Safe Emulsion Agar Gel
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SEAgel (Safe Emulsion Agar gel) is one of a class of high-tech foam materials known as
aerogel Aerogels are a class of synthetic porous ultralight material derived from a gel, in which the liquid component for the gel has been replaced with a gas, without significant collapse of the gel structure. The result is a solid with extremely low ...
s. It is an excellent
thermal insulator Thermal insulation is the reduction of heat transfer (i.e., the transfer of thermal energy between objects of differing temperature) between objects in thermal contact or in range of radiative influence. Thermal insulation can be achieved with s ...
and among the least dense solids known. SEAgel was invented by Robert Morrison at the
Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory (LLNL) is a federal research facility in Livermore, California, United States. The lab was originally established as the University of California Radiation Laboratory, Livermore Branch in 1952 in response ...
in 1992. SEAgel is made of
agar Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from ogonori (''Gracilaria'') and "tengusa" (''Gelidiaceae''). As found in nature, agar is ...
, a carbohydrate material that comes from kelp and
red algae Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority ...
, and has a density of 200 mg/cm3. SEAgel can be made lighter than air using hydrogen, causing it to float or hang in the air. It insulates against temperature, noise, and electric current. SEAgel is also completely biodegradable, as it is made entirely of biological material and can even be eaten. Initially, SEAgel starts out as a gelatin-like mixture of agar and water. After it is freeze-dried to remove the water, it is left as a honeycomb of dried agar filled with air, with cell sizes two to three micrometers (2-3 µm) in diameter. SEAgel can have many different uses. Laboratory scientists use SEAgel as targets for
x-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10  picometers to 10  nanometers, corresponding to frequencies in the range 30&nb ...
laser experiments because it can be doped with other materials, such as selenium. In order to eliminate the volatile
hydrodynamics In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids—liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) and ...
that occur when a solid-density target explodes before it reaches the density required for
lasing A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The firs ...
, scientists are trying to develop an x-ray laser target with a density that is less than the critical density of laser light (4×1021 electrons/cm3 for 0.53-µm light). SEAgel can help them achieve a more uniform
plasma Plasma or plasm may refer to: Science * Plasma (physics), one of the four fundamental states of matter * Plasma (mineral), a green translucent silica mineral * Quark–gluon plasma, a state of matter in quantum chromodynamics Biology * Blood pla ...
, which will ultimately improve the quality of the x-ray laser beam. SEAgel could also be used as food packaging or the encapsulating material of timed-release medical pills, as it is safe to digest. SEAgel could also replace balsa wood, to insulate supertankers, and to provide sound damping in high-speed trains. SEAgel was covered under U.S. patents 5,382,285 ("
Biofoam Biofoams are biological or biologically derived foams, making up lightweight and porous cellular solids. A relatively new term, its use in academia began in the 1980s in relation to the scum that formed on activated sludge plants. Biofoams is a br ...
") and 5,360,828 ("Biofoam II").


References


External links


''Physics News Update'' — (Story #4), August 19, 1992 by Phillip F. Schewe and Ben Stein


Aerogels Brand name materials {{chemistry-stub