Super-hydrophobic and self-cleaning PVDF film fabricated by chemical bath deposition

Self-cleaning surfaces have received a great deal of attention recently, both in theoretical studies and commercial applications. The self-cleaning surface of lotus leaf is hydrophobic and rough, showing a micro- and nanoscale morphology. The micro-reliefs of lotus leaf were mimicked using polyvinylidene fluoride (PVDF) film and nano-scale peaks on the top of the micro-reliefs were implemented by the reaction between methyltrichlorosilane and the reactive groups of PVDF film treated by oxygen plasma. A lotus-leaf-like surface of the PVDF film was clearly observed by scanning electronic microscopy (SEM) and atomic force microscope (AFM). Elemental composition analysis by X-ray photoelectron spectroscopy ( XPS ) revealed that the material of the nanostructure of PVDF film was polymethylsiloxane. The superhydrophobic property of the mimicked self-cleaning surface was validated by the water contact angle and sliding angle on the lotus-leaf-like PVDF film, which were 156.6° and 4°, respectively. In this case, water droplets can easily move across the PVDF film surface, carrying dirt particles away, leaving no contamination.