EP2571535A1 - Compositions, systems, and/or methods involving chlorine dioxide ("cio2") - Google Patents

Abstract

Certain exemplary embodiments can provide a composition of matter comprising a solid form of chlorine dioxide complexed with a cyclodextrin. The concentration of chlorine dioxide in said solid form is greater than approximately 5.8 percent by weight. Certain exemplary embodiments can provide a method comprising forming a solid complex comprising chlorine dioxide and cyclodextrin, wherein a concentration of chlorine dioxide in the solid complex is greater than 5.8 percent by weight.

Description

Compositions, Systems, and/or Methods Involving Chlorine Dioxide ("C102")

Cross-References to Related Applications

[1] This application claims priority to, and incorporates by reference herein in its entirety, pending United States Provisional Patent Application 61/346,112 (Attorney Docket 1099-037), filed 19 May 2010.

Brief Description of the Drawings

[2] A wide variety of potentially practical and useful embodiments will be more

readily understood through the following detailed description of certain exemplary embodiments, with reference to the accompanying exemplary drawings in which:

[3] FIG. 1 is a block diagram of an exemplary embodiment of a method 1000;

[4] FIG. 2 is a graph of an exemplary embodiment's ability to retain C102;

[5] FIG. 3 is a graph of an exemplary embodiment's ability to retain C102;

[6] FIG. 4 is a table describing specifics of individual examples; and

[7] FIG. 5 is a flowchart of an exemplary embodiment of a method 5000.

Detailed Description

[8] Certain exemplary embodiments can provide a composition of matter comprising chlorine dioxide complexed with a cyclodextrin.

[9] Chlorine dioxide ("C102") can be an excellent disinfectant, and/or can be

effective against a wide range of organisms. For example, C102 can provide excellent control of viruses and bacteria, as well as the protozoan parasites Giardia, Cryptosporidium, and/or amoeba Naegleria gruberi and their cysts.

[10] In addition to disinfection, C102 can have other beneficial uses in water

treatment, such as color, taste and odor control, and removal of iron and manganese. There are also important uses outside of water treatment, such as bleaching pulp and paper (its largest commercial use), disinfection of surfaces, and sanitization/preservation of fruits and vegetables.

[11] C102 can present certain challenges, which can stem largely from its inherent physical and chemical instability. C102 in pure form is a gaseous compound under normal conditions. As a gas, it can be sensitive to chemical decomposition, exploding at higher concentrations and when compressed. Because C102 can be highly soluble in water, C102 can be used as a solution of C102 gas dissolved in water.

[12] However, the gaseous nature of C102 means that it can be volatile, thus C102 tends to evaporate rapidly from solutions when open to the atmosphere (physical instability). This tendency can limit the practically useful concentrations of C102 solutions. With concentrated solutions, this rapid evaporation can generate gaseous C102 concentrations that can present an unpleasantly strong odor, and can pose an inhalation hazard to users. A closed container of the solution can quickly attain a concentration in the headspace of the container that is in equilibrium with the concentration in the solution. A high concentration solution can have an equilibrium headspace concentration that exceeds the explosive limits in air (considered to be approximately 10% by weight in air).

[13] For these and other reasons, virtually all commercial applications to date have required that C102 be generated at the point of use to deal with these challenges. However, on-site generation also can have significant draw-backs, particularly in the operational aspects of the equipment and the need to handle and store hazardous precursor chemicals. It can be desirable to have additional forms of ready-made C102.

[14] Certain exemplary embodiments can provide a composition of matter comprising a solid form of chlorine dioxide complexed with a cyclodextrin. When stored, a concentration of the chlorine dioxide in the composition of matter can be retained at, for example, greater than 12% for at least 14 days and/or greater than 90% for at least 80 days, with respect to an initial concentration of chlorine dioxide in said composition of matter. Certain exemplary embodiments can provide a method comprising releasing chlorine dioxide from a solid composition comprising chlorine dioxide complexed with a cyclodextrin.

[15] Certain exemplary embodiments can provide a solid complex formed by

combining C102 with a complexing agent such as a cyclodextrin, methods of forming the complex, and/or methods of using the complex as a means of delivering C102, such as essentially instantly delivering C102.

[16] C102 is widely considered to be inherently unstable. Also, C102 is widely

considered to be reactive with a fairly wide range of organic compounds, including glucose, the basic building block of cyclodextrins such as alpha- cyclodextrin. It is reasonable to assume that C102 will react with cyclodextrins in solution. Additionally, relatively impure C102 systems containing chlorite and/or chlorate impurities might be expected to destroy cyclodextrins due to the reactivity of chlorite/chlorate with organic compounds.

[17] Chlorine dioxide can be generated by the method described in the OxyChem

Technical Data Sheet "Laboratory Preparations of Chlorine Dioxide Solutions— Method II: Preparation of Reagent-Grade Chlorine Dioxide Solution". Nitrogen has generally been used in our laboratory as the stripping and diluting gas, but it is expected that any inert gas can be used. It is believed that the combined

C102/nitrogen gas stream can be used in any convenient concentration between 0% and the explosive limit.

[ 18] That method specifies the following equipment and reagents:

[19] three-neck reaction flask, 1 -liter (1)

[20] pressure equalizing addition funnel, 125 -mis (2)

[21] gas inlet tube, with adapter (3) [22] gas exit adapter (4)

[23] gas scrubbing tower, 1 -liter (5)

[24] amber reagent bottle, 1 liter (6)

[25] gas inlet tube, without adapter (7)

[26] ice bath (8)

[27] flexible tubing (rubber or Tygon®)

[28] Technical Sodium Chlorite Solution 31.25

[29] concentrated sulfuric acid, 36N

That method specifies, inter alia, the following procedure:

[31] Assemble the generator setup as shown in FIG. 1. To ensure airtight assembly use standard taper glassware and silicon grease if possible.

Rubber stoppers are an acceptable alternative.

[32] Fill the reaction flask and gas scrubbing tower with 500 mis of

approximately 2.5% (wt) NaC102 solution. Make certain all gas inlets are submerged. (2.5 % NaC102 solution may be prepared by diluting

OxyChem Technical Sodium Chlorite Solution 31.25 1 : 10 with DI water).

[33] Prepare 50 mis of 10%> (vol) sulfuric acid solution and place this solution in the addition funnel. WARNING: Always add acid to water; never add water to acid.

[34] Fill the amber reagent bottle with 500 to 750 mis. of DI water and place in an ice bath.

[35] Turn on the air flow to the generation setup (there should be bubbles in all three solutions.) If there are not, check the setup for leaks.

[36] Once there are no leaks, slowly add the acid solution (5 to 10 mis at a time). Wait 5 minutes between additions. Continue the air flow for 30 minutes after the final addition.

[37] Store the chlorine dioxide solution in a closed amber bottle in a

refrigerator. Properly stored solutions may be used for weeks, but should be standardized daily, prior to use, by an approved method, such as Method 4500-C1O2, Standard Methods for the Examination of Water and Wastewater., 20th Ed., APHA, Washington, D.C., 1998, pp 4-73 to 4-79.

