Gelled films, articles containing gelled films, and methods of making and using same

Abstract

A film comprising a plurality of particles of a water-soluble glue and a water-soluble polymer contacting at least a portion of the surface of the particles of the water-soluble glue, said film having a surprisingly high coating weight. Articles comprising such films on a substrate. Methods of making and using such films and articles. Dispersions useful in making such films and articles.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Application No. 63 / 348,495, filed on June 3, 2022, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The field of the invention relates generally to polymer films and their preparation and use. Background Art

[0004] US5869321 discloses a thin film culture plate having culture medium particles containing a mixture of nutrients and a gelling agent. The gelling agent is a material such as a carbohydrate, and specifically a mixture of xanthan gum, locust bean gum and guar gum.

[0005] US9988600 discloses dry powder cell culture media having polymer embedded components.

[0006] US2020019431 discloses a device for distinguishing and enumerating coliform bacteria and Escherichia coli microorganisms. The device comprises a first sheet having a first cold water-soluble gelling agent adhered to the first sheet, and a second sheet having a second cold water-soluble gelling agent adhered to the second sheet. As gelling agents, guar gum, polyacrylamide, locust bean gum and agar are mentioned, of which guar gum and xanthan gum alone or in combination are preferred, and guar gum is an example.

[0007] US20150225691 teaches a method for preparing a flowable, aggregated nutrient medium using a fluidized bed aggregation chamber. A gelling agent may be included. A binder may be optionally included. Among the binders, PEG, polyvinyl pyrrolidone, polyvinyl alcohol, polysaccharides, dextran, dextrin, maltodextrin, microcrystalline cellulose, HPMC, methylcellulose, starch and sugar are mentioned.

[0008] US10995356 provides a culture device for counting colonies of microbial flora. A cold water soluble gelling agent, a dry buffer system, a dry carbon dioxide generation system and a dry oxygen scavenging agent are provided in the growth compartment. The gelling agent mentioned includes algin, carboxymethyl cellulose, tara gum, hydroxyethyl cellulose, guar gum, locust bean gum, xanthan gum, polyacrylamide, polyurethane and polyethylene oxide. Guar gum, locust bean gum and xanthan gum alone or in combination are preferred.

[0009] Feng et al. published “Determination of Petrifilm TM The article concluded that liquefied organisms can hydrolyze guar gum, which can have “two effects on the accuracy [of colony counts]: (i) liquefied areas may allow motile organisms to move and multiply…resulting in more than one colony from a cell, resulting in an overestimation of the microbial load, and (ii) smudged areas obscure other colonies, leading to a potential underestimation.” DETAILED DESCRIPTION

[0010] In this application, terms such as "a", "an", and "the" are not intended to refer to only a single entity, but include general categories that can be illustrated by specific examples. The terms "a", "an", and "the" are used interchangeably with the phrases "at least one" and "one or more". The phrases "at least one of" and "comprising at least one of" following a list refer to any one item in the list and any combination of two or more items in the list.

[0011] Use of terms such as "common," "commonly," "often," "frequently," and "frequently" refers to features that are commonly employed in the invention, but does not imply that the described feature was known or common prior to this disclosure unless otherwise stated.

[0012] Unless stated otherwise, the use of "or" means "and / or".

[0013] The use of "comprise", "comprises", "comprising", "include", "includes", and "including" are interchangeable and are not intended to be limiting. In addition, when the description of one or more embodiments uses the term "comprising", those skilled in the art will appreciate that in some specific cases, the language "consisting essentially of" and / or "consisting of" may be used to alternatively describe one or more embodiments.

[0014] As used herein, the term "about" refers to a ±10% variation of the nominal value. It should be understood that such variations are always included in any given value provided herein, whether or not specifically indicated.

[0015] Any range given in absolute or approximate terms is intended to encompass both, and any definitions used herein are intended to clarify rather than limit. Although the numerical ranges and parameters defining the broad scope of the invention are approximate, the numerical values ​​given in the specific examples are reported as accurately as possible. In addition, all ranges disclosed herein are to be understood to encompass any and all subranges (including all fractional and integer values) contained therein.

[0016] "PEO" refers to a water-soluble organic polymer having repeating units of the chemical formula -OCH2CH2-. PEO as used herein refers only to the chemical structure of the polymer and includes not only polymers known as polyethylene oxide, but also polymers known as poly(ethylene glycol) or PEG, which have repeating units of the same chemical formula as polyethylene oxide, but which may (but not necessarily) have different end groups. PEO can have a variety of end groups, including but not limited to hydroxyl and alkoxy. When one or more of the end groups are alkoxy, the alkoxy can be a C1-C4 alkoxy or typically a C1 alkoxy. Mixing of end groups is also possible. PEO is most commonly linear; however, a small amount of branching is also possible.

[0017] "PVP" refers to the water-soluble polymer polyvinylpyrrolidone.

[0018] "Total coating weight" refers to the coating weight (g / 24 in) of a dry film comprising a water-soluble gum and a water-soluble polymer prepared according to the methods disclosed herein. 2 ).

[0019] Unless otherwise indicated, all particle sizes in this disclosure and claims refer to average particle sizes as determined by light scattering.

[0020] Unless otherwise indicated, all pH in this disclosure and claims refers to pH values ​​measured at about 20°C.

[0021] Unless otherwise indicated, all molecular weights of polymeric materials in the present disclosure and claims are weight average molecular weights, reported in Daltons (D) or kilodaltons (kD), as appropriate, and determined by gel permeation chromatography in tetrahydrofuran by comparison to narrow poly(styrene) standards.

[0022] Thin film culture devices, such as those disclosed in US5869321, US9988600 and US202001943, comprise a substrate with a film, and the film generally comprises a water-soluble glue, such as guar gum, xanthan gum or locust bean gum. These glues are commercially available in the form of particles, which are dissolved in water to produce a viscous solution. It is a challenge to form a film of a water-soluble glue on a substrate, particularly in a manufacturing environment, where a film with a precisely defined coating weight must be formed consistently and repeatedly. The current method for forming a film of glue involves powder coating, which is an expensive process requiring highly specialized equipment and harsh operating conditions, especially when carried out on a commercial scale.

