Experiments were conducted to determine particle release rates from surfaces due to air jet impingement. We utilize monodisperse fluorescent polymer spheres ranging from 1m to 45m diameter distributed on polycarbonate surfaces and muslin cloth. Particle removal efficiencies are determined from cloth that simulates clothing or fabrics, surfaces important for trace explosives detection. Optical images of the sample surface are taken using a fluorescent microscope (488 nm radiation) before being challenged by a pulsed air or nitrogen jet. The jet is oriented at 45 degrees with respect to the particle laden substrate and is precisely aligned to the center of the opticle axis for the microscope. Fluorescence micrographs are taken of the same surface area after the interrogation by the jet. Particle removal rates are determined by particle counting implemented by image processing and analysis. We found that the cloth surface has a release rate comparable to the rate for polycarbonate surface under similar jet conditions. As expected, there is a particle size dependence on removal rate, with larger particles being more easily removed.
Citation: Aerosol Science and Technology
Pub Type: Journals
air jet paritcle release, adhersion to surfaces, fluorescent microspheres, removal from cloth