[38] We have unexpectedly discovered that, by bubbling sufficiently pure gaseous

C102 diluted in nitrogen (as generated by this method) at a rate of, for example, approximately 100 ml/minute to approximately 300 ml/minute, through a near- saturated solution of alpha-cyclodextrin (approximately 11% to approximately 12% w/w) in place of plain water, at or below room temperature, a solid precipitate formed. The minimum C102 concentration required to obtain the solid precipitate lies somewhere in the range of approximately 500ppm to

approximately 1500ppm. A 1 : 1 molar ratio of C102 to cyclodextrin—

approximately 7600ppm C102 for approximately 11% alpha-cyclodextrin— is presumed to be needed in order to complex all the alpha-cyclodextrin. We believe that the use of even more C102 will maximize the amount of precipitate that forms. Precipitation may begin before C102 addition is complete, or may take up to approximately 2 to approximately 3 days, depending on the amount of C102 added and the temperature of the system.

[39] Another method of preparing this solid material is as follows. A solution of

alpha-cyclodextrin is prepared. That solution can be essentially saturated

(approximately 11%). A separate solution of C102 can be prepared by the method referenced above, potentially such that it is somewhat more concentrated than the alpha-cyclodextrin solution, on a molar basis. Then the two solutions can be combined on approximately a 1 : 1 volume basis and mixed briefly to form a combined solution. Concentrations and volumes of the two components can be varied, as long as the resultant concentrations in the final mixture and/or combined solution are sufficient to produce the precipitate of the complex. The mixture and/or combined solution then can be allowed to stand, potentially at or below room temperature, until the precipitate forms. The solid can be collected by an appropriate means, such as by filtration or decanting. The

filtrate/supernatant can be chilled to facilitate formation of additional precipitate. A typical yield by this unoptimized process, after drying, can be approximately 30 to approximately 40% based on the starting amount of cyclodextrin. The filtrate/supernatant can be recycled to use the cyclodextrin to fullest advantage.

[40] The collected precipitate then can be dried, such as in a desiccator at ambient pressure, perhaps using Drierite desiccant. It has been found that the optimum drying time under these conditions is approximately 24 hours. Shorter drying times under these conditions can leave the complex with unwanted free water. Longer drying times under these conditions can result in solid containing a lower C102 content.

[41] Since we have observed that the residence time of the complex in a desiccating chamber has a distinct effect on the resulting C102 content of the dried complex, it is expected that the use of alternate methods of isolating and/or drying the complex can be employed to alter yield rates and obtain a C102 cyclodextrin complex with specific properties (stability, C102 concentration, dissolution properties, etc.) suitable for a particular application. Lyophilization and spray- drying are examples of these kinds of alternate methods, which can dry the precipitated complex, and/or isolate the complex as a dry solid from solution- phase complex, and/or from the combined precipitate/solution mixture.

[42] Based on methods used to form other complexes with cyclodextrins, it is believed that any of several additional methods could be utilized to form the C102 cyclodextrin complex. Slurry complexation, paste complexation, solid phase capture, and co-solvent systems are examples of additional preparatory options. In one unoptimized example of a modified slurry process, 1 lg of solid alpha- cyclodextrin was added directly to a lOOg solution of 7800ppm C102 and mixed overnight. While a majority of the cyclodextrin went into solution, approximately 20% of the powder did not. This was subsequently found to have formed a complex with C102 that upon isolation, contained approximately 0.8% C102 by weight. In one unoptimized example of a solid phase capture process, C102 gas was generated by the method described in the OxyChem Technical Data Sheet. The C102 from the reaction was first passed through a chromatography column packed with a sufficient amount of Drierite to dry the gas stream. Following this drying step, 2.0g of solid alpha-cyclodextrin was placed in-line and exposed to the dried C102 in the vapor phase for approximately 5 hours. The alpha-cyclodextrin was then removed, and found to have formed a complex with C102 containing approximately 0.75% C102 by weight.

[43] This precipitate is assumed to be a C102/alpha-cyclodextrin complex.

Cyclodextrins are known to form complexes or "inclusion compounds" with certain other molecules, although for reasons presented above it is surprising that a stable complex would form with C102. Such a complex is potentially characterized by an association between the cyclodextrin molecule (the "host") and the "guest" molecule which does not involve covalent bonding. These complexes are often formed in a 1 : 1 molecular ratio between host and guest, but other ratios are possible. One portion of this putative C102/alpha-cyclodextrin complex has been subjected to X-ray crystallography. The results of this study indicate a regular crystalline array in which one C102 molecule occupies the cavity of each cyclodextrin molecule, in said 1 : 1 molecular ratio.

[44] There are a number of reaction conditions that affect the process leading to the formation of the complex. Any of these conditions can be optimized to enhance the yield and/or purity of the complex. Several of these conditions are discussed below.

[45] The pH at which the complexation takes place between C102 and cyclodextrin has been observed to affect the yield and C102 content of the resulting C102 complex. Therefore, this parameter might affect the stability and/or properties of the resulting complex. An approximately 11% alpha-cyclodextrin solution was combined with an approximately 9000ppm C102 solution on a 1 : 1 molar basis and the pH immediately adjusted from approximately 3.5 to approximately 6.7 with approximately 10% NaOH. A control was set up in the same fashion with no pH adjustment after combining the approximately 11% cyclodextrin and approximately 9000ppm C102 solution. The resulting yield of the pH adjusted preparation was approximately 60% lower than the control and had approximately 20%) less C102 content by weight.

[46] The temperature at which the complexation takes place between C102 and

cyclodextrin has been observed to affect the yield and C102 content of the resulting C102 complex. Therefore, this parameter might affect the stability and/or properties of the resulting complex. An approximately 11% alpha- cyclodextrin solution was combined with an approximately 7800ppm C102 solution on a 1 : 1 molar basis in 2 separate bottles. One of these was placed in a refrigerator at approximately 34°F and the other was left at room temperature. Upon isolation and substantial dry down of the resulting complexes, the refrigerated preparation produced approximately 25% more complex by weight and a lower C102 concentration.

[47] The stirring rate and/or level of agitation during the formation of a C102

cyclodextrin complex has been observed to affect the yield and C102 content of the resulting C102 complex. Therefore, this parameter might affect the stability and/or properties of the resulting complex. An approximately 11% alpha- cyclodextrin solution was combined with an approximately 7800ppm C102 solution on a 1 : 1 molar basis in 2 separate bottles. One of the bottles was placed on a magnetic stir plate at approximately 60 rpm, while the other remained undisturbed. After approximately 5 days, the precipitated complex from each was isolated and dried down. The preparation that was stirred resulted in an approximately 20% lower yield and approximately 10% lower C102

concentration by weight. [48] The addition of other compounds to the complexation mixture has been observed to affect the yield and/or C102 content of the resulting C102 complex. Therefore, the use of additives in the preparation process might affect the stability and/or properties of the resulting complex and/or lead to a C102 complex with properties tailored to a specific application. For example, we have found that very low concentrations of water soluble polymers (approximately 0.1% w/v), such as polyvinylpyrrolidone and carboxymethylcellulose, have resulted in C102 concentrations higher and lower, respectively, than that observed in a control preparation containing only cyclodextrin and C102. In both cases however, the yield was approximately 10% lower than the control. In another example, we found that the addition of approximately 0.5% acetic acid to the complexation mixture resulted in approximately 10% higher yield and approximately 40% lower C102 content.

[49] When isolated and dried, the resulting solid typically has a granular texture,

appears somewhat crystalline, with a bright yellow color, and little or no odor. It can be re-dissolved in water easily, and the resulting solution is yellow, has an odor of C102, and assays for C102. The C102 concentration measured in this solution reaches its maximum as soon as all solid is dissolved, or even slightly before. The typical assay method uses one of the internal methods of the Hach DR 2800 spectrophotometer designed for direct reading of C102. The solution also causes the expected response in C102 test strips such as those from Selective Micro Technologies or LaMotte Company. If a solution prepared by dissolving this complex in water is thoroughly sparged with N2 (also known as Nitrogen or N₂,), the solution becomes colorless and contains virtually no C102 detectable by the assay method. The sparged C102 can be collected by bubbling the gas stream into another container of water.

