Nanometer size chemical modified materials and uses

Abstract

Ligand compositions and stationary phases comprising polyhedral oligomeric silsesquioxane moieties are incorporated in to chromatographic stationary phases, and these phases are incorporated into chromatography devices, such as columns. The compositions and devices are of use to separate molecular mixtures.

What is claimed is: 
     
         1 . A method of separating analytes in a liquid sample, the method comprising:
 flowing the liquid sample through a chromatography column configured for use in liquid chromatography, the chromatography column containing therein a composition, the composition comprising:
 a solid support having an exterior surface; and 
 a ligand comprising a polyhedral oligomeric silsesquioxane moiety covalently 
   bound to the exterior surface, wherein the polyhedral oligomeric silsesquioxane moiety is not a cross-linker.   
     
     
         2 . The method of  claim 1 , wherein the liquid sample comprises anions, cations and uncharged molecules, each essentially retained by the composition. 
     
     
         3 . The method of  claim 1 , wherein the polyhedral oligomeric silsesquioxane moiety is covalently bound to the exterior surface through a linker covalently bound to both the polyhedral oligomeric silsesquioxane moiety and the exterior surface. 
     
     
         4 . The method of  claim 3 , wherein the linker comprises at least 4 carbon atoms in sequence. 
     
     
         5 . The method of  claim 3 , wherein the linker comprises at least one heteroatom selected from N, O, S and a combination thereof. 
     
     
         6 . The method of  claim 1 , wherein the solid support is a particle. 
     
     
         7 . The method of  claim 1 , wherein the solid support comprises a flow-through monolith. 
     
     
         8 . The method of  claim 1 , wherein the solid support is in particulate form, and wherein multiple support particles are disposed in a packed bed. 
     
     
         9 . The method of  claim 1 , wherein the solid support comprises a member selected from silica, alumina, titania, zirconia, and combinations thereof. 
     
     
         10 . The method of  claim 1 , wherein the solid support comprises a silica monolith. 
     
     
         11 . The method of  claim 1 , wherein the solid support comprises silica gel. 
     
     
         12 . The method of  claim 1 , wherein the solid support comprises a silica/organic polymer hybrid. 
     
     
         13 . The method of  claim 1 , wherein the solid support comprises a silica core/shell material. 
     
     
         14 . The method of  claim 1 , wherein the solid support further comprises a plurality of pores each of which defines an interior space and the ligand is covalently bound to both the external surface and the interior space. 
     
     
         15 . The method of  claim 1 , wherein the solid support comprises a synthetic organic polymer. 
     
     
         16 . The method of  claim 1 , wherein the ligand comprises an alkyl chain having at least 11 carbon atoms in sequence. 
     
     
         17 . The method of  claim 16 , wherein at least two of the carbon atoms in sequence are part of a ring selected from substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl and substituted or unsubstituted cycloalkyl. 
     
     
         18 . The method of  claim 1 , wherein the ligand comprises an alkyl chain imparting reverse phase chromatographic properties to the composition. 
     
     
         19 . The method of  claim 1 , wherein the ligand includes an ion exchange moiety, imparting ion exchange properties to the composition. 
     
     
         20 . The method of  claim 1 , wherein one or more silicon atom of the polyhedral oligomeric silsesquioxane is independently bonded to an R group selected from H, OH, unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted heterocycloalkyl. 
     
     
         21 . The method of  claim 1 , wherein one or more silicon atom of the polyhedral oligomeric silsesquioxane is independently bonded to an R group selected from alkyl or aryl carboxylic acid, alkyl or aryl sulfonate, alkyl or aryl imide, alkyl or aryl thiol, alkyl or aryl epoxide, fluoroalkyl, and poly(ethylene glycol). 
     
     
         22 . The method of  claim 1 , wherein one or more silicon atom of the polyhedral oligomeric silsesquioxane is bonded to an R group independently selected from H, ethyl, i-butyl, i-octyl, cyclohexyl, cyclopentyl, phenyl, propylamino, glycidyl, propylmethacrylate, and vinyl. 
     
     
         23 . The method of  claim 1 , wherein the liquid sample comprises at least one aromatic compound and an aqueous mobile phase. 
     
     
         24 . The method of  claim 1  further comprising: exposing the chromatographic column to an acid for at least 50 hours. 
     
     
         25 . The method of  claim 24 , in which the liquid sample is at an elevated temperature of 50 degrees Celsius