What is silica surface?
Silica coatings are an amorphous network of silicon and oxygen that encapsulate the particle with a coating that can be many nanometers thick. The silica is added to the particle surface via the base catalyzed condensation of various silanes, usually alkoxyl silanes such as tetraethylethoxysilane (TEOS).
What is the surface charge of silica?
In this context, silica and silicate glass surfaces immersed in water are known to acquire a negative surface charge density, primarily through the dissociation of terminal silanol groups.
Is silica negatively charged?
Our results are consistent with literature values confirming that silica nanoparticles (Np) are negatively charged in a pH range between 2 and 14.
What is the process of silica?
Precipitated silica is manufactured by precipitation method. Sodium silicate and mineral acid react under high temperature in alkaline conditions, during which the primary particle is grown rapidly to a diameter of approximately 100nm. It is precipitated then aggregated by flocculation into the alkaline liquid.
What does silica gel absorb?
Contrary to its name, silica gel is actually a dry solid that absorbs and holds water vapor. Silica Gel is typically found in “bead” form with the beads being contained by a porous packet material allows the beads to freely absorb moisture in the air.
Are silica particles charged?
Untreated silica nanoparticles were determined to be highly negatively charged and have stable hydrodynamic sizes in a wide pH range.
What is the uses of silica?
Silica also is used in grinding and polishing glass and stone; in foundry molds; in the manufacture of glass, ceramics, silicon carbide, ferrosilicon, and silicones; as a refractory material; and as gemstones. Silica gel is often used as a desiccant to remove moisture.
What size is silica dust?
.01 to 100 μm
Silica dust particles from . 01 to 100 μm in diameter and 10 microns or less in length are a significant health concern. To put this particle size into perspective, a human hair is about 100 μm in diameter.
What is the main use of silica?
Silica has widespread industrial applications including use as a food additive, i.e., anti-caking agent, as a means to clarify beverages, control viscosity, as an anti-foaming agent, dough modifier, and as an excipient in drugs and vitamins.