Patent Application
20120315240
This disclosure relates to compositions and methods for capturing microbes, particularly bacteria and algae, and for preventing microbial proliferation.
Certain microbes, for example gram negative bacteria and algae, exude viscoelastic extracellular polymeric substances called exopolysaccharides (EPS), and these exo-polysaccharides and their complexes with proteins act to protect the microbial cell from external physical and chemical attacks. The EPS also are critical in cellular cohesion responsible for the formation of films, and EPS are involved in adhesion of the microbial cells to surfaces. EPS materials and EPS/protein complexes are extremely viscoelastic, a feature that can cause unexpected yet severe problems in aqueous environments. For example, the viscoelasticity of less than one pound of brown algae on the total hydroplane surfaces of many naval destroyers is sufficient to reduce top speed from 22 knots to 18 knots and cause fuel consumption to increase by as much as 20%.
The presence of these materials in sea water causes reverse osmosis membranes to lose 20% of their flux within one hour of engagement due to the formation of a monomolecular layer of EPS, which can result in a four-fold increase in the polar component of the surface energy of the membrane. For example,
Conventionally, materials such as copper, silver, organic anti-microbial compounds, and other compositions and materials have been employed to prevent microbial growth. While the exact mechanisms by which these materials operate often are not understood, some compositions such as organic bactericides function primarily by interfering with cell wall formation. The interference with cellular metabolism and respiration is implicated in other materials, as in the case of the metals. In effect, all of these conventional materials act in some manner as poisons, which can impart adverse effects on human health and ecology. Therefore, coatings treated with these materials and their direct introduction into water is generally undesirable due to their negative effects on flora, fauna, and humans.
In order for microbes to reproduce and anchor to a surface, they must first exude an EPS “nest” which causes divided cells to cohere to each other, and provides the necessary conditions for them to anchor to a substrate. This EPS nest is in fact critical to cell survival, and without such a structure, cells generally will wither and die. However, conventional antimicrobial treatments that produce dead cells also can be problematic because of the adverse effects of cell membrane decomposition products, for example the components of the cell walls of certain dead bacteria. These membrane decomposition products are known as endotoxins, and endotoxins can cause human diseases through inhalation of aerosols containing these materials, through ingestion, and through skin contact. Moreover, endotoxins have also been identified as one of the sources of EPS materials responsible for fouling filtration surfaces such as in membrane filtration devices and in anti-bacterial filters.
Further, there are adverse effects to water treatment and purification devices which arise from the presence of microbes and their decomposition products in water, and which are problematic to human health. For example, water purification devices often experience what is referred to microbial “grow-through”. Media filters, sand filters, carbon filters, clay filters, and others have limited life spans due to the growth of bacteria. As a result, these materials become septic and malodorous and release cellular decomposition products as part of their effluent. These decomposition products foul and interfere with the efficient operation of downstream treatment technologies, such as membrane filtration and ion exchange. Therefore, the presence of cellular decomposition products in water can cause human health concerns through various routes of entry. Although poisons such as silver and bactericides may kill microbes, they do nothing to address the microbial decomposition products, and their use can in some cases actually enhance the pathogenicity of the water.
Therefore, what are needed are non-toxic compositions and methods that provide antimicrobial activity, which can address the need for safer and more environmentally benign ways to protect various substrates, media, and surfaces from microbial growth and proliferation. One possible approach would be to develop compositions and methods that could help prevent the EPS from fulfilling its role in cellular organization and cohesion. It would be desirable if the non-toxic compositions and methods could not simply exhibit antimicrobial activity, but also address the problems from endotoxins that may arise from that antimicrobial activity. Desirably, these materials would not result in negative effects on flora, fauna, and humans.
Now in accordance with the present disclosure, it has been discovered that compositions disclosed in certain prior patents of the present applicant, which compositions comprise a homogeneous thermal reaction product of an oil component selected from the group consisting of glycerides, fatty acids, alkenes and alkynes, and a methacrylate or acrylate polymer component, can unexpectedly be used as extremely effective microbial growth inhibition (“MGI”) agents, by applying the compositions to portions of a material where the microbes thereafter deposit as a result of contact with a liquid carrier in which the microbes are dispersed. These compositions, which for convenience may be referred to herein as “MGI absorption compositions”, are disclosed in U.S. Pat. Nos. 6,805,727; 6,475,393; 6,180,010; 5,437,793; 5,698,139; 5,837,146; and 5,961,823, all of which disclosures are hereby incorporated by reference. The compositions are taught in these prior patents for use in capturing and immobilizing a wide variety of fluid contaminants such as hydrocarbons, finely suspended particulates and the like.
