Giant nanomembrane of covalently-hybridized epoxy resin and silica

A simple fabrication process of hybrid nanomembranes of epoxy resin and silica is described. Neat poly[(o-creyl glycidyl ether)-co-formaldehyde] (PCGF) and 3-aminopropyl triethoxysilane (APS) were allowed to react at room temperature, diluted with chloroform, and subjected to spin-coating. Upon baking at 120 °C, robust, defect-free nanomembranes with uniform thickness in the range of 20-50 nm were formed. It is apparent that the two components were homogeneously mixed due to chemical linking of the epoxy and amine groups. The nanomembrane was hydrophobic and remained intact on the water surface. It also showed excellent chemical stability without swelling in most organic solvents, and its membrane morphology was maintained when it was heated at 600 °C for 3 h, in spite of complete elimination of the organic component. The mechanical property was not drastically altered from that of the epoxy-only nanomembrane which we reported previously. The relevance of cross-linking density and hybridization in relation to the stability of various giant nanomembranes was discussed.