount of ethylene oxide or other alkylene oxide to monofunctionalize the ends of the block copolymer, producing the intermediate shown. Deprotection of the functional group gives a difunctional telechelic block copolymer, which can be reacted with additional A monomer to give a pentablock copolymer.

[0095]

[0096] In another embodiment, anionic polymerization can be initiated with a difunctional initiator, reacted with C monomer, B monomer and A monomer to produce a pentablock copolymer.

[0097]

[0098] One suitable method of making a triblock copolymer includes the steps of a) anionic polymerization of a B block monomer such as styrene with a functional initiator, b) polymerization of a C block monomer such as isoprene, c) capping, deprotection of the block copolymer formed in step a) and step b) with a capping agent, and further polymerization of the polymer of step c) with a ring opening polymerizable monomer such as ethylene oxide.

[0099] In another embodiment, a lithium initiator can be reacted with a C monomer, followed by a B monomer to produce a Li-[B block]-[C block] intermediate. This intermediate can then be reacted with an amount of ethylene oxide or other alkylene oxide to mono-functionalize the end of the block copolymer to produce a mono-hydroxyl HO-[B block]-[C block] intermediate, which can be reacted with additional A monomer to produce a triblock copolymer.

[0100] In another embodiment, anionic polymerization can be initiated with an initiator, reacted with a C monomer, a B monomer, and an A monomer to produce a triblock copolymer.

[0101] With reference to each of the synthetic reaction schemes, it is to be understood that some amount of A, B, C, BC, BCB, or ABC polymer or copolymer will also be present in the isolated polymer or copolymer blend. Typically, greater than 50% by weight of the resulting blend will be the desired triblock copolymer or pentablock copolymer as determined by GPC and / or NMR.

[0102] In addition to the block copolymer, the porous film can also contain at least one additive such as, for example and without limitation, homopolymers, diblock copolymers, triblock copolymers, and combinations thereof. These additives are not the primary component in the film, but are present in an amount ranging from 1% to 49% by weight of the total weight of the film, inclusive.

[0103] In some embodiments, the preferred weight ratio of the B block to the C block ranges from 2.3: 1 B block to C block to 1.7: 1 B block to C block, for example about 2: 1 B block to C block.

[0104] In some embodiments, the weight average molecular weight of the C block is 6,000 grams per mole (g / mol) or greater, 8,000 g / mol or greater, 10,000 g / mol or greater, 15,000 g / mol or greater, 20,000 g / mol or greater, 30,000 g / mol or greater, 40,000 g / mol or greater, 50,000 g / mol or greater, 60,000 g / mol or greater, 70,000 g / mol or greater, 80,000 g / mol or greater, or 100,000 g / mol or greater; and 200,000 g / mol or less, 190,000 g / mol or less, 180,000 g / mol or less, 170,000 g / mol or less, 160,000 g / mol or less, 150,000 g / mol or less, 140,000 g / mol or less, 130,000 g / mol or less, 120,000 g / mol or less, or 110,000 g / mol or less. In other words, the C block optionally has a weight average molecular weight ranging from 6,000 g / mol to 200,000 g / mol, inclusive, such as ranging from 60,000 g / mol to 200,000 g / mol, inclusive.

[0105] In selected embodiments, the block copolymer has a dispersity ranging from 1.0 to 5.0, 1.0 to 4.0, 1.0 to 3.0, or 1.0 to 2.0, each range inclusive.

[0106] In some embodiments, the uniform pore membrane is positioned within a porous substrate. The porous substrate can be embossed prior to coating. For example, the pores of the porous substrate can be filled with a composition comprising a solvent and a solid, the solid comprising a triblock copolymer or a pentablock copolymer, to form a membrane within the porous structure of the porous substrate. Wicking (and optionally additional evaporation) of the solvent from the composition membrane removes at least a portion of the solvent and forms a uniform pore membrane positioned within the porous substrate.

[0107] Embodiments

[0108] In a first embodiment, the present disclosure provides an article. The article includes a uniform pore membrane disposed on a porous substrate. The uniform pore membrane comprises a triblock copolymer or a pentablock copolymer. The uniform pore membrane has a thickness and is uniform-pored throughout the thickness.

[0109] In a second embodiment, the present disclosure provides the article of the first embodiment, wherein the thickness of the uniform-pore membrane from the major surface of the porous substrate is 1000 nanometers (nm) or less, 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 40 nm or less, or 30 nm or less; and 20 nm or more, 25 nm or more, 30 nm or more, 40 nm or more, 55 nm or more, 65 nm or more, 75 nm or more, 85 nm or more, 95 nm or more, or 105 nm or more.

[0110] In a third embodiment, the present disclosure provides the article of the first embodiment, wherein the uniform-pore membrane is located within the porous substrate.

[0111] In a fourth embodiment, the present disclosure provides the article of any one of the first through third embodiments, wherein the triblock or pentablock copolymer comprises an A block comprising a poly(alkylene oxide), a polymerized substituted epoxide, a polyoxamide, or a substituted polycarbonate.

[0112] In a fifth embodiment, the present disclosure provides the article of any one of the first through third embodiments, wherein the triblock or pentablock copolymer comprises an A block selected from the group consisting of poly(D-lactide), poly(L-lactide), poly(D / L-lactide), poly(ethylene oxide), poly(propylene oxide), poly(ethyloxyethyl glycidyl ether), poly(4-vinylpyridine), poly(2-vinylpyridine), polyhydroxystyrene, polyacrylamide, polyacrylic acid, poly(methacrylic acid), poly(dimethylacrylamide), poly(N-isopropylacrylamide), polyhydroxyethyl methacrylate, poly-e-caprolactone, and poly(propylene carbonate).

[0113] In a sixth embodiment, the present disclosure provides the article of any one of the first through fifth embodiments, wherein the triblock or pentablock copolymer comprises a B block comprising a polyalkyl methacrylate.

[0114] In a seventh embodiment, the present disclosure provides the article of any one of the first through fifth embodiments, wherein the triblock or pentablock copolymer comprises a B block selected from the group consisting of styrene, p-methylstyrene, a-methylstyrene, poly(tert-butylstyrene), and poly(methyl methacrylate).

[0115] In an eighth embodiment, the present disclosure provides the article of any one of the first through seventh embodiments, wherein the triblock or pentablock copolymer comprises a C block comprising a polyacrylate or a polysiloxane.

[0116] In a ninth embodiment, the present disclosure provides the article of any one of the first through seventh embodiments, wherein the triblock or pentablock copolymer comprises a C block selected from the group consisting of polyisoprene, polybutadiene, polyisobutylene, polydimethylsiloxane, polyethylene, poly(ethylene-alt-propylene), poly(ethylene-co-butylene-co-propylene), polybutylene, and poly(ethylene-random-butylene).

[0117] In a tenth embodiment, the present disclosure provides the article of the eighth or ninth embodiment, wherein the C block has a weight average molecular weight ranging from 6,000 g / mole to 200,000 g / mole, inclusive.

[0118] In an eleventh embodiment, the present disclosure provides the article of any one of the sixth through tenth embodiments, wherein the weight ratio of the B block to the C block ranges from 2.3: 1 to 1.7: 1.

[0119] In a twelfth embodiment, the present disclosure provides the article of any one of the fourth through eleventh embodiments, wherein the triblock copolymer comprises an ABC or ACB block copolymer.

[0120] In a thirteenth embodiment, the present disclosure provides the article of any one of the fourth through eleventh embodiments, wherein the pentablock copolymer comprises an ABCBA or ACBCA block copolymer.

[0121] In a fourteenth embodiment, the present disclosure provides the article of any one of the first through thirteenth embodiments, wherein the uniform pore membrane is attached to the porous substrate.

[0122] In a fifteenth embodiment, the present disclosure provides the article of any one of the first through fourteenth embodiments, wherein the porous substrate comprises pores having an average pore diameter at a surface of the porous substrate ranging from 500 nm or less to 1 nm or more.

[0123] In a sixteenth embodiment, the present disclosure provides the article of any one of the first through fifteenth embodiments, wherein the porous substrate comprises a membrane, a nonwoven substrate, or a combination thereof.

[0124] In a seventeenth embodiment, the present disclosure provides the article of the sixteenth embodiment, wherein the porous substrate membrane is a microfiltration membrane or an ultrafiltration membrane.

[0125] In an eighteenth embodiment, the present disclosure provides the article of any one of the first through seventeenth embodiments, wherein when the average pore diameter at the surface of the uniform pore membrane is in the range of 5 nm to 15 nm, the standard deviation of the pore diameter at the surface of the uniform pore membrane from the average pore diameter at the surface of the uniform pore membrane is 4 nm or less, when the average pore diameter at the surface of the uniform pore membrane is in the range of greater than 15 nm to 25 nm, the standard deviation of the pore diameter at the surface of the uniform pore membrane from the average pore diameter at the surface of the uniform pore membrane is 6 nm or less, and when the average pore diameter at the surface of the uniform pore membrane is in the range of greater than 25 nm to 50 nm, the standard deviation of the pore diameter at the surface of the uniform pore membrane is 25% or less of the average pore diameter at the surface of the uniform pore membrane.

[0126] In a nineteenth embodiment, the present disclosure provides the article of any one of the first through seventeenth embodiments, wherein a portion of the uniform pore membrane is integral with the major surface of the porous substrate.

[0127] In a twentieth embodiment, the present disclosure provides the article of any one of the first through nineteenth embodiments, wherein the uniform pore membrane is spontaneously water wettable.

[0128] In a twenty-first embodiment, the present disclosure provides the article of any one of the first through twentieth embodiments, wherein the porous substrate is spontaneously or wettable by water when subjected to a pressure of 210 kiloPascals or less.

[0129] In a twenty-second embodiment, the present disclosure provides a method of making the article of any one of the first through twenty-first embodiments. The method includes depositing a composition on a porous substrate, thereby forming a membrane, and removing at least a portion of a solvent from the membrane, thereby forming a uniform pore membrane comprising a plurality of pores. The composition comprises a solvent and a solid, the solid comprising a triblock copolymer or a pentablock copolymer. The uniform pore membrane has a thickness and is uniform in pores throughout the thickness of the uniform pore membrane.

[0130] In a twenty-third embodiment, the present disclosure provides the method of making the article of the twenty-second embodiment, wherein removing comprises wicking and comprises, optionally, evaporating at least a portion of the solvent in a time of 1 second or more, 5 seconds or more, 10 seconds or more, 15 seconds or more, 20 seconds or more, 25 seconds or more, or 30 seconds or more; and in a time of 600 seconds or less, 500 seconds or less, 400 seconds or less, 300 seconds or less, 200 seconds or less, 100 seconds or less, 80 seconds or less, 60 seconds or less, 50 seconds or less, or 40 seconds or less.