[50] One sample of the dried solid complex was allowed to stand in an uncovered container for approximately 30 hours before being dissolved in water, and appeared to have lost none of its C102 relative to a sample that was dissolved in water immediately after drying. Four portions from one batch of solid complex left in open air for periods of time ranging from approximately 0 to approximately 30 hours before being re-dissolved in water all appeared to have approximately the same molar ratio of C102 to alpha-cyclodextrin. Other batches appeared to have somewhat different ratios of C102 to alpha-cyclodextrin. This difference may simply reflect differences in sample dryness, but it is known that

cyclodextrin-to-guest ratios in other cyclodextrin complexes might vary with differences in the process by which the complex was formed. However, samples of the present complex prepared by an exemplary embodiment tended to contain close to, but to date not greater than, a 1 : 1 molar ratio of C102 to cyclodextrin. That is, their C102 content approached the theoretical limit for a 1 : 1 complex of approximately 6.5% by weight, or approximately 65,000ppm, C102. Assuming that a 1 : 1 molar ratio represents the ideal form of the pure complex, the ratio of C102 to cyclodextrin can be targeted as close to 1 :1 as possible, to serve as an efficient C102 delivery vehicle. However, solid complexes with a net C102 to cyclodextrin ratio of less than 1 : 1 can be desirable in some cases. (We believe such a material is probably a mixture of 1 : 1 complex plus uncomplexed cyclodextrin, not a complex with a molar ratio of less than 1 : 1.)

An aqueous solution of C102 having such a high concentration (e.g., approaching approximately 65,000ppm) can pose technical and/or safety challenges in handling, such as rapid loss of C102 from the solution into the gas phase

(concentrated and therefore a human exposure risk), and/or potentially explosive vapor concentrations in the headspace of a container in which the solution is contained. The solid appears not to have these issues. Release into the gas phase is relatively slow, posing little exposure risk from the complex in open air. The lack of significant odor can be an important factor in the users' sense of safety and/or comfort in using the solid. For example, a small sample has been left in the open air for approximately 72 hours, with only an approximately 10% loss of C102. At such a slow rate, users are unlikely to experience irritation or be caused to feel concern about exposure. Gas-phase C102 concentration in the headspace of a closed container of the complex can build up over time, but appears not to attain explosive concentrations. Even solid complex dampened with a small amount of water, so that a "saturated" solution is formed, to date has not been observed to create a headspace C102 concentration in excess of approximately 1.5% at room temperature. It is commonly believed that at least a 10% concentration of C102 in air is required for explosive conditions to exist.

[52] The freshly-prepared complex is of high purity, since it is obtained by combining only highly pure C102 prepared by OxyChem Method II, cyclodextrin, and water. Some cyclodextrins are available in food grade, so the complex made with any of these is suitable for treatment of drinking water and other ingestible materials, as well as for other applications. Other purity grades (technical, reagent,

pharmaceutical, etc.) of cyclodextrins are available, and these could give rise to complexes with C102 that would be suitable for still other applications.

[53] In certain embodiments, the solid complex can be quickly and conveniently

dissolved directly in water that is desired to be treated. Alternatively, the solid can be dissolved, heated, crushed, and/or otherwise handled, processed, and/or treated to form, and/or release from the solid, a solution, such as an aqueous chlorine dioxide solution, and/or another form of C102, such as a C102 vapor, that then can be used for disinfecting surfaces, solids, waters, fluids, and/or other materials. For example, solutions of C102 prepared by dissolving the complex in water, either the water to be treated or an intermediate solution, can be used for any purpose known in the art for which a simple aqueous solution of comparable C102 concentration would be used, insofar as this purpose is compatible with the presence of the cyclodextrin. These uses can include disinfection and/or deodorization and/or decolorization of: drinking water, waste water, recreational water (swimming pools, etc.), industrial reuse water, agricultural irrigation water, as well as surfaces, including living tissues (topical applications) and foods (produce, meats) as well as inanimate surfaces, etc. [54] It is anticipated that the complex can be covalently bound, via the cyclodextrin molecule, to another substrate (a polymer for example) for use in an application where multiple functionality of a particular product is desired. For example, such a complex bound to an insoluble substrate can, upon contact with water, release its C102 into solution while the cyclodextrin and substrate remain in the solid phase.

[55] It has been found that this solid complex ordinarily experiences a slow release of C102 gas into the air. Conditions can be selected such that the concentration level of the C102 released into the air is low enough to be safe (a condition suggested by the lack of conspicuous odor) but at a high enough concentration to be efficacious for disinfection and/or odor control in the air, and/or disinfection of surfaces or materials in contact with the air.

[56] The solid complex can release C102 directly, via the gas phase, and/or via

moisture that is present, into other substances. The solid can be admixed with such substances, such as by mixing powdered and/or granular solid complex with the other substances in powdered and/or granular form. The solid complex can be applied to a surface, such as skin and/or other material, either by "rubbing in" a sufficiently fine powder of the complex, and/or by holding the solid complex against the surface mechanically, as with a patch and/or bandage. The substance receiving the C102 from the complex can do so as a treatment of the substance and/or the substance can act as a secondary vehicle for the C102.

[57] In some instances, the complex can impart different and/or useful

reactivity/properties to C102. By changing its electronic and/or solvation environment, the reactivity of complexed C102 will almost certainly be quantitatively, and perhaps qualitatively, different.

[58] FIG. 2 illustrates the ability of an exemplary complex to retain C102 when stored at room temperature, either in the open air (e.g., an uncapped jar) or in a closed and/or substantially C102-impermeable container with relatively little headspace. It appears that C102 is retained somewhat more effectively in the closed, low- headspace container, and it may be possible to improve C102 retention further by reducing the headspace further. However, C102 retention is remarkable in either case, considering that the complex is an essentially waterless medium containing a reactive gaseous molecule.

Early indications are that C102 retention can be greatly enhanced by cold storage. FIG. 3 illustrates retention by samples stored at room temperature (RT) (at approximately 20C to approximately 26C) compared to those stored in a refrigerator (at approximately 1C and at approximately 3C) and those stored in a freezer (at approximately -18C). For example, to one of ordinary skill in the art, FIG. 3 illustrates that a sample stored at room temperature for 14 days, retained greater than 0 percent to greater than 65 percent, including all values and subranges therebetween (e.g., 6.157, 12, 22.7, 33, 39.94, 45, etc., percent), and in fact approximately 70 percent of its original C102 content. Another sample, when stored at room temperature for 56 days, retained greater than 0 percent to greater than 20 percent, including all values and sub-ranges therebetween, and in fact approximately 24 percent of its original C102 content. As another example, FIG. 3 illustrates that a sample stored at approximately 3C for 28 days retained greater than 0 percent to greater than 90 percent, including all values and sub-ranges therebetween, and in fact approximately 94 percent of its original C102 content. FIG. 3 also illustrates that a sample stored at approximately 1C for at least 35 days retained greater than 0 percent to greater than 95 percent, including all values and sub-ranges therebetween, and in fact approximately 96 percent of its original C102 content. One of ordinary skill can determine additional retention amounts, percentages, and times by a cursory review of FIG. 3. While not wishing to be bound by any particular theory, these retention results might be due in part to the fact that C102 in the pure state, though a gas at room temperature, is a liquid at temperatures below 11C (down to -59C, at which temperature it freezes into a solid). [60] The solid complex can be packaged and/or stored in a range of forms and packages. Forms can include granulations/powders essentially as recovered from the precipitation process. The initially obtained solid complex can be further processed by grinding and/or milling into finer powder, and/or pressing into tablets and/or pucks and/or other forms known to the art. Other materials substantially unreactive toward C102 can be combined with the solid complex to act as fillers, extenders, binders, and/or disintegrants, etc.

