Nanoparticles are particles between 1 and 100 nanometers in size. There are several types of nanoparticles made commercially. Silicon is one of the safest particles that are widely used in in our life. Silica, or silicon dioxide, is the same material used to make glass. In nature, silica makes up quartz and the sand at the beach.
Silicon dioxide nanofilms, a layer of silicon dioxide molecules that can be as thin as 1 nm, are used to provide electrical insulation between two parts of a device, such as a transistor. This method is used in making computer chips. ( Nanotechnology For Dummies, 2nd edition). More researches are now focusing its other applications such as drug delivery in pharmacy, suncreen, hydrophobia, hardiness, etc.
Based on available research data Claudia Fruijtier-Pölloth had a review on the effect Synthetic Amorphous Silica (SAS) on health :
“Commercial SAS types (including colloidal silicon dioxide and surface-treated forms) are well-studied materials that have been in use for decades with significant exposures resulting from their use in oral and topical pharmaceutical and cosmetic products and as an anti-caking agent in food. There were no reports of adverse reactions from these uses.“
For more information please click here for the review article.
In general, silicone is a man-made chemical compound and has various characteristics. Therefore, it has been used as a raw material in a variety of industrial fields, and has been useful in our lives. Take, for example, cosmetics, sport wears, personal computers and cars, silicone is used in our daily life everywhere. However, we do not usually recognize it, because it is invisible. Silicone will be more and more indispensable in our life in the future, since it is excellent in their adaptability to the environment.
What Is Silicone?
Among the components that make up the surface of the earth, Si is the second element in terms of the amount that exists next to oxygen. Since Si the strong familiarity in quality with oxygen, it does not exist as an individual element. It usually exists as Si-stone (sand, crystal, quarts).
By deoxidizing this Si-stone, we make metallic Si (metallic chemical compound consisting only of Si-atom = silicon), and through complex chemical reactions, we create “silicone” which contains both organic and inorganic nature. Silicone has the main bone of siloxane bond (Si-O-Si) which is made by close combination of silicone and oxygen, and by combining organic groups, it shows various characteristics like it has strong durability toward heat and cold, ultra-violet rays and water repellency.
Also, there are a variety of kinds of silicone such as oil, resin and gum, which are used in different industrial areas as in aircraft, electronics apparatus, chemistry fiber, foo, cosmetics, architecture, etc.
Properties of Silicone
Silicon is a material with high functionality which has both organic and inorganic nature. What makes this excellent nature is the siloxane bond and its molecular structure.
A silicon atom has four hands. These four hands become longer and longer by joining hands with other silicon atoms through oxygen.
This bond of silicon and oxygen (-Si-O-Si-) is called the siloxane bond. Also it is possible to add to various characteristics by combining methyl group, phenyl group, and other organic groups (or functional group) and the hand of silicon.
As the siloxane bond has the same structure as inorganics such as glass and quartz, it has much greater combination energy than C-C bond or C-O bond which is the principal chain of organic polymer. Therefore, even if the temperature goes up to 200℃, the bond is not broken and chemically stable which highly strengthen the characteristics of heat and weather resistance.
Silicone’s 3 States
Silicone is normally recognized as oil, resin and gum according to its states.
Silicone Oil There are silicon oils from the smooth and soft substance like water to the starch syrup like substance.
Silicone Oil The picture shows silicon oil which has high viscosity. This has excellent transparency.
Silicone Resin We have products ranging from powder type to solid type as in the pictures.
Transparent Silicone Gum This is transparent like water and glitters when it is exposed to the light.
RTV Gum This is RTV gum for mold making. We can recreate original mold accurately.
Main Industries and The Use of Silicone
Silicone products are used in various industrial fields and for various purposes. The following are representative industrial fields where silicon is used.