A facile strategy for ceramic microparticles coating via prolonging particle motion trajectory

Coating for the Geldart C class ceramic microparticles by fluidized bed–chemical vapor deposition method is challenging due to the poor fluidization characteristics. To overcome this problem, a dynamic transport coating process is proposed in this study. Through the helical pipes microreactor, the residence time of ceramic microparticles is extended by increasing the microparticle trajectory by 20 times. The residence time of particles can be adjusted by adjusting the flow rate of carrier gas. A carbon layer of nanoscale thickness was coated on the 5–30 µm sized SiO 2 ceramic microparticles via dynamic chemical vapor deposition in the microreactor. The microstructure and formation mechanism of the coating were studied. The coating can serve as a barrier to protect SiO 2 ceramic microparticles from long‐term corrosion by hydrofluoric acid. This method is an effective strategy to be extended to the coating process of other ceramic microparticles and to realize continuous and large‐scale production.