[61] Suitable packages are those that can retain gaseous C102 to a degree that provides acceptable overall C102 retention, consistent with its inherent stability, as discussed above, and/or that provide adequate protection from moisture. Suitable materials to provide high C102 retention can include glass, some plastics, and/or unreactive metals such as stainless steel. The final form of the product incorporating the solid complex can include any suitable means of dispensing and/or delivery, such as, for example, enclosing the solid in a dissolvable and/or permeable pouch, and/or a powder/solid metering delivery system, and/or any other means known in the art.

[62] Other cyclodextrins: Most of the above material relates to alpha-cyclodextrin and the complex formed between it and C102. This is the only C102/cyclodextrin complex yet isolated. We believe that beta-cyclodextrin may form a complex with C102, which techniques readily available to us have not been able to isolate. Whereas the complex with alpha-cyclodextrin is less soluble than alpha- cyclodextrin alone, leading to ready precipitation of the complex, it may be that the C102/beta-cyclodextrin complex is more soluble than beta-cyclodextrin alone, making isolation more difficult. Such solubility differences are known in the art surrounding cyclodextrin complexes. Techniques such as freeze-drying may be able to isolate the complex in the future. [63] However indirect evidence for the complex has been observed. Beta-cyclodextrin has a known solubility in water. If the water contains a guest substance that produces a cyclodextrin complex more soluble than the cyclodextrin alone, more of the cyclodextrin will dissolve into water containing that guest than into plain water. This enhanced solubility has been observed for beta-cyclodextrin in water containing C102. Two separate lOOg slurries of beta-cyclodextrin solutions were prepared. The control solution contained 5% beta-cyclodextrin (w/w) in ultrapure water, and the other contained 5% beta-cyclodextrin (w/w) in 8000ppm C102. Both slurries were mixed at 200rpm for 3 days, at which time the undissolved beta-cyclodextrin was isolated from both solutions and dried for 2 days in a desiccator. The weight of the dried beta-cyclodextrin from the C102 containing slurry was 0.32g less than the control slurry indicating that a soluble complex might exist between the beta-cyclodextrin and C102 in solution. It is believed, by extension, that C102 might form complexes with gamma-cyclodextrin and/or chemically derivatized versions of the natural (alpha- ("a"), beta- ("β"), and gamma- ("γ")) cyclodextrins. In the case of beta- and/or gamma-cyclodextrin and/or other cyclodextrins having internal cavities larger than that of alpha- cyclodextrin, it might be that the complex(es) formed with C102 will incorporate numbers of C102 molecules greater than one per cyclodextrin molecule.

[64] Related inclusion complex formers: It is expected by extension of the observed cyclodextrin complexes that some other molecules known to form inclusion compounds will also complex C102. In particular, cucurbiturils are molecules known primarily for having ring structures that accommodate smaller molecules into their interior cavities. These interior cavities are of roughly the same range of diameters as those of the cyclodextrins. It is anticipated that combining the appropriate cucurbituril(s) and C102 under correct conditions will produce cucurbituril/C102 complex(es), whose utility can be similar to that of

cyclodextrin/C102 complexes.

Examples Example 1— Complex Preparation by Generation Process:

[65] C102 generated by the OxyChem Method II referenced above was bubbled as a stream mixed with nitrogen, at a rate of approximately 100-300ml per minute, into an approximately 120mL serum bottle containing approximately lOOg of approximately 11% (by weight) alpha-cyclodextrin solution at RT. Precipitation of the complex was observed to begin within approximately 1 hour, with C102 ultimately reaching a concentration of approximately 7000ppm or more in the solution. Precipitation occurred very rapidly, and over the course of

approximately 10 minutes enough complex was formed to occupy a significant volume of the bottle. The bottle was capped and placed in the refrigerator to facilitate further complex formation. After approximately 1 week the solid was removed from the solution onto filter paper and dried in a desiccator with Drierite for approximately 4 days. Yield was approximately 50% (by weight of starting cyclodextrin), and C102 concentration in the complex was approximately 1.8%.

Examples 2-10— Complex Preparation by Combining Solutions:

[66] The general method used was as follows. See FIG. 4 for a table describing

specifics of individual examples. A nearly saturated (approximately 11%) solution of alpha-cyclodextrin was prepared. A separate solution of C102 was prepared by OxyChem Method II, such that it was somewhat more concentrated than the alpha-cyclodextrin solution, on a molar basis. The two solutions were combined at approximately a 1 : 1 volume basis, i.e., approximately 500ml of each, and mixed briefly to combine thoroughly. The mixture was then allowed to stand at room temperature, until the precipitate formed. Stirring during precipitation did not appear to improve the yield or quality of product. The solid was collected by filtration or decanting. In certain cases the filtrate/supernatant was chilled to facilitate formation of additional precipitate. The collected precipitate was then dried in a desiccator at ambient pressure using Drierite desiccant. Additional Examples

[67] Other experiments showed a wide variety in initial C102 concentrations in freshly prepared complex. For example, in several experiments, complex formed by the combining solutions approach yielded C102 concentrations such as 1.8% and 0.9%. In other experiments, complex formed by the generation method in which the C102 was captured in an ice-chilled cyclodextrin solution yielded 0.2%> C102.

[68] Additional experiments at room temperature resulted in a wide variety of C102 retention results. For example, when complex formed by the combining solutions approach was sealed in approximately 10ml vials with a nitrogen blanket, approximately 56% of the original C102 concentration was retained after 35 days, and approximately 31% was retained after 56 days. As another example, when complex formed by the generation method was left open to the air in a dark storage area, approximately 42% of the original C102 concentration was retained after 35 days, and approximately 25% was retained after 56 days. As yet another example, when complex formed by the generation method was sealed in approximately 10ml clear glass vials with a nitrogen blanket and stored under white fluorescent light, approximately 13% of the original C102 concentration was retained after 14 days. As still another example, when complex formed by the generation method was stored in an approximately 2 ounce jar covered with Parafilm, approximately 6% of the original C102 concentration was retained after 59 days.

[69] Further experiments at refrigerator temperature (approximately 1 degree C) also resulted in a wide variety of C102 retention results with respect to the original C102 concentration, including 91%> after 30 days, 95% after 85 days, and 100% after 74 days.

