An environmental-friendly oil-based dust suppression microcapsules: Structure with chitosan derivative as capsule wall

In this study, environmentally friendly microcapsules with chitosan quaternary ammonium salt (HACC) and sodium alginate (SA) shells and rapeseed oil cores were used to harmlessly reduce the dangers of open pit coal mine dust to coal miners. Due to the electrostatic attraction between -NH3+ of HACC and -COOH- of SA, the complex coacervation method was used to coat the rapeseed oil core material to prepare a type of oil-based dust suppression microcapsules. Optical and scanning electron microscopy showed that the microcapsules had a spherical structure, smooth surface without holes, core-shell structure, and sustained release properties. Infrared spectroscopy and X-ray diffraction showed that HACC and SA were electrostatically attracted to form a kind of "eggshell" structure-coated core material. Thermogravimetric analysis showed that the microencapsulated rapeseed oil had good thermal stability. Performance tests showed that rapeseed oil adheres well to the dust, the shell material and the dust form a strong solid layer, and the core and shell materials work synergistically to suppress coal dust. The dust suppression rate reached up to 91.98 %. In addition, the dust suppression microcapsules have good water retention performance and degradability, which can reduce the harm to the environment.