Patent Publication Number: US-2023144468-A1

Title: Polymer immobilization matrix for containment of hazardous materials and methods of using the same

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Divisional Application of U.S. Pat. Application No. 16/817,770, filed Mar. 13, 2020, which is related to and claims benefit of U.S. Provisional Pat. Application No. 62/837,520, filed on Apr. 23, 2019, entitled “POLYMER IMMOBILIZATION MATRIX FOR CONTAINMENT OF HAZARDOUS MATERIALS AND METHODS OF USING THE SAME,” hereby incorporated by reference in entirety. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     The present invention generally relates to materials and methods for rendering hazardous materials inert, or less hazardous, so that they can be handled or disposed of properly. 
     Many hazardous or dangerous materials present themselves as powders or crystals. These materials could be unknown chemicals, unknown drug substances, biological agents, chemical warfare agents, explosive materials, etc. When such a material is discovered in a public place, and the materials are perceived to be a threat, it is the job of first responders to remove the materials without further threat to the public. If the material is an explosive, there is an immediate need render the explosive inert, or unable to initiate while handling or in transport. Current strategies for handling and removal of such materials include sending in a robot, or suited person, to isolate and move the material to a heavy-walled transport container. If the material is perceived to be of high sensitivity, sometimes the decision is to burn the material in place. If the material is perceived to be a biological threat, the protocol is much more rigorous to ensure it is not inadvertently dispersed throughout the area. 
     With the rise in contact-hazard materials, such as fentanyl or other harmful narcotics, there is an urgent need for new materials and methods of safe handling, storage, and if necessary, destruction. Identification of the aforementioned hazardous materials may be difficult or impossible given minimal resources in the field. Therefore, it is critical to have a solution that is universally effective at immobilizing all of these hazardous materials in a variety of settings. 
     SUMMARY OF THE INVENTION 
     The present disclosure describes a unique, two-part water-soluble polymer matrix material, and a method of application of the two-part water soluble matrix material that immobilizes a wide variety of hazardous materials and renders them “safe” or at least “safer” for handling and transport. 
     The instant polymer matrix material can be a two-part polymer material comprising a liquid or gel cross-linking polymer (hydrogel) and a cross-linking agent or initiator contained in a solution. The cross-linking agent functions to cross-link the polymer and cause it to harden in place. 
     The cross-linking polymer can, initially, be in a liquid or viscous gel form, and when applied to a hazardous loose powder, or crystals, permeates the loose material to isolate it from its surroundings. The liquid or gel can, in some embodiments, be viscous enough to remain in a localized area and not spread too thin. The cross-linking agent can then be sprayed onto the polymer to harden the polymer on-site to create a mass that can be more easily handled. Hardening of the polymer immobilizes the powder or crystals and isolates the powder or crystals from each other. In the case of an explosive, this physical separation significantly reduces the risk of accidental initiation of an explosive although it likely could be detonated with some effort. If the powder or crystal is a biological or drug threat, the immobilization can prevent air volatilization or scattering of the material. Once immobilized, the material (explosive, drug, or biological) can be safely transported, and a portion (the matrix can be cut or broken up) can be sent to an analytical facility for testing. 
     The present materials are thus effective for desensitizing explosive materials to reduce hazards of electrostatic discharge initiation, physical initiation by friction or physical impact, and also effective for isolating and immobilizing drug, biological, and chemical materials, including volatile chemical materials, from human contact. 
