PREPARATION OF LOW DENSITY MICROCELLULAR MATERIALS FROM FULLERENES

LOW DENSITY MICROCELLULAR MATERIALS (LDMMS) ARE CARBON- OR SILICON-BASED POROUS SOLIDS WITH HIGH SPECIFIC SURFACE AREAS. THESE MATERIALS HAVE BEEN DEVELOPED EXTENSIVELY OVER THE LAST DECADE, AND THEY ARE MOVING TOWARD SUBSTANTIAL COMMERCIAL DEVELOPMENT IN A VARIETY OF APPLICATIONS. AN OPPORTUNITY TO PREPARE NOVEL LDMMS WITH IMPROVED PROPERTIES NOW ARISES WITH THE RECENT DISCOVERY OF FULLERENE CARBON. FULLERENES ARE PARTICULARLY SUITED AS BUILDING BLOCKS OF LDMMS BECAUSE OF THEIR LOW DENSITY, INHERENT STIFFNESS, THERMAL STABILITY, AND TENDENCY TO REACT AT MULTIPLE SITES (WHICH FAVORS CROSS-LINKING REACTIONS). A VERY PROMISING SYNTHETIC ROUTE TO FULLERENE LDMMS HAS BEEN IDENTIFIED. IN PHASE I, BY COMBINING REACTIONS THAT YIELD ORGANIC LDMMS WITH RECENTLY REPORTED REACTIONS OF FULLERENES, POROUS, MONOLITHIC SOLIDS CONTAINING FULLERENES ARE BEING PREPARED. THE PRODUCTS ARE CHARACTERIZED BY DETERMINING SPECIFIC SURFACE AREA, POROSITY, CELL SIZE DISTRIBUTION, AND COMPRESSIVE STRENGTH AND MODULUS. ADSORPTION AND DESORPTION WILL THEN BE MEASURED FOR SELECTED ADSORBATES; THIS INFORMATION WILL BE COMBINED WITH DATA FROM A CURRENT PROJECT THAT IS STUDYING ADSORPTION ON FULLERENES TO BETTER UNDERSTAND SORPTION ON THE NEW LDMMS. PHASE I IS ALSO CONSIDERING POTENTIAL APPLICATIONS OF THE NEW MATERIALS AS WELL AS THE STRUCTURAL PROPERTIES REQUIRED FOR IMPROVED PERFORMANCE. OTHER FORMS OF CARBON CURRENTLY HAVE IMPORTANT COMMERCIAL APPLICATIONS, SUCH AS ACTIVATED CARBON IN ADSORPTION AND VITREOUS CARBON AS ELECTRODE MATERIALS. FULLERENE CARBON CAN NOW BE PREPARED IN A FORM SUITABLE FOR SIMILAR USES, WITH A GREATER DEGREE OF SYNTHETIC CONTROL BEING EXERCISED OVER STRUCTURE THAN IS POSSIBLE WITH OTHER FORMS OF CARBON. PHASE II WILL DEVELOP THE REACTION CHEMISTRY TO ENABLE THE PREPARATION OF FULLERENE SOLIDS WITH CONTROLLED PORE SIZE DISTRIBUTION, SPECIFIC SURFACE AREA, AND COMPRESSIVE STRENGTH.