Accordingly, this disclosure describes compositions and methods for capturing microbes, particularly bacteria and algae, and for inhibiting proliferation of these microbes. In addition, the subject compositions and methods can also capture microbial membrane and cell wall decomposition products in addition to immobilizing and prevent proliferation of the microbes themselves. Further, this disclosure relates to compositions and methods for capturing microbes such as bacteria and algae, that can function in an aqueous environment to remove and suppress their growth.
The term “microbes” as used in this disclosure shall mean those microorganisms that exude viscoelastic exopolysaccharides (EPS), for example, bacteria and algae. Examples of algae that in accordance with the disclosure are subject to capture and growth inhibition include brown algae and green algae. Examples of bacteria that in accordance with the disclosure are subject to capture and growth inhibition include: gram negative bacteria; gram negative sulfate-reducing bacteria; exopolysaccharide-producing cyanobacteria; facultative anaerobic organisms that produce exopolysaccharides; any type of exopolysaccharide-producing marine bacteria; and the like. Additional examples of microorganisms that are subject to such capture and growth inhibition include those disclosed in: Lee et al., “Culture and Identification of Bacteria from Marine Biofilms”, The Journal of Microbiology 2003, 41(3), 183-188; and Poli et al., “Bacterial Exopolysaccharides from Extreme Marine Habitats: Production, Characterization and Biological Activities”, Marine Drugs 2010, 8, 1779-1802. In one aspect, fungal species including fungal spores can be excluded from the term microbe.
This disclosure is distinguished from the present inventor's international publication WO 2009/061462 by, among other things, the feature that WO 2009/061462 is directed to a filtration system that removes bacteria and fungal spores dispersed in an air stream. Because the carrier media is a gas, and because the devices and mechanisms by which gas and liquid filtration are effected are generally recognized as entirely distinct and not comparable or transferable between each other, it is entirely unexpected that microbial inhibition could occur in aqueous media using these compositions. Moreover, while not intended to be bound by theory, it is thought that the mechanisms of operation of interference with bacterial growth in the gas phase relate to the present compositions displacing and substantially eliminating the availability of water to the microbes. Such a process is entirely distinct from what could occur in an aqueous carrier environment; therefore, the efficacy of the present compositions in an aqueous medium to interfere with the growth mechanisms of living microbes is most unexpected and unobvious.
In addition, while there may be some recognition that inert fragments that are products of bacterial disintegration (endotoxins) dispersed in a liquid carrier can be captured by the said compositions, in the similar manner as other particulates (see e.g. U.S. Pat. No. 7,449,119), it has not heretofore been known that such compositions when used as prescribed by the present disclosure could effectively disrupt the growth mechanisms of living bacteria dispersed in a liquid carrier. No additional chemical or photochemical components such as oxidants or UV radiation are necessary for interference of the growth mechanisms of living microbes using the present compositions and methods.
Therefore in one aspect and while not theory bound, it is thought that the disclosed compositions and methods function in a fundamentally novel way by their extremely high affinity for EPS and other viscoelastic and oleophilic materials. Therefore, the materials are capable of incorporation, capture, or assimilation of this external layer of the microbial cell, which results in cell death by preventing anchoring of the cell to surfaces and cohesion of the cell to other cells. Additionally, the present compositions and methods are able to incorporate and remove cellular decomposition products containing these oleophilic, viscoelastic components, including endotoxins, thereby preventing downstream fouling and decreasing the pathogenicity of water aerosols. It is thought that the compositions are effective due to their viscoelastic and amphiphatic properties, which impart an extremely high cohesive affinity for EPS, resulting in antimicrobial activity.
In another aspect, for example, disclosed embodiments provide methods and compositions capable of preventing microbial growth on filter substrates and other surfaces, and of capturing the decomposition products of microbial membranes and cell walls by incorporation of the viscoelastic components into the MGI absorption composition-treated substrate. For example, there is provided a method for inhibiting bacterial growth at a material which in use is subjected to contact with a liquid media in which the bacteria are contained or suspended, said method comprising: coating the portions of said material which during use are accessible to bacterial contact with a bacterial growth inhibiting absorption composition comprising a homogeneous thermal reaction product of an oil component selected from the group consisting of glycerides, fatty acids, alkenes and alkynes, and a methacrylate or acrylate polymer component.