[0131] In a twenty-fourth embodiment, the present disclosure provides the method of making an article according to the twenty-second or twenty-third embodiment, wherein the solvent is selected from the group consisting of dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, 1,4-dioxane, 1,3-dioxane, 1,1-dioxothiophane, methyl ethyl ketone, tetrahydrofuran, sulfolane, acetone, hexane, methyl THF, and combinations thereof.

[0132] In a twenty-fifth embodiment, the present disclosure provides the method of making an article according to the twenty-second or twenty-third embodiment, wherein the solvent includes a pore former.

[0133] In a twenty-sixth embodiment, the present disclosure provides the method of making an article according to any one of the twenty-second through twenty-fifth embodiments, wherein at least a portion of the solids in the composition are present in the form of micelles or micellar aggregates.

[0134] In a twenty-seventh embodiment, the present disclosure provides the method of making an article according to any one of the twenty-second, twenty-third, or twenty-sixth embodiments, including a single solvent.

[0135] In a twenty-eighth embodiment, the present disclosure provides the method of making an article according to any one of the twenty-second through twenty-sixth embodiments, wherein the solvent includes a blend of N-methylpyrrolidone and methyl ethyl ketone, or a blend of tetrahydrofuran with one of dimethylacetamide, N-methylpyrrolidone, acetone, or dimethylformamide.

[0136] In a twenty-ninth embodiment, the present disclosure provides the method of making an article according to any one of the twenty-second through twenty-eighth embodiments, wherein removing includes wicking the solvent into the porous substrate.

[0137] In a thirtieth embodiment, the present disclosure provides the method of making an article according to any one of the twenty-second through twenty-ninth embodiments, wherein the solids are present in an amount of 0.5 percent by weight (wt%) or greater, 1.0 wt% or greater, 1.5 wt% or greater, or 2.0 wt% or greater of the total composition; and 7 wt% or less, 6 wt% or less, 5 wt% or less, 4 wt% or less, or 3 wt% or less of the total composition.

[0138] In a thirty-first implementation, the present disclosure provides the method of making an article of any of the twenty-second through thirtieth implementations, wherein a bar gap height of 1 micron or greater, 12.5 microns or greater, 15 microns or greater, 25 microns or greater, 35 microns or greater, 50 microns or greater, or 60 microns or greater is used; and a bar gap height of 100 microns or less, 88 microns or less, 75 microns or less, or 65 microns or less is used to cast the composition.

[0139] In a thirty-second implementation, the present disclosure provides the method of making an article of any of the twenty-second through thirty-first implementations, further comprising washing the uniform pore membrane and the porous substrate to remove residual solvent.

[0140] In a thirty-third implementation, the present disclosure provides the method of making an article of any of the twenty-second through thirty-second implementations, wherein the pores of the uniform pore membrane have an average pore size in a range of 1 nanometer (nm) to 500 nm, inclusive, at a surface of the uniform pore membrane.

[0141] Examples

[0142] Film Preparation

[0143] Chemicals used in polymer synthesis and membrane preparation are summarized in Table 1.

[0144] Table 1

[0145] Substrates used in membrane preparation are summarized in Table 2.

[0146] Table 2

[0147] Techniques

[0148] Dynamic Light Scattering

[0149] A dynamic light scattering (DLS) system (available under the trade designation "ZETASIZER NANO ZS" from Malvern Instruments, Malvern, UK) was used to analyze the morphology of the block copolymer (free chains, micelles, or aggregates) in dilute solution. Solutions for DLS were prepared at 0.1 wt% polymer in solvent and allowed to stand at greater than 40 °C for at least 12 hours to dissolve. The clear, colorless solutions were filtered through a 0.22 micron or 0.45 micron polypropylene syringe filter into a quartz cuvette for measurement. Measurements were made at 25 °C after the sample had equilibrated at 25 °C in the holder for 2 minutes. The instrument software automatically optimized the measurement settings at 173° by adjusting the measurement position and attenuator. In the case of a single solvent system or a two solvent mixture with at least 75% of one solvent, the pure solvent was used as the dispersion, or in the case of a two solvent mixture with less than 75% of one solvent, the pure solvent was used as a 50 / 50 mixture. To report the relative intensities of the free chain, micelle, and aggregate forms, when a form has a signal intensity within plus or minus 20% of another form, each form is shown using upper case letters, while when a form has a signal intensity outside of this range, the form with the higher intensity signal (e.g., the dominant form) is shown using upper case letters (i.e., F, M, or A) and the form with the lower intensity signal (non-dominant form) is shown using lower case letters (i.e., f, m, or a).

[0150] Formation of Composite Films

[0151] The block copolymers were dissolved in solvent mixtures at concentrations ranging from 1.5 wt% to 18 wt% and cast onto commercially available porous supports ("TESLIN SP 700", "PAN350", and "PV400") using an anti-sag instrument (available under the trade designation "AP-B5402" from Paul N. Gardner Company, Inc., Pompano Beach, FL) or a multi-gap square applicator (available under the trade designation "AP-B5355" from Paul N. Gardner Company) with a gap height ranging from 0.5 mil to 6 mil. Some samples were simply dried under air flow to remove solvent. Other samples were introduced into a water bath to remove residual solvent. After removal of residual solvent, the samples were dried under ambient conditions.

[0152] Flux Test Procedure for Composite Films Coated on Porous Substrates

[0153] Composite film samples were cut into 44 mm diameter discs and pre-wet with water. The samples were placed in a stirred cell holder (purchased under the trade designation "AMICON STIRRED CELL MODEL 8050" from EMD Millipore Corporation, Billerica, MA). Stirring was applied by a magnetic stir plate at a rate greater than or equal to 200 rpm and pressure was applied through a regulator using laboratory compressed air at 20 psi (137.9 kPa). The sample disc was conditioned with a steady transmembrane water flow to achieve a permeate volume of 40 mL or for 15 minutes, whichever came first. Steady state flux was measured at this time point. Flux measurements were in units of liters per hour per square meter per bar (LMH / bar).

[0154] In a secondary method for testing flux, the membrane sample was cut to a diameter of 25 mm and placed in a disc holder connected to a pressure tank. The pressure tank was filled with water and pressurized to 20 psi (137.9 kPa). The tubing and filter holder headspace were purged of air bubbles and flux was measured over a 5 minute interval.

[0155] Atomic Force Microscopy (AFM) Imaging

[0156] Atomic force microscopy (AFM) is an imaging technique consisting of a flexible cantilever and a sharp tip attached to the free end of the cantilever. AFM utilizes the interaction forces between the probe tip and the sample, which cause the cantilever to deflect as it is scanned across the surface. At each x-y position, the deflection of the cantilever is measured via a laser beam reflected from the backside of the cantilever and detected by a photodiode. The z(x,y) data is used to construct a three-dimensional topography map of the surface. In tapping mode AFM, the tip / cantilever assembly oscillates near the resonance frequency of the cantilever; the amplitude of the vertical oscillation is an input parameter for the feedback loop used in topography mapping. In AFM topography images, "brighter areas" correspond to peaks, while "darker areas" correspond to valleys. The phase signal is the phase difference between the photodiode output signal and the driving excitation source, and is a map of how the phase of the AFM cantilever oscillation is affected by the tip-surface interaction. The physical meaning of the phase data is complex, and the phase contrast is often influenced by material property differences such as composition, adhesion, viscoelasticity, dissipation, and topographical features contributions. The AFM data presented here were generated using one of two AFM instruments (obtained from Bruker Corp., Santa Barbara, CA under the trade designation "DIMENSION ICON" or "DIMENSION FASTSCAN") along with a controller (obtained from Bruker Corp., Santa Barbara, CA under the trade designation "NANOSCOPE V") and software (obtained from Bruker Corp., Santa Barbara, CA under the trade designation "NANOSCOPE 8.15"). The "DIMENSION FASTSCAN" instrument was used with two probes (obtained from Bruker AFM Probes, Camarillo, CA under the trade designations "FASTSCAN-A" [f0= 1.4 MHz, k = 18 N / m, tip radius (nom) = 5 nm] or "OTESPA R3" [f0= 300 kHz, k = 26 N / m, tip radius (nom) = 7 nm]). The "DIMENSION ICON" AFM instrument was used with only the "OTESPA R3" probe. It is believed that the results are considered equivalent regardless of which AFM instrument and AFM probe is employed for the purposes of the tests described in these examples. The tapping set point was typically 85% of the free air amplitude. All AFM imaging was performed under ambient conditions. Image processing and analysis were performed using software (obtained from Bruker Corp. under the trade designation "NANOSCOPE ANALYSIS 1.80," and from Image Metrology A / S, Horsholm, Denmark under the trade designation "SPIP 6.5.1").Typically, images are 1storder planar fit processed to remove sample tilt, 0thorder planarization processed to eliminate z-offset or horizontal jump artifacts. In some cases, to enhance visualization of features, images are 3rdorder planar fit processed to remove tilt and curvature, or L-filter processed to remove background waviness.

[0157] Scanning Electron Microscopy (SEM) Imaging

[0158] Surface imaging samples were mounted on a conductive carbon tape tab. The tab was mounted on a SEM stub, and a thin coating of AuPd (20 mA / 25 seconds) was deposited to make it conductive. Imaging was performed at 2 kv, and 4.0 mm-4.3 mm working distance (WD), with a secondary electron (SE) detector and low-magnetic mode, without tilt, at magnifications of 30 kx or 70 kx. A field emission scanning electron microscope (available under the trade designation “HITACHI SU-8230” from Hitachi High-Technologies, Tokyo, Japan) was used to perform the imaging. Cross sections of samples for cross-sectional images were made by cutting under liquid nitrogen, and mounted for examination. A thin metal coating was deposited to make the sample conductive. Conditions used were 2 kv, 4.3 mm WD, with SE detector, no tilt, and magnifications employed included: 10 kx, 30 kx, and 70 kx.

