(95t) Comparison of Fluorocarbon and Hydrocarbon Functional Group Incorporation into Nanoporous Silica Using Fluorinated and Hydrocarbon Surfactants as Templating Agents

Organic functionalized nanoporous silica particles have been successfully synthesized by the ?one-pot' (direct) synthesis method using two cationic fluorinated surfactants, C₆F₁₃C₂H₂NC₅H₅Cl (FSPCl-1) and C₈F₁₇C₂H₂NC₅H₅Cl (FSPCl-2), a hydrocarbon analogue surfactant, cetylpyridinium bromide (CPB), and CTAB (a typical hydrocarbon surfactant) as templates. Fluorocarbon and hydrocarbon functional groups, tridecafluoro-1, 1, 2, 2-tetrahydrooctyl and n-octyl, respectively, have been incorporated into nanoporous silica to examine the role of hydrocarbon and fluorocarbon surfactant and functional group interactions on the properties of the functionalized silica. The materials' pore structure and order were analyzed using powder X-ray diffraction and transmission electron microscopy (TEM), which show the presence of 2-D hexagonal pore structures. Type IV isotherms were observed in nitrogen adsorption experiments, suggesting that the materials are mesoporous. Fourier transform infra-red (FTIR) analysis was performed on all the materials to confirm surfactant removal and functional group incorporation. Most of the octyl functionalized materials possess smaller pore sizes with larger total surface areas when compares to the fluorocarbon functionalized materials. Longer chain fluoro-surfactant (FSPCl-2) templated materials with fluorocarbon functional group was observed to have low structural pore order while CTAB template gave fluorocarbon functionalized material of highest order. This surprising result could be described by the effect of the fluorinated silica precursor on self-assembly in the presence of hydrocarbon or fluorocarbon templating agents.