While not intending to be bound by theory, it is thought that disclosed embodiment can function by incorporating the microbial-exuded EPS “nest” and preventing the cells from anchoring, which causes them to wither and die. The MGI absorption compositions, for example when diffused on a surface, can capture cells and render them unable to multiply due to incorporation of the exopolysaccharide biofilm matrix which the multiplying cell must exude in order for the new cell to anchor and protect itself. The present disclosure also provides embodiments that are able to prevent microbial growth without employing poisons or oxidants, by cohesive incorporation and capture of the EPS which is critical to cell survival. This property enables substances which have been treated with the composition to capture and incorporate cell membrane decomposition products from dead cells. These membrane decomposition products are known as endotoxins, and are known to cause human diseases through inhalation of aerosols containing these materials, through ingestion and through skin contact.
In one aspect, there is provided a method for suppressing microbial growth, the method comprising:
Among other things, EPS materials are amphiphatic and therefore are not efficiently removed by simply oleophilic materials or substrates which are not also amphiphatic and also exhibit viscoelastic properties like the EPS. Amphiphatic materials and chemicals generally possess both hydrophilic and lipophilic properties. When in water, amphiphatic molecules fold in a manner such that the hydrophilic components of the molecule are external and the oleophilic components are unexposed.
While not intending to be limited by theory, it is thought that the present amphiphatic and viscoelastic compositions work well for the disclosed methods as compared to a simple oleophilic substances for the following reasons. When an amphiphatic molecule comes in contact with an oleophilic substrate such as an EPS, the oleophilic part of the EPS dissolves into the oleophilic substrate leaving the hydrophilic component exposed. Thus, the oleophilic substrate is unable to remove additional EPS's due to the formation of an insulating monomolecular boundary layer. Because the present compositions are also amphiphatic like the EPS, they can exploit the mutual affinity that like compounds have for each other as well as the viscoelasticity of the EPS. Also in contrast to a surface absorption method, the present compositions and methods incorporate and capture the EPS into a cohesive, oleophilic and viscoelastic mass. Once such a mass is formed, introduction of additional EPS results in its continued incorporation and a larger mass is simply formed. In contrast, once an oleophilic substance has dissolved its limit of oleophilic portion of an EPS, a blinding off occurs with these conventional oleophilic materials, resulting from formation of an insulting boundary layer. Therefore, it is thought that a surface must be oleophilic and viscoelastic in order to capture EPS without fouling or developing high differential pressures.
The chemistry for the present disclosure is provided by the thermal reaction product of a drying oil or oils which are caused to crosslink in the presence of oxygen or in a reducing atmosphere. Polymers such as methacrylates should also be present. The resultant reaction product is viscoelastic upon combining with oil or EPS, in addition to being amphiphatic with a strong oleophilic component (HLB less than 13). Such reaction products are in accord with the disclosures in the previously referenced patents of the present inventor, and may also be referred to herein as MYCELX®, the registered trademark of MyCelx, Inc., the assignee of the said patents, and the commercial source for the compositions.
The present compositions are readily synthesized from a polymer component and an oil component selected from the group consisting of glycerides, fatty acids, alkenes and alkynes. In a preferred embodiment, the product is synthesized from an isobutyl methacrylate polymer, and the oil component is one derived from a natural oil, such as linseed oil, tang oil, or sunflower oil. Optionally, the composition is then diluted with a solvent, such as 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate or acetone, and the diluted composition can then be applied to a desired substrate for use as a filtration media as disclosed herein.
The polymer component of the present composition can be a synthetic polymer such as polymers derived from methacrylates. In one aspect, the polymer is derived from methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, or n-butyl methacrylate, or may be a copolymer containing a methacrylate polymer. For example, in some embodiments, the polymer is a poly(isobutyl methacrylate) polymer such as that obtainable from ICI Acrylics as ELVACITE™ 2045, or a methacrylate/methacrylic acid copolymer such as ELVACITE™ 2008 or 2043. However, other similar polymers can be used to prepare similar compositions that can be used according to this disclosure. Combinations of polymers can be used to advantage in the preparation of the present compositions.
