Self-assembled monolayer of mica coating using organobisphosphonic acid

A hexadecane-1,1-bisphosphonic acid monolayer was grafted on the surface of muscovite mica via a simple self-assembled method. The result of AFM showed that the height of the bisphosphonate SAMs was about 2.40 nm, corresponding to both monolayer-like coverage and the hydrocarbon chain length. TOF-SIMS indicated that the reaction between bisphosphonic acid and silicon was took place on the surface of mica substrate. It can be proved from IR, AFM, XPS, and TOF-SIMS that the alkylbisphosphonate SAM was bonded to the mica with the mode of double-tridentate attachment. In addition, organobisphosphonate SAM possessed excellent orderliness and stability, which provides a theoretical basis for its efficient application in the field of organic modification.