[0159] Reagent Drying

[0160] Polymer synthesis and reagent manipulation were performed in a glovebox (available under the trade designation “MBRAUN LABMASTER SP” from MBraun Inc., Stratham, NH, USA) or in custom glassware designed to enable anionic polymerization (see, e.g., Ndoni et al., Laboratory-scale Setup for Anionic Polymerization under Inert Atmosphere, Rev. Sci. Instrum. 66(2): 1090-1095 (1995)). Reagent manipulation was performed using standard air-free techniques. Review of Scientific Instruments

[0161] Benzene was degassed by bubbling with argon (Ar) for over an hour, after which it was transferred with a cannula to a Strauss flask containing degassed 1,1-diphenyl ethylene.

[0162] ​Then under Ar counterflow, sec-butyllithium was added via syringe, causing the color to change very slowly from light yellow to deep burgundy over the course of 1 hour.

[0163] Styrene was stirred over CaH2overnight, degassed with three freeze-pump-thaw cycles, and then vacuum transferred to a Schlenk bulb containing dry dibutyl magnesium. After stirring under Ar overnight, the styrene was again vacuum transferred to the receiving flask to provide the final dry monomer.

[0164] THF solvent was purified via a solvent purification system (available from Pure Process Technology, LLC, Nashua, New Hampshire).

[0165] Isoprene was dried by vacuum transfer from CaH2and dibutyl magnesium in sequence as detailed for styrene.

[0166] Butadiene was condensed into a flask containing liquid nitrogen-cooled n-butyllithium (solvent removed under vacuum), thawed in an ice water bath at 0 °C and stirred for 30 minutes, vacuum transferred to a second flask containing n-butyllithium (solvent removed under vacuum) and stirred for an additional 30 minutes at 0 °C, and then the purified monomer was collected in a flask by vacuum transfer.

[0167] Ethylene oxide was condensed into a flask cooled with liquid nitrogen, thawed in an ice water bath at 0 °C, vacuum transferred to a second flask containing n-butyllithium (solvent removed under vacuum) and stirred for 30 minutes at 0 °C, and then the purified monomer was collected in a flask by vacuum transfer.

[0168] 1,2-Dipiperidinylethane was first purified with CaH2, then purified with a sodium mirror (as it is very hygroscopic), and then it was dissolved in benzene until the appropriate concentration for each experiment was reached.

[0169] All other chemicals were used as received.

[0170] Gel Permeation Chromatography (GPC)

[0171] The GPC instrument includes a liquid chromatography system (obtained under the trade designation "1260 INFINITY LC" from Agilent Technologies, Santa Clara, CA) including a quaternary pump, an autosampler, a column oven, and a diode array detector. It is operated at a flow rate of 1.0 milliliter per minute (mL / min). The GPC column set includes two 300 millimeter (mm) long by 7.5 mm internal diameter columns (obtained under the trade designations "PLGEL MIXED-A" and "PLGEL MIXED-B" from Agilent Technologies, Santa Clara, CA). The detection includes an 18-angle light scattering detector, a viscometer, and a differential refractometer detector (obtained under the trade designations "DAWN HELEOS II," "VISCOSTAR," and "OPTILAB T-REX," respectively, from Wyatt Technology Corporation, Santa Barbara, CA). Commercially available software (obtained under the trade designation "ASTRA" (version 6) from Wyatt Technology Corporation) is used to collect and analyze the data. The column oven, viscometer, and differential refractometer detector are set to 40 °C. The solvent and eluent (or mobile phase) includes "OMNISOLV" grade tetrahydrofuran modified with 5% (volume / volume) triethylamine (stabilized with 250 ppm of butylated hydroxytoluene) (both obtained from EMD Millipore Corporation, Burlington, MA). The weight average molecular weight (Mw) M w ), number average molecular weight (Mn) M n ), and polydispersity (D) Ð .

[0172] Nuclear Magnetic Resonance (NMR)

[0173] A portion of the polymer sample is analyzed as a solution in deuterated chloroform (CDCI3) at an unknown concentration (typically approximately 12 milligrams per milliliter (mg / mL)). NMR spectra are acquired on a Bruker AVANCE 600 MHz NMR spectrometer (Billerica, MA, USA) equipped with a reverse cold probe.

[0174] Preparation Example 1 : Preparation of Hydroxyl-Terminated Polyisoprene-Polystyrene (IS-OH)

[0175] In a glove box, benzene (about 600 mL) and styrene (43.60 g, 419 mmol) were added to a 1 L Schlenk flask equipped with a stir bar. With vigorous stirring, TBDMSPL (0.63 mL, 0.63 mmol) was quickly injected with a syringe. Over the course of 15 minutes, the reaction color slowly changed from colorless to orange. The polymerization was stirred at room temperature for 48 hours inside the glove box. After 48 hours, isoprene (21.10 g, 309 mmol) was added, causing the color of the reaction to quickly change to light yellow. The polymerization was stirred for another 24 hours, during which time the composition became more viscous. Twenty-four hours after the introduction of isoprene, the polymerization was quenched with degassed isopropanol.

[0176] The solvent was then removed from the polymer solution under reduced pressure, and the polymer product was redissolved in about 400 mL THF. TBAF (5.0 mL, 5.0 mmol) was then added, and the reaction was stirred at room temperature under a nitrogen blanket for 8 hours. Next, about 15 mL of acetic acid was added, and the solution was stirred for another hour. The reaction was then precipitated from methanol, and the isolated solid was redissolved in cyclohexane. After filtration through silica gel, the polymer was precipitated from isopropanol and dried under reduced pressure. The polymer product was analyzed by 1 H-NMR and GPC. The product was found to contain 65.5 mass% styrene and 33.5 mass% isoprene. The molecular weight was determined by GPC to be 101 kg / mol and the dispersity was 1.02. M w H-NMR and GPC. The product was found to contain 65.5 mass% styrene and 33.5 mass% isoprene. The molecular weight was determined by GPC to be 101 kg / mol and the dispersity was 1.02.

[0177] Preparation Example 2: Preparation of Polyisoprene-b-Polystyrene-b- Polypropylene Oxide (ISP)

[0178] Preparation Example 1 (63.1 g, 0.549 mmol -OH) and toluene (235 mL) were added to a 420 mL glass pressure vessel equipped with a glass stir bar under an inert Ar atmosphere. Once the polymer was completely dissolved, Verkade base (165 mg, 0.549 mmol dissolved in 5 mL toluene) was added, causing the color to very slightly change to light yellow. The solution was stirred at room temperature for 1 hour. After 1 hour, propylene oxide (65 mL) was added and the solution was stirred for five minutes to ensure complete dissolution. After five minutes, triisobutylaluminum (2.1 mL, 2.1 mmol) was added and the pressure vessel was quickly capped. Within a few minutes, bubbles formed in the solution and the viscosity increased. After five minutes, the reaction flask felt warm / hot to the touch. The exotherm persisted for several hours, during which time the viscosity grew further, but not at the rate of the first 10 minutes after aluminum addition.

[0179] The reactants were stirred for three days, after which time a hazy, opaque solution resulted. The reaction product was precipitated from HC1 / methanol (about 500 mL MeOH, about 30 mL concentrated HC1), isolated by filtration, and dried, then redissolved in THF (minimally, about 200 mL). The THF solution was precipitated from acidic methanol (same concentration as before), and isolated by filtration. The fine supernatant was compressed by centrifugation (10 minutes at 3000 rpm) prior to filtration. The white polymer was dried and analyzed by 1 H-NMR and GPC were performed. The product was found to contain 57.4 mass% styrene, 27.3 mass% isoprene, and 15.3 mass% propylene oxide. The molecular weight was determined by GPC to be 143 kg / mol and the dispersity was 1.02. M w H-NMR and GPC were performed. The product was found to contain 57.4 mass% styrene, 27.3 mass% isoprene, and 15.3 mass% propylene oxide. The molecular weight was determined by GPC to be 143 kg / mol and the dispersity was 1.02.

[0180] Hydroxyl-terminated polystyrene b Preparation of polyisoprene (SI-OH)

[0181] Generally, SI-OH is prepared by sequential anionic polymerization initiated with a silane-protected initiator. The product polymer is then deprotected to yield a hydroxyl-terminated diblock copolymer. A representative synthesis procedure is outlined below. Changes to the amounts of reagents are used to provide corresponding products with higher or lower molecular weight and different weight fractions of polystyrene or polyisoprene.

[0182] In a glove box, benzene (about 600 mL) and isoprene (20.23 g, 297 mmol) were added to a 1 L Schlenk flask fitted with a stir bar. With vigorous stirring, the protected initiator (0.38 mL, 0.38 mmol) was rapidly injected with a syringe. The polymerization system was stirred at room temperature for 24 hours inside the glove box. After 24 hours, styrene (44.55 g, 428 mmol) was added, causing the color of the reaction system to quickly turn orange. The polymerization system was stirred for another 24 hours, during which time the composition became more viscous. The polymerization was then quenched with degassed isopropanol.

[0183] The solvent was then removed from the polymer solution under reduced pressure, and the polymer product was dissolved in about 400 mL THF. TBAF (5.0 mL, 5.0 mmol) was then added, and the reaction was stirred at room temperature under a nitrogen blanket for 8 hours. Next, about 15 mL acetic acid was added, and the solution was stirred for another hour. The reaction was then precipitated from methanol, and the isolated solid was dissolved in cyclohexane. After filtration through silica gel, the polymer was precipitated from isopropanol and dried under reduced pressure. The polymer product was analyzed by 1 H-NMR and GPC. The results are summarized in Table 3.

[0184] Table 3

[0185] Preparation of Polystyrene-b-Polyisoprene-b-Polypropylene Oxide (SIP)

[0186] Typically, SIPs are prepared by chain extension of SI-OH with anionic ring opening polymerization of propylene oxide. A representative synthesis procedure for Preparation Example 6 is outlined below. Changes to the amount of reagents were used to provide corresponding products of polystyrene, polyisoprene, and polypropylene oxide with higher or lower molecular weights and different weight fractions.

[0187] In a glove box, Preparation Example 4 (59.17 g, 0.392 mmol-OH) and toluene (235 mL) were added to a 420 mL glass pressure vessel equipped with a glass stir bar. Once the polymer was completely dissolved, Verkade base (132 mg, 0.439 mmol dissolved in 5 mL toluene) was added, causing the color to very slightly change to a light yellow. The solution was stirred at room temperature for 1 hour. After 1 hour, propylene oxide (60 mL) was added and the solution was stirred for five minutes to ensure complete dissolution. After five minutes, triisobutylaluminum (1.7 mL, 1.7 mmol) was added and the pressure vessel was quickly capped. Within a few minutes, bubbles formed in the solution and the viscosity increased. After five minutes, the reaction flask felt warm / hot to the touch. The exotherm continued for several hours, during which time the viscosity grew further, but not at the rate of the first 10 minutes after aluminum addition.