In one embodiment of the absorbent composition, the oil component of the composition is a glyceride derived from natural oils such as oils of vegetable or animal origin. Of the vegetable oils, drying oils such as sunflower, tung, linseed, and the like; and semi-drying oils, such as soybean and cottonseed oil, have been shown to be useful as the glyceride component of the disclosure. Animal oils, such as, for example, fish oil, tallow and lard can also be used as a glyceride component of the composition if desired. It is anticipated that any drying oil or semi-drying oil will work in the composition. Generally, a drying oil is defined as a spreadable liquid that will react with oxygen to form a comparatively dry film. Optionally, combinations of two or more glycerides can be used as reactants with the polymer to provide useful absorbent compositions.
In one embodiment, the oil component of the absorbent composition is a glyceride derived from a drying oil, such as linseed oil, that can be obtained from Cargill, Inc. as Supreme Linseed Oil, or sunflower oil. Where the oil component of the composition is a fatty acid or alkene or alkyne utilized as the reactant with the polymer, it contains from about 8 to 24 carbon atoms, and preferably from about 10 to 22 carbon atoms. Typical fatty acids include both saturated and unsaturated fatty acids, such as lauric acid [dodecanoic acid], linolenic acid, cis-5-dodecanoic acid, oleic acid, erucic acid [cis-docosanoic acid], 10-undecynoic acid, stearic acid, caprylic acid, caproic acid, capric acid [decanoic acid], palmitic acid, docosanoic acid, myristoleic acid [cis-9-tetradecenoic acid], and linoleic acid. Combinations of fatty acids can also be used. Typical alkenes and alkynes contain at least one and preferably one or two degrees of unsaturation, and from about 8 to 24 carbon atoms, with 10-20 carbon atoms being preferred. Preferred alkenes and alkynes are those such as 1-decene, trans-5-decene, trans-7-tetradecene, 1,13-tetradecadiene, 1-tetradecene, 1-decyne, and 5,7-dodecadiyne.
The absorbent composition is a product with characteristics different from either of the starting materials or a simple mixture of the two starting materials, thus showing that a new composition is produced by the thermal reaction. Specifically, the oil/polymer absorbent compositions pass a clear pill test after being heated at the elevated temperatures and do not separate into two parts upon being cooled but, rather form a homogenous, uniphase compound.
Some embodiments of the disclosure can include filter media and granular media impregnated or infused and cured with the reaction product chemistry. For example, when such devices used to treat produced water from oil and gas production, flow of process water and boiler condensate can be restricted by sulfate-reducing bacteria which are able to grow rapidly in aerobic and anaerobic conditions without the need for sunlight.
Treatment of the selected media with MYCELX® allows the media to intercept the microbes based on chemical affinity for the external EPS layer while at the same time, causing cell death due to an elimination of the ability to anchor. Decomposition products that are generated by the media are greatly reduced thereby reducing fouling of downstream processes. If desired, fugitive endotoxins can be treated by downstream MYCELX® polishing filters. Elimination of the ability of the media to support microbial growth prevents production of endotoxins and EPS and prevents sepsis of downstream processes. A second use of the current disclosure is the incorporation of this chemistry into paints and coatings to prevent fouling and microbial growth. In this aspect, the incorporation of the compositions into paints and coatings can prevent fouling and growth of the microbes such as bacteria and algae as disclosed herein, but also can prevent fungal growth and fouling on surfaces when so incorporated.
The present methods and compositions are also applicable to the capture and inhibition of so-called nanomicrobes or nanobacteria, as follows. The science of microbial growth, EPS, and their decomposition products has seen considerable advances recently, such as those by J. Craig Ventner and others who have conducted DNA sequencing of ocean water and other natural water sources. Based on these DNA sequencing experiments, researchers have discovered the existence of between 1 and 10 million new species of bacteria. In many cases, these bacteria have not been visualized due to their extremely small size that places them below the capability of optical microscopy, and also due to the destructive nature of electron microscopy. Some researchers believe that these “nanomicrobes” are not only ubiquitous in water, but also may be responsible for much of the chemistry on earth. Confirmation of the existence of these microbes can explain some phenomena which have been anomalous to date, one example of which follows.
