April 2014 – Completion of Procter and Gamble (P&G) Advanced Colloids Experiment (ACE) Sample (ACE-M-1) Operations on International Space Station (ISS): The tenth and last ACE-M-1 sample was started on April 4, 2014, and successfully completed on April 7, in the Light Microscopy Module (LMM) on the ISS. The Principal Investigator, and P&G Principal Scientist Dr. Matthew Lynch, will present the experiment findings as the Keynote Speaker at the American Society for Gravitational and Space Research (ASGSR) annual meeting. The data is expected to guide near term product improvements at P&G (e.g., longer shelf-life, higher concentrations, improved product formulation, better stabilizers). These improvements will lead to products that are more environmentally friendly (products that last longer, take less packaging, and have lower transportation impact). Flight data from ACE-M-1 will also be used in the design of the first 3-dimen-sional confocal ACE study scheduled for mid-2016.
The experiment used two sizes of particles (2.2 and 1.8 micron diameter) and depletion attraction to form a stabilized gel. By using two sizes of particles, this polydisperse system is more like an industrial system (which is often not monodisperse). The different particle sizes were dyed to fluoresce at different colors and they were each observed at 63X, 40X and 20X. In post processing, the images will be over-laid and “false” colored to tag the different particles sizes. The two images below show the final data points after 72 hours of sample evolution.