Analysis of the Apollo 16 Free-Fluid Electrophoresis Experiment

The Apollo 16 free-fluid electrophoresis experiment attempted the separation in microgravity of two different-size monodisperse polystyrene latexes under conditions that would give a completely roiled sample on earth because of the thermal convection. The instrument comprised three parallel 0. 63-cm inside diameter 10. 2-cm long Lexan polycarbonate electrophoresis channels, with ted from the channel by semipermeable membranes. The latex samples were contained in cylindrical chambers separated from the electrode by a fixed semipermeable membrane and from the Lexan tube by a movable Kapton polyimide film. Two channels contained 0. 80μm- and 0. 23μ-diameter monodisperse polystyrene latexes and the third, a mixture of the two sizes. The experiment was initiated in microgravity by removing the Kapton films which separated the latex samples from the electrophoresis channels and applying a potential of 300 volts across the electrodes. The results were recorded by photographs taken every 20 seconds.