Salted mesostructures: salt-liquid crystal templating of lithium triflate-oligo (ethylene oxide) surfactant-mesoporous silica nanocomposite films andmonoliths

A lyotropic lithium triflate-silicate liquid crystal is utilized as a supra molecular template for a 'one-pot' synthesis of a novel ionically conductin g nanocomposite material, denoted meso-SiO2-C-12(EO)(10)OH-LiCF3SO3, in the form of a film or monolith. In this structure Li+ ions interact; in a crow n ether-like fashion, with oligo(ethylene oxide) head groups of anon-ionic surfactant assembly that is imbibed within the channels of hexagonal agonal mesoporous silica. Details of the acid catalyzed polymerization of the sil icate oligo(ethylene oxide) surfactant-co-assembly in the presence of lithi um triflate have been investigated using polarized optical microscopy (POM) , powder X-ray diffraction (PXRD), multinuclear nuclear magnetic resonance (NMR) spectroscopy and impedance spectroscopy. Insight into the incorporati on of Li+ and CF3SO3- ions into meso-SiO2-C-12(EO)(10)OH-LiCF3SO3 was obtai ned: using NMR and Fourier transform (FT) Raman spectroscopy. Collectively the results maleate that lithium ions coordinate to oxygens of the oligo (e thylene oxide) head group, maintain the structural integrity of both the si licate liquid crystal and templated mesoporous silica, and are essentially completely:dissociated with respect to the triflate counteranion. ac Impeda nce spectroscopy, which bodes well for their use in the fields of polymer e lectrolytes and battery technology for meso-SiO2-C-12(EO)(10)OH-LiCP3SO3 ha ve demonstrated high ionic conductivities at room temperature measurements. Salt-liquid crystal templating may offer a:general approach for synthesizi ng diverse kinds of salted mesostructures including redox active transition metal complexes, which may be reductively agglomerated to form metal clust er-based meso-SiO2-C-12(EO)(10)OH-M-n or sulfided with H2S to produce semic onductor cluster-based meso-SiO2-C-12(EO)(10)OH-(MS)(n) nanocomposites.