Synthesis of inorganic/organic raspberry-like composite particles for superhydrophobic and superlipophilic coatings

A facile synthetic route to composite particles with raspberry-like structure was reported, and further led to superhydrophobic and superlipophilic surface by the usage of these composite particles. In this approach, the poly(styrene-co-3-methacryloxypropyl trimethoxysilane) (P(St-MPS)) particles were fabricated by one-step dispersion polymerization. Then, the P(St-MPS)@SiO2 composite particles with raspberry-like structure were obtained by hydrolysis of tetraethoxysilane (TEOS) with (P(St-MPS)) particles under alkaline conditions. The morphology of the (P(St-MPS))@SiO2 composite particles could be controlled by adjusting the ratio of the initial reactants 3-methacryloxypropyl trimethoxysilane (MPS) and styrene (St). A possible mechanism of the morphology changes was also discussed, the reactive siloxane groups of the (P(St-MPS)) particles induce the growth of silica generated by the hydrolysis of tetraethoxysilane (TEOS) on its surface to form raspberry-like structure. In addition, the water contact angle (WCA) of the coating was 152° ± 2°, and the oil contact angle (OCA) of the coating was close to 0°, which demonstrated a superhydrophobic and superlipophilic properties by a rational surface modification of this P(St-MPS)@SiO2 composite particles with raspberry-like structure. Hydrophobic properties could be adjusted by varying the surface morphology of the P(St-MPS)@SiO2 composite particles. The coatings could be used in applications such as self-cleaning and oil-water separation and whole process was carried out under mild conditions and did not involve complex steps.