Patterning of nanoscale pores in ultrathin silica films has been achieved via the self-organization of an organic spacer molecule in a monolayer of an alkyltrimethoxysilane. Langmuir-Blodgett films of monolayers of octadecyltrimethoxysilane (OTMS) doped with octadecylsulfonate sodium salt were deposited from a pure water subphase onto silicon substrates. The samples were heat treated at 80 -101℃ yielding highly condensed, molecularly flat films with good surface coverage. Removal of the organicsand spacer molecules via calcination of the monolayers at 450℃for 8-10 h yielded thin (0.5 - 0.7 nm) silica films decorated with circular pores of uniform size, ranging from 0.8 to 400 nm dependent upon the ratio of spacer molecule to OTMS. Scanningforce microscopy was used to image the nanoscale features generated in the films and also to provide some qualitative information on the mechanical properties of the films. The ability to create uniform pore sizes in metal oxide thin-films is attractivefor selectively sorbent materials for sensors and separation membranes.
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