[0188] The reaction was stirred for three days, after which time a hazy, opaque white solution resulted. The reaction product was precipitated from HC1 / methanol (about 500 mL MeOH, about 30 mL concentrated HC1), isolated by filtration, and dried, then dissolved in THF (minimally, about 200 mL). The THF solution was precipitated from acidic methanol (same concentration as before), and isolated by filtration. The fine supernatant was compressed by centrifugation (10 minutes at 3000 rpm) prior to filtration. The white polymer was dried and analyzed by 1 H-NMR and GPC. The results are summarized in Table 4.

[0189] Table 4

[0190] Preparation of Hydroxyl-Terminated Poly(isoprene-styrene-isoprene) Using Sequential Addition and Ethylene Oxide Termination Block Copolymer (HO-ISI-OH)

[0191] A 2 L polymerization reactor apparatus was constructed and an inert Ar atmosphere was established, then 666 g of purified benzene was added to the reactor. The TBDMSPL protected initiator (0.45 mL) was then added to the reactor and stirred for 30 minutes. Purified isoprene (10.1 g) was then added to the reactor. After about 1 hour of reaction at room temperature, the reactor was heated using a water bath set to 40 °C. After about 5 hours of isoprene addition, purified styrene (37.1 g) was added to the reactor. After about 18 hours of styrene addition, a second amount of purified isoprene (10.1 g) was added to the reactor. After about 5 hours of the second isoprene addition, a large molar excess (2 g) of ethylene oxide was added to the reactor. The reactor was then allowed to cool to room temperature. After about 72 hours of ethylene oxide addition, the reaction was terminated with degassed methanol to yield a monohydroxyl terminated RO-ISI-OH triblock copolymer.

[0192] To obtain a dihydroxyl terminated ISI triblock copolymer (HO-ISI-OH), the benzene solvent was removed by rotary evaporation and the resulting polymer was dissolved in 400 mL of tetrahydrofuran. A 10-fold molar excess of TBAF relative to the initiator was added to the THF solution (4.5 mL of 1.0 M TBAF in THF) and the solution was stirred at room temperature for at least 18 hours. The THF solvent was removed by rotary evaporation and the resulting polymer was dissolved in 400 mL of methylene chloride. The methylene chloride solution was washed with several 300 mL aliquots of distilled water. The methylene chloride was removed by rotary evaporation and the polymer was redissolved in about 400 mL of THF, the solution was precipitated out of an isopropanol / methanol mixture (1 :3), the resulting white solid was isolated by filtration and vacuum dried to yield 55 g of dry polymer.

[0193] By 1 The polymer composition was determined by H-NMR; the polymer molecular weight and dispersity were determined by GPC analysis. The results are summarized in Table 5.

[0194] Table 5

[0195] Preparation of Poly(ethylene oxide-isoprene-styrene-isoprene-ethylene oxide) Block Copolymer (OISIO)

[0196] A 1 L polymerization reactor apparatus was constructed and an inert Ar atmosphere established. The Preparation 7 triblock copolymer (15.0 g) was dissolved in about 100 mL of benzene added to the reactor. The reactor was sealed, the benzene solution was chilled using liquid nitrogen, and then the reactor was placed under dynamic vacuum to remove the benzene solvent by freeze drying over a period of about 24 hours. Tetrahydrofuran (614 g) was then added to the reactor. The reactor was stirred and heated with an oil bath set at a temperature of 45 °C to dissolve the polymer.

[0197] A naphthyl potassium initiator solution was prepared by adding a 10% molar excess of naphthalene (2.88 g) and dry tetrahydrofuran solvent (119 g) to potassium metal (0.8 g). This solution was stirred under an Ar atmosphere for at least 24 hours to give a dark green solution.

[0198] The naphthyl potassium initiator solution was added slowly dropwise to the reactor until a light green persisted for at least 30 minutes, indicating the titration end point of deprotonating the HO-ISI-OH triblock copolymer. Ethylene oxide (2.5 g) was added to the reactor and the reaction was allowed to proceed for about 72 hours, then terminated with degassed methanol bubbled with argon for 60 minutes.

[0199] To isolate the solid polymer, the tetrahydrofuran solvent was removed by rotary evaporation and the resulting polymer was dissolved in 300 mL of methylene chloride and washed with several 300 mL aliquots of distilled water. The methylene chloride solvent was removed by rotary evaporation and the resulting polymer was dissolved in 150 mL of benzene and freeze dried to give an off-white polymer.

[0200] The polymer composition was determined by1H-NMR; the polymer molecular weight and dispersity were determined by GPC analysis. The results are summarized in Table 6. 1 The polymer composition was determined by1H-NMR; the polymer molecular weight and dispersity were determined by GPC analysis. The results are summarized in Table 6.

[0201] Table 6

[0202] Hydroxyl-Terminated Poly(styrene-isoprene-styrene) Block Copolymer (HO-SIS-OH) Using Sequential Addition and Ethylene Oxide Termination Table 7

[0203] Generally, HO-SIS-OH was prepared by sequential anionic polymerization using a protected initiator. A representative synthesis procedure for Preparation 9 is outlined below. Changes to the amounts of reagents were used to provide corresponding products with higher or lower molecular weight and different weight fractions of polystyrene and polyisoprene.

[0204] A 2L polymerization reactor was constructed, and an inert Ar atmosphere was established. 730 g of purified benzene was added to the reactor. Then, 0.37 mL of TBDMSPL protecting initiator was added to the reactor and stirred for 30 minutes. Subsequently, 15.3 g of purified styrene was added to the reactor. After reacting at room temperature for approximately 1 hour, the reactor was heated to 40°C via a water bath. Approximately 24 hours after the addition of styrene, 12.5 g of isoprene was added to the reactor. Approximately 24 hours after the addition of styrene, 15.6 g of styrene was added to the reactor. Approximately 24 hours after the second addition of styrene, a large molar excess (3.5 g) of ethylene oxide was added to the reactor, causing the color to change from orange to colorless. The reactor was then cooled to room temperature. From approximately 16 to 96 hours after the addition of ethylene oxide, the reaction was terminated with degassed methanol to obtain a monohydroxy-terminated RO-SIS-OH triblock copolymer.

[0205] To obtain the dihydroxy-terminated SIS triblock copolymer (HO-SIS-OH), the benzene solvent was removed by rotary evaporation, and the resulting polymer was dissolved in 400 mL of tetrahydrofuran. A 10-molar excess of TBAF relative to the initiator was added to the THF solution (3.7 mL of 1.0 M TBAF in THF), and the solution was stirred at room temperature for at least 18 hours. The THF solvent was removed by rotary evaporation, and the resulting polymer was dissolved in 500 mL of dichloromethane. The dichloromethane solution was washed with at least three 300 mL aliquots of distilled water. The washed dichloromethane solution was precipitated in cold methanol, and the resulting white solid was separated by filtration and dried under vacuum.

[0206] pass 1 The polymer composition was determined by ¹H-NMR; the molecular weight and dispersity of the polymer were determined by GPC analysis. The results are summarized in Table 7.

[0207] Synthesis of Poly(propylene oxide-styrene-isoprene-styrene-propylene oxide) Block Copolymer (PSISP)

[0208] Table 8

[0209] As described in Example 4 of WO2018098023, PSISP block copolymers were prepared by chain extension of HO-SIS-OH with propylene oxide. Variations in reagent amounts were used to provide corresponding products with higher or lower molecular weights and different weight fractions of polypropylene oxide. In Preparation Examples 17, 18, 19, and 20, Verkade base was used instead of P4 phosphazene base (1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)-phosphonoamino]-2λ, obtained from Sigma-Aldrich Ltd., St. Louis, Missouri).5 ,4λ 5 - Bis(phosphazene). In Preparation Example 18, Preparation Example 19, and Preparation Example 20, triethylborane (obtained from Sigma-Aldrich Co. LLC, St. Louis, MO as a 1.0 M hexane solution) was used in place of triisobutylaluminum. The PSISP block copolymer molecular weights and compositions are summarized in Table 8.

[0210] Synthesis of Poly(ethylene oxide-styrene-isoprene-styrene-ethylene oxide) Block Copolymer (OSISO)

[0211] Table 9

[0212] The OSISO block copolymers were prepared as described in Example 2 of WO2018098023 and summarized in Table 9.

[0213] Preparation Example 25: Preparation of Polyisoprene-b-Polystyrene-b-1,2- Polybutadiene (ISB)

[0214] Preparation Example 26: Hydrosilylation of ISB with ClMe2SiH and Substitution with 2-Methoxyethanol

[0215] The polymerization of isoprene, followed by the polymerization of styrene and the polymerization of butadiene are the three basic steps via anionic polymerization and high vacuum techniques to synthesize the final linear triblock terpolymers.

[0216] In a 2 L glass apparatus, the PI living chains [PI (-) Li (+) ] were synthesized by polymerizing 9.0 g of isoprene (0.13 mol) with sec-BuLi (2 x 10-4mol) in 1200 mL of benzene at room temperature for 24 hours. The molecular weight of the first block (PI) was measured using GPC, yielding a M n (numerical average molecular weight) value of approximately equal to 43.000 g / mol and a dispersity of 1.03. To increase the rate of initiation of the styrene (second monomer) towards the PI (-) Li (+) macroinitiator, a small amount of THF (1 ml - 2 ml) was added, resulting in a very fast initiation step and ensuring a narrow distribution of the intermediate two-block product. After that, 18.0 g of styrene (0.17 mol) was added and allowed to react at room temperature for 24 hours. The total molecular weight of the two-block copolymer (PI-b-PS) was measured using GPC, yielding a M n (numerical average molecular weight) value of approximately equal to 128.000 g / mol and a dispersity of 1.04. Then, 3 ml of 1,2-Dipip (4 x 10-4mol) diluted in benzene was added to the PI-b-PS(-) Li (+) solution and the solution was kept under stirring for 1 hour to change the polarity. The ratio between the initial initiator concentration and the Dipip concentration was about 1 :2. Finally, 3.0 g (0.055 mol) of 1,3-butadiene was added and left to react for 24 hours at 4°C to better control the polymerization reaction. This process pushes the reaction kinetics under the specific conditions (concentrations, temperature, solvent mixture) towards a close to 100% -1,2 addition, instead of the usual 92% -1,4 and 8% -1,2, which would be obtained during anionic polymerization without a polar additive. The total molecular weight of the final triblock terpolymer (PI-b-PS-b-PB1,2) was measured using GPC, giving a M n (number average molecular weight) value of 142.000 g / mol and a dispersity of 1.07.

