Synthesis of Biomimetic Brochosome-Shaped Microspheres via Droplets Assembly Strategy

Artificial brochosome-shaped microspheres closely mimicking natural brochosomes are highly desired however challenging to synthesize. Herein silica brochosome-shaped microspheres (SiO2 BMs) are successfully synthesized by simply adjusting the NH4OH/p-xylene ratio. The obtained BMs, with a diameter of 530 nm and highly accessible open pores of ∼130 nm, demonstrate high similarity to natural brochosomes in size, shape, and pores geometry. A mechanism of droplets assembly originating from the surface charge transformation of the emulsion droplets is proposed by carefully investigating the in situ dynamic evolution of BMs intermediates. The priority growth of primary particles at the interface of the adjusting droplets forms the pores wall of BMs with regular distribution. Benefiting from the unique structure, the SiO2 BMs show excellent antiadhesion (superhydrophobic) and antireflection (at least 70% reduction for vertical reflection), indicating the high functional similarity to natural brochosomes. The synthesized BMs demonstrate sufficient load capacity, suggesting great potential in energy conversion and biomedical applications.