Reverse osmosis membranes experience an almost instantaneous decrease in flux and increase in differential pressure upon exposure to water. For example, if a membrane is employed in recirculation mode to clean 55 gallons of water in a drum, the differential pressure of the membrane will increase by 20% within only one hour. If the same water is then recirculated through a new membrane, the same decrease in flux and increase in pressure is experienced. Spectroscopic analysis for chlorophyll indicates the presence of chlorophyll even after the second challenge, even though it would be expected that fouling factors present on the second membrane would have been removed or at least diminished by treatment of the water by the first membrane. This observation can be explained by the production of additional fouling factor, in this case EPS and endotoxins, and essentially confirms that nanobacteria are ubiquitous and very difficult to remove even in treated water. The observation also suggests that such nanobateria, EPS and endotoxins probably resist removal by adhesion to surfaces. One explanation for the replenishment of the EPS and the endotoxins initially removed is that reverse osmosis of the water decreases the electrolyte concentration and the osmotic pressure, thus killing some of the microbes. This results in the production of cellular decomposition products in the form of endotoxins. Moreover, EPS may be replenished due to enhanced production by the surviving cells as a means of protecting themselves from the environmental insult generated by electrolyte reduction. This results in increased EPS production by the microbe as this its primary way of protecting itself from external chemical and osomotic challenges.
In contrast to aspects of this disclosure, U.S. Pat. No. 7,449,119 to Brown discloses that MYCELX® is used to remove bacterial endotoxins or other bacterial fragments that are freely present after bacteria have been destroyed by chlorine dioxide, and chlorine dioxide is required in all embodiments of the Brown disclosure. The methods disclosed herein can be carried out in the absence of contacting the liquid media or the bacteria with an oxidant or poisons. Therefore, the present compositions are capable of preventing bacterial growth on surfaces or filtration media to which such compositions are applied without oxidants or poisons by cohesive incorporation and capture of the EPS which is critical to cell survival. This feature also enables substances which have been treated with the composition to capture and incorporate endotoxins and other cell membrane decomposition products from dead cells, once they are formed.
It also has been discovered that, unlike the U.S. Pat. No. 7,449,119 to Brown, the present compositions and methods are capable of preventing or inhibiting microbial growth, particularly of bacteria and algae, using a absorption composition comprising a homogeneous thermal reaction product of an oil component selected from the group consisting of glycerides, fatty acids, alkenes and alkynes, and a methacrylate or acrylate polymer component, including those in which the absorption composition is viscoelastic, amphiphatic, and has a hydrophilic-lipophilic balance (HLB) of less than 13. The Brown patent discloses a number of natural or synthetic materials are capable of physically removing endotoxins, including synthetic materials such as polyurethane, polyethylene, polypropylene and other synthetic oleophiles including cross-linked polymers and rubber materials. In contrast to the present disclosure, these materials are not capable of preventing or inhibiting microbial growth, likely because they can not prevent the EPS from fulfilling its role in cellular organization and cohesion. It is theorized that cells captured on a PAAC or TRPI infused surface are unable to multiply due to incorporation of the exopolysaccharide biofilm matrix which the multiplying cell must exude in order for the new cell to anchor itself and to protect the new cell from the environment
The present disclosure provides a means to address even the persistent replenishment of the EPS and the endotoxins that arise due to enhanced production by the surviving cells from an initial treatment. Conventional treatments do not afford such versatile, targeted methods and compositions that area capable of this functionality. In addition, more conventional or traditional treatments are generally toxic compositions, and do not provide the environmentally safe methods to protect various substrates and surfaces from microbial growth and proliferation. Therefore, the present materials can avoid the negative effects on flora, fauna, and humans, and afford long-term functionality from its continued incorporation of microbes, their EPS, and endotoxins that is so desirable.
The following examples are provided to illustrate various embodiments of the disclosure and the claims. Unless otherwise specified, reagents were obtained from commercial sources. Various aspects of the compositions, their precursors and components, and their syntheses are provided in the following references, each of which is incorporated by reference herein in its entirety: U.S. Pat. Nos. 5,437,793; 5,698,139; 5,746,925; 5,837,146; 5,961,823; 6,180,010; 6,475,393; and 6,805,727.
The term MYCELX® is used herein to refer to the homogeneous thermal reaction product of an oil component selected from the group consisting of glycerides, fatty acids, alkenes and alkynes, and a methacrylate or acrylate polymer component.
A composition prepared according to any one of Examples 1-3 of U.S. Pat. No. 5,698,139, was prepared as disclosed. The resulting chemistry is applied to a MBPP (melt blown polypropylene) depth filter and then caused or made to cure by use of heat, actinic radiation, or organic or inorganic polymerization initiators as disclosed in U.S. Pat. Nos. 6,180,010; 6,475,393; 6,491,822; and 6,805,727. Each of U.S. Pat. Nos. 5,698,139; 6,180,010; 6,475,393; 6,491,822; and 6,805,727 are incorporated by reference herein in their entireties.
