Surface modification through self-assembled microrod networks

Surface modification by the construction and surface polymerisation of microrod networks is demonstrated here. The hydrophobic microrod networks are produced through the self-assembly of a novel organic molecule, N'1,N'6-bis(3-(1-pyrrolyl)propanoyl) hexanedihydrazide (DPH). The microrods generated grow to create a network structure that enhances hydrophobicity by providing roughness on a surface, leading to a ~20° increase in the water contact angle. The hydrophobic surface was modified to become a hydrophilic surface by treatment with a chemical oxidant that induced polymerisation of the pyrrole rings on the surface of the micronetwork. In addition to the hydrophilic conversion of the surface functional groups, surface roughness was also reduced by the polymerisation. This study demonstrates that the self-assembly of the DPH molecule can be exploited to customise surfaces that require facile hydrophobic/hydrophilic surface modification.