[70] FIG. 5 is a flowchart of an exemplary embodiment of a method 5000. At activity 5100, a solution of cyclodextrin can be combined with a solution of chlorine dioxide, such as on an approximately 1 : 1 molar basis, to form a combined solution, which can form and/or precipitate a solid and/or solid complex comprising the chlorine dioxide complexed with the cyclodextrin. At activity 5200, the precipitate can be isolated and/or separated from the combined solution, and/or the combined solution and/or precipitate can be dried, solvent-washed, lyophilized, and/or spray-dried. At activity 5300, the resulting solid complex can be bonded, such as via covalent bonding, to, for example, a substrate and/or a polymer. Bonding of the complex via the cyclodextrin to a substrate might be possible at this stage, but it might be more feasible to bond the cyclodextrin to the substrate before forming the complex with C102. At activity 5400, the solid complex can be stored, such as in a closed and/or substantially C102-impermeable container, at a desired temperature, such as at ambient, room, refrigerated, and/or heated temperature. At activity 5500, the solid complex can retain a

concentration of chlorine dioxide, with respect to an initial concentration of chlorine dioxide in the complex, at, for example, greater than 60% for at least 42 days. At activity 5600, the chlorine dioxide can be released from the complex, such as by dissolving the complex in water. At activity 5700, the chlorine dioxide can be applied to a target, such as a volume of liquid, such as water, a fluid, and/or a solid, such as a surface.

Table 1— Summarized results from the above Examples

Example Gross yield C102 content Yield, pure

number (%) (%) complex basis (%>)

1 47 1.8 13

4 6.27 5.60 5.40

5 23.94 5.30 19.52

6 29 3.25 14

7 31 5.05 24

8 42 4.35 28

10 30.02 5.80 26.79 An Alternative Method

[71] It is believed that uncomplexed cyclodextrin can be present in the product due to

1) co-precipitation of uncomplexed cyclodextrin along with the complex, and/or

2) loss of C102 from a portion of the complex. It is believed that loss of C102 from the complex can occur more rapidly when the complex is wet. Thus, drying the complex rapidly, under the correct conditions, might help increase the amount of C102 retained in the complex.

[72] To test these beliefs, an alternative method can be conducted as follows: A

laboratory scale C102 generator can provide a gaseous stream of C102 in nitrogen. The gaseous stream can be bubbled into 500g of an aqueous solution of a-cyclodextrin (from approximately 5% to approximately 12% by weight). This method has been conducted at room temperature, but also can be performed at any reduced temperature above the freezing point of the solution. The cyclodextrin solution can be agitated throughout the C102 injection period by mixing with an approximately 45mm diameter disperser blade attached to an overhead laboratory stirrer, operating at approximately 600 rpm. After approximately 45 minutes, and/or as the C102 concentration in the cyclodextrin solution reaches

approximately 6000-7000ppm, the product complex can begin to precipitate. Usually within approximately 30 minutes of commencement of heavy

precipitation the reaction is complete. The precipitate can be isolated at once, or the slurry of precipitate can be stored for separation later.

[73] The precipitate can be isolated by vacuum filtration. After the filter cake has reached the consistency of a dry paste, the product can be washed with a solvent in which water is soluble, but in which the product is not appreciably soluble. For example, the product filter cake can be transferred to a screw cap bottle containing approximately 400ml of acetone. (We have found that ethanol also gives acceptable results, and reasonably predict that solvents that can dissolve substantial quantities of water (preferably miscible with water), don't dissolve appreciable amounts of the product complex, and/or evaporate completely relatively quickly (generally having a boiling point <80°C), such as any of methanol, isopropanol, n-propanol, t-butanol, methyl ethyl ketone, acetonitrile, diethyl ether, 1 ,2-dimethoxy-ethane, ethyl acetate, and/or tetrahydrofuran might also give acceptable results.) The bottle can be shaken on a laboratory bench top shaker for approximately 10 minutes at a setting high enough to achieve a vigorous mix. Once again vacuum filtration can be used to isolate the solid. When the filter cake is free of excess solvent, an additional approximately 50ml of fresh acetone can be added and pulled through. Vacuum can be pulled through the filter cake until the odor of acetone is no longer discemable. The product thus obtained generally can be found to be dry to the desired degree.

[74] This method of product isolation and drying by solvent washing can be preferred on the basis of brevity. However, it is believed that other means of drying the product beneficially can be used instead of or in conjunction with the solvent washing and vacuum filtration method. For example, the product obtained before or after solvent washing might be freeze dried, or it might be dried in a desiccator with a drying agent such as Drierite, at atmospheric pressure and room

temperature, and/or under vacuum refrigeration.

[75] The degree of dryness can be determined by a heated weight loss test. Before heating, an approximately 0.4 g portion of the solid can be weighed. Then, the portion can be heated in a suitable heatproof dish in a muffle furnace at approximately 125°C for approximately 30 minutes (meaning that the ambient temperature in the furnace is 125C when the product is placed in the furnace and that ambient temperature is held at 125C for the entirety of that 30 minutes). Then, after cooling in a desiccator to approximately room temperature, the sample can be re-weighed. The weight loss can be in the range of approximately 9 to approximately 15.5%, such as in the range of approximately 9 to approximately 12%. If the weight loss is higher than approximately 12%, the product can be further dried by additional solvent washing and/or by drying in a desiccator with a drying agent such as Drierite.

[76] The resulting product can be a yellow powder, similar in character to that

obtained by other processes described herein, although it can contain a significantly higher C102 concentration. This powder can be relatively fine in texture, can dry relatively rapidly and thoroughly, can dissolve relatively rapidly in water (which can provide for rapid release and availability of C102), and/or can be relatively amenable to tableting or other bulk forming operations.

[77] In addition to being stored, transported, and/or used as is, the product can be combined with beneficial additives. In particular, it is believed that the product can be combined with a range of beneficial additives that are also in solid form, by simply dry-blending the product with the solid additive, where the solid additive has a suitable powder/granular form. These can be additives which enhance the aesthetics of the product as is or in use, such as colorants and/or powder flow-control agents, or which add secondary performance benefits, such as cleaning agents, rheology-modifiers, etc. In many cases these additives can be substantially incompatible with C102 if combined in aqueous solution. However, such combinations of solids can provide little opportunity for the C102 to interact with the additives, due to the absence of any common medium (solvent) in which the two can commingle and interact, resulting in effectively compatible mixtures.

[78] The product also can be combined with beneficial additives that are normally liquids. Liquid additives that are compatible with C102 can be directly mixed with the product by known methods. Liquid additives that are normally incompatible with C102 can cause mutual destruction if mixed directly with the product. However, these additives can be combined with the product with greater compatibility if complexed, adsorbed, absorbed, or otherwise disposed in a solid medium, including complexation in cyclodextrins, prior to dry-blending with the product. Such additives can be those that enhance the aesthetics of the product as is and/or in use, such as colorants and/or fragrance materials, and/or that add secondary performance benefits, such as cleaning agents, rheology-modifiers, etc.

[79] The product can be sensitive to light. To protect it from degradation by light, the product can be: stored in the dark, stored in packaging that protects it from short wavelength light, such as light below 500nm, and/or combined with suitable "UV absorbers" and/or "UV blockers" that are effective in the proper wavelength range, such as, for example:

[80] UVA filters: Avobenzone (Parsol 1789), Bisdisulizole disodium (Neo Heliopan AP), Diethylamino hydroxybenzoyl hexyl benzoate (Uvinul A Plus), Ecamsule (Mexoryl SX), and/or Methyl anthranilate, etc.;

[81] UVB filters: 4-Aminobenzoic acid (PABA), Cinoxate, Ethylhexyl

triazone (Uvinul T 150), Homosalate, 4-Methylbenzylidene camphor (Parsol 5000), Octyl methoxycinnamate (Octinoxate), Octyl salicylate (Octisalate), Padimate O (Escalol 507), Phenylbenzimidazole sulfonic acid (Ensulizole), Polysilicone-15 (Parsol SLX), and/or Trolamine salicylate, etc.; and/or

[82] UVA+UVB filters: Bemotrizinol (Tinosorb S), Benzophenones 1-12, Dioxybenzone, Drometrizole trisiloxane (Mexoryl XL), Iscotrizinol (Uvasorb HEB), Octocrylene, Oxybenzone (Eusolex 4360), Sulisobenzone Bisoctrizole (Tinosorb M), Titanium dioxide, and/or Zinc oxide, etc.

