Chemical in situ polymerization of polypyrrole nanoparticles on the hydrophilic/hydrophobic surface of SiO ₂ substrates

Polypyrrole (PPy) nanoparticles formed by chemical in situ polymerization were deposited on the hydrophilic/hydrophobic surface of SiO ₂ substrates to give the diversely morphology, respectively. The morphologies of PPy nanoparticles deposit were investigated using optical microscope, scanning electron microscope (SEM), and atomic force microscope (AFM) imaging techniques. The morphology of Y-and T-shape wrinkles was observed on the hydrophilic surface of SiO ₂ substrate, while the morphology of polygon-shape wrinkles on the hydrophobic surface of SiO ₂ substrate, and this distinction is due to the difference of the surface energy between the hydrophilic and hydrophobic surface of SiO ₂ substrate and so-called memory effect.