[0023] Prior to the advances described herein, solvent coating (as used herein to include coating from any dispersion of a solid in a liquid, and not limited to coating from a solution in which a solute is dissolved in a liquid) which is generally more easily performed on a commercial scale and is considered unacceptable. Prior to the advances described in the present disclosure, coating an aqueous solution of a high molecular weight glue at a low glue concentration at a sufficient thickness required a large amount of aqueous coating liquid, which meant that a large amount of water had to be removed to form a dry film. Removing large amounts of water requires a large amount of heat and time, and is therefore cost-prohibitive because it slows down production, requires too much energy to heat, or both. At higher concentrations, less water can be used, but the glue increases the viscosity of the coating liquid to a level that makes it uncoatable.

[0024] Thus, the problem to be solved can be stated as how to provide a film comprising a solvent coated glue. Alternatively, the problem can be stated as how to prepare a concentrated dispersion of glue with a sufficiently low viscosity to be suitable for use in a solvent coating process.

[0025] membrane

[0026] Briefly, the solution to one or more of these problems and other problems lies in a film comprising a plurality of water-soluble colloidal particles and a water-soluble polymer contacting at least a portion of the surface of the water-soluble colloidal particles, and in methods of making the film, articles comprising the film, and methods of using the film.

[0027] Any water-soluble glue can be used, regardless of whether the glue swells when in contact with water. Without wishing to be limited by any particular theory, when the glue contacts water (e.g., when the amount of water used is not enough to dissolve all or part of the glue), the glue can swell and can gel. Most commonly, the glue is a natural gum, but synthetic gums can also be used. The most commonly used glues are xanthan gum, locust bean gum and guar gum, and mixtures thereof. The most frequently used is guar gum.

[0028] Glue is in the form of particles. Glue particles are commercially available, for example, under the trade name MEYPROGAT (Danisco, Switzerland) and VISCOGUM (Cargill, Minnesota, the U.S.). In principle, the particle size of glue is only limited by its ability to form a film, for example, by the method described herein. In some embodiments, the particle size can be from about 25 microns to about 200 microns. In other embodiments, the particle size can be from about 25 microns to about 200 microns, from about 50 microns to about 175 microns, from about 75 microns to about 150 microns or, from about 100 microns to about 125 microns.

[0029] In principle, any water-soluble polymer can be used, but the most common water-soluble polymer is a synthetic polymer. In some cases, it is advantageous that the water-soluble polymer is also dissolved in a solution of water and a water-soluble (or even more advantageously water-miscible in some cases) organic solvent, because this type of solution (that is, a solution of a water-soluble polymer in water and a water-soluble organic solvent, particularly a water-miscible organic solvent) is more convenient to adopt than a solution of a water-soluble polymer in separate water in the context of the present disclosure. Therefore, most of the water-soluble polymers used are water-soluble polymers that are also dissolved in a mixture of water and at least one water-soluble organic solvent, more particularly a water-miscible organic solvent. The water-miscible organic solvent mentioned can be selected from isopropanol, ethanol, methanol, tetrahydrofuran, diethyl ether, methyl ethyl ether, dimethyl ether and acetone. More commonly, the water-miscible organic solvent is selected from isopropanol, ethanol and methanol. Most commonly, the water-miscible organic solvent mentioned in this section is isopropanol. However, it should be noted that it is not necessary for the water-soluble polymer to be dissolved in a water-soluble organic solvent or a water-miscible organic solvent, and it is not necessary to use a water-soluble organic solvent or a water-miscible organic solvent even if the water-soluble polymer is also dissolved in a water-soluble organic solvent or a water-miscible organic solvent. On the other hand, in some cases, even if the polymer is water-soluble, a water-soluble organic solvent or a water-miscible organic solvent is used instead of water.

[0030] Regarding the chemical nature of the water-soluble polymer, it can be selected from a variety of polymers, including polymer surfactants, polyelectrolytes such as polyanions, polycations and polyzwitterions, and polar polymers. The water-soluble polymer can be selected from PVP and PEO, wherein PEO is more commonly used to a certain extent.

[0031] In principle, the water-soluble polymer and the glue particles can be in any ratio in the film. In some embodiments, the ratio of polymer to glue (weight / weight) is not less than about 1:200 and not more than about 2:1, optionally not less than about 1:100 and not more than about 1:1, for example, not less than about 1:50 and not more than about 1.5:1, or not less than about 1:100 and not more than about 1:1, or not less than about 1:40 and not more than about 1:1. Water-soluble polymers of various molecular weights can be used. The molecular weight will depend primarily on factors related to how the film is prepared, which is discussed in detail below.

[0032] In some embodiments, the water-soluble polymer and the glue particles can be in any ratio in the film. For example, the ratio of polymer to glue (weight / weight) is about 1:200 to about 2:1, about 1:100 to about 1:1, about 1:50 to about 1.5:1, about 1:100 to about 1:1, or about 1:40 to about 1:1.

[0033] The water-soluble polymer at least contacts the surface of the glue particles. According to the ratio of the water-soluble polymer to the glue particles, the glue particles can be partially or completely entrained in the matrix of the water-soluble polymer. When, for example, at least a portion of the glue particles is completely surrounded by the matrix, the glue particles can be partially entrained in the water-soluble polymer matrix. When more than half of the glue particles, in some cases substantially all (that is, not less than about 80%, not less than about 85%, not less than about 90%, not less than about 95%, or even not less than about 99%) of the glue particles are completely surrounded by the matrix, the glue particles can be completely entrained by the matrix. The glue particles can be entrained by the matrix by about 80% to about 99%, about 85% to about 95%, or about 90%.

[0034] The water-soluble polymer can be partially or completely coated on the surface of the colloidal particles (e.g., water-soluble coated colloidal particles). In some cases, the particles can also be partially or completely entrained in the matrix of the water-soluble polymer. The water-soluble polymer does not necessarily exist as the matrix, because when the water-soluble polymer only contacts at least a portion of the surface of the water-organic solvent mixture or the organic solvent-insoluble colloidal particles, at least some desired results can be achieved.

[0035] Additional components may be included in the membrane. For example, when the membrane is used as part of a culture device, one or more nutrients (for one or more microorganisms), indicator compounds such as dyes, more particularly such as redox dyes, and selection agents such as antibiotics may be included.

[0036] Products

[0037] An article comprising any of the films discussed above may comprise: a substrate comprising a first major surface; and any of the films discussed above, the film contacting at least a portion of the first major surface of the substrate. Any suitable substrate may be used, as long as the film is laminated well enough to the substrate so as to maintain its integrity until use. The substrate may be plastic, metal, or glass. Plastic is the most common.