[0217] The final triblock terpolymer ISB (about 27 grams) was precipitated in an excess of methanol and the precipitated final product was dried in a vacuum oven at 50°C for 48 hours. After the polymerization of each monomer, a small amount (about 1 g) was always taken out of the apparatus to be characterized via GPC. The 100% -1,2 microstructure in the PB segment is simple when compared to PB synthesized by anionic polymerization of butadiene in a non-polar environment, leading to a 92% 1,4-content and 8% 1,2-content, as it appears in a specific chemical shift, as indicated by the H-NMR (proton nuclear magnetic resonance) spectrum. 1 H-NMR (proton nuclear magnetic resonance) spectrum.

[0218] Preparation of Poly(4-vinylpyridine)-b-polystyrene-b-polyisoprene-b- polystyrene-b-poly(4-vinylpyridine) (VSISV)

[0219] In a 350 mL sealable glass pressure vessel equipped with a stirring rod, ISB (12.53 g, 42.6 mmol 1,2-polybutadiene repeat units) was dissolved in THF (70.0 mL). Once the polymer had been dissolved, Karstedt catalyst (0.350 mL, 7 mg Pt, 0.036 mmol Pt) was added, followed by dimethylchlorosilane (4.0 mL, 36 mmol). The pressure vessel was capped and heated to 85°C for 12 hours, then cooled to room temperature. The initiation, indicated by a darkening of the solution from colorless to dark yellow, orange or light brown color, was observed when Pt nanoparticles were formed. A highly variable lag phase in the range of 10 minutes to four hours was observed.

[0220] Once cooled to room temperature, aniline (5.0 mL, 54.9 mmol) and 2-methoxyethanol (4.3 mL, 54.5 mmol) were added sequentially. A fine white precipitate formed over a period of thirty minutes. After stirring for an additional two hours, the reaction was filtered through CELITE 545 and evaporated to dryness. The polymer residue was extracted with dichloromethane and the solution filtered through CELITE 545. The product filtrate was then redissolved in THF before being precipitated out of methanol.

[0221] After drying, the polymer was characterized by NMR and GPC. 1 H-NMR indicated approximately 60% conversion of the polybutadiene side chain C=C and less than 10% conversion of the polyisoprene side chain C=C. GPC showed a slight increase in dispersity to approximately 1.3.

[0222] Table 10 Comparative Examples Coated on Dense Membranes

[0223] Typically, VSISV is prepared by sequential anionic polymerization using a bifunctional anion initiator derived from sec-BuLi and 1,3-bis(1-phenylvinyl)benzene.

[0224] 1,3-bis(1-phenylvinyl)benzene was added to a 1 L reactor flask and dissolved in benzene. Once dissolved, sec-butyllithium (2 equivalents relative to 1,3-bis(1-phenylvinyl)benzene) was added, causing the color to immediately change from colorless to deep burgundy. The contents of the flask were stirred at room temperature for 8 hours, after which isoprene was added, causing the color to immediately change from deep red to light yellow. Once isoprene was added, the polymerization system was stirred at room temperature for 24 hours. Next, styrene was added, causing the color to gradually change from light yellow to orange. The polymerization was allowed to react for an additional 24 hours at room temperature.

[0225] 1,1-diphenyl ethylene (1.2 equivalents relative to sec-butyllithium) was added and the reaction was stirred for 1 hour. The polymerization system was then diluted with THF (3x volume of benzene used) and then cooled to -78 °C. After cooling, 4-VP was added and the polymerization system was stirred at -78 °C for two hours, after which it was quenched with degassed isopropanol.

[0226] The polymer was isolated by precipitation from water. The isolated polymer was then dried under reduced pressure, redissolved in minimal THF, and precipitated again from water to yield a white rubbery solid. The product polymer was characterized by 1 H-NMR and GPC. The results are summarized in Table 10.

[0227] PSISP Coated on PET Membrane

[0228] Examples Coated on Porous Membranes

[0229] PSISP Coated on Polyacrylonitrile Ultrafiltration Membrane

[0230] The PSISP block copolymer from Preparation 16 was dissolved in 60 / 40 w / w NMP / MEK at a concentration of 13 wt%. The solution was coated onto polyethylene terephthalate (PET) film (available under the trade designation "LUMIRROR" from Toray Plastic America, Inc., North Kingstown, RI) using a draw down bar with gap heights ranging from 1 to 6 mils (25.4 to 152.4 microns) in increments of 0.5 mils (12.7 microns). After a 15 second delay, the coatings were immersed in water to remove residual solvent. All coatings exhibited features at least 100 nm in size by AFM analysis. No evidence of uniform porosity was observed at any gap height.

[0231] Table 11

[0232] PSISP Coated on Teslin Porous Polyolefin Membrane

[0233] The PSISP block copolymer from Preparation 16 was dissolved in 60 / 40 w / w NMP / MEK at a concentration of 13 wt%. The sample was coated onto polyacrylonitrile ultrafiltration membranes ("PAN350") using a draw down bar with gap heights ranging from 1 to 6 mils (25.4 to 152.4 microns) in increments of 0.5 mils (12.7 microns). After a 15 second delay, the coatings were immersed in water to remove residual solvent. Conditions and results are summarized in Table 11. Coatings with gap heights of 1 mil and 1.5 mils (25.4 and 38.1 microns) exhibited uniform porosity by AFM analysis. At higher gap heights, non-uniform structures were seen.

[0234] Table 12

[0235] PSISP Coated on Polyvinylidene Fluoride Ultrafiltration Membrane

[0236] The PSISP block copolymer from Preparation 16 was dissolved in a 60 / 40 w / w solution of NMP / MEK at a concentration of 13 wt%. The sample was coated onto a porous polyolefin film ("TESLIN SP 700") using an anti-sag instrument with coating gap heights ranging from 1 mil to 6 mils (25.4 microns to 152.4 microns) in increments of 0.5 mils (12.7 microns). After a 15 second delay, the coating was immersed in water to remove residual solvent. The conditions and results are summarized in Table 12. Coatings with gap heights of 1 mil, 1.5 mils, and 2 mils (25.4 microns, 38.1 microns, and 50.8 microns) exhibited uniform pores according to AFM analysis. At higher gap heights, non-uniform pore structures were seen.

[0237] Table 13

[0238] PSISP Film Composite Membrane from DMA / THF

[0239] The PSISP block copolymer from Preparation 16 was dissolved in a 60 / 40 w / w solution of NMP / MEK at a concentration of 13 wt%. The sample was coated onto a polyvinylidene fluoride ultrafiltration membrane ("PV400") using an anti-sag instrument with coating gap heights ranging from 1 mil to 6 mils (25.4 microns to 152.4 microns) in increments of 0.5 mils (12.7 microns). After a 15 second delay, the coating was immersed in water to remove residual solvent. The conditions and results are summarized in Table 13. Coatings with a gap height of 1 mil (25.4 microns) exhibited near-uniform porosity according to AFM analysis. At higher gap heights, non-uniform pore structures were seen.

[0240] Table 14

[0241] PSISP Coated from Different Solvents, Coating Concentrations, and Interstitial Heights

[0242] The PSISP block copolymer from Preparation 16 was dissolved in a 60 / 40 (w / w) DMA / THF solution at a concentration of 16 wt%. The sample was coated onto "PAN350" using an anti-sag instrument with coating gap heights ranging from 1 mil to 6 mils (25.4 microns to 152.4 microns) in increments of 0.5 mils (12.7 microns). The coated film was immediately immersed in water to remove residual solvent. The conditions and results are summarized in Table 14. At gap heights of 1 mil to 3 mils, the coatings exhibited uniform or near-uniform porosity. At gap heights greater than or equal to 3.5 mils, the coatings ranged from near-uniform to having a broad pore size distribution.

[0243] Table 15

[0244] Table 16

[0245] PSISP block copolymer from Preparation 18 was dissolved in a solvent mixture of 60 / 40 w / w DMA / THF at 1.5 wt% - 6 wt%. The sample was coated onto "PAN350" using a multi-gap square applicator at a gap height of 0.5 mil or 1 mil (12.7 microns or 25.4 microns) and the coating was immediately immersed in water to remove residual solvent. Conditions and results are summarized in Table 15. Flux was not observed at polymer concentrations of 4 wt% or higher. At lower concentrations, flux was observed, with higher flux seen at lower coating concentrations.

[0246] Table 17

[0247] PSISP block copolymer from Preparation 18 was dissolved in a solvent mixture of 90 / 10 w / w NMP / THF at 1.5 wt% - 5 wt%. The sample was coated onto "PAN350" using a multi-gap square applicator at a gap height of 0.5 mil (12.7 microns) and the coating was immediately immersed in water to remove residual solvent. Conditions and results are summarized in Table 16. Very low flux (4 LMH / bar) was observed at 5 wt%. At lower concentrations, higher flux was observed, with at least 70 LMH / bar seen at 1.5 wt%.

[0248] PSISP Composite Films from Different NMP / MEK Solvent Ratios

[0249] PSISP block copolymer from Preparation 18 was dissolved in a solvent mixture of 90 / 10 w / w acetone / THF at 1.5 wt% - 5.5 wt%. The sample was coated onto "PV400" using a multi-gap square applicator at a gap height of 0.5 mil (12.7 microns) and the coating was immediately immersed in water to remove residual solvent. Results are summarized in Table 17. Flux was observed at all coating concentrations, ranging from 70 LMH / bar at 5.5 wt% to 280 LMH / bar at 1.5 wt%.

[0250] Table 18

[0251] PSISP Composite Films from Different DMA / THF Solvent Ratios

[0252] The PSISP block copolymer from Preparation 18 was dissolved at 1.5 wt% in solvent mixtures of NMP / MEK at ratios ranging from 40 / 60 to 80 / 20 w / w. The sample was coated on "PAN350" using a multi-gap square applicator at a gap height of 0.5 mil (12.7 microns) and the coating was immediately immersed in water to remove residual solvent. Conditions and results are summarized in Table 18. At 40 / 60 to 60 / 40 w / w NMP / MEK, the sample appeared identical to the uncoated "PAN350" substrate, indicating a conformal coating. For NMP contents of 65 wt% - 100 wt%, a uniform-pore coating was seen. Once a non-conformal coating was reached, a significant drop in flux from the uncoated PAN350 was observed.

