A smart gel is a material that gels in response to a specific physical property. For example, it may gel at a specific temperature or pressure.
The mechanisms that create a gel in response to a given environment are
not well understood. So developing this understanding is key to being able to
create materials that gel at designated points.
The potential for applications of smart gels is enormous.
Since smart gels expand or contract in response to external stimuli,
they could be useful in applications such as an artificial pancreas
that releases insulin inside the body in response to high sugar level.
Smart gels might someday be used to make exotic foods, cosmetics,
medicines, and sensors.
The NIST team is studying a subclass of these materials called shake gels. Through some complex and as
yet unknown process, these watery mixtures of clays and polymers firm up into gels when shaken, and then
relax again to the liquid phase after some time has passed. A shake gel might be used, for example, in
shock absorbers for cars. The material would generally be a liquid but would form a gel when the car drove
over a pothole; the gel thickness would adjust automatically to the weight of the car and the size of the
pothole. A more esoteric application might be the formation of gelled areas within a liquid where
holograms could be created using a laser.
Immersive visualization helps scientists understand how the molecules
in the smart gel interact. Scientists immerse themselves in the 3D
environment constructed using data from theoretical studies.
This enables researchers to answer questions that might otherwise defy
attempts at solution.
The 3-D visualization helped the scientists see that for the shake gel
it is the water's oxygen atoms, instead of the
hydrogen atoms as previously thought, that attach to the clay.
The team has also made theoretical
calculations that may help to explain why and how the components of
the liquid mixture bind together into
a semisolid form. Electrical charges affect the binding process,
resulting in water binding to clay surfaces
in a perpendicular arrangement, which is believed to help create
the firmness of the gel.
For more information refer to http://www.nist.gov/public_affairs/newsfromnist_smartgels.htm
The immersive visualization used by the scientists is based on open source
software, DIVERSE and additional software
created in-house. The output of the numerical simulation is a series of time
steps. At each time step, the x,y,z position and atom type for each atom is
produced. In collaboration with Carlos Gonzales, Steven Satterfield developed
software to connect the appropriate bonds between the atoms and output a
series of graphics files. These graphics files are then loaded into
Diversifly, the DIVERSE display and explore utility. Diversifly has the
ability to animate the time series of graphics files in an immersive
visualization environment.
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Yosslen Aray, Manuel Marquez, Jesus Rodr}4guez, Santiago Coll,
Yamil Simo4n-Manso, Carlos Gonzalez, and David A. Weitz, "Electrostatics for
Exploring the Nature of Water Adsorption on the Laponite Sheets'
Surface", J. Phys. Chem. B 2003, 107, 8946-8952 |
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| Carlos Gonzalez studies shake gel |
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