New method for preventing nano particles from re-agglomerating during rapid expansion of supercritical fluid

The invention provides a treatment method for preventing nano particles from re-agglomerating. The treatment method is characterized in that the RESS technology is adopted, and the suspending liquid containing both the nano particles and dissolved small organic molecules of supercritical fluid is directly sprayed to a container through spray microtubes and collected. Due to the instantaneous release of the supercritical fluid, the small organic molecules moving with the airflow are supersaturated to separate out solid particles, and the solid particles deposit and grow on the scattered nano particles to form a layer of film on each nano particle, so as to prevent the nano particles from re-agglomerating. The treatment method has the advantages that no volatile organic compound is needed, the operation is simple, the structures of the nano particles are not damaged, and industrialization is facilitated. The treatment method has a good effect and a high practical value in preventing nano particles from re-agglomerating.