Novel nanocomposites and their application as monolith columns

Abstract

Novel materials for chromatographic separations, processes for their preparation, and separation devices containing the chromatographic materials. In particular, hybrid inorganic/organic monolith materials comprising a polymerized scaffolding nanocomposite (PSN), wherein the nanocomposite contains a scaffolding functionality capable of chemically interacting with a surface of a second material are described. The hybrid inorganic/organic materials have enhanced wall adhesion and increased resistance to shrinkage as compared to prior art monolith materials. The improved adhesion of the monoliths enable the preparation of capillary columns with an internal diameter (I.D.) ≧50 μm.

1 . A hybrid inorganic/organic material comprising a polymerized scaffolding nanocomposite (PSN), wherein the nanocomposite contains a scaffolding functionality capable of chemically interacting with a surface of a second material.  
     
     
         2 . The hybrid material of  claim 1 , wherein the second material is a containment vessel.  
     
     
         3 . The hybrid material of  claim 1 , wherein the scaffolding functionality is selected from the group consisting of vinyl, acrylate, methacrylate, acrylamide, methacrylamide, styrene, divinylbenzene, itaconate, fumarate, alkyne, and combinations thereof.  
     
     
         4 . The hybrid material of  claim 1 , wherein the surface of the second material is derivatized with an anchoring functionality.  
     
     
         5 . The hybrid material of  claim 4 , wherein the anchoring functionality is selected from the group consisting of vinyl, acrylate, methacrylate, acrylamide, methacrylamide, styrene, divinylbenzene, itaconate, fumarate, alkyne, azo compounds, and combinations thereof.  
     
     
         6 . The hybrid material of  claim 4 , wherein the scaffolding functionality and the anchoring functionality are copolymerizable.  
     
     
         7 . The hybrid material of  claim 2 , wherein containment vessel is selected from the group consisting of a capillary column, a glass lined steel column, a radial compression column, a trap column, a microfluidic device, a microchip, a sensor, an electronic circuit, a miniaturized SPE device, and an on-column frit.  
     
     
         8 . The hybrid material of  claim 2 , where the containment vessel is a fused silica capillary column.  
     
     
         9 . The hybrid material of  claim 1 , wherein the chemical interaction is formation of a covalent bond.  
     
     
         10 . The hybrid material of  claim 9 , wherein the covalent bond is formed by polymerization.  
     
     
         11 . The hybrid material of  claim 10 , wherein the polymerization is initiated with a radical initiator.  
     
     
         12 . The hybrid material of  claim 11 , wherein the radical initiator is minimally water soluble.  
     
     
         13 . The hybrid material of  claim 11 , wherein the initiator is selected from the group consisting of 2,2′-azobis(isobutyronitrile), 2,2′-azobis(2-methylpropionamidine)dihydrochloride, 4,4′-azobis(4-cyanovaleric acid), potassium persulfate, and peracetic acid.  
     
     
         14 . The hybrid material of  claim 1 , wherein the inorganic portion of the hybrid material is a material selected from the group consisting of alumina, silica, titanium oxide, zirconium oxide, and ceramic material.  
     
     
         15 . The hybrid material of  claim 1 , wherein the inorganic portion of the hybrid material is silica.  
     
     
         16 . The hybrid material of  claim 1 , wherein the PSN is the product of a reaction of an organosilane and an inorganic silane monomer.  
     
     
         17 . The hybrid material of  claim 16 , wherein the PSN is the product of a reaction of a tetraalkoxysilane and an organosilane containing at least one polymerizable group.  
     
     
         18 . The hybrid material of  claim 17 , wherein said tetraalkoxysilane has the formula Si(OR 1 ) 4 , where R 1  is a C 1 -C 3  alkyl moiety.  
     
     
         19 . The hybrid material of  claim 17 , wherein said organosilane is an organoalkoxysilane having the formula R 2 Si(OR 1 ) 3  or R 6 [Si(OR 1 ) 3 ] m  where R 2  is a styryl, vinyl, an acrylate, methacrylate, acrylamide, methacrylamide, divinylbenzene, itaconate, fumarate, substituted or unsubstituted C 1 -C 18  alkenylene, alkynylene or arylene, or a combination thereof; R 1  is a C 1 -C 4  alkyl moiety; R 6  is a substituted or unsubstituted C 1 -C 18  alkenylene, alkynylene or arylene moiety bridging two or more silicon atoms; and m is an integer greater than or equal to two.  
     
     
         20 . The hybrid material of  claim 19  wherein R 2  is vinyl, methacryloxypropyl, methacrylamidepropyl, or styrylethyl and R 1  is methyl or ethyl; or R 6  is a bridging N,N-bis(propylene)acrylamide group, m=2, and R 1  is ethyl or methyl.  
     