[0253] DLS was performed on 0.1 wt% of the PSISP block copolymer from Preparation 18 at a subset of these solvent ratios. Results are also listed in Table 18. At 50 / 50 NMP / MEK and 60 / 40 NMP / MEK, a significant population of free chains and micelles was observed. For 70 / 30 NMP / MEK and 80 / 20 NMP / MEK, the intensity of the particle size distribution signal was significantly higher in the micelle particle size range, with lower signal intensity from free chains. This decrease in free chain contribution is consistent with a shift in coating appearance from conformal to uniform-pore. At 100% NMP, only a micelle signal could be seen.

[0254] Table 19 F and f: free chains (peak at 5 nm - 20 nm), M: micelles (peak at 40 nm - 200 nm); when forms have signal intensities within plus or minus 20% of each other, each form is shown in upper case, while when forms have signal intensities outside of this range, the form with the higher intensity signal is shown in upper case and the form with the lower intensity signal is shown in lower case Figure 1A The PSISP block copolymer from Preparation 18 was dissolved at 1.5 wt% in solvent mixtures of DMA / THF at ratios ranging from 40 / 60 to 60 / 40 w / w. The sample was coated on "PAN350" using a multi-gap square applicator at a gap height of 0.5 mil (12.7 microns) and the coating was immediately immersed in water to remove residual solvent. Conditions and results are summarized in Table 19. At 40 / 60 w / w DMA / THF, the sample appeared identical to the uncoated "PAN350" substrate, indicating a conformal coating. For 60 / 40 w / w DMA / THF, a uniform-pore coating was seen. Once a non-conformal coating was reached, a significant drop in flux from the uncoated PAN350 was observed. DLS was performed at 60 / 40 w / w DMA / THF at 0.1 wt% of the PSISP block copolymer from Preparation 18. A significant population of free chains (5-10 nm) and micelles (200-600 nm) was observed.

[0255] Figure 1B

[0256] SEM surface and cross-section imaging was performed on the 60 / 40 DMA / THF sample (at 1.5 wt% and 0.5 mil gap height) (Figures 19 and 20, respectively). PSISP Composite Films from Different DMF / THF Solvent Ratios and Table 20 ). Uniform-pore features were observed on the surface, while the cross-section image showed a very thin, porous layer (about 50 nm) formed exactly at the surface of the substrate. Below this layer, the cross-section appeared identical to that of the uncoated "PAN350".

[0257] PSISP Composite Films from Different NMP / THF Solvent Ratios

[0258] The PSISP block copolymer from Preparation 18 was dissolved at 1.5 wt% in solvent mixtures of DMF / THF at ratios ranging from 40 / 60 to 65 / 35 w / w. The sample was coated on "PAN350" using a multi-gap square applicator at a gap height of 0.5 mil (12.7 microns) and the coating was immediately immersed in water to remove residual solvent. Conditions and results are summarized in Table 20. At 40 / 60 w / w DMF / THF, the sample appeared identical to the uncoated "PAN350" substrate, indicating a conformal coating. At 50 / 50 w / w DMF / THF, a porous coating with irregular self-assembled pores could be seen. For greater than 60 wt% DMF, a uniform-pore coating was seen. Once a non-conformal coating was reached, a significant drop in flux from the uncoated "PAN350" was observed.

[0259] Table 21

[0260] PSISP Composite Films from Different Hexane / THF Solvent Ratios

[0261] The PSISP block copolymer from Preparation 18 was dissolved at 1.5 wt% in solvent mixtures of NMP / THF in ratios ranging from 70 / 30 w / w to 100 / 0 w / w. The samples were coated on a "PAN350" substrate using a multi-gap square applicator at a gap height of 0.5 mil (12.7 microns) and the coating was immediately immersed in water to remove residual solvent. The conditions and results are summarized in Table N. At less than or equal to 80 wt% NMP, the sample appeared identical to the uncoated "PAN350" substrate, indicating a conformal coating. For NMP contents greater than 90 wt%, a uniform pore coating was seen. Once a non-conformal coating was reached, a significant drop in flux from the uncoated "PAN350" was observed.

[0262] DLS was performed at 0.1 wt% of PSISP-212 in a subset of these solvent ratios. The results are likewise listed in Table 21. At 70 / 30 w / w NMP / THF, the majority of the particle size distribution signal was in the micelle particle size range, with a few contributions from free chains. At greater than 80 wt% NMP, only a micelle signal could be seen.

[0263] Table 22 F and f: free chains (peaks at 5 nm - 20 nm), M: micelles (peaks at 40 nm - 200 nm), capital and lowercase letters as indicated for Table 18 above.

[0264] PSISP Composite Films from Different Acetone / THF Solvent Ratios

[0265] The PSISP block copolymer from Preparation 18 was dissolved at 1.5 wt% in solvent mixtures of hexane / THF in ratios ranging from 70 / 30 w / w to 100 / 0 w / w. The samples were coated on a "PAN350" substrate using a multi-gap square applicator at a gap height of 0.5 mil (12.7 microns) and the coating was immediately immersed in water to remove residual solvent. The conditions and results are summarized in Table 22. At 60 / 40 w / w hexane / THF, the sample appeared identical to the uncoated "PAN350" substrate, indicating a conformal coating. For hexane contents greater than 70 wt%, a coating with worm-like structures was seen. Once a non-conformal coating was reached, a significant drop in flux from the uncoated "PAN350" was observed.

[0266] Figure 2A

[0267] Figure 2B

[0268] The PSISP block copolymer from Preparation 18 was dissolved at 1.5 wt% in solvent mixtures of acetone / THF in ratios ranging from 60 / 40 w / w to 90 / 10 w / w. The sample was coated on a "PAN350" substrate using a multi-gap square applicator at a gap height of 0.5 mil (12.7 microns), and the coating was then air dried in a fume hood. Conditions and results are summarized in Table P. At 60 / 40 to 70 / 30 w / w acetone / THF, coatings with approximately 30 nm worm-like features were present at the surface (e.g., Table 23 The surface of Example 90 is shown). At 80 / 20 w / w acetone / THF, a mixture of round and elongated holes were seen. For greater than 85 wt% acetone, a near-homogeneous coating was seen with a minority population of elongated holes (e.g., OSISO Composite Films from Different Acetone / THF Solvent Ratios The surface of Example 93 is shown). Flux was observed to be significantly lower than that of uncoated "PAN350".

[0269] DLS was performed at 0.1 wt% of the PSISP block copolymer from Preparation 18 at a subset of these solvent ratios. Results are likewise listed in Table 23. At 70 / 30 w / w acetone / MEK, only free chains were observed. At 80 / 20 w / w acetone / MEK, the majority of the particle size distribution signal was in the micelle particle size range with a minority contribution from free chains. This reduction in free chain contribution is consistent with a shift in coating appearance from a significant population of elongated holes to a majority of round holes. At greater than 85% acetone, only a micelle signal could be seen.

[0270] Figure 3A F and f: free chains (peaks at 10 nm - 30 nm), M: micelles (peaks at 40 nm - 200 nm), upper and lower case as indicated for Table 18 above.

[0271] ​

[0272] The OS ISO block copolymer from Preparation 21 was dissolved at 1.5 wt% in solvent mixtures of acetone / THF in ratios ranging from 60 / 40 to 90 / 10 w / w. The sample was coated on a “PAN350” substrate using a multi-gap square applicator at a gap height of 0.5 mil (12.7 microns) and the coating was air dried in a fume hood. Conditions and results are summarized in Table 24. At 60 / 40 w / w acetone / THF, the sample appeared identical to the uncoated “PAN350” substrate, indicating a conformal coating. As the acetone content increased up to 80 wt%, a uniform-pore coating was seen (e.g., ​ The surface of Example 96 is shown). At acetone contents of 85 wt% and higher, it appears that the micelles in solution no longer fully fuse during the drying process, resulting in an appearance of about 50 nm to 80 nm toroid objects at the coating surface (e.g., Figure 3B The surface of Example 100 is shown). For both the uniform-pore and toroid object coatings, the flux was much lower than that of the uncoated “PAN350”.

[0273] DLS was performed at a subset of these solvent ratios at 0.1 wt% of the OS ISO block copolymer from Preparation 21. Results are also listed in Table 24. At 50 / 50 w / w acetone / THF, a mixture of free chains and micelles was observed. At 75 / 25 w / w acetone / THF, only micelles were observed. This decrease in free chain contribution is consistent with the shift in coating appearance from conformal to uniform-pore. At 90 wt% acetone, there was a significant aggregate component in solution.

[0274] Table 24 A: aggregates or not dissolved, F: free chains (peak at 20 nm - 50 nm), M: micelles (peak at 60 nm - 100 nm); capital letters as indicated for Table 18 above.

[0275] Comparative Example: SIPS cast OSISO material used

[0276] OS ISO block copolymers from Preparation 21 and Preparation 23 were dissolved at concentrations of 12 wt% - 18 wt% in various solvent mixtures and cast using a multi-gap square applicator at a coating gap height of 8 mil (203.2 microns) with evaporation periods of 0 seconds to 60 seconds and then immersed in a water bath. Conditions and results are summarized in Table 25. A range of results were seen, including collapse, gelling to give transparent dry films, and some opaque film pieces with pore structure (e.g., membranes). Samples that did not collapse remained adhered to the plastic coating support.

[0277] Table 25

[0278] Casting of OSISO film composites

[0279] OSISO block copolymers from Preparation Example 22, Preparation Example 23, and Preparation Example 24 were dissolved at 1.5% in solvent mixtures of acetone / THF at ratios ranging from 50 / 50 w / w to 90 / 10 w / w. The samples were coated on a "PAN350" substrate using a multi-gap square applicator at a gap height of 1 mil (25.4 microns) and the coatings were air dried in a fume hood. The conditions and results are summarized in Table 26. In each series of solvents, a shift from conformal coatings to mostly uniform-pore coatings was observed by AFM as the acetone content increased (e.g., see surface of sample 62). Figure 4A SEM of the same sample surface confirmed the presence of mostly open uniform-pore structures Figure 4B .

[0280] DLS was performed at 0.1 wt% of the OSISO material at the same solvent ratios. The results are also listed in Table 26. Across each series, there was a shift in solution character from mostly free chains at higher acetone content to mostly micelles at higher THF content.

[0281] Table 26 Solution not dissolved A: aggregates or not dissolved, F: free chains (peak at 10 nm - 30 nm), M: micelles (peak at 40 nm - 100 nm). Capital letters are as indicated for Table 18 above.