[0038] The one or more film-contacting portions of the first major surface may be the outermost layer of one or more layers of the substrate, and do not necessarily have an adhesive on the first major surface of the substrate. This is because in many cases, the film can be laminated to the substrate during the coating process without the need for an adhesive on the film. In other cases, the one or more film-contacting portions of the first major surface may include an adhesive on the first major surface of the substrate. Note that for the purposes of this disclosure and the claims, even if an adhesive layer such as an adhesive film is present on all or part of the first major surface of the substrate, the first major surface is considered to be in contact with the film, because in this case, the adhesive layer or film is considered to be part of the first major surface of the substrate. Although it is advantageous to omit the adhesive when it is not needed because the cost of the product can be lower or the product can be more easily manufactured without the adhesive, in many cases, the adhesive is used to improve the durability or shelf life of the product, to ensure complete and repeatable adhesion between the film and the first major surface, or for other considerations.

[0039] When the article is a cell culture device such as a thin film culture device, the membrane can be disposed within a growth compartment of the thin film culture device.

[0040] Preparation method

[0041] The film can be prepared by any suitable method. For example, a plurality of water-soluble colloidal particles are dispersed in water, dispersed in at least one water-soluble organic solvent, more particularly at least one water-miscible organic solvent, or dispersed in a mixture of water and at least one water-soluble organic solvent. In most cases, the water-soluble organic solvent is a solvent discussed herein about a water-soluble polymer. Most commonly, when water and at least a water-soluble organic solvent are used, they are in a single-phase mixture; however, in the case where at least one water-soluble organic solvent is not miscible in water, it is feasible that a two-phase mixture can be used. When at least one water-soluble polymer will not fully dissolve in an anhydrous system, a mixed solvent system containing water and at least one water-soluble organic solvent is generally required. When at least one water-soluble polymer is dissolved in a separate organic solvent, a separate organic solvent can be used; however, even in this case, it is also desirable to use a mixed solvent system to reduce the amount of organic solvent used in the process.

[0042] In some embodiments, the solid percentage of a plurality of water-soluble colloidal particles is not less than about 5% by weight and not more than about 60% by weight, for example, not less than about 5%, not less than about 10%, not less than about 20%, not less than about 15%, not less than about 30%, or not less than about 40% by weight (regardless of the solvent system used). In other embodiments, the solid percentage of a plurality of water-soluble colloidal particles is not more than about 50%, not more than about 40%, not more than about 30%, not more than about 25%, not more than about 20%, not more than about 15%, or even not more than about 10% by weight.

[0043] In some embodiments, the solid percentage of the plurality of water-soluble colloidal particles is about 5 wt % to about 50 wt %, about 5 wt %, about 10 wt %, about 15 wt %, about 20 wt %, about 25 wt %, about 30 wt %, about 35 wt %, about 40 wt %, about 45 wt % or about 50 wt %.

[0044] At least one water-soluble polymer is then added to the dispersion and can be dissolved in the dispersion, which water-soluble polymer is also usually dissolved in a mixture of water and an organic solvent and in some cases in a separate organic solvent. The addition of the water-soluble polymer and the addition of the colloidal particles can be carried out in any order, or the water-soluble polymer and the colloidal particles can be added simultaneously. If any other reagent will be included in the film, they can also be added to the dispersion as dissolved solutes or as dispersed particles.

[0045] The organic solvent is at least partially dissolved in water. The process can be a single-phase process, in which there is no separate solvent phase. In some cases, the process can be carried out in a multiphase system such as an emulsion system.

[0046] In some cases, stirring the water-soluble polymer of the dissolving gained and the dispersion of the colloidal particles of dispersion for example about 1 minute to about 1 hour thereby breaking up any particle of aggregation can be useful.In some embodiments, stirring the water-soluble polymer of the dissolving gained and the dispersion of the colloidal particles of dispersion for about 2 minutes to about 55 minutes, about 3 minutes to about 50 minutes, about 4 minutes to about 45 minutes, about 5 minutes to about 40 minutes, about 10 minutes to about 35 minutes, about 15 minutes to about 30 minutes or about 20 minutes to about 25 minutes.When stirring, can be by manually carrying out, perhaps can be by using standard laboratory equipment such as agitator, roller or vibrator to carry out.Because aggregation does not always occur, stirring the dispersion is not always necessary.

[0047] The ratio of water soluble polymer to colloidal particles is the same as that in the resulting film. The ratios discussed herein are relevant to films.

[0048] Any suitable concentration of water-soluble polymer can be used. This concentration is subject to the solubility limitation of water-soluble polymer in the mixture of water and organic solvent or organic solvent, and is subject to the limitation of the viscosity of the dispersion or solution of water-soluble polymer, because when this viscosity is too high, then the obtained liquid may be difficult to process or be coated on substrate, or is subject to the limitation of the combination of solubility and viscosity. The molecular weight of water-soluble polymer can also change. It is not desirable to be limited by any particular theory, as the molecular weight of water-soluble polymer increases, the solution viscosity under the same polymer concentration (mass / mass) increases. Such degree depends on the property of polymer to a great extent. Therefore, although the molecular weight and concentration of water-soluble polymer can change, the combination of the molecular weight and concentration of water-soluble polymer is selected to dissolve the water-soluble polymer. The example of suitable molecular weight includes not less than about 100 kD and not more than about 7000 kD. For example, a molecular weight in the range of about 100 kD to about 7000 kD can be used. In some embodiments, molecular weights including not less than about 100 kD, not less than about 1000 kD, not less than about 2000 kD, not less than about 4000 kD, or not less than about 5000 kD may be used. Other exemplary molecular weights are not more than about 7000 kD, not more than about 5000 kD, not more than about 4000 kD, not more than about 2000 kD, and not more than about 1000 kD. However, these molecular weights are exemplary only, and other molecular weights may also be used as long as the final viscosity is acceptable.

[0049] The concentration of the water-soluble polymer is not less than about 0.25% by weight and not more than about 20% by weight. For example, the concentration of the water-soluble polymer may be in the range of about 0.25% by weight to about 20% by weight. In some embodiments, the concentration may be not less than about 0.5% by weight, not less than about 1% by weight, not less than about 5% by weight, not less than about 10% by weight, not less than about 15% by weight, not more than about 20% by weight, not more than about 15% by weight, not more than about 12.5% ​​by weight, not more than about 10% by weight, or not more than about 5% by weight.

[0050] In some embodiments, the molecular weight of the water-soluble polymer may be about 100 kD to about 7000 kD. In some embodiments, the molecular weight may be in the range of about 1000 kD to about 7000 kD, 2000 kD to about 5000 kD, 3000 kD to about 5000 kD, and may be about 500 kD, about 1000 kD, about 2000 kD, about 3000 kD, about 4000 kD, or about 5000 kD.