     
         21 . The hybrid material of  claim 17 , wherein the organosilane is minimally water soluble.  
     
     
         22 . The hybrid material of  claim 17  wherein said tetraalkoxysilane is selected from the group consisting of tetramethoxysilane and tetraethoxysilane.  
     
     
         23 . The hybrid material of  claim 17 , wherein the tetraalkoxysilane is tetramethoxysilane.  
     
     
         24 . The hybrid material of  claim 17 , wherein the polymerizable group is 3-methacryloxypropyl.  
     
     
         25 . The hybrid material of  claim 17 , wherein the polymerizable group is styrylethyl.  
     
     
         26 . The hybrid material of  claim 17 , wherein the tetraalkoxysilane is minimally water soluble.  
     
     
         27 . The hybrid material of  claim 17 , wherein the organosilane is (3-methacryloxypropyl)trimethoxysilane.  
     
     
         28 . The hybrid material of  claim 1 , wherein said pore structure of said hybrid material is modified by further including a surfactant or combination of different surfactants in said reaction, and by subjecting said material to hydrothermal treatment.  
     
     
         29 . The hybrid material of  claim 28 , wherein said surfactant or combination of surfactants are nonionic surfactants.  
     
     
         30 . The hybrid material of  claim 29 , wherein the surfactants are selected from the group consisting of surfactants comprised of block copolymers of polyethylene glycol and polypropyleneglycol, surfactants comprised of alkylphenoxypolyethoxyethanol, and polyethyleneglycol.  
     
     
         31 . The hybrid material of  claim 29 , wherein the surfactant is Pluronic F38,  
     
     
         32 . The hybrid material of  claim 28 , wherein said surfactant or combination of surfactants are selected from surfactants with a hydrophile-lipophile balance ranging from about 0 to 60.  
     
     
         33 . The hybrid material of  claim 28 , wherein said surfactant or combination of surfactants are selected from surfactants with a hydrophile-lipophile balance ranging from about 10 to 50.  
     
     
         34 . The hybrid material of  claim 28 , wherein said surfactant or combination of surfactants are selected from surfactants with a hydrophile-lipophile balance ranging from about 20 to 40.  
     
     
         35 . The hybrid material of  claim 28 , wherein said surfactant or combination of surfactants are selected from surfactants with a hydrophile-lipophile balance ranging from about 30 to 40.  
     
     
         36 . The hybrid material of  claim 28 , wherein said surfactant or combination of surfactants are selected from surfactants with a hydrophile-lipophile balance is about 33.  
     
     
         37 . The hybrid material of  claim 1 , wherein said material has been surface modified by a surface modifier selected from the group consisting of an organic group surface modifier, a silanol group surface modifier, a polymeric coating surface modifier, and combinations thereof.  
     
     
         38 . The hybrid material of  claim 37 , wherein said material has been surface modified by a polymeric coating surface modifier.  
     
     
         39 . The hybrid material of  claim 37 , wherein said material has been surface modified by a combination of an organic group surface modifier and a silanol group surface modifier.  
     
     
         40 . The hybrid material of  claim 37 , wherein said material has been surface modified by a combination of an organic group surface modifier and a polymeric coating surface modifier.  
     
     
         41 . The hybrid material of  claim 37 , wherein said material has been surface modified by a combination of a silanol group surface modifier and a polymeric coating surface modifier.  
     
     
         42 . The hybrid material of  claim 37 , wherein said material has been surface modified by a combination of an organic group surface modifier, a silanol group surface modifier, and a polymeric coating surface modifier.  
     
     
         43 . The hybrid material of  claim 37 , wherein said material has been surface modified by a silanol group surface modifier.  
     
     
         44 . The hybrid material of  claim 37 , wherein said material has been surface modified via formation of an organic covalent bond between an organic group of the material and a surface modifier.  
     
     
         45 . The hybrid material of  claim 37 , wherein the surface modifier has the formula Z a (R′) b Si—R, where Z=Cl, Br, I, C 1 -C 5  alkoxy, dialkylamino or trifluoromethanesulfonate; a and b are each an integer from 0 to 3 provided that a+b=3; R′ is a C 1 -C 6  straight, cyclic or branched alkyl group, and R is a functionalizing group.  
     
     
         46 . The hybrid material of  claim 45  wherein R′ is selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, t-butyl, sec-butyl, pentyl, isopentyl, hexyl and cyclohexyl.  
     
     
         47 . The hybrid material of  claim 45  wherein said functionalizing group R is a C 1 -C 30  alkyl group.  
     