[83] This alternative method can follow the OxyChem method described herein, such as beginning at paragraph 16 and/or illustrated in FIG. 1, except that the volume and concentration of sulfuric acid can be increased to approximately 200mL and approximately 25%, respectively. In addition, the approximately 2.5% (by wt) concentration of NaC102 used in the reaction flask and gas scrubbing tower can be approximately doubled for this alternative method.

Experiment 1 C102 was generated by the alternative method described above and bubbled as a stream mixed with nitrogen, at a rate of approximately 250mL per minute into a 1L reaction kettle. The kettle was placed in an ice bath and contained

approximately 500g of approximately 11.5% (by wt) alpha-cyclodextrin. The cyclodextrin solution was agitated throughout the C102 injection period by mixing with an approximately 45mm diameter disperser blade attached to an overhead laboratory stirrer, operating at approximately 600 rpm. Precipitation of the product complex began approximately 40 minutes after the onset of C102 generation and at a C102 concentration of approximately 4500ppm. Generation of C102 was continued for approximately 10 minutes beyond the onset of precipitation of the product complex. The slurry of precipitate was quickly transferred to a 500mL bottle and placed into a refrigerator. The bottle of precipitated product was removed from the refrigerator after approximately 3 hours and then the precipitate was collected on a filter paper using vacuum filtration and dried to a dry paste. One portion (1 A) of the product was then placed into a 250mL bottle containing approximately 200mL of cold acetone and capped, while the other portion (IB) was placed into a 250mL bottle containing approximately 200mL of cold ethanol and capped. Both bottles were placed on a laboratory shaker for approximately 10 minutes of vigorous mixing. In both cases the majority of the product was insoluble in the solvent. Vacuum filtration was then used to remove the bulk of the acetone from the product complex 1 A in that bottle, followed by two additional washes with approximately 50mL of fresh acetone. The filtration was continued until no acetone odor was detectable over the dried product. The same vacuum filtration procedure was then applied to the product IB in the ethanol bottle as well, using ethanol for the additional washes with fresh solvent. Heating the acetone dried product 1A to approximately 125°C for approximately 30 minutes showed a weight loss of approximately 11%. The C102 concentration was approximately 5.8% (by wt). The ethanol dried product IB showed a weight loss of approximately 12% and had a C102 concentration of approximately 6.3% (by wt). Experiment 2

[85] C102 was generated as in Experiment 1 above and bubbled into a 1L reaction kettle containing approximately 500g of approximately 11.5% (by wt) alpha- cyclodextrin in an ice bath. Agitation was provided as in Experiment 1.

Precipitation of the product complex began approximately 35 minutes after the onset of C102 generation and at a C102 concentration of approximately 6500ppm. Generation of C102 was continued for approximately 10 minutes beyond the onset of precipitation of the product complex. The slurry of precipitate was immediately vacuum filtered to a dry paste. The product was then dried using the procedure described in Experiment 1 above using both acetone and ethanol.

Heating the acetone dried product (2A) to approximately 125°C for

approximately 30 minutes showed a weight loss of approximately 12.8%. The C102 concentration was approximately 5.94% (by wt). The ethanol dried product (2B) showed a weight loss of approximately 13.5% and had a C102 concentration of approximately 6.2% (by wt).

Experiment 3

[86] C102 was generated as in Experiments 1 and 2 above and bubbled into a 1L

reaction kettle containing approximately 500g of approximately 11.5% (by wt) alpha-cyclodextrin, with the same mode of agitation. For this experiment, the reaction kettle was not placed in an ice bath, so the product was formed at room temperature. Precipitation of the product complex began approximately 40 minutes after the onset of C102 generation and at a C102 concentration of approximately 7500ppm. Generation of C102 was continued for approximately 25 minutes beyond the onset of precipitation of the product complex. The slurry of precipitate was immediately vacuum filtered to a dry paste. The product was then dried using the procedure described in Experiments 1 and 2 above, except that approximately 380mL of acetone was used and the solvent was at room temperature. Heating the acetone dried product to approximately 125°C for approximately 30 minutes showed a weight loss of approximately 15%. The C102 concentration was approximately 6.3% (by weight).

Experiment 4

[87] C102 was generated as in Experiments 1, 2, and 3 above, and bubbled into a 1L reaction kettle containing approximately 500g of approximately 11.5% (by wt) alpha-cyclodextrin, with the same mode of agitation. As in Experiment 3 above, the reaction kettle was not placed in an ice bath. Precipitation of the product complex began approximately 45 minutes after onset of C102 generation and at a C102 concentration of approximately 7800ppm. Generation of C102 was continued for approximately 20 minutes beyond the onset of precipitation of the product complex. The product was then dried using the procedure described in Experiments 1, 2, and 3 above, except that approximately 460mL of acetone was used and the solvent was at room temperature. Heating the acetone dried product to approximately 125°C for approximately 30 minutes showed a weight loss of approximately 15.4%. The product complex was then placed in a dessicator for additional drying for approximately 16 hours in a refrigerator. Heating the acetone dried product to approximately 125°C for approximately 30 minutes showed a weight loss of approximately 11.2%. The C102 concentration was approximately 6.5%> (by weight).

Table 2— Summarized results from the above Experiments

Experiment Solvent used Gross yield (%) C102 content Yield, pure number for drying (%) complex basis

(%)

1A Acetone 61 5.8 54

IB Ethanol 6.2 58

2A Acetone 56 5.9 51

2B Ethanol 6.2 54 3 Acetone 70 6.3 68

4 Acetone 61 6.5 61

[88] The alternative method can result in:

a C102 content in the range of approximately 5.8 to approximately 6.5% (vs. a theoretical of 6.5%); and/or

an overall yield (on a pure complex basis) of complex in the range of approximately 50% to approximately 68%.

Definitions

[89] When the following terms are used substantively herein, the accompanying

definitions apply. These terms and definitions are presented without prejudice, and, consistent with the application, the right to redefine these terms during the prosecution of this application or any application claiming priority hereto is reserved. For the purpose of interpreting a claim of any patent that claims priority hereto, each definition (or redefined term if an original definition was amended during the prosecution of that patent), functions as a clear and unambiguous disavowal of the subject matter outside of that definition.

[90] a - at least one.

[91] activity - an action, act, step, and/or process or portion thereof.

[92] adapted to - made suitable or fit for a specific use or situation.

[93] air - the earth's atmospheric gas.

[94] and/or - either in conjunction with or in alternative to.

[95] apparatus - an appliance or device for a particular purpose

[96] apply - to place in contact with and/or close physical proximity to and/or to lay and/or spread on.

[97] approximately - about and/or nearly the same as.

[98] aqueous - related to and/or containing water

[99] at least - not less than.

[100] bond - to attach and/or fasten.

[101] can - is capable of, in at least some embodiments. [102] chlorine dioxide - a highly reactive oxide of chlorine with the formula C102 or C10₂, it can appear as a reddish-yellow gas that crystallizes as orange crystals at -59 °C, and it is a potent and useful oxidizing agent often used in water treatment and/or bleaching.