[0051] In some embodiments, the concentration of the water-soluble polymer is about 0.25% to about 20% by weight. In other embodiments, the concentration is about 0.25%, about 0.5%, about 1%, about 5%, about 10%, about 12.5%, about 15%, or about 20%.

[0052] The resulting dispersion can then be solvent coated on substrates such as plastics, glass, etc. Any suitable solvent coating method can be used, depending on the desired properties of the product. Examples of coating methods include dye coating, blade coating, solvent casting, and spin coating. Solvent coating is feasible because the viscosity of the dispersion will not increase with the addition of colloidal particles of a suitable concentration.

[0053] The viscosity of the dispersion is not less than about 200 cP and not more than about 10,000 cP. For example, the viscosity of the dispersion can be about 200 cP to about 10,000 cP. In some embodiments, the viscosity of the dispersion is about 1,000 cP to about 10,000 cP, 200 cP to about 1,000 cP, 1,000 cP to about 5,000 cP, or 4,000 cP to about 10,000 cP.

[0054] In some embodiments, the resulting dispersion has a viscosity that facilitates coating of the dispersion on a substrate. For example, the dispersion is pumpable, that is, the dispersion has a viscosity that allows the dispersion to be fed through a nozzle.

[0055] After coating, the article can be dried to remove water and organic solvents. The drying step can be carried out to constant weight, but this is not always necessary depending on the desired properties of the final product.

[0056] The total coating weight of the dry film can be about 500 mg / 24 in. 2 About 2500 mg / 24 in 2 In some embodiments, the total coating weight is about 600 mg / 24 in 2 About 2400 mg / 24 in 2 , about 700 mg / 24 in 2 About 2400 mg / 24 in 2 , about 700 mg / 24 in 2 About 2000 mg / 24 in 2 , about 800 mg / 24 in 2 About 2200 mg / 24in 2 , about 900 mg / 24 in 2 About 2100 mg / 24 in 2 , about 1000 mg / 24 in2 About 2000 mg / 24 in 2 , about 700mg / 24 in 2 About 1600 mg / 24 in 2 , about 1100 mg / 24 in 2 About 1900 mg / 24 in 2 , about 1200 mg / 24 in 2 About 1800 mg / 24 in 2 , about 1300 mg / 24 in 2 About 1700 mg / 24 in 2 , about 1400 mg / 24 in 2 To about 1600mg / 24 in 2 , or about 500 mg / 24 in 2 About 1000 mg / 24 in 2 .

[0057] In some embodiments, the present invention relates to a membrane comprising:

[0058] A plurality of water-soluble colloid particles and a water-soluble polymer contacting at least a portion of the surface of the water-soluble colloid particles, wherein the total coating weight of the film is about 500 mg / 24 in 2 About 2500 mg / 24 in 2 within the range.

[0059] In other embodiments, the present invention relates to a membrane comprising:

[0060] A plurality of guar gum particles and a water soluble polymer contacting at least a portion of the surface of the guar gum particles, wherein the total coating weight of the film is about 500 mg / 24 in 2 About 2500 mg / 24 in 2 , or about 700 mg / 24 in 2 To about 2400mg / 24 in 2 , or about 700 mg / 24 in 2 About 2000 mg / 24 in 2 within the range.

[0061] In other embodiments, the present invention relates to a membrane comprising:

[0062] A plurality of guar gum particles and a PVP contacting at least a portion of the surface of the guar gum particles, wherein the total coating weight of the film is about 500 mg / 24 in 2 About 2500 mg / 24 in2 , or about 700 mg / 24 in 2 About 2400 mg / 24 in 2 , or about 700 mg / 24 in 2 About 2000 mg / 24 in 2 within the range.

[0063] In other embodiments, the present invention relates to a membrane comprising:

[0064] A plurality of guar gum particles and PEO contacting at least a portion of the surface of the guar gum particles, wherein the total coating weight of the film is about 500 mg / 24 in 2 About 1500 mg / 24 in 2 , or about 500 mg / 24 in 2 About 1000 mg / 24 in 2 within the range.

[0065] Without wishing to be bound by any particular theory, one advantage of the present invention is that it prevents the phenomenon of gel blocking in dispersion coated substrates or films. Gel blocking is a phenomenon that occurs when the top layer of a dispersion coated substrate or film completely swells or gels upon rehydration, which creates gel blocking on the top layer and prevents complete rehydration of the dispersion coated substrate or film.

[0066] Another advantage of the present invention is that high total coating weights can be achieved by the resulting films prepared by the methods encompassed by the present invention while maintaining optimal swelling or gelling properties of the dispersed colloidal particles.

[0067] How to use

[0068] When the article is a cell culture device such as a thin film culture device, it can be used in the same manner as a conventional cell culture device prepared by prior art methods and lacking a water-soluble polymer. The water-soluble nature of the water-soluble polymer means that when the membrane portion of the cell culture device is contacted with an aqueous sample containing one or more microorganisms to form an inoculated article, the water-soluble polymer will dissolve, allowing water in the aqueous sample to hydrate the colloidal particles.

[0069] The inoculated preparation can then be incubated for a period of time sufficient to allow the microorganisms to undergo at least one reproduction and to detect the presence of the microorganisms. The incubation time can vary greatly depending on the type of microorganism and the temperature. Exemplary incubation times are disclosed in, for example, US5869321, US9988600, and US202001943. After incubation, one or more microorganisms can be detected or colonized by any suitable means. For example, Petrifilm TMThe Plate Reader Advanced (available from 3M Company, St. Paul, MN) is a commercially available device for counting colonies on thin-film culture plates, such as Petrifilm TM The device is available under the brand name ANTIQUID® (also from 3M Company).

[0070] Example

[0071] Material

[0072] BACTO tryptic soy broth (TSB) was obtained from Becton, Dickinson and Company, Franklin Lakes, NJ. Butterfield buffer was obtained from 3M Company, Maplewood, MN. 2,3,5-Triphenyltetrazolium chloride (TTC) was obtained from MilliporeSigma Company, St. Louis, MO. Isopropyl alcohol (IPA) was obtained from VWR International, Radnor, PA.

[0073] Polyvinylpyrrolidone (PVP), grade K90, was obtained from Ashland Incorporated, Wilmington, Delaware.

