The goal of Binary Colloidal Alloy Test-6: Phase Separation (BCAT-6-Phase Separation) is to gain unique insights into how gas and liquid phases separate and come together in microgravity. These fundamental studies on the underlying physics of fluids could provide the understanding needed to enable the development of less expensive, longer shelf-life household products, foods, and medicines.Principal Investigator(s)
ZIN Technologies Incorporated, Cleveland, OH, United States
National Aeronautics and Space Administration (NASA)Sponsoring Organization
Human Exploration and Operations Mission Directorate (HEOMD)Research Benefits
Information PendingISS Expedition Duration:
September 2010 - March 2014Expeditions Assigned
25/26,27/28,29/30,31/32,33/34,35/36,37/38Previous ISS Missions
The BCAT predecessors; BCAT-3 operated on ISS, and BCAT, operated on Mir in 1997 and 1998. BCAT-4 launched March 11, 2008 on 1J/A, and BCAT-5 launched June 13, 2009 on 2J/A.
When water boils in a pot, liquid and gas water coexist. If this pot of water is sealed, as the temperature and pressure rise, a point will be reached where liquid and gas are no longer distinct phases and above this point you no longer have a liquid or gas, but a supercritical fluid. A supercritical fluid has properties of both liquids and gases; it has the ability to transport dissolved materials and thermal energy (like liquids) and it flows easily (like gases). These combined qualities are used for things like extracting biomolecules from plants for pharmaceutical research, for decaffeinating coffee beans, and it is being looked at by JPL as a propellant for future rocket engines. These BCAT samples model supercritical fluids, and this model is used throughout industry. This experiment is making measurements that cannot be made on Earth and BCAT-3 microgravity experiment has shown that the present model that is used to predict the location of when a supercritical fluid is formed in these model systems is at best incomplete.
The Binary Colloidal Alloy Test-6, Phase Separation (BCAT-6, Phase Separation) experiments examine conditions that result in colloidal crystallization, melting, self-organization, and phase separation of colloidal systems. The evolution toward equilibrium through time is captured on the International Space Station (ISS) or with the accurate measurement of time frames correlated to the pictures taken by a new kind of automated camera.
There are three principle objectives associated with the phase separation studies in BCAT-6, Phase Separation. The first objective is to measure phase separation rates in microgravity in order to develop the underlying theory for predicting product shelf life. The second is to understand how to control the colloidal forces between particles to determine the physics underlying the phase separation process that forces the placement of additives in products to extend their shelf life. It is for this reason, among others, that finding the critical point is so important. The critical point is the point at which gas transitions into a liquid or supercritical fluid. A supercritical fluid has the properties of both a gas and a liquid. The final objective is to understand the fundamental properties of colloid-polymer mixtures to further improve the commercial utilization of these systems. The fundamental fluid physics research could provide the understanding needed to enable the development of better, less expensive, longer shelf-life household products, foods, and medicines. Stabilizers in these products are expensive, take up volume, and are needed to extend the life of products.
Results from these experiments could help to develop more efficient phase-separation processes for life-support systems.Earth Applications
These samples will provide important data that is not available on Earth. The data may guide our understanding of phase separation. Additionally, product shelf-life may be dependent upon bi-nodal decomposition and possibly upon Ostwald ripening in the emulsion samples.
The BCAT-6 consists of a set of ten small samples of colloidal particles. The BCAT-6 samples are each contained within a small case the size of a school textbook. The experiment requires a crew member to set up the experiment using a handrail/seat track configuration, ISS Laptop and the Kodak 760 or Nikon D2Sx camera to take digital photographs of the samples at close range. The pictures are down-linked to investigators on the ground for analysis.
The current plan for this experiment is to conduct it over a 7 or 14-day session, each of which can be run incrementally and require about 7 hours of crew time; a third session to mix and photograph all 10 samples (about 4.6 hours of crew time) and then a fourth session at six months to photograph all ten samples which is slotted to take about four hours of crew time. As such, new information will undoubtedly be learned, and the nature of the experiments conducted will evolve to take advantage of this new information.
BCAT-6 typical operations consists of:
Session 1: Set up hardware, take baseline photos of all ten samples; homogenize samples 6-10 then samples 9 and 10, then automatically photograph sample 1 (using EarthKAM software on laptop) every hour for 7 days. Perform sample 1 daily status check each day. After seven-day run, perform crystal search/photography on 6-10. Homogenize sample 2, automatically photograph sample 2 (using EarthKAM software on laptop) every hour for 7 days. Perform sample 1 daily status check each day. After seven-day run, perform crystal search/photography on 6-10. If necessary, tear down after operations are complete but keeping setup intact is preferred to save crew time.
Session 2: Set up hardware, homogenize samples 3, 4 and 5 one at a time then automatically photograph each sample (using EarthKAM software on laptop) every hour for 14 days each. Perform Crystal Check and Photography procedures on 6-10 if crystals not found/photographed in Session 1. If necessary, tear down after operations are complete but keeping setup intact is preferred to save crew time. .
Session 3: Homogenize and photograph samples 1-10 (using EarthKAM software on laptop) and stow sample module for six months. The experiment is torn down after operations are complete. .
Session 4: At six months after homogenization, manually photograph samples 1 through 10. Re-stow sample module and tear down after operations are complete.