[103] closed - having boundaries, enclosed.

[ 104] combine - to join, unite, mix, and/or blend.

[105] complex - a compound comprising a reversible association of molecules, atoms, and/or ions.

[106] composition of matter - a combination, reaction product, compound, mixture, formulation, material, and/or composite formed by a human and/or automation from two or more substances and/or elements.

[107] compound - composed of two or more substances, parts, elements, and/or ingredients.

[108] comprising - including but not limited to, what follows.

[109] concentration - measure of how much of a given substance there is

mixed, dissolved, contained, and/or otherwise present in and/or with another substance.

[110] container - an enclosure adapted to retain a filling and having a closable opening via which a filling can be introduced. Examples of a container include a vial, syringe, bottle, flask, etc.

[I l l] covalently - characterized by a combination of two or more atoms by sharing electrons so as to achieve chemical stability under the octet rule. Covalent bonds are generally stronger than other bonds.

[112] cyclodextrin - any of a group of cyclic oligosaccharides, composed of 5 or more a-D-glucopyranoside units linked l->4, as in amylose (a fragment of starch), typically obtained by the enzymatic hydrolysis and/or conversion of starch, designated α-, β-, and γ-cyclodextrins (sometimes called cycloamyloses), and used as complexing agents and in the study of enzyme action. The 5-membered macrocycle is not natural. Recently, the largest well-characterized cyclodextrin contains 32 1,4- anhydroglucopyranoside units, while as a poorly characterized mixture, even at least 150-membered cyclic oligosaccharides are also known. Typical cyclodextrins contain a number of glucose monomers ranging from six to eight units in a ring, creating a cone shape, typically denoted as: a-cyclodextrin: six-membered sugar ring molecule; β-cyclodextrin: seven sugar ring molecule; and γ-cyclodextrin: eight sugar ring molecule.

[113] deliver - to provide, carry, give forth, and/or emit.

[114] device - a machine, manufacture, and/or collection thereof.

[115] dissolve - to make a solution of, as by mixing with a liquid and/or to pass into solution.

[116] dry - (v) to lose and/or remove moisture from; (adj) substantially free from moisture or excess moisture; not moist; not wet.

[117] food grade - determined by the US Food and Drug Administration as safe for use in food.

[118] form - (v) to construct, build, generate, and/or create; (n) a phase,

structure, and/or appearance.

[119] from - used to indicate a source.

[120] further - in addition.

[121] greater - larger and/or more than.

[122] initial - at a beginning.

[123] lyophilize - to dry by freezing in a high vacuum.

[124] may - is allowed and/or permitted to, in at least some embodiments.

[125] method - a process, procedure, and/or collection of related activities for accomplishing something.

[126] mix - to combine (substances, elements, things, etc.) into one mass,

collection, or assemblage, generally with a thorough blending of the constituents.

[127] molar ratio - the ratio of moles of one substance to moles of another substance.

[128] not - a negation of something.

[129] pharmaceutical grade - determined by the US Food and Drug

Administration as safe for use in drugs. plurality - the state of being plural and/or more than one.

polymer - any of numerous natural and synthetic compounds of usually high molecular weight consisting of up to millions of repeated linked units, each a relatively light and simple molecule.

precipitate - a substance separated in solid form and/or phase from a solution.

predetermined - established in advance.

probability - a quantitative representation of a likelihood of an occurrence.

release - to let go and/or free from something that restrains, binds, fastens, and/or holds back.

repeatedly - again and again; repetitively.

result - an outcome and/or consequence of a particular action, operation, and/or course.

retain - to restrain, keep, and/or hold.

said - when used in a system or device claim, an article indicating a subsequent claim term that has been previously introduced.

separate - to disunite, space, set, or keep apart and/or to be positioned intermediate to.

set - a related plurality.

solid - neither liquid nor gaseous, but instead of definite shape and/or form.

solution - a substantially homogeneous molecular mixture and/or combination of two or more substances.

spray dry - to eject a liquid stream into a hot vapor stream, thereby separating a solute or suspension in the liquid as a solid and the solvent and/or remaining liquid into a vapor. The solid is usually collected in a drum or cyclone.

store - to take in, hold, and/or secure,

substantially - to a great extent or degree,

substrate - an underlying layer. [148] surface - the outer boundary of an object or a material layer constituting or resembling such a boundary.

[149] system - a collection of mechanisms, devices, machines, articles of manufacture, processes, data, and/or instructions, the collection designed to perform one or more specific functions.

[150] technical grade - containing small amounts of other chemicals, hence slightly impure.

[151] temperature - measure of the average kinetic energy of the molecules in a sample of matter, expressed in terms of units or degrees designated on a standard scale.

[152] utilize - to use and/or put into service.

[153] via - by way of and/or utilizing.

[154] water - a transparent, odorless, tasteless liquid containing approximately 11.188 percent hydrogen and approximately 88.812 percent oxygen, by weight, characterized by the chemical formula H₂0, and, at standard pressure (approximately 14.7 psia), freezing at approximately 32°F or 0C and boiling at approximately 212°F or lOOC.

[155] weight - a force with which a body is attracted to Earth or another

celestial body, equal to the product of the object's mass and the acceleration of gravity; and/or a factor assigned to a number in a computation, such as in determining an average, to make the number's effect on the computation reflect its importance.

[156] when - at a time.

[157] wherein - in regard to which; and; and/or in addition to.

[158] with respect to - in relation to.

Notes

[159] Various substantially and specifically practical and useful exemplary

embodiments of the claimed subject matter are described herein, textually and/or graphically, including the best mode, if any, known to the inventor(s), for implementing the claimed subject matter by persons having ordinary skill in the art. Any of numerous possible variations (e.g., modifications, augmentations, embellishments, refinements, and/or enhancements, etc.), details (e.g., species, aspects, nuances, and/or elaborations, etc.), and/or equivalents (e.g., substitutions, replacements, combinations, and/or alternatives, etc.) of one or more

embodiments described herein might become apparent upon reading this document to a person having ordinary skill in the art, relying upon his/her expertise and/or knowledge of the entirety of the art and without exercising undue experimentation. The inventor(s) expects skilled artisans to implement such variations, details, and/or equivalents as appropriate, and the inventor(s) therefore intends for the claimed subject matter to be practiced other than as specifically described herein. Accordingly, as permitted by law, the claimed subject matter includes and covers all variations, details, and equivalents of that claimed subject matter. Moreover, as permitted by law, every combination of the herein described characteristics, functions, activities, substances, and/or structural elements, and all possible variations, details, and equivalents thereof, is encompassed by the claimed subject matter unless otherwise clearly indicated herein, clearly and specifically disclaimed, or otherwise clearly contradicted by context.

[160] The use of any and all examples, or exemplary language (e.g., "such as")

provided herein, is intended merely to better illuminate one or more embodiments and does not pose a limitation on the scope of any claimed subject matter unless otherwise stated. No language herein should be construed as indicating any non- claimed subject matter as essential to the practice of the claimed subject matter.