     The present materials and methods can be safely, effectively, and inexpensively deployed by bomb squads, hazmat teams, military, and law enforcement officers to reduce localized hazardous material threats and permit safer storage of such materials. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       While the specification concludes with claims particularly pointing out and distinctly claiming particular embodiments of the instant invention, various embodiments of the invention can be more readily understood and appreciated from the following descriptions of various embodiments of the invention when read in conjunction with the accompanying drawings in which: 
         FIGS.  1 A and  1 B  illustrate one exemplary formulation for the instant two-part, water soluble polymer matrix materials; 
         FIGS.  2 A-C  illustrates exemplary form factors for the part one hydrogel materials; 
         FIGS.  3 A-C  illustrates an exemplary preparation of the part one hydrogel material from a concentrate material formulation; 
         FIGS.  4 A-F  illustrates an exemplary method of application of the part one hydrogel to a hazardous material and further application of the part two cross-linking agent to harden the material for removal; 
         FIG.  5    chemically illustrates an example of the cross-linking action when the cross-linking agent is applied to the part one polymer material; 
         FIG.  6    illustrates exemplary testing of the reduced sensitivity of an explosive material treated with the present immobilization material; and 
         FIGS.  7   a  and  7   b    illustrate an exemplary use of the formulation to encapsulate and immobilize a volatile material. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     Referring now to the drawings, exemplary embodiments of the invention are generally described and illustrated in the attached figures. 
     Referring to  FIGS.  1 - 7   , the present disclosure teaches a novel two-part, water soluble polymer matrix material and a method of application that immobilizes a wide variety of hazardous materials and renders them “safe” or at least “safer” for handling and transport. 
     Referring to  FIGS.  1 - 7   , the present disclosure teaches a novel two-part, water soluble polymer matrix material and a method of application that can immobilize a wide variety of hazardous materials and renders them “safe” or at least “safer” for handling and transport. The instant two-part material thereby renders otherwise unsafe materials transportable to aid in protecting the public, or other officials, by removing them from areas which the public would otherwise have access to. 
     Referring to  FIGS.  1 A and  1 B , the polymer matrix material in general can be a two-part polymer material comprising a liquid or gel cross-linking polymer (hydrogel)  100  and a cross-linking agent or cross-linking initiator  200  contained in a sprayable solution in a spray container  250 . The cross-linking agent  200 , when combined with the polymer material  100 , can function to immediately cross-link the polymer  100  and cause it to harden in place. Once hardened, the potentially offending material can thus be rendered “inert” such that it can be deemed less of a threat and no longer be inhaled, exploded, or otherwise endanger those in the area. 
     PART ONE (Hydrogel Polymer) 
     The first part of the instant two-part material can generally include various water-soluble polymers, such as polyvinyl alcohol, agar, gelatin, and sodium alginate. Such materials  100  were found to be suitable for use as Part One of the instant material. An exemplary, but not exhaustive, list of suitable polymers is set forth in Table 1 below. The polymer can preferably be in a ready-to-use liquid or gel form  110 , shown in  FIG.  3 A , but can also be provided in a powder form  112  to be mixed with water or other appropriate solvent (ethanol/methanol) at the time of use. Alternatively, the polymer can be provided in a concentrate form in a syringe  120 , to be mixed with water or other solvent  125  at the time of use, as shown in  FIG.  2 B . Examples of gel concentrate and ready-to-use materials are illustrated in  FIG.  2 C  in a syringe  130 .  
     
