18649

Silicon dioxide

acid washed

• Synonym(s): Cristobalite, Quartz, Sand, Silica
• Linear Formula: SiO₂
• CAS Number: 60676-86-0
• Molecular Weight: 60.08
• MDL number: MFCD00011232
• UNSPSC Code: 12352303
• PubChem Substance ID: 57647755
• NACRES: SB.52

Properties

• form: solid
• Quality Level: 100
• quality: acid washed
• impurities: ≤0.01% in acid soluble iron (Fe); ≤0.5% soluble in HCl
• loss: ≤0.5% loss on ignition, 800 °C
• refractive index: n20/D 1.544 (lit.)
• mp: 1610 °C (lit.)
• density: 2.6 g/mL at 25 °C (lit.)
• anion traces: chloride (Cl^-): ≤100 mg/kg
• SMILES string: O=[Si]=O
• InChI: 1S/O2Si/c1-3-2
• InChI key: VYPSYNLAJGMNEJ-UHFFFAOYSA-N

Description

General description

Silicon dioxide (SiO₂) exists in three crystalline forms, namely quartz, tridymite and cristobalite. It reacts with hydrofluoric acid to form silicon tetrafluoride (SiF₄) and water. Silicates are formed on reacting SiO₂ with alkali melts. SiO₂ is the main component in glass, brick and concrete and also forms the insulator in silicon devices. The alteration of the surface of SiO₂ with (3-aminopropyl)triethoxysilane (APTES) for binding lactate dehydrogenase (LDH) to form an amino layer has been reported. The silicon-silicon dioxide structure has been investigated at liquid nitrogen temperature by electron spin resonance spectra.

Application

Silicon dioxide may be used to produce silicon by electrochemical reduction in the presence of calcium chloride (CaCl₂) electrolyte. It may also be used to prepare FeCl₃/SiO₂, a supported reagent for the oxidative coupling reactions.

Safety Information

• Storage Class Code: 11 - Combustible Solids
• WGK: nwg
• Flash Point(F): Not applicable
• Flash Point(C): Not applicable
• Personal Protective Equipment: dust mask type N95 (US), Eyeshields, Gloves