[161] Thus, regardless of the content of any portion (e.g., title, field, background,

summary, description, abstract, drawing figure, etc.) of this document, unless clearly specified to the contrary, such as via explicit definition, assertion, or argument, or clearly contradicted by context, with respect to any claim, whether of this document and/or any claim of any document claiming priority hereto, and whether originally presented or otherwise: [162] there is no requirement for the inclusion of any particular described characteristic, function, activity, substance, or structural element, for any particular sequence of activities, for any particular combination of substances, or for any particular interrelationship of elements;

[163] no described characteristic, function, activity, substance, or structural element is "essential";

[164] any two or more described substances can be mixed, combined, reacted, separated, and/or segregated;

[165] any described characteristics, functions, activities, substances, and/or structural elements can be integrated, segregated, and/or duplicated;

[166] any described activity can be performed manually, semi-automatically, and/or automatically;

[167] any described activity can be repeated, any activity can be performed by multiple entities, and/or any activity can be performed in multiple jurisdictions; and

[168] any described characteristic, function, activity, substance, and/or structural element can be specifically excluded, the sequence of activities can vary, and/or the interrelationship of structural elements can vary.

[169] The use of the terms "a", "an", "said", "the", and/or similar referents in the

context of describing various embodiments (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context.

[170] The terms "comprising," "having," "including," and "containing" are to be

construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted.

[171] When any number or range is described herein, unless clearly stated otherwise, that number or range is approximate. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value and each separate subrange defined by such separate values is incorporated into the specification as if it were individually recited herein. For example, if a range of 1 to 10 is described, that range includes all values therebetween, such as for example, 1.1, 2.5, 3.335, 5, 6.179, 8.9999, etc., and includes all subranges therebetween, such as for example, 1 to 3.65, 2.8 to 8.14, 1.93 to 9, etc.

[172] When any phrase (i.e., one or more words) appearing in a claim is followed by a drawing element number, that drawing element number is exemplary and non- limiting on claim scope.

[173] No claim of this document is intended to invoke paragraph six of 35 USC 112 unless the precise phrase "means for" is followed by a gerund.

[174] Any information in any material (e.g., a United States patent, United States patent application, book, article, etc.) that has been incorporated by reference herein, is incorporated by reference herein in its entirety to its fullest enabling extent permitted by law yet only to the extent that no conflict exists between such information and the other statements and drawings set forth herein. In the event of such conflict, including a conflict that would render invalid any claim herein or seeking priority hereto, then any such conflicting information in such material is specifically not incorporated by reference herein.

[175] Within this document, and during prosecution of any patent application related hereto, any reference to any claimed subject matter is intended to reference the precise language of the then-pending claimed subject matter at that particular point in time only.

[176] Accordingly, every portion (e.g., title, field, background, summary, description, abstract, drawing figure, etc.) of this document, other than the claims themselves and any provided definitions of the phrases used therein, is to be regarded as illustrative in nature, and not as restrictive. The scope of subject matter protected by any claim of any patent that issues based on this document is defined and limited only by the precise language of that claim (and all legal equivalents thereof) and any provided definition of any phrase used in that claim, as informed by the context of this document.

Claims

What is claimed is:

1. A composition of matter comprising:

a solid form of chlorine dioxide complexed with a cyclodextrin, wherein a concentration of chlorine dioxide in said solid form is greater than approximately 5.8 percent by weight.

2. The composition of matter of claim 1, wherein:

said cyclodextrin is alpha-cyclodextrin.

3. The composition of matter of claim 1, wherein:

said cyclodextrin is not covalently bonded to the chlorine dioxide.

4. The composition of matter of claim 1, wherein:

a molar ratio of said cyclodextrin to said chlorine dioxide in said composition of matter is approximately 1 : 1.

5. The composition of matter of claim 1, wherein:

a concentration of chlorine dioxide in said composition of matter is greater than approximately 6.0 percent by weight.

6. The composition of matter of claim 1, wherein:

a concentration of chlorine dioxide in said composition of matter is greater than approximately 6.2 percent by weight.

7. The composition of matter of claim 1, wherein:

said cyclodextrin is food grade.

8. The composition of matter of claim 1, wherein:

said cyclodextrin is pharmaceutical grade.

9. The composition of matter of claim 1, wherein: said cyclodextrin is technical grade.

10. The composition of matter of claim 1, wherein:

upon heating in an approximately 125°C environment for approximately 30 minutes, the weight loss is less than approximately 15%.

11. A method comprising:

combining a solution of cyclodextrin with chlorine dioxide to form a combined solution; and

separating a resulting precipitate, said precipitate comprising a solid form of said chlorine dioxide complexed with said cyclodextrin, wherein a concentration of chlorine dioxide in said precipitate is greater than 5.8 percent by weight.

12. The method of claim 11, further comprising:

bubbling said chlorine dioxide as a gas mixed with an inert gas into said cyclodextrin solution.

13. The method of claim 11, further comprising:

removing water from said precipitate via solvent washing.

14. The method of claim 11, further comprising:

removing water from said precipitate via solvent washing, wherein said solvent is miscible with water.

15. The method of claim 11, further comprising:

removing water from said precipitate via solvent washing, wherein said solvent does not dissolve appreciable amounts of said precipitate.

16. The method of claim 11, further comprising: removing water from said precipitate via solvent washing, wherein said solvent has a boiling point of approximately 80 degrees C or less.

17. The method of claim 11, further comprising:

removing water from said precipitate via solvent washing, wherein said solvent is selected from a group consisting of: ethanol, acetone, methanol, propanol (iso- and n-), t-butanol, methyl ethyl ketone, acetonitrile, diethyl ether, 1 ,2-dimethoxy-ethane, ethyl acetate, and tetrahydrofuran.

18. The method of claim 11, further comprising:

removing water from said precipitate via solvent washing, and drying a resulting solvent- washed product to attain a weight loss of less than approximately 15% upon heating in an approximately 125°C environment for approximately 30 minutes.

19. The method of claim 11, wherein:

an overall yield of complex, on a pure complex basis, is greater than approximately 30%.

20. The method of claim 11, wherein:

an overall yield of complex, on a pure complex basis, is greater than approximately 50%.

21. The method of claim 11 , further comprising:

drying said combined solution.

22. The method of claim 11, further comprising:

drying said precipitate.

23. The method of claim 11, further comprising:

lyophilizing said combined solution and/or said precipitate. The method of claim 11, further comprising:

spray-drying said combined solution.

A method comprising:

forming a solid complex comprising chlorine dioxide and cyclodextrin, wherein a concentration of chlorine dioxide in said solid complex is greater than 5.8 percent by weight.

The method of claim 25, further comprising:

covalently bonding said solid complex to a substrate.

The method of claim 25, further comprising:

covalently bonding said cyclodextrin to a substrate before said forming a solid complex.

The method of claim 25, further comprising:

covalently bonding said solid complex to a polymer.

A method comprising:

dissolving in water a composition of matter comprising a solid form of chlorine dioxide complexed with a cyclodextrin, wherein a concentration of chlorine dioxide in said solid form is greater than 5.8 percent by weight.

A method comprising:

forming an aqueous chlorine dioxide solution by mixing in water a solid form of chlorine dioxide complexed with a cyclodextrin, wherein a concentration of chlorine dioxide in said solid form is greater than 5.8 percent by weight.

The method of claim 30, further comprising:

applying said aqueous chlorine dioxide solution to water. The method of claim 30, further comprising:

applying said aqueous chlorine dioxide solution to a surface.

The method of claim 30, further comprising:

applying said aqueous chlorine dioxide solution to air.

A method comprising:

releasing chlorine dioxide from a solid complex comprising chlorine dioxide complexed with a cyclodextrin, wherein a concentration of chlorine dioxide in said solid complex is greater than 5.8 percent by weight.

The method of claim 34, further comprising:

applying said chlorine dioxide to air.

The method of claim 34, further comprising:

applying said chlorine dioxide to open air.