Fabrication and mechanism study of the nitrocellulose aqueous dispersions by solvent displacement method

The traditional preparation methods of nitrocellulose emulsion have many problems, such as high emulsifier content, complex preparation processes, or the need for high energy-consuming emulsification equipment. To address these issues, in this paper, the emulsifier-free NC dispersion was successfully prepared by a simple, low-energy solvent displacement method for the first time and the formation and stabilization mechanism of NC nanoparticles was also thoroughly investigated. The formation mechanism of the NC particles based on the “nucleation and aggregation” and the stabilization mechanism of the NC aqueous dispersions based on the electrostatic repulsion of anions were proposed and supported by experimental results. At the same time, we achieved effective control of the solid content of the NC dispersion by vacuum concentration. The obtained NC dispersion had a large range of adjustable sizes (63.82–143.43 nm), uniform size distribution (PDI < 0.2), a wide range of tunable solid content (0.5%–16%), and good stability (zeta potential < −20 mV), which has potential application in adhesives and coatings as promising candidates for traditional NC organic coatings.