Self-assembly of amino-functionalized monolayers on silicon surfaces and preparation of superhydrophobic surfaces based on alkanoic acid dual layers and surface roughening

Reproducibly smooth amino-functionalized surfaces were obtained by deposition of aminopropyltrimethoxysilane (APTMS) at the vapor/solid interface. Characteristics of these amino-functionalized surfaces were evaluated based on atomic force microscopy, water contact angle measurement and X-ray photoelectron spectroscopy. The results showed that APTMS modified surfaces are very homogeneous and the chemical reactivity of modified surfaces can be ensured with high free amino content. Furthermore, for the purpose of tailoring the wettability of silicon surface, dual self-assembled films were achieved by performing reaction between amino-functionalized surface and n-alkanoic acids with different chain length. The wettability of the self-assembled films can be adjusted with altering the hydrocarbon chain length of alkanoic acids. Moreover, cooperation of dual self-assembled films with surface roughening, superhydrophobic surfaces with CA larger than 153° were obtained. Thus, the wettability of modified surfaces can be altered greatly with changing hydrocarbon chain length of self-assembled films.