Using a method analogous to that described in Example 1, 40% by w/w Tung Oil, 40% Linseed Oil w/w, and 20% isobutyl methacrylate (IBMA) w/w are combined and heated to 375° F. or until the third endothermic phase transition occurs. The resulting composition is applied and cured as indicated in Example 1.
Using a method analogous to that described in Example 1, 30% Soy Bean Oil w/w and 70% IBMA w/w are combined and heated, and the resulting composition is applied and cured.
The composition as in Example 2 is prepared and applied to sand. This composition is capable of intercepting bacteria and algae from an aqueous media and preventing their proliferation and also capable of removing bacterial endotoxins from the aqueous media.
Spa filters are treated with the MYCELX® composition prepared according to Example 3. The microbial count is measured for pool water which has been filtered using both MYCELX® treated and untreated nylon spa filters, using AOAC method 965.13 [Official Methods of Analysis of the AOAC International]. A four log reduction on microbial count is observed when using MYCELX®-treated spa filters as compared to the untreated spa filters.
Melt-blown polypropylene (MBPP) spill response materials are treated with the chemistry from Example 1 and deployed in a swamp adjacent identical untreated pads and booms. After a three-month deployment, the untreated pads and booms exhibit water-logging and rampant microbial growth. In contrast, the MYCELX®-treated pads and booms remain dry and free of microbial growth.
Using a method analogous to that described in Example 1, 70% Safflower Oil w/w and 30% IBMA w/w are used to synthesize the composition as above and are cured into carbon and glass fiber air filters. The resulting filters are deployed in an automotive plant side-by-side with the untreated version of the same carbon and glass fiber air filters. After three months, the untreated filter was wet and exhibited the sulfurous smell indicative of microbial growth. In contrast, the MYCELX®-treated carbon and glass fiber air filters were dry and odor free. A 1-cm coupon was taken from each filter and placed in an Agar Petri dish and allowed to incubate for 9 days at 27° C. After this incubation period the samples were inspected and the dish with the untreated coupon was covered in microbial growth. In contrast, the treated coupon exhibited no microbial growth and no odor.
The publications discussed or listed in this disclosure are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the inventor is not entitled to antedate any such published disclosure by virtue of prior invention. If a term used in this disclosure is not specifically defined herein and requires referring to extrinsic sources for construction, the definition from the IUPAC Compendium of Chemical Terminology, 2nd Ed (1997) can be applied, as long as that definition does not conflict with any other disclosure or definition applied herein, or render indefinite or non-enabled any claim to which that definition is applied. To the extent that any definition or usage provided by any document or portion thereof incorporated herein by reference conflicts with the definition or usage provided herein, the definition or usage provided herein controls.
The Abstract of the disclosure is provided herewith to satisfy the requirements of 37 C.F.R. §1.72 and the purpose stated in 37 C.F.R. §1.72(b), and is not intended to be used to construe the scope of the appended claims or to limit the scope of the subject matter disclosed herein. Any use of the past tense to describe an example is not intended to reflect that all or any step of the example has actually been carried out.
Unless indicated otherwise, when a range of any type is disclosed or claimed, for example a range of weight percents, particles sizes, time periods, and the like, it is intended to disclose or claim individually each possible individual number that such a range could reasonably encompass, including any sub-ranges encompassed therein. For example, when the Applicant disclose or claim a weight percent can be from about 30% to about 40%, Applicant intends to recite that the weight percent can be about 30%, about 31%, about 32%, about 33%, about 34%, about 35%, about 36%, about 37%, about 38%, about 39%, or about 40%, including any ranges, sub-ranges, or combinations thereof between any disclosed values. Accordingly, Applicant reserves the right to proviso out or exclude any individual members of any such group, including any sub-ranges or combinations of sub-ranges within the group, that can be claimed according to a range or in any similar manner, if for any reason Applicant chooses to claim less than the full measure of the disclosure, for example, to account for a reference that Applicant is unaware of at the time of the filing of the application.
This application claims priority from U.S. provisional patent application Ser. No. 61/520,646, filed on Jun. 13, 2011, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61520646 | Jun 2011 | US |
