Generation of Polystyrene Latex Spheres with Incorporated Fluorescent Dyes

Although polystyrene microspheres are often the seed material of choice for subsonic airflow studies. These seed materials, however, do not provide any benefit for near wall measurements compared to other state-of-the-art seed materials. Consequently, in this innovation NASA scientists have developed this method of generating dye-doped polystyrene microspheres using novel synthetic approaches. The novel features of this invention are the utility of specific chemical functionalities, monomeric species, environmental additives (buffers), and polyelectrolytes to promote incorporation of dye molecules into developing polystyrene microspheres while enabling control of the spectral properties of the dye relative to pH dependence. These particles will have great utility for wind tunnel measurements near the wall where the state-of-the-art seed materials are not able to collect data. Additionally, the incorporation of these dyes will offer other avenues of data collection including temperature and pressure of the airflows and wind tunnel regions. Likewise, the ability to selectively filter the data collected from these dye-doped polystyrene microspheres can have further applications including the direct visualization of 2 or more fluid flows mixing, among other applications.