[0074] POLYOX WSR 301 polyethylene oxide (PEO) polymer (4,000,000 g / mol), POLYOX WSR 303 polyethylene oxide (PEO) polymer (7,000,000 g / mol), POLYOX WSR N12K polyethylene oxide (PEO) polymer (1,000,000 g / mol), and POLYOX WSR N60K polyethylene oxide (PEO) polymer (2,000,000 g / mol) were obtained from DuPont, Wilmington, Delaware.

[0075] Guar gum (Meyprogat 150) was obtained from Danisco, Copenhagen, Denmark. Guar gum was sterilized with ethylene oxide and aerated thoroughly to remove residual sterilant.

[0076] Unless otherwise stated, water was obtained from a MILLI-Q water purification system (EMD Millipore, Billerica, MA).

[0077] Preparation Example 1 . Inoculum preparation

[0078] Bacterial strains Escherichia coli (ATCC 25922), Escherichia coli (ATCC 8739), Escherichia coli (ATCC51813), Staphylococcus aureus (ATCC 25923), Staphylococcus aureus (ATCC6538), Acinetobacter sp. (ATCC 51819) and Chryseobaterium shigense (ATCC 51823) were obtained from Microbiologics, Incorporated (St. Cloud, Minnesota) or from VWR International and were individually incubated overnight in tryptic soy broth (TSB) at 37°C and 200 rpm in an INNOVA44 incubator (New Brunswick Scientific, Enfield, Connecticut). Each inoculum was prepared by serial dilution of a single culture sample with Butterfield buffer. Each culture sample was diluted to produce a final concentration of approximately 50 to 250 colony forming unit (cfu) counts per 1 mL of inoculum.

[0079] Examples 1-24 . Dispersion preparation of guar gum, PVP (K90) and isopropyl alcohol

[0080] 24 separate formulations were prepared using different amounts (in grams) of the components as listed in Table 1. For each formulation, isopropyl alcohol (IPA) and PVP (K90) were added to a glass jar (4 oz) and mixed with a magnetic stir bar until the PVP dissolved. Guar gum was then added to the jar and the mixture was stirred for 30 minutes with a magnetic stir bar, followed by additional mixing by placing the covered jar on a laboratory roller. Roller mixing was continued for at least 1 hour to remove large, visible aggregates.

[0081] Table 1.

[0082]

[0083] Examples 25-34 . Dispersion formulation of guar gum, POLYOX WSR Nl2K PEO polymer, isopropyl alcohol and water

[0084] Ten separate formulations were prepared using different amounts of components (in grams) as listed in Table 2. For each formulation, isopropyl alcohol and POLYOX WSR N12K polyethylene oxide polymer were added to a glass jar (16 ounces) and mixed with a magnetic stirring bar until the polymer was dispersed. Water was added to the jar and the contents were mixed with a magnetic stirring bar for 1 hour. If the polymer was not completely dissolved, the covered jar was placed on a laboratory roller until the polymer was dissolved. Guar gum was then added to the jar, first by manually shaking the jar, and then by placing the covered jar on a laboratory roller for additional mixing for at least 1 hour. Roller mixing was continued for at least 1 hour to remove large, visible aggregates.

[0085] Table 2.

[0086]

[0087] Examples 35-36 . Dispersion formulation of guar gum, POLYOX WSR N60K PEO polymer, isopropyl alcohol and water

[0088] The same procedure reported in Examples 25-34 was followed except that POLYOX N60K polyethylene oxide polymer was used instead of POLYOX WSR N12K polyethylene oxide polymer in the formulation. Two formulations were prepared using different amounts (in grams) of the components listed in Table 3.

[0089] Table 3.

[0090]

[0091] Examples 37-38 . Dispersion formulation of guar gum, POLYOX WSR 301 PEO polymer, isopropyl alcohol and water

[0092] The same procedure reported in Examples 25-34 was followed except that POLYOX WSR 301 polyethylene oxide polymer was used instead of POLYOX WSR N12K polyethylene oxide polymer in the formulation. Two formulations were prepared using different amounts (in grams) of the components listed in Table 4.

[0093] Table 4.

[0094]

[0095] Examples 39-42 . Dispersion formulation of guar gum, POLYOX WSR 303 PEO polymer, TSB, isopropyl alcohol and water

[0096] 4 kinds of independent preparations were prepared using the components of different amounts (in grams) as listed in Table 5.For each preparation, isopropyl alcohol and POLYOX WSR 303 polyethylene oxide polymers were added in a glass jar (16 ounces), and mixed with a magnetic stirring bar until polymer dispersion.Water was added to the jar, and mixed with an IKA Eurostar 60 overhead stirrer (IKA Works, Wilmington, North Carolina) equipped with 4 impellers until polymer dissolution.TSB powder was added to the solution, and then mixed with an overhead stirrer until the color and consistency of the dispersion were uniform.Then guar gum was added to the jar and stirred with an overhead stirrer until the dispersion color and consistency were uniform.

[0097] Table 5.

[0098]

[0099] Examples 43-53 Films prepared by coating the formulations of Examples 1-12 on a PET substrate

[0100] Twelve separate films were prepared by coating a single formulation selected from the formulations of Examples 1-12 onto the surface of a polyethylene terephthalate (PET) film substrate (3.8 mil (0.1 mm) thick). Each PET substrate sample was coated using a 14 mil (0.35 mm) wet gap and notched bar. The coated films were placed in an oven set at 85°C for 12 minutes. The total coating weight (g / 24 in) of the resulting dry film was determined. 2 ), and the coating weight of each component (PVP and guar gum) of each film was also calculated based on the weight of each component (PVP and guar gum) in the coating formulation. The results are reported in Table 6.

[0101] Table 6.

[0102]

[0103] Examples 55-66. Films prepared by coating the formulations of Examples 13-24 on a BOPP substrate

[0104] A biaxially oriented polypropylene (BOPP) film (1.6 mil (0.04 mm) thick) was prepared according to the procedure described in Example 4 of U.S. Patent No. 5,409,838 (Wickert) and laminated on one surface with a pressure sensitive adhesive [isooctyl acrylate / acrylic acid (98 / 2 weight ratio) with TTC indicator].

[0105] Twelve separate films were prepared by coating a single formulation selected from the formulations of Examples 13-24 onto the adhesive surface of a BOPP film substrate. Each BOPP substrate sample was coated using a 14 mil (0.35 mm) wet gap and notched bar. The coated films were placed in an oven set at 85°C for 12 minutes. The total coating weight (g / 24 in) of the resulting dry film was determined. 2 ), and the coating weight of each component (PVP and guar gum) of each film was also calculated based on the weight of each component (PVP and guar gum) in the corresponding coating formulation. The results are reported in Table 7.

