NASA - National Aeronautics and Space Administration

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Experiment Overview


Brief Summary

The BCAT-C1 experiment will study nano-scale particles dispersed in liquid, known as a colloidal suspension, commonly found in such commercial commodities as paint, electronic polishing compounds and food products. These suspensions will have the unique property that the particles will phase separate (like oil and water) and the particles will self-assemble into crystals that interact strongly with light (like opal). Photographing these samples in microgravity will allow the measurement of these processes while avoiding the effects of particle sinking due to gravity. This study will allow the development of new insights into this important material process.

Principal Investigator(s)

Barbara Frisken, Ph.D., Simon Fraser University, Burnaby, British Columbia, Canada

Co-Investigator(s)/Collaborator(s)

Paul M. Chaikin, Ph.D., New York University, New York, NY, United States

Andrew Hollingsworth, Ph.D., New York University, New York, NY, United States

Arthur Bailey, Ph.D., Simon Fraser University, Burnaby, British Columbia, Canada

Developer(s)

ZIN Technologies Incorporated, Cleveland, OH, United States
Canadian Space Agency (CSA), Saint-Hubert, Quebec, Canada

Sponsoring Space Agency

Canadian Space Agency (CSA)

Sponsoring Organization

Information Pending

ISS Expedition Duration:

May 2012 - September 2014

Expeditions Assigned

31/32,33/34,35/36,37/38,39/40

Previous ISS Missions

The BCAT series of investigations began on ISS Expedition 8.

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Experiment Description

Research Overview

• Colloidal suspensions are used in innumerable applications ranging from the polishing of silicon wafers in the electronics industry to the filtering of fruit juices in the food industry. Scientifically, colloidal suspensions serve as models of molecular systems for the study of inter-particle interactions and phase (i.e. gas/liquid/solid) transitions because the interactions between the suspended particles can be varied with relative ease. Depending upon the sample preparation conditions, the suspended particles form gas, liquid and crystal phases. Transitions between gas and liquid are characterized by growth of domains of one phase within the other. Formation of crystals from a well-mixed sample involves the growth of crystallites within the sample. Each of these phenomena has been studied, but simultaneous crystallization and phase separation remains largely uncharacterized.



• The researchers plan to study samples consisting of colloidal suspensions with added polymer that, in equilibrium, contain more than one phase so that the effect of phase separation on crystal growth can be studied. On Earth, gravity causes the colloids to settle making such a study particularly difficult.



• Performing these experiments in the microgravity environment of the International Space Station will allow study of the growth of much larger structures, and, thus, maximize the extent to which the behaviour can be explored. Improved understanding of these processes will lead to more refined manufacturing processes and commercial products.

Description

The focus will be specifically on the effect of phase separation on crystal growth. On Earth, gravity causes the colloids to settle, making such a study particularly difficult. Performing these experiments in the microgravity environment of the International Space Station will allow scientists to study growth of much larger structures, and, thus, maximize the extent to which the behavior can be explored. Improved understanding of these processes will lead to more refined manufacturing processes and commercial products. The competition between a phase separation process and an order-disorder transition remains largely unstudied and offers an opportunity to observe some fascinating behavior. The overarching goal of all these experiments is to develop the key knowledge to help make colloidal engineering a reality. In addition, this experiment should help scientists understand some of the fundamental properties of colloid-polymer mixtures to further improve the commercial use of such systems.

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Applications

Space Applications

Information Pending

Earth Applications

Information Pending

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Operations

Operational Requirements

BCAT-C1 samples are contained within a small case the size of a school textbook. The experiment requires a crew member to set up on the Maintenance Work Area (MWA) or on a handrail/seat track configuration , set up EarthKAM hardware and start the EarthKAM software to take digital photographs of each sample at close range using the onboard Kodak DCS760 camera. Scripts for running the EarthKAM camera can be uploaded from earth to control the experiment once it is running. All samples also require that manual photographs (at least initially) be taken by an astronaut. The pictures are down-linked to investigators on the ground for analysis.

Operational Protocols

1. Crew sets up the historical Video camera to document the BCAT-C 1 operations as performed on-board the ISS.

2.Crew sets up all hardware on MWA of seat track rails (Slow Growth Sample Module, DCS760 Camera, flash and EarthKAM software with SSC Laptop.

3. Crew homogenizes (mixes) the sample(s) and takes the first photographs manually. This helps them optimize the setup and shows that the samples were initially fully homogenized when publishing results later.

4. EarthKAM software automates the rest of the photography session over a 3-day to 3-week period.

5. Crew performs a Daily Status Check once a day (when time is available) to assure proper alignment and focus.

6. At the completion of the run, a crew member tears down and stows all hardware (30 minutes).

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Results/More Information

Information Pending

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Related Websites

NIH BioMed-ISS Meeting, 2009?BCAT-C1

NIH BioMed-ISS Meeting Video Presentation, 2009?BCAT-C1

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Imagery

NASA Image: ISS016E027863 - Astronaut Dan Tani took this photograph of the BCAT-3 Sample Module using his own design for a ceiling mount in Node 2 of the International Space Station. Great high contrast pictures of difficult to capture images resulted from using this setup (February 2008).
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NASA Image: ISS032E022445 Image of BCAT-C1.

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NASA Image: ISS032E022512 - BCAT-C1

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