Biocatalytic microcapsules for catalyzing gas conversion

Abstract

Methods of forming such microcapsules, in accordance with some embodiments, include: emulsifying at least one biocatalyst in a polymer precursor mixture; emulsifying the polymer precursor mixture in an aqueous carrier solution; crosslinking one or more polymer precursors of the polymer precursor mixture to form a plurality of microcapsules each independently comprising: a polymeric shell permeable to one or more target gases; and at least one biocatalyst disposed in an interior of the polymeric shell. In further embodiments, corresponding methods of using the inventive microcapsules for catalyzing one or more target gases using include: exposing a plurality of the biocatalytic microcapsules to the one or more target gases.

What is claimed is: 
     
         1 . A method of forming microcapsules for selective catalysis of gases, the method comprising:
 emulsifying at least one biocatalyst in a polymer precursor mixture;   emulsifying the polymer precursor mixture in an aqueous carrier solution;   crosslinking one or more polymer precursors of the polymer precursor mixture to form a plurality of microcapsules each independently comprising:
 a polymeric shell permeable to one or more target gases; and 
 at least one biocatalyst disposed in an interior of the polymeric shell. 
   
     
     
         2 . The method as recited in  claim 1 , wherein emulsifying at least one biocatalyst in a polymer precursor mixture and emulsifying the polymer precursor mixture in an aqueous carrier solution forms a double emulsion comprising the biocatalyst, the polymer precursor mixture, and the aqueous carrier solution. 
     
     
         3 . The method as recited in  claim 1 , wherein the biocatalyst is suspended in a buffer. 
     
     
         4 . The method as recited in  claim 3 , wherein the buffer excludes reducing agents. 
     
     
         5 . The method as recited in  claim 1 , the at least one biocatalyst comprising one or more biocatalytic components selected from: one or more enzymes configured to catalyze the one or more target gases; one or more enzyme cofactors; one or more cell membrane fragments; one or more cytosolic cell components; and reconstituted whole cells. 
     
     
         6 . The method as recited in  claim 1 , wherein the aqueous carrier solution comprises:
 water present in an amount from about 50 wt % to about 60 wt %;   glycerol present in an amount from about 30 wt % to about 40 wt %; and   polyvinyl alcohol present in an amount from about 1 wt % to about 5 wt %.   
     
     
         7 . The method as recited in  claim 1 , wherein the polymer precursor mixture comprises one or more polymer precursors selected from a group consisting of:
 polydimethylsiloxane (PDMS); polyethylene glycol (PEG); polyethylene glycol diacrylate (PEGDA); hexanediol diacrylate (HDDA); polyvinyl alcohol (PVA); poly(lactic acid) (PLA); polyimide; poly(2-methyl-2-oxazoline) (PXMOA); poly(ether ether ketone) (PEEK); cellulose acetate; polypropylene (PP); and silicone acrylate.   
     
     
         8 . The method as recited in  claim 1 , comprising:
 isolating the plurality of microcapsules from the aqueous carrier solution; and   drying the plurality of microcapsules.   
     
     
         9 . A method for catalyzing one or more target gases using biocatalytic microcapsules, the method comprising:
 exposing a plurality of the biocatalytic microcapsules to the one or more target gases, wherein the biocatalytic microcapsules each independently comprise:   a polymeric shell permeable to the one or more target gases; and   at least one biocatalyst disposed in an interior of the polymeric shell.   
     
     
         10 . The method as recited in  claim 9 , wherein the biocatalytic microcapsules are arranged in a configuration selected from: a packed bed; a moving bed; a fluidized bed; immobilized in or on a substrate; a microcapsule-embedded mesh; a packet containing the biocatalyic microcapsules; and a microcapsule-embedded adhesive. 
     
     
         11 . The method as recited in  claim 9 , the one or more target gases each independently being a C1-C3 compound. 
     
     
         12 . The method as recited in  claim 11 , the one or more target gases being selected from: methane, carbon monoxide, carbon dioxide, ethane, ethylene; propane; and propylene, hydrogen and oxygen. 
     
     
         13 . The method as recited in  claim 9 , the at least one biocatalyst comprising one or more biocatalytic components selected from: one or more enzymes configured to catalyze the one or more target gases; one or more enzyme cofactors; one or more cell membrane fragments; one or more cytosolic cell components; and reconstituted whole cells.