     
         48 . The hybrid material of  claim 45  wherein said functionalizing group R is a C 1 -C 20  alkyl group.  
     
     
         49 . The hybrid material of  claim 45  wherein said surface modifier is selected from the group consisting of octyltrichlorosilane, octadecyltrichlorosilane, octadecyldimethyl-N,N-dimethylaminosilane, octyldimethylchlorosilane, and octadecyldimethylchlorosilane.  
     
     
         50 . The hybrid material of  claim 45 , wherein said surface modifier is octadecyldimethyl-N, N-dimethylaminosilane.  
     
     
         51 . The hybrid material of  claim 45 , wherein said functionalizing group R is selected from the group consisting of alkyl, alkenyl, alkynyl, aryl, cyano, amino, diol, nitro, ester, a cation or anion exchange group, an alkyl group containing an embedded polar functionality and an aryl group containing an embedded polar functionality.  
     
     
         52 . A hybrid inorganic/organic monolith comprising a polymerized scaffolding nanocomposite (PSN), wherein the nanocomposite contains a scaffolding functionality capable of chemically interacting with a surface of a second material.  
     
     
         53 - 105 . (canceled)  
     
     
         106 . A method of preparation of the hybrid inorganic/organic monolith of  claim 52 , said method comprising the steps of 
 a) forming a sol-gel by the reaction of two or more monomers;    b) initiating a polymerization reaction; and    c) allowing the monomers to react through a polymerization sol-gel (PSG) reaction, thereby preparing the hybrid inorganic/organic monolith.    
     
     
         107 . The method of  claim 106  further comprising 
 modifying the pore structure of the material.    
     
     
         108 - 181 . (canceled)  
     
     
         182 . A separations device comprising 
 a) a surface capable of accepting a monolith material comprising a polymerized scaffolding nanocomposite (PSN) material, said surface comprising an anchoring functionality and    b) a hybrid inorganic/organic monolith comprising a polymerized scaffolding nanocomposite (PSN), wherein the nanocomposite contains a scaffolding functionality capable of chemically interacting with the anchoring functionality on said surface, and wherein said hybrid organic/inorganic monolith is anchored to said surface by a chemical interaction between said scaffolding functionality and anchoring functionality.    
     
     
         183 . The separations device of  claim 182 , wherein said device is selected from the group consisting of chromatographic columns, thin layer plates, filtration membranes, sample cleanup devices, and microtiter plates.  
     
     
         184 - 193 . (canceled)  
     
     
         194 . The separations device of  claim 183 , wherein the device is a fused-silica capillary column.  
     
     
         195 . The fused-silica capillary column of  claim 194 , wherein the capillary column has an inner diameter (I.D.) greater than 50 μm.  
     
     
         196 - 245 . (canceled)  
     
     
         246 . A method of in situ preparation of a hybrid inorganic/organic monolith in a fused-silica capillary column, said method comprising: 
 forming an anchoring functionality on an interior surface of said capillary column; and    forming inside said capillary column a hybrid inorganic/organic monolith comprising a polymerized scaffolding nanocomposite (PSN), wherein the nanocomposite contains a scaffolding functionality capable of chemically interacting with the anchoring functionality on said surface, said monolith being formed by:    a) forming a sol-gel by the reaction of two or more monomers;    b) initiating a polymerization reaction; and    c) allowing the monomers to react through a polymerization sol-gel (PSG) reaction;    whereby said scaffolding functionality and said anchoring functionality chemically interact to thereby anchor said monolith to said surface, such that a hybrid inorganic/organic monolith is prepared in situ in the fused-silica capillary column.    
     
     
         247 . The method of  claim 246  further comprising 
 modifying the pore structure of the monolith.    
     
     
         248 . The inorganic/organic hybrid monolith of  claim 52 , produced by a process comprising the steps of 
 a) forming a sol-gel by the reaction of two or more monomers;    b) initiating a polymerization reaction; and    c) allowing the monomers to react through a polymerization sol-gel (PSG) reaction.    
     
     
         249 . The inorganic/organic hybrid monolith of  claim 248 , wherein the process further comprises 
 modifying the pore structure of the monolith.    
     
     
         250 . A method of preparation of a hybrid inorganic/organic material of  claim 1 , comprising the steps of 
 a) forming a sol-gel by the reaction of two or more monomers;    b) initiating a polymerization reaction; and    c) allowing the monomers to react through a polymerization sol-gel (PSG) reaction,    thereby preparing the hybrid inorganic/organic material.    
     
     
         251 . The method of  claim 250 , further comprising 
 modifying the pore structure of the material.