Advanced Colloids Experiment-Temperature-6 (ACE-T-6) - 04.26.17

Overview | Description | Applications | Operations | Results | Publications | Imagery

ISS Science for Everyone

Science Objectives for Everyone
Colloids are suspensions of microscopic particles in a liquid, and they are found in products ranging from milk to fabric softener. Consumer products often use colloidal gels to distribute specialized ingredients, for instance droplets that soften fabrics, but the gels must serve two opposite purposes: they have to disperse the active ingredient so it can work, yet maintain an even distribution so the product does not spoil. Advanced Colloids Experiment-Temperature-6 (ACE-T-6) studies the microscopic behavior of colloids in gels and creams, providing new insight into fundamental interactions that can improve product shelf life.
Science Results for Everyone
Information Pending

The following content was provided by Matthew Lynch, Ph.D., and is maintained in a database by the ISS Program Science Office.
Experiment Details

OpNom:

Principal Investigator(s)
Matthew Lynch, Ph.D., Procter and Gamble, West Chester, OH, United States

Co-Investigator(s)/Collaborator(s)
Thomas Kodger, Harvard University, Cambridge, MA, United States

Developer(s)
NASA Glenn Research Center, Cleveland, OH, United States
ZIN Technologies Incorporated, Cleveland, OH, United States

Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)

Sponsoring Organization
National Laboratory (NL)

Research Benefits
Earth Benefits, Scientific Discovery

ISS Expedition Duration
April 2017 - September 2017

Expeditions Assigned
51/52

Previous Missions
Information Pending

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Experiment Description

Research Overview

  • Most colloidal research has been done in idealized, mono-dispersed systems, where the various components in the dispersion are of a single size. However, recent experiments demonstrate that polydispersity, or multiple sizes of particles in the polymer, makes a huge difference in the time scale of coarsening of weak gels, in many cases in excess of several orders of magnitude in time.
  • Commercial products generally consist of complicated polydispersed systems that are not well understood. At present, no basic measurements/theories exist that allow us to understand the role of polydispersity in these processes. As a consequence, the ability to design effective products is greatly deficient.
  • Advanced Colloids Experiment-Temperature-6 (ACE-T-6) studies the microscopic behavior of colloids in order to understand the evolution (coarsening) of microstructure in gels and creams, and to help find ways to control these systems. On earth this process occurs on a timescale of minutes due to gravitational sedimentation; while on the International Space Station (ISS), the timescale will be several days to weeks in duration.
  • Microgravity is required to detach phase separation from coarsening. There is a basic need for the practical application of these concepts to product design, as products are inherently polydisperse.

Description

Precious little is known about the coarsening of real-world colloidal gels. An understanding of the evolution (coarsening) of microstructure is required to control these systems. On earth this process occurs on a timescale of minutes due to gravitational sedimentation; while on the International Space Station (ISS) the timescale is several days to weeks in duration. Microgravity is required to detach phase separation from coarsening. This is crucial for the practical application of these concepts to product design.
 
Research on colloids is limited by gravity on Earth, which can mask some of the particles’ interactions. Studying colloids in microgravity provides much better data, enabling materials scientists to understand coarsening, or the process that causes colloidal particles to sink and clump together and spoil a product. Results from this investigation improve the manufacturing process for consumer products, yielding colloidal mixtures that last longer on Earth and in space.
 
Most research on colloids studies particles of one size, but recent studies have shown that varying particle sizes can dramatically affect the way a product separates, clumps together and spoils. Results from this investigation provide new understanding of colloidal mixtures’ microscopic structure and dynamics, which is currently poorly understood. Advanced Colloids Experiment-Temperature-6 (ACE-T-6) studies the behavior of colloidal mixtures which can help materials scientists design products with longer shelf lives, reducing waste and benefiting people on Earth.

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Applications

Space Applications
Research on colloids is limited by gravity on Earth, which can mask some of the particles’ interactions. Studying colloids in microgravity provides much better data, enabling materials scientists to understand coarsening, or the process that causes colloidal particles to sink and clump together and spoil a product. Results from this investigation improve the manufacturing process for consumer products, yielding colloidal mixtures that last longer on Earth and in space.

Earth Applications
Most research on colloids studies particles of one size, but recent studies have shown that varying particle sizes can dramatically affect the way a product separates, clumps together and spoils. Results from this investigation provide new understanding of colloidal mixtures’ microscopic structure and dynamics, which is currently poorly understood. Understanding the behavior of colloidal mixtures can help materials scientists design products with longer shelf lives, reducing waste and benefiting people on Earth.

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Operations

Operational Requirements and Protocols

For ACE-T-6, one experiment is performed per week for 3-7 days. Repeat until all 3 samples in a sample module are tested. Sample Modules should be switched if air bubbles are too big. No operations on second week to analyze data, re-write scripts, adjust parameters. The number of samples per experiment limited by: 1) data bottlenecks on Image Processing and Storage Units (IPSU) and Input/Output Processor (IOP). 2) XY position repeatability (need to return to the same particle set or don’t move during experiment one well position. Images can be registered in post-processing via port or stir bar location, or by using the pattern of particles stuck to bottom of cover slip. 3) Oil availability--- too much repeat movement from well to well may lose immersion oil, so limit test points; air objective has no such constraints.
 
Crew member inspects samples to be tested. The ground team chooses the first sample for testing and relay decision back to crew. Crew member uses defined test procedures to mix the sample and time capture the separation process of the solution using microscopic photography. Repeat at 20-minute intervals. Test is completed upon dynamics evaluation by ground principal investigator (estimate 3- to 7-day duration). Imaging goal is to resolve particle centroid positions with less than 20% error. Shutter lamp is to be closed between image sets to prevent sample photo bleaching. Repeat of cycles is desired every 60 minutes, but desired as often as every 20 minutes.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Information Pending

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Related Websites
Current ACE website

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Imagery