[0282] Comparative Example: SIPS cast OSISO material used

[0283] OISIO pentablock copolymers from Preparation Example 8 were dissolved in various MEK / DMF and THF / DMF solvent mixtures at concentrations of 9 wt% - 14 wt%. For the MEK / DMF system, solutions were either phase separated (12 wt% and 14 wt%) or gelled (9 wt% - 11 wt%). For the THF / DMF system, solutions with 50% or less THF were found to gel. Those at higher THF content and lower concentration were cast using a multi-gap square applicator at a coating gap height of 8 mils (203.2 microns) with evaporation periods of 5 seconds to 15 seconds, then immersed in a water bath. They formed translucent or transparent cohesive films. Table 27 contains a summary of the coating conditions used and the results.

[0284] Table 27

[0285] Casting of OISIO film composites

[0286] The OISIO block copolymer from Preparation Example 8 was dissolved at 1.5 wt% in NMP or in solvent mixtures of various ratios of DMF / THF, DMA / THF, and acetone / THF. The samples were coated onto "PAN350" using a multi-gap square applicator at a coating gap height of 0.5 mil (12.7 microns) and the coatings were either air dried in a fume hood (for acetone / THF) or immediately immersed in water to remove residual solvent (for NMP, DMF / THF, and DMA / THF). The conditions and results are summarized in Table 28. For the DMF / THF and DMA / THF ratios tested, uniform or near-uniform structures with some elongated pores were observed by AFM. In the NMP and acetone / THF ratios tested, micellar or lamellar type structures were observed. Moderate fluxes were observed in the DMF / THF, DMA / THF, and acetone / THF systems, while higher fluxes were seen in the NMP system. In the DLS results for OISIO-61 in 70 / 30 w / w DMF / THF, only a micellar peak was seen. DLS observations of a dilute solution of OISIO-61 in 70 / 30 DMF / THF are also reported in Table 28.

[0287] Table 28 M: micellar (peak at 40 nm - 200 nm).

[0288] Casting of ISP film composites

[0289] The ISP block copolymer from Preparation Example 2 was dissolved at 1.5 wt% in NMP or in solvent mixtures of 90 / 10 acetone / THF or 80 / 20 NMP / THF. The samples were coated onto "PAN350" using a multi-gap square applicator at a coating gap height of 0.5 mil (12.7 microns) and the coatings were either air dried in a fume hood (for acetone / THF) or immediately immersed in water to remove residual solvent (for NMP and 80 / 20 NMP / THF). The conditions and results are summarized in Table 29. Near-uniform structures with more variable pore shape and size were observed for NMP and 90 / 10 acetone / THF. Uniformity was seen in the 80 / 20 NMP / THF system. Moderate fluxes were observed in all systems, well below the flux of the uncoated substrate.

[0290] Table 29

[0291] Comparative Example: SIP material cast using SIPS at 16 wt%

[0292] The SIP block copolymer from Preparation Example 5 was dissolved at a 16 wt% concentration in a solvent mixture of 50 / 50 w / w THF / DMAc and 70 / 30 w / w MEK / NMP and cast at 8 mil (203.2 microns) with an evaporation period of 10 seconds - 25 seconds. The sample was then immersed in water to remove residual solvent. While in the bath, the coating became opaque and remained attached to the plastic support sheet. After removal from the water bath and drying, the sample was examined by AFM to assess surface topography. Coating conditions and results are summarized in Table 30. Neither nanoscale dot features nor uniform pores were seen in the coating.

[0293] Table 30

[0294] Casting of SIP film composites at 16 wt%

[0295] The SIP block copolymer from Preparation Example 5 was dissolved at a 16 wt% concentration in a solvent mixture of 50 / 50 w / w THF / DMAc and 70 / 30 w / w MEK / NMP and cast onto "PAN350" using a multi-gap square applicator at a coating gap height of 2 mil (50.8 microns) with an evaporation period of 10 seconds. The sample was then immersed in water to remove residual solvent. Coating conditions and results are summarized in Table 31. Uniform or near uniform pore features were seen in the coating.

[0296] Table 31

[0297] Casting of SIP film composites at 6 wt%

[0298] The SIP block copolymer from Preparation Example 6 was dissolved at a 6 wt% concentration in solvent mixtures of 50 / 50 w / w THF / DMA and 70 / 30 w / w MEK / NMP and cast onto "PAN350" using a multi-gap square applicator at a coating gap height of 1-6 mils (25.4 microns-152.4 microns). After 10 seconds of evaporation, the sample was then immersed in water to remove residual solvent. Coating conditions and results are summarized in Table 32. For the 50 / 50 w / w THF / DMA series, uniform pore features were seen up to 3 mils (76.2 microns) in the coating, after which the surface became more sparse with nanoscale pore features. For the 70 / 30 w / w MEK / NMP series, uniform pore features were seen up to approximately 2 mils (50.8 microns) in thickness. At lower thicknesses, conformal coatings were observed, while at higher thicknesses, a mixture of uniform pores and larger dots were seen.

[0299] Table 32

[0300] Casting of VSISV film composites

[0301] The VSISV block copolymers from Preparation Example 27, Preparation Example 28, and Preparation Example 29 were dissolved at 2 wt% in solvent mixtures of diglyme / dioxane / THF and cast onto "PAN350" using a multi-gap square applicator at a coating gap height of 0.5 mils (12.7 microns). The samples were immediately immersed in water to remove residual solvent. Coating conditions and results are summarized in Table 33.

[0302] DLS was performed at 0.1 wt% of the VSISV material at the same solvent ratios. In the DLS results for all solvent mixtures, a significant contribution from both free chains and micelles was observed. In both cases (Example 148 and Example 150), at 38 / 32 / 30 w / w / w and 18 / 32 / 50 w / w / w, a peak at 200-300 nm was also observed for aggregates. The presence of micelles translated into AFM structures, where many of the coatings appeared as small, coalesced micelles. However, in two of the VSISV coatings, at 18 / 32 / 50 w / w / w (e.g., Figure 5A The surface of Example 146 is shown) and 8 / 32 / 60 w / w / w (e.g., Figure 5B The surface of Example 147 is shown) uniform pore structures were seen.

[0303] Table 33 F: free chains (peaks at 10-20 nm), M: micelles (peaks at 50-200 nm), A: aggregates (greater than 200 nm). Capital letters as indicated for Table 18 above.

[0304] Casting of ISB film composites

[0305] The ISB block copolymer from Preparation 26 was dissolved at 2 wt% in solvent mixtures of 50 / 50 w / w acetone / THF and 50 / 50 w / w NMP / MEK and cast onto "PAN350" using a multi-gap square applicator at a coating gap height of 0.5 mil (12.7 microns). The acetone / THF sample was air dried while the NMP / MEK sample was immediately immersed in water to remove residual solvent. Coating conditions and results are summarized in Table 34. Under AFM, the 50 / 50 w / w acetone / THF sample appeared to be conformally coated while the 50 / 50 w / w NMP / MEK sample appeared to be uniform-pored. DLS examination of the dilute solutions of ISB-239 at the same solvent ratios indicated that in the acetone / THF case the majority was free chain contribution while the NMP / MEK case indicated the majority was micelle contribution.

[0306] Table 34 F and f: free chains (peaks at 10-40 nm), M and m: micelles (peaks at 60-200 nm), a: aggregates (peaks at 400-2000 nm), capital and lower case letters as indicated for Table 18 above.

[0307] Continuous deposition of film composites through slot die

[0308] The OSISO block copolymer from Preparation 22 was dissolved at 1 wt% in a solvent mixture of 80 / 20 w / w acetone / THF. The PSISP block copolymer from Preparation 19 was dissolved at 1 wt% in a solvent mixture of 90 / 10 NMP / MEK. Continuous deposition was performed using an experimental scale roll-to-roll coating line equipped with a slit die. Coating speed was controlled at 5 ft / min (2.5 cm / s) and coating width was 4 inches (10.2 cm). Coating solutions were metered onto "PAN350" or "PV400" using syringe pumps at 1.5 mL / min to 3 mL / min. Acetone / THF coatings were dried on the production line at room temperature before winding, while NMP / MEK coated substrates were removed from the coating line to be immersed in a water bath. Coating conditions and results are summarized in Table 35. In Example 154 (e.g., Figure 6The surfaces of Example 154 and Example 155 are shown (e.g., Figure 7 Uniform porosity was observed in the surface of Example 155. Except for the difference in thickness and location on a different substrate (“PV400”), Example 156 is the same coating as Example 114, and in this case, instead of uniform porosity, partially molten annular structures were observed (e.g., Figure 8 (The surface of Example 156 is shown).

[0309] Table 35

[0310] Inkjet deposition of film composites

[0311] The PSISP block copolymer from Preparation Example 20 was dissolved at 1% by weight in a solvent mixture of 90 / 10 (w / w) NMP / MEK. A benchtop material deposition system (available under the trade name "DIMATIX MATERIALS PRINTER" from Fuji Corporation, Santa Clara, California) capable of precisely jetting fluid materials was used to deposit the block copolymer solution onto "PAN350" in a controlled droplet-by-drop manner. A disposable piezoelectric inkjet cartridge (available under the trade name "DIMATIX MATERIALS CARTRIDGES 11610" from Fuji Corporation) was used to deposit 10 pL droplets. The coating was printed with a droplet spacing of 30 micrometers, followed by 25 purging cycles (Example 157). After printing, the composite sheet was immersed in water to remove residual solvent. AFM showed a deposited coating exhibiting uniform porosity (e.g., Figure 9 (The surface of Example 157 is shown).

[0312] Electrospray deposition of film composites

[0313] The PSISP block copolymer from Preparation Example 20 was dissolved at a concentration of 0.1% by weight in a 90 / 10 (w / w) acetone / THF solvent mixture. A custom electrospray deposition apparatus (as described in Chowdhury et al., “3D Printed Polyamide Membranes for Desalination,” *Science*) was used. Science (As described in Volume 361, Issue 6403, 2018, pp. 682-686) was used to deposit a block copolymer solution onto “PAN350” using 10 scan layers and an accelerating voltage of 11 kV (Example 158). Following the electrospray deposition process, the composite sheet was air-dried at room temperature. SEM analysis revealed a deposited coating exhibiting a combination of uniform porosity and open and closed pores (e.g., Figure 10The surface of Example 158 is shown.

