Novel preparation of functionalized graphene oxide for large scale, low cost, and self-cleaning coatings of electronic devices

Superhydrophobic coating is a very useful method to lower the moisture adsorption and improve the reliability of electronic devices. Here we report a facile fabrication of superhydrophobic surfaces by functionalization of graphene oxide (GO), an important precursor for preparing graphene. Several aliphatic amines molecules were used to react with GO, including hexamine, dodecylamine, hexadecylamine and octadecylamine. These amphiphilic amine molecules, with hydrophobic tails and hydrophilic heads, are chemically grafted onto the GO surface by nucleophilic reaction between epoxide and amine groups. The hydrophobic tail is exposed which lower the surface energy of modified GO sheets. The functionalized GO films exhibit an enhanced surface roughness, which is essential for the superhydrophobicity. It was found that only hexadecylamine and octadecylamine lead to superhydrophobicity after a previously developed functionalization reaction. For octadecylamine-modified GO film, a large contact angle (above 150°) and low hysteresis (below 5°) was observed. Such superhydrophobic coating can be applied on electronic devices by various methods, such as drop coating, dip coating and spray coating. This method is promising in terms of low-cost and large-scale superhydrophobic coatings for device protection.