[0106] Table 7.

[0107]

[0108] Examples 67-76 Films prepared by coating the formulations of Examples 25-34 on a PET substrate

[0109] Ten individual films were prepared by coating a single formulation selected from the formulations of Examples 25-34 onto the surface of a PET film substrate (3.8 mil (0.1 mm) thick). Each PET substrate sample was coated using a 14 mil (0.35 mm) wet gap and notched bar. The coated films were placed in an oven set at 85° C. for 12 minutes. The total coating weight (g / 24 in) of the resulting dry film was determined. 2 ), and the coating weight of each component (PEO and guar gum) of each film was also calculated based on the weight of each component (PEO and guar gum) in the corresponding coating formulation. The results are reported in Table 8.

[0110] Table 8.

[0111]

[0112] Examples 77-78 Films prepared by coating the formulations of Examples 35-36 on a PET substrate

[0113] Two separate films were prepared by coating a single formulation selected from the formulations of Examples 35 and 36 onto a PET film substrate (3.8 mil (0.1 mm) thick). Each PET substrate sample was coated using a 14 mil (0.35 mm) wet gap and notched bar. The coated films were placed in an oven set at 85° C. for 12 minutes. The total coating weight (g / 24 in) of the resulting dry film was determined. 2 ), and the coating weight of each component (PEO and guar gum) of each film was also calculated based on the weight of each component (PEO and guar gum) in the corresponding coating formulation. The results are reported in Table 9.

[0114] Table 9.

[0115]

[0116] Examples 79-80 Films prepared by coating the formulations of Examples 37-38 on a PET substrate

[0117] Two separate films were prepared by coating a single formulation selected from the formulations of Examples 37 and 38 onto a PET film substrate (3.8 mil (0.1 mm) thick). Each PET substrate sample was coated using a 14 mil (0.35 mm) wet gap and notched bar. The coated films were placed in an oven set at 85° C. for 12 minutes. The total coating weight (g / 24 in) of the resulting dry film was determined. 2 ), and the coating weight of each component (PEO and guar gum) of each film was also calculated based on the weight of each component (PEO and guar gum) in the corresponding coating formulation. The results are reported in Table 10.

[0118] Table 10:

[0119]

[0120] Examples 81-84. Films prepared by coating the formulations of Examples 39-42 on a BOPP substrate

[0121] Four separate films were prepared by coating a single formulation selected from the formulations of Examples 39 to 42 onto the adhesive surface of the BOPP film substrate described in Examples 55-66. Each BOPP substrate sample was coated using a 14 mil (0.35 mm) wet gap and notched bar. The coated films were placed in an oven set at 85° C. for 12 minutes. The total coating weight (g / 24 in) of the resulting dry film was determined. 2 ), and the coating weight of each component (PEO, guar gum and TSB) of each film was calculated based on the weight of each component (PEO, guar gum and TSB) in the corresponding coating formulation. The results are reported in Table 11.

[0122] Table 11.

[0123]

[0124] Embodiment 85 . Preparation of thin film culture device

[0125] The BOPP film substrate of the coating of embodiment 81-84 is cut into 76 mm wide, 102 mm long segments.Take off cover sheet (76 mm wide, 102 mm long) from PETRIFILM Aerobic Count Plates (available from 3M Corporation, Maplewood, Minnesota).Through using double-sided tape, cover sheet is pasted on the film substrate of coating along an edge (76 mm edge) of the film of coating (in hinged mode) to assemble the film culture device.For each device, cover sheet and substrate orientation are made to align the edge, and the guar gum coating surface of cover sheet is towards the coating surface on the film substrate of coating.

[0126] Embodiment 86 . Bacterial count using the device of Example 85

[0127] The final film culture device of Example 85 was inoculated with any of the following inoculants: Escherichia coli (ATCC25922), Escherichia coli (ATCC 8739), Escherichia coli (ATCC 51813), Staphylococcus aureus (ATCC 25923), Staphylococcus aureus (ATCC 6538), Acinetobacter species (ATCC 51819) or Acinetobacter aureus (ATCC 51823). The device was placed on a flat, horizontal surface. The cover sheet of each device was lifted and a single inoculum of 1 mL (i.e., the final dilution described in Preparation Example 1) was carefully added to the compact area in the center of the coated substrate at one time with a pipette. The cover sheet was gently returned to its original position. A 3M PETRIFILM diffuser (obtained from 3M Company) was applied to the outer surface of the cover sheet to diffuse the inoculum to form a circular area with a diameter of about 2 inches (5.1 cm). Each device was incubated at 32° C. for 48 hours. At the end of the incubation period, the bacterial colony formation of the evaluation device was evaluated. The red dot-like colonies distributed on the surface of each device were counted by visual inspection. The results are presented in Table 12 as the average colony counts (cfu / mL) of two experiments (n=2). As a control, 3M PETRIFILM Aerobic Count Plates were also used to analyze the inoculum according to the manufacturer's instructions. The average colony counts (cfu / mL) using the control plates (n=2) are reported in Table 12.

[0128] Table 12.

[0129]

[0130] List of implementation methods

[0131] The following is a non-limiting list of implementations:

[0132] 1. A membrane comprising:

[0133] A plurality of water-soluble colloid particles and a water-soluble polymer contacting at least a portion of the surface of the water-soluble colloid particles, wherein the total coating weight of the film is about 500 mg / 24 in 2 About 2500 mg / 24 in 2 , or about 700 mg / 24in 2 About 2400 mg / 24 in 2 , or about 700 mg / 24 in 2 About 2000 mg / 24 in 2 within the range.

[0134] 2. A membrane according to embodiment 1, wherein the water-soluble polymer is also dissolved in a solution of water and a water-soluble organic solvent, wherein the water-soluble organic solvent is optionally selected from isopropanol, ethanol, methanol, tetrahydrofuran, diethyl ether, methyl ethyl ether, dimethyl ether and acetone, wherein the water-soluble organic solvent is further optionally selected from isopropanol, ethanol and methanol, and even further optionally wherein the water-soluble organic solvent is isopropanol.

[0135] 3. The membrane of any of the preceding embodiments, wherein the polymer is selected from PEO and PVP.

[0136] 4. The film according to any one of the preceding embodiments, wherein the water-soluble glue is capable of gelling when in contact with cold water.

