Transmission electron microscopy characterization and application of sol-gel membranes

Using standard square mesh grids as supports, we have prepared sol-gel memb ranes from a functionalized silane precursor, bis[3-(triethoxysilyl)propyl] tetrasulfide in various organic solvents. These mesh-supported membranes al low direct characterization of their microstructure and morphology by trans mission electron microscopy (TEM). Homogeneous membranes without prominent microstructural features (or featureless) at nanometer scale were obtained from dimethyl formamide (DMF), isopropanol, and butanol solutions. However, highly porous membranes were produced from DMF and ethylene glycol binary system. Heterogeneous membranes filled with nanoparticles were formed from dimethyl sulfoxide solution. The featureless sol-gel membranes with tunable performances provide a useful alternative as supporting films for TEM appl ications.