Self-assembled heteromorphous raspberry-like colloidal particles from Pickering-like emulsion polymerization

Abstract

Heteromorphous raspberry-like poly(vinylidene fluoride)/polystyrene (PVDF/PS) complex colloidal particles (CCPs) were prepared by a facile and high-efficiency approach with one pot Pickering-like emulsion polymerization following conventional free radical polymerization mechanism. Difference of hydrophobicity between PVDF and PS drove the initial generated snowman-like particles self-assembling into colloidal particle clusters and then a Pickering-like emulsion continued polymerization till formation of the heteromorphous raspberry-like PVDF/PS CCPs. In order to achieve heteromorphous raspberry-like PVDF/PS CCPs with homogeneous size and morphology, influences of St/PVDF feed ratio, polymerization time, and polymerization temperature were systematically investigated. When the feed ratio of St/PVDF was high for synthesis of the CCPs, double crystallization peaks for PVDF were observed with a strong peak at about 132 °C and a weak peak at near 70 °C, indicating that partial PVDF seed particles were covered completely by PS. Furthermore, the static water contact angle of latex nanocoating prepared with the heteromorphous raspberry-like PVDF/PS CCPs reached 153.9°, exhibiting a superhydrophobicity. As a result, an alternative way is provided for fabrication of hierarchical colloidal particles and even superhydrophobic smart coatings.