Silica gels with tunable nanopores through templating of the L-3 phase

We describe a detailed synthesis of a silicified inorganic/organic nanoporo us monolithic composite conforming to the lyotropic liquid crystalline L-3 phase. The pore dimensions of the silicified LQ phase scale with the solven t volume fraction in the synthesis reaction mixture. Changing the solvent f raction in the initial solution changes the ultimate pore diameter in the s ilicate, providing a simple method for tuning the diameter of the pores in the matrix. The resulting monolith is optically isotropic and transparent w ith a nonperiodic network. Accessible pores (which permeate the entire stru cture) in the silicified materials correlate with the solvent domain of the original liquid crystalline phase and therefore negate the need to remove the surfactant in order to gain access to the pore network. Measured charac teristic dimensions are from 6 to well over 35 nm. X-ray scattering studies indicate a low polydispersity in the pore diameters for a given solvent fr action. Transmission electron and atomic force microscope images are consis tent with a random morphology and measured surface areas exceed 960 m(2) g( -1) in extracted materials.