SEAgel (Safe Emulsion Agar gel) is one of a class of high-tech

foam Foams are materials formed by trapping pockets of gas in a liquid or solid. A bath sponge and the head on a glass of beer are examples of foams. In most foams, the volume of gas is large, with thin films of liquid or solid separating the ...

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 lo ...

s. It is an excellent thermal insulator 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 ...

, a carbohydrate material that comes from

kelp Kelps are large brown algae seaweeds that make up the order Laminariales. There are about 30 different genera. Despite its appearance, kelp is not a plant - it is a heterokont, a completely unrelated group of organisms. Kelp grows in "under ...

and red algae, 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 Freeze drying, also known as lyophilization or cryodesiccation, is a low temperature Food drying, dehydration process that involves freezing the product and lowering pressure, removing the ice by Sublimation (phase transition), sublimation. This ...

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 X-rays (or rarely, ''X-radiation'') are a form of high-energy electromagnetic radiation. In many languages, it is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it in 1895 and named it ' ...

laser experiments because it can be doped with other materials, such as

selenium Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and telluriu ...

. In order to eliminate the volatile hydrodynamics 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 fir ...

, 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, 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 ''Ochroma pyramidale'', commonly known as the balsa tree, is a large, fast-growing tree native to the Americas. It is the sole member of the genus ''Ochroma''. The tree is famous for its wide usage in woodworking, with the name ''balsa'' being ...

, to insulate

supertanker An oil tanker, also known as a petroleum tanker, is a ship designed for the bulk transport of oil or its products. There are two basic types of oil tankers: crude tankers and product tankers. Crude tankers move large quantities of unrefined c ...

s, 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