[0137] 5. The film according to any one of the preceding embodiments, wherein the gum is selected from guar gum, locust bean gum and xanthan gum, and optionally wherein the gum is guar gum.

[0138] 6. The membrane according to any one of the preceding embodiments, wherein at least a portion of the particles of the water-soluble gum are completely entrained by the water-soluble polymer.

[0139] 7. The film according to any of the preceding embodiments, wherein the ratio of polymer to gum is not less than about 1:200 and not more than about 2:1, optionally not less than about 1:100 and not more than about 1:1.

[0140] 8. An article comprising a substrate and a film according to any one of the preceding embodiments, the film contacting at least a portion of a first major surface of the substrate, wherein the substrate comprises at least one of plastic, metal or glass, and preferably wherein the substrate comprises plastic.

[0141] 9. The article of embodiment 8, wherein the portion of the first major surface of the substrate that contacts the film is free of adhesive.

[0142] 10. The article of embodiment 8 or 9, wherein the membrane is disposed in a growth compartment of a thin film culture device.

[0143] 11. The article of any one of embodiments 8-10, wherein the film further comprises at least one nutrient for promoting the growth of at least one microorganism.

[0144] 12. The article according to any one of embodiments 8 to 11, wherein the film further comprises at least one dye, optionally at least one redox dye.

[0145] 13. A method of preparing an article, the method comprising:

[0146] The dispersion is formed by the following steps:

[0147] dispersing particles of at least one water-soluble glue in a liquid containing water, at least one water-soluble organic solvent, or a mixture of water and at least one organic solvent, and

[0148] dissolving at least one water-soluble polymer in the liquid containing water, at least one water-soluble organic solvent, or a mixture of water and at least one organic solvent to form a dispersion of particles of the at least one water-soluble colloid and the at least one water-soluble polymer in the liquid,

[0149] as well as

[0150] The dispersion is solvent coated on a substrate to form a film on the substrate; wherein

[0151] The article is optionally an article according to any one of embodiments 8-12; and wherein

[0152] The membrane is optionally a membrane according to any one of embodiments 1-7.

[0153] 14. The method according to embodiment 13 further comprises drying the product to constant weight.

[0154] 15. A method according to any one of embodiments 13-14, wherein the at least one organic solvent comprises one or more of isopropanol, ethanol, methanol, tetrahydrofuran, diethyl ether, methyl ethyl ether, dimethyl ether and acetone, or is optionally one or more of isopropanol, ethanol, methanol, tetrahydrofuran, diethyl ether, methyl ethyl ether, dimethyl ether and acetone, wherein the water-soluble organic solvent is further optionally selected from isopropanol, ethanol and methanol, and even further optionally wherein the water-soluble organic solvent is isopropanol.

[0155] 16. The method of any one of embodiments 13-15, wherein the polymer is PEO, PVP, or a mixture thereof.

[0156] 17. The method according to any one of embodiments 13-16, wherein the ratio of the water to the water-soluble organic solvent is from about 2:1 to about 1:5.

[0157] 18. The method of any one of embodiments 13-17, wherein the dispersed colloidal particles are present in the dispersion at a solids concentration between about 5% and about 50% by weight / volume.

[0158] 19. The method of any one of embodiments 13-18, wherein the concentration of dissolved polymer in the dispersion is from about 20% to about 0.25% on a weight / volume basis.

[0159] 20. A method of using the preparation according to any one of embodiments 8-12, the method comprising contacting the preparation with an aqueous sample containing one or more microorganisms to form an inoculated preparation, incubating the inoculated preparation for a period of time sufficient for the microorganisms to undergo at least one reproduction, and detecting the presence of the microorganisms.

[0160] 21. According to the method according to embodiment 20, the method further comprises performing a colony count on the microorganisms.

[0161] 22. A dispersion comprising:

[0162] a liquid component comprising water, a water-soluble organic solvent at least partially soluble in the water, or both;

[0163] colloidal particles dispersed in the liquid component, and

[0164] A water-soluble polymer is dissolved in the liquid component.

[0165] 23. The dispersion of embodiment 22, wherein the gum particles comprise one or more of guar gum, xanthan gum, or locust bean gum.

[0166] 24. A dispersion according to embodiment 22 or 23, wherein the water-soluble organic solvent is selected from isopropanol, ethanol, methanol, tetrahydrofuran, diethyl ether, methyl ethyl ether, dimethyl ether and acetone, optionally selected from isopropanol, ethanol and methanol, and even further optionally wherein the water-soluble organic solvent is isopropanol.

[0167] 25. The dispersion according to any one of embodiments 22-24, wherein the ratio of water to water-soluble organic solvent is from about 2:1 to about 1:5.

[0168] 26. The dispersion of any one of embodiments 22-25, wherein the dispersed gum is present at a solids concentration of between about 5% and about 60%, or between about 30% and about 60%, or between about 50% and about 60% by weight / volume.

[0169] 27. The dispersion of any one of embodiments 22-26, wherein the concentration of dissolved polymer is between about 20% and about 0.5% on a weight / volume basis.

[0170] 28. The dispersion of any one of embodiments 22-27, wherein the organic polymer is PEO, PVP, or a mixture thereof.

[0171] 29. The dispersion according to any one of embodiments 22-28, wherein the dispersed gum is present at a solids concentration between about 5% and about 60% by weight / volume.

[0172] 30. The dispersion of any one of embodiments 22-29, wherein the concentration of dissolved polymer is 20% to 0.5% on a weight / volume basis.

[0173] 31. The dispersion of any one of embodiments 22-30, or the method of any one of embodiments 12-18, wherein the viscosity of the dispersion is between about 200 cP and about 10,000 cP.

[0174] 32. The film of any one of embodiments 1-7, or the article of any one of embodiments 8-12, wherein the total coating weight of the film is about 500 mg / 24 in 2 About 2500 mg / 24 in 2 within the range.

[0175] 33. The method of any one of embodiments 13-19, or the dispersion of any one of embodiments 22-31, wherein the dispersion when dried forms a total coating weight of about 500 mg / 24 in. 2 About 2500 mg / 24 in 2 Membrane within the range.

[0176] References

[0177] A number of patents and publications are cited above to more fully describe and disclose the present invention and the state of the art to which the present invention relates. Full citations for these references are provided below. Each of these references is incorporated by reference into the present disclosure in its entirety, to the same extent as if each individual reference was specifically and individually indicated to be incorporated by reference.

