Fluorinated Nanosilica Size Effect on Hierarchical Structure and Superhydrophobic Properties of the Epoxy Nanocomposite Film

A series of perfluorosilane in situ modified nanosilica particles with different diameters was successfully synthesized and characterized. The epoxy-based nanocomposite films were prepared by a coaxial electrospraying process, in which the nanosilica dispersion was used as the sheath liquid, while epoxy solution was used as the core liquid. The effects of fluorinated nanosilica on the surface morphology and contact angle of the prepared polymer nanocomposite films were systematically investigated. Under the condition of coaxial electrospraying, the nanosilica with diameters between 150 and 200 nm can be densely coated on the epoxy microparticle surface, forming a superhydrophobicity required micro/nano hierarchical morphology. Additionally, the amine curing agent can electrostatically attract negatively charged nanosilica under the high-voltage electrostatic field, forming good interfacial interaction between the nanosilica and the epoxy particles after curing. The prepared epoxy nanocomposite film has both superhydrophobic properties and excellent chemical stability and enhanced mechanical properties.