574e Synthesis and Application of Fluorocarbon Functionalized Mesoporous Silica

Gifty Osei-Prempeh1, Barbara L. Knutson1, Stephen E. Rankin1, and Hans-Joachim Lehmler2. (1) Department of Chemical and Materials Engineering, University of Kentucky, 177 Anderson Hall, Lexington, KY 40506-0046, (2) University of Iowa, 222 IREH , Department of Occupational and Environmental Health, Iowa City, IA 52242-5000

The pore structure of mesoporous silica materials synthesized by sol-gel processing can be tailored through the choice of surfactants or polymers templates. The direct incorporation organic groups into the framework of these materials through the incorporation of organic functionalized precursors is also affected by the template. In this work, we demonstrate the direct synthesis of fluorocarbon (heptadecafluoro-1,1,2,2-tetrahydrodecyl and tridecafluoro-1,1,2,2-tetrahydrooctyl) functionalized ordered mesoporous silica. Ordered bi-functional (3-aminopropyl- tridecafluoro-1,1,2,2-tetrahydrooctyl) porous silica have also been achieved. These materials were synthesized using cationic fluorocarbon surfactants, tridecafluoro-1,1,2,2-tetrahydrooctyl pyridinium chloride (FSPCl-1: C6F13C2H4NC5H5Cl), heptadecafluoro-1,1,2,2-tetrahydrodecyl pyridinium chloride (FSPCl-2: C8F17C2H4NC5H5Cl) and hydrocarbon surfactant cetylpyridinium bromide (CTAB: C16H33NC5H5Br) as templating agents. The incorporation of the organic groups is confirmed by FTIR and TGA analysis. The materials' pore order and structure are analyzed using powder X-ray diffraction (XRD) and TEM, and the physical properties are obtained using nitrogen adsorption analysis. Incorporation of the fluorocarbon functional group results in materials of high hydrophobic and lipophobic nature and also high thermal and chemical resistance. These advanced materials have potential application in chromatography, catalysis, sensing, and as gas purification adsorbents. The application of these fluorocarbon functionalized mesoporous silica particles to fluorous phase separation is demonstrated.