       
         
          TABLE 1
           
               
               
             
               
                   
               
               
                 Polymer 
                 Crosslinker 
               
             
            
               
                 Poly Vinyl Alcohol 
                 Sodium Borate, Boric Acid, and Glyoxal 
               
               
                 Starch 
                 Glyoxal 
               
               
                 Cellulose 
                 Glyoxal 
               
               
                 Protein and Gelatin 
                 Glyoxal 
               
               
                 Agarose and chitosan 
                 Oxidized dextrin 
               
               
                 Chitosan 
                 Glutaraldehyde 
               
               
                 Guar Gum 
                 Epichlorohydrin 
               
               
                 Gellan gum 
                 Endogen Polyamine spermidine 
               
               
                 Glycol Chitosan 
                 Oxidized Alginate 
               
               
                 Hydroxamated alginates 
                 +2 and +3 Metal Cations 
               
               
                 Seleroglucan 
                 Borax 
               
               
                 Poly (acrylic-co-vinylsulfonic) acid 
                 Ethylene glyco dimethacrylate 
               
               
                 Polyacrylamide 
                 N,N′-methlynebisacrylamide 
               
               
                 Polyacrylamide/guar gum graft 
                   
               
               
                 copolymer 
                 Glutaraldehyde 
               
            
           
         
       
     
     In one example,  FIG.  3 A  illustrates one exemplary method of mixing a concentrated hydrogel polymer  120  into a water  125  for use in the field. In a preferred exemplary composition, a solution of water, sodium alginate, and an organic solvent can be combined. The percent of sodium alginate can vary depending on the form factor and in one use case can account for 1% to 20% percent of the total solution. Appropriate organic solvents can include, but are not limited to, methanol, ethanol, and isopropanol. The percent of organic solvent used can be between 1% to 50% percent with 5% to 20% being preferred of the total solution. Once combined, the concentrated hydrogel polymer  120  and solvent  125 , can be shaken for two minutes, or until mixed. 
     Part Two (Cross-Linking Agent) 
     Referring back to  FIG.  1   , an exemplary cross-linking solution  200  can include a metal salt with a cation of +2 or +3 charge. Appropriate examples of metal salts include, but are not limited to, calcium, zinc, iron, aluminum, copper, nickel, and magnesium salts with salts of calcium, zinc, and iron being preferred. The percent of salt in Part Two can vary between 10% to 50% of the total solution, with 15% being a preferred example. Other cross-linking agents can be used for different hydrogels, examples of suitable cross-linking agent are included in TABLE 1 above. The cross-linking agent  200  can preferably be deployed in a solvent as a sprayable material, in a spray bottle  250 , for quick and easy application over a wide surface area. 
     In another exemplary embodiment, a biocide can be added to the cross-linking solution to retard the growth of any biological materials within the Part One composition. Biocides include but are not limited to calcium hypochlorite and sodium hypochlorite. 
       FIGS.  4 A-F  illustrate an exemplary embodiment of the chemical interaction and cross-linking of the polymer chains when the cross-linking agent is applied. In general, a hazardous material  300  can be found or identified by a member of the public or an official, as shown in  FIG.  4 A . An officer, agent or other first responder, can then determine that it is necessary to immobilize the aforementioned hazardous material  300  to protect themselves during removal or the public at large. As shown in  FIG.  4 B , the user can apply the Part One composition  330  to the target material until full coverage of the area of is achieved such that the hazardous material  300  is isolated, as shown in  FIG.  4 C . Once the hazardous material is isolated  300   a , the user or first responder can then apply the Part Two composition  350  as shown in  FIG.  4 D , by the use of a spray bottle for example. After application of the Part Two composition  350 , the Part One  330  and Part Two  350  compositions can be crosslinked  400  to harden the material, as shown in  FIG.  5   . After the cross-linking occurs, the now cross-linked polymer matrix  400  is hardened, as shown in  FIG.  4 E , and the encapsulated material  300   b  can be picked up and removed. In some embodiments, the process can be completed in a time frame of less than one minute. In some instances, the encapsulated and hardened hazardous material  300   b  can be placed in a sample container  360  for further testing in a lab like setting, as shown in  FIG.  4 F . 
     Advantageously, the solidified (encapsulated) explosive  300   b  can, as shown in  FIG.  6   , exhibit increased safety threshold margins. For example, the resultant hazardous material can have increased thresholds for initiation by electrical discharge (ESD), friction, and impact as compared to an explosive material (TATP) by itself. Testing of the instant two-part matrix material shows an insensitivity to impact initiation at maximum height of instrument, a 15 times improvement in electrostatic discharge initiation, and a 150 times improvement in friction initiation. 
     Turning to  FIGS.  7 A- 7 B , the polymer and initiation as described hereinabove can also be used to encapsulate volatile materials  500  which emit questionable and potentially dangerous fumes  502  into the surrounding air ( FIG.  7 A ). Once the volatile materials  500  are encapsulated with the cross-linked matrix  400 , the volatile material  500  may have a dramatically lower mobility and thus increase the ability to safely handle the material.  500  ( FIG.  7   ). 
     While there is shown and described herein certain specific structures embodying various embodiments of the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims.