SUPERCRITICAL FLUID NUCLEATION FOR IMPROVED DISSEMINATION OF POWDERED MATERIALS

SUPERCRITICAL FLUID NUCLEATION (SFN) IS PROPOSED AS THE MECHANISM FOR AN INNOVATIVE, IMPROVED METHOD FOR THE DISSEMINATION OF ULTRA-FINE PARTICLES. THE CONCEPT, AS APPLIED TO THE STATED TOPIC, INVOLVES THE RAPID EXPANSION OF A SOLUTION OF RIOT CONTROL AGENTS IN SUPERCRITICAL OR NEAR CRITICAL CARBON DIOXIDE FROM A SMALL CANISTER TO PRODUCE A FINE AEROSOL OF SOLID PARTICLES WHOSE SIZE CAN BE CONTROLLED BY EXPANSION CONDITIONS. SFN HAS BEEN DEMONSTRATED PREVIOUSLY FOR ITS ABILITY TO PRODUCE PREDICTABLE PARTICLE SIZES RANGING FROM SUBMICRON TO TENS OF MICRONS AND IS CURRENTLY UNDER EVLAUATION AS A MEANS OF PROVIDING A SUBMICRON MONODISPERSED PARTICLE GENERATED FOR LASER DOPPLER VELOCIMETRY. EXPLOITING SFN TECHNOLOGY AS A MEANS OF DISPERSING RIOT CONTROL AGENTS HAS A NUMBER OF POTENTIAL ADVANTAGES. FIRST, SUBMICRON PARTICLES, WHICH HAVE BENEFICIAL ADSORPTION AND TRANSPORT PROPERTIES, CAN BE PRODUCED. SECONDLY, CARBON DIOXIDE IS NON-TOXIC AND INFLAMMABLE AND BECAUSE GAS EXPANSION IS THE MECHANISM FOR PARTICLE RELEASE, PYROTECHNIC MATERIAL IS ELIMINATED. FINALLY, BECAUSE THE CONCEPT UTILIZES A SOLUTION OF RIOT CONTROL AGENTS IN CARBON DIOXIDE THE PRODUCTION, HANDLING, AND PACKAGING OF NOXIOUS FINE PARTICLES IS ELIMINATED.