Hydrophobic sand (or magic sand) is a toy made from sand coated with a hydrophobe compound. The presence of the hydrophobic compound causes the grains of sand to adhere to one another and form cylinders (to minimize surface area) when exposed to water, and form a pocket of air around the sand.
History
The earliest reference to waterproof sand is in the 1915 book
The Boy Mechanic Book 2 published by
Popular Mechanics. The Boy Mechanic states waterproof sand was invented by East Indian magicians. The sand was made by mixing heated sand with melted
wax. The wax would repel water when the sand was exposed to water.
It was originally developed to trap ocean by being sprinkled on floating petroleum; the sand would mix with the oil and cause it to sink. Due to the expense of production, however, it is no longer used for this purpose.
Hydrophobic sand has also been tested by utility companies in Arctic regions as a foundation for , as it never freezes. It is also used as an aerating medium for potted plants.
Properties
Magic sand
The properties of Magic sand are achieved using ordinary beach sand, which contains tiny particles of pure
silica, and exposing it to vapors of
trimethylsilanol (
Methyl)
3siliconhydroxyl, an
organosilicon compound. Upon exposure, the trimethylsilanol compound bonds to the silica particles while forming water. The exteriors of the sand grains are thus coated with
hydrophobe groups. When Magic sand is removed from water, it is completely dry and free-flowing.
Brands
- Kinetic Sand
-
A toy trademarked and produced by Spin Master.
[ Database of the EUIPO; trademark #1198085; information, see ] Kinetic Sand looks like regular wet sand but is available in different colors. It can be molded into any desired shape. It never dries out, and it sticks to itself.
- Aqua Sand
-
Similar properties as above.
- Asbestos in Play Sand in Australia
See also
External links
-
acs.org, Magic Sand experiment from the American Chemical Society
-
youtube.com, Video of how to make Magic Sand
