Structural characterization of self-assembled multilayers by FTIR

We have used attenuated total reflection infrared spectroscopy (ATR-IR) to probe the structural order in zirconium-phosphonate self-assembled multilayers. Very well-ordered alkylsiloxane anchor layers can be prepared on silicon substrates after suitable etching. However, the IR spectra indicate that zirconium-organophosphonate multilayers deposited onto the anchor layer are disordered. The disorder correlates with introduction of zirconium and appears to be a result of the poor match of the hydrocarbon lattice with the stronger inorganic Zr-phosphonate lattice. There is no additional degradation in packing order with the deposition of multiple layers. Ramifications for possible device application are discussed.