Claims

1. A method of making an article, the method comprising: a) depositing a composition onto a porous substrate, thereby forming a film, the composition comprising a solvent and a solid, the solid comprising a triblock copolymer; b) removing at least a portion of the solvent from the film, thereby forming a uniform pore film comprising a plurality of pores, wherein the uniform pore film has a thickness and is uniform-pored throughout the thickness; wherein the triblock copolymer comprises an A block comprising a hydrophilic block, and wherein the uniform pore film is formed without applying a non-solvent induced phase inversion step to create porosity.

2. The method of claim 1, wherein the hydrophilic block is a poly(ethylene oxide).

3. The method of claim 1, wherein the solid is present in an amount of 0.5 percent by weight (wt%) or greater, 1.0 wt% or greater, 1.5 wt% or greater, or 2.0 wt% or greater of the total dispersion, and 7 wt% or less, 6 wt% or less, 5 wt% or less, 4 wt% or less, or 3 wt% or less of the total composition.

4. The method of claim 1, wherein at least a portion of the solid in the composition is present in the form of colloidal block copolymer particles.

5. The method of claim 4, wherein the block copolymer particles are present in the form of micelles or micellar aggregates.

6. The method of claim 1, wherein the composition is a dispersion containing 15 percent by volume (vol%) or more of total block copolymer present as particles, such as 25 vol% or more, 30 vol% or more, 35 vol% or more, 40 vol% or more, 45 vol% or more, 50 vol% or more, 55 vol% or more, 60 vol% or more, 65 vol% or more, 70 vol% or more, or 75 vol% or more of total block copolymer present as particles in the composition; and 100 vol% or less, 99.9 vol% or less, 99.5 vol% or less, 99 vol% or less, 95 vol% or less, or 90 vol% or less of total block copolymer present as particles in the composition.

7. The method of claim 1, wherein the removing comprises wicking, and comprises evaporating at least a portion of the solvent, optionally, over a period of 1 second or more, 5 seconds or more, 10 seconds or more, 15 seconds or more, 20 seconds or more, 25 seconds or more, or 30 seconds or more, and over a period of 600 seconds or less, 500 seconds or less, 400 seconds or less, 300 seconds or less, 200 seconds or less, 100 seconds or less, 80 seconds or less, 60 seconds or less, 50 seconds or less, or 40 seconds or less.

8. The method of claim 1, wherein the solvent is selected from the group consisting of dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, 1,4-dioxane, 1,3-dioxane, 1,1-dioxothiapyran, methyl ethyl ketone, tetrahydrofuran, sulfolane, acetone, hexane, methyl THF, and combinations thereof.

9. The method of claim 1, comprising a single solvent.

10. The method of claim 1, wherein the solvent is included in the composition in an amount in the range of 65 wt% to 99.9 wt% of the total solution, including the endpoints, 65 wt% to 95 wt% of the total solution, including the endpoints, or 85 wt% to 99.9 wt% of the total solution, including the endpoints.

11. The method of claim 1, wherein the composition is cast using a bar gap height of 1 micron or greater, 12.5 microns or greater, 15 microns or greater, 25 microns or greater, 35 microns or greater, 50 microns or greater, or 60 microns or greater, and using a bar gap height of 100 microns or less, 88 microns or less, 75 microns or less, or 65 microns or less.

12. The method of claim 1, wherein the triblock copolymer comprises a B block, the B block comprising 30 wt% to 80 wt% of the triblock copolymer.

13. The method of claim 12, wherein the B block is formed from a vinyl aromatic monomer.

14. The method of claim 13, wherein the B block is selected from the group consisting of styrene, a-methylstyrene, p-methylstyrene, 4-methylstyrene, 3-methylstyrene, 4-ethylstyrene, 3,4-dimethylstyrene, 2,4,6-trimethylstyrene, 3-tert-butyl-styrene, 4-tert-butylstyrene, 4-methoxystyrene, 4-trimethylsilylstyrene, 2,6-dichlorostyrene, vinyl naphthalene, and vinyl anthracene.

15. The method of claim 13, wherein the B block is selected from the group consisting of styrene, p-methylstyrene, a-methylstyrene, poly(tert-butylstyrene), and polymethyl methacrylate.

16. The method of claim 1, wherein the triblock copolymer comprises a C block, the C block selected from the group consisting of polymerized (i) conjugated diene monomers, or (ii) silicon polymers, and (iii) mixtures of monomers in which the segments comprising polymerized conjugated diene monomers are optionally hydrogenated.

17. The method of claim 16, wherein the C block comprises polymerized conjugated diene monomers, the diene monomers selected from the group consisting of butadiene, isoprene, and 1,3-cyclodiene monomers.

18. The method of claim 1, wherein the triblock copolymer comprises a C block, the C block comprising a polyacrylate or a polysiloxane.

19. An article comprising a uniform pore membrane disposed on a porous substrate, the uniform pore membrane comprising a triblock copolymer, wherein the uniform pore membrane has a thickness and is uniform-pored throughout the thickness; and wherein the article is manufactured using the method of claim 1.

20. The article of claim 19, wherein the triblock copolymer comprises an A block comprising a hydrophilic block.

21. The article of claim 20, wherein the hydrophilic block is poly(ethylene oxide).

22. The article of claim 19, wherein the thickness of the uniform pore membrane from a major surface of the porous substrate is 1000 nanometers (nm) or less, 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 40 nm or less, or 30 nm or less; and 20 nm or more, 25 nm or more, 30 nm or more, 40 nm or more, 55 nm or more, 65 nm or more, 75 nm or more, 85 nm or more, 95 nm or more, or 105 nm or more.

23. The article of claim 19, wherein the triblock copolymer comprises a B block selected from the group consisting of styrene, p-methylstyrene, a-methylstyrene, poly(tert- butylstyrene), and polymethyl methacrylate.

24. The article of claim 19, wherein the triblock copolymer comprises a C block comprising a polyacrylate or a polysiloxane.

25. The article of claim 19, wherein the uniform pore membrane is attached to the porous substrate.

26. The article of claim 19, wherein the porous substrate comprises pores having an average pore diameter of 500 nm or less to 1 nm or more at a surface of the porous substrate.

27. The article of claim 19, wherein when an average pore diameter at a surface of the uniform pore membrane is in a range of 5 nm to 15 nm, a standard deviation of pore diameters at the surface of the uniform pore membrane from the average pore diameter at the surface of the uniform pore membrane is 4 nm or less, when the average pore diameter at the surface of the uniform pore membrane is in a range of greater than 15 nm to 25 nm, the standard deviation of pore diameters at the surface of the uniform pore membrane from the average pore diameter at the surface of the uniform pore membrane is 6 nm or less, and when the average pore diameter at the surface of the uniform pore membrane is in a range of greater than 25 nm to 50 nm, the standard deviation of pore diameters at the surface of the uniform pore membrane is 25% or less of the average pore diameter at the surface of the uniform pore membrane.

28. The article of claim 19, wherein a portion of the uniform pore membrane is integral with a major surface of the porous substrate.

29. The article of claim 19, wherein the uniform pore membrane is spontaneously water wettable.

30. The article of claim 19, wherein the porous substrate comprises a microfiltration membrane or an ultrafiltration membrane.

31. An article comprising a uniform pore membrane disposed on a porous substrate, the uniform pore membrane comprising a triblock copolymer, wherein the triblock copolymer comprises a hydrophilic block, wherein the hydrophilic block comprises poly(ethylene oxide), wherein the uniform pore membrane has a thickness and is uniform-pored throughout the thickness.

32. The article of claim 31, wherein the thickness of the uniform pore membrane from a major surface of the porous substrate is 1000 nanometers (nm) or less, 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 40 nm or less, or 30 nm or less; and 20 nm or more, 25 nm or more, 30 nm or more, 40 nm or more, 55 nm or more, 65 nm or more, 75 nm or more, 85 nm or more, 95 nm or more, or 105 nm or more.

33. The article of claim 31, wherein the triblock copolymer comprises a B block, the B block comprising from 30 wt% to 80 wt% of the triblock copolymer.

34. The article of claim 33, wherein the B block is formed from a vinyl aromatic monomer.

35. The article of claim 33, wherein the B block is selected from the group consisting of styrene, a-methylstyrene, p-methylstyrene, 4-methylstyrene, 3-methylstyrene, 4-ethylstyrene, 3,4-dimethylstyrene, 2,4,6-trimethylstyrene, 3-tert-butyl-styrene, 4-tert-butylstyrene, 4-methoxystyrene, 4-trimethylsilylstyrene, 2,6-dichlorostyrene, vinyl naphthalene, and vinyl anthracene.

36. The article of claim 31, wherein the triblock copolymer comprises a B block, the B block selected from the group consisting of styrene, p-methylstyrene, a-methylstyrene, poly(tert-butylstyrene), and polymethyl methacrylate.

37. The article of claim 31, wherein the triblock copolymer comprises a C block, the C block selected from the group consisting of polymerized (i) conjugated diene monomers, or (ii) silicon polymers, and (iii) mixtures of monomers in which the segments comprising polymerized conjugated diene monomers are optionally hydrogenated.

38. The article of claim 37, wherein the C block comprises polymerized conjugated diene monomers, the diene monomers selected from the group consisting of butadiene, isoprene, and 1,3-cyclodiene monomers.

39. The article of claim 31, wherein the triblock copolymer comprises a C block, the C block comprising a polyacrylate or a polysiloxane.

40. The article of claim 31, wherein the uniform pore membrane is attached to the porous substrate.

41. The article of claim 31, wherein the porous substrate comprises pores having an average pore diameter at a surface of the porous substrate of 500 nm or less to 1 nm or more.

42. The article of claim 31, wherein when an average pore diameter at a surface of the uniform pore membrane is in a range of 5 nm to 15 nm, a pore diameter at the surface of the uniform pore membrane to a standard deviation of the average pore diameter at the surface of the uniform pore membrane is 4 nm or less, when the average pore diameter at the surface of the uniform pore membrane is in a range of greater than 15 nm to 25 nm, the pore diameter at the surface of the uniform pore membrane to the standard deviation of the average pore diameter at the surface of the uniform pore membrane is 6 nm or less, and when the average pore diameter at the surface of the uniform pore membrane is in a range of greater than 25 nm to 50 nm, the standard deviation of the pore diameter at the surface of the uniform pore membrane is 25% or less of the average pore diameter at the surface of the uniform pore membrane.

43. The article of claim 31, wherein a portion of the uniform pore membrane is integral to a major surface of the porous substrate.

44. The article of claim 31, wherein the uniform pore membrane is spontaneously water wettable.

45. The article of claim 31, wherein the porous substrate comprises a microfiltration membrane or an ultrafiltration membrane.

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