[0178] All publications mentioned herein are incorporated by reference to the extent that they support the present invention.

Claims

1. A film comprising: A plurality of water-soluble colloid particles and a water-soluble polymer contacting at least a portion of the surface of the water-soluble colloid particles, wherein the total coating weight of the film is about 500 mg / 24 in 2 About 2500 mg / 24 in 2 , or about 700 mg / 24 in 2 About 2400 mg / 24 in 2 , or about 700 mg / 24 in 2 About 2000 mg / 24 in 2 within the range.

2. The film of claim 1, wherein the water-soluble polymer is also dissolved in a solution of water and a water-soluble organic solvent, the water-soluble organic solvent being optionally selected from isopropanol, ethanol, methanol, tetrahydrofuran, diethyl ether, methyl ethyl ether, dimethyl ether and acetone, wherein the water-soluble organic solvent is further optionally selected from isopropanol, ethanol and methanol, and even further optionally wherein the water-soluble organic solvent is isopropanol.

3. The film according to any one of the preceding claims, wherein the polymer is selected from PEO and PVP.

4. A film according to any preceding claim, wherein the water soluble glue is capable of gelling when in contact with cold water.

5. A film according to any one of the preceding claims, wherein the gum is selected from guar gum, locust bean gum and xanthan gum, and optionally wherein the gum is guar gum.

6. A membrane according to any preceding claim, wherein at least a portion of the particles of the water-soluble gum are completely entrained by the water-soluble polymer.

7. The film of any of the preceding claims, wherein the ratio of polymer to gum is not less than about 1:200 and not more than about 2:1, optionally not less than about 1:100 and not more than about 1:

1.

8. An article comprising a substrate and a film according to any one of the preceding claims, the film contacting at least a portion of a first major surface of the substrate, wherein the substrate comprises at least one of plastic, metal or glass, and preferably wherein the substrate comprises plastic.

9. The article of claim 8, wherein the portion of the first major surface of the substrate that contacts the film is free of adhesive.

10. The article of claim 8 or 9, wherein the membrane is disposed in a growth compartment of a thin film culture device.

11. The article of any one of claims 8-10, wherein the film further comprises at least one nutrient for promoting the growth of at least one microorganism.

12. The article of any one of claims 8 to 11, wherein the film further comprises at least one dye, optionally at least one redox dye.

13. A method for preparing an article, the method comprising: The dispersion is formed by the following steps: dispersing particles of at least one water-soluble glue in a liquid containing water, at least one water-soluble organic solvent, or a mixture of water and at least one organic solvent, and dissolving at least one water-soluble polymer in the liquid containing water, at least one water-soluble organic solvent, or a mixture of water and at least one organic solvent to form a dispersion of particles of the at least one water-soluble colloid and the at least one water-soluble polymer in the liquid, as well as coating the dispersion solvent on a substrate to form a film on the substrate; in The article is optionally an article according to any one of claims 8 to 12; and wherein The membrane is optionally a membrane according to any one of claims 1-7.

14. The method of claim 13, further comprising drying the article to constant weight.

15. The method according to any one of claims 13-14, wherein the at least one organic solvent comprises one or more of isopropanol, ethanol, methanol, tetrahydrofuran, diethyl ether, methyl ethyl ether, dimethyl ether and acetone, or optionally isopropanol, ethanol, methanol, tetrahydrofuran, diethyl ether, methyl ethyl ether, dimethyl ether and acetone, wherein the water-soluble organic solvent is further optionally selected from isopropanol, ethanol and methanol, and even further optionally wherein the water-soluble organic solvent is isopropanol.

16. The method according to any one of claims 13-15, wherein the polymer is PEO, PVP or a mixture thereof.

17. The method of any one of claims 13-16, wherein the ratio of the water to the water-soluble organic solvent is from about 2:1 to about 1:

5.

18. The method of any one of claims 13-17, wherein the dispersed colloidal particles are present in the dispersion at a solids concentration of about 5% to about 50% by weight / volume.

19. The method of any one of claims 13-18, wherein the concentration of dissolved polymer in the dispersion is from about 20% to about 0.25% by weight / volume.

20. A method of using the preparation according to any one of claims 8-12, the method comprising contacting the preparation with an aqueous sample containing one or more microorganisms to form an inoculated preparation, incubating the inoculated preparation for a period of time sufficient for the microorganisms to undergo at least one reproduction, and detecting the presence of the microorganisms.

21. The method of claim 20, further comprising performing a colony count on the microorganisms.

22. A dispersion comprising: a liquid component comprising water, a water-soluble organic solvent at least partially soluble in the water, or both; colloidal particles dispersed in the liquid component, and A water-soluble polymer is dissolved in the liquid component.

23. The dispersion of claim 22, wherein the gum particles comprise one or more of guar gum, xanthan gum, or locust bean gum.

24. The dispersion according to claim 22 or 23, wherein the water-soluble organic solvent is selected from isopropanol, ethanol, methanol, tetrahydrofuran, diethyl ether, methyl ethyl ether, dimethyl ether and acetone, optionally selected from isopropanol, ethanol and methanol, and even further optionally wherein the water-soluble organic solvent is isopropanol.

25. The dispersion of any one of claims 22-24, wherein the ratio of water to water-soluble organic solvent is from about 2:1 to about 1:

5.

26. The dispersion of any one of claims 22-25, wherein the dispersed gum is present at a solids concentration of 50% to 5% by weight / volume.

27. The dispersion of any one of claims 22-26, wherein the concentration of dissolved polymer is between about 20% and about 0.5% by weight / volume.

28. The dispersion of any one of claims 22-27, wherein the organic polymer is PEO, PVP or a mixture thereof.

29. The dispersion of any one of claims 22-28, wherein the dispersed gum is present at a solids concentration of 50% to 5% by weight / volume.

30. A dispersion according to any one of claims 22 to 29, wherein the concentration of dissolved polymer is from 20% to 0.5% by weight / volume.

31. The dispersion of any one of claims 22-30, or the method of any one of claims 12-18, wherein the viscosity of the dispersion is from about 200 cP to about 10,000 cP.

32. The film of any one of claims 1-7, or the article of any one of claims 8-12, wherein the total coating weight of the film is about 500 mg / 24 in. 2 About 2500 mg / 24 in 2 within the range.

33. The method of any one of claims 13-19, or the dispersion of any one of claims 22-31, wherein the dispersion when dried forms a total coating weight of about 500 mg / 24 in. 2 To about 2500mg / 24 in 2 Membrane within the range.

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