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S5505

Sigma-Aldrich

Silica, fumed

powder, 0.2-0.3 μm avg. part. size (aggregate)

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Synonym(s):
Silica, Silicic anhydride, Silicon dioxide, Silicon dioxide amorphous
Linear Formula:
SiO2
CAS Number:
Molecular Weight:
60.08
MDL number:
UNSPSC Code:
12352103
PubChem Substance ID:
NACRES:
NA.22

form

powder

Quality Level

surface area

200 m2/g (±25 m2/g)

refractive index

n20/D 1.46 (lit.)

avg. part. size

0.2-0.3 μm (aggregate)

density

2.3 lb/cu.ft at 25 °C (bulk density)(lit.)

SMILES string

O=[Si]=O

InChI

1S/O2Si/c1-3-2

InChI key

VYPSYNLAJGMNEJ-UHFFFAOYSA-N

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Application

Fumed Silica (SiO2) has been used as a precursor to synthesize:
  • Chlorosilanes via silanization, which are used to prepare silica/polydimethylsiloxane membranes to study permeation performance.
  • Silicon carbide (SiC) nanoparticles by sol-gel method.
  • Calcium silicate hydrate (C-S-H) by treating with CaO and water via hydrothermal reaction.
  • Si/PtO2 catalyst for the selective conversion of cinnamaldehyde to cinnamic acid by aerobic oxidation.


It can be also used in the preparation of:
  • Silica sulfuric acid catalyst used in the synthesis of 3,4-dihydropyrimidin-2(1H)-ones via one-pot three-component Biginelli reaction.
  • HClO4-SiO2 heterogeneous catalyst used in the synthesis of tetrasubstituted imidazoles.

Features and Benefits

Has interesting thickening and thixotropic properties, and an enormous external surface area.

Other Notes

Particle sizes are for primary particles, which form branched, chain-like aggregates a few tenths of a micron long.

WGK

WGK 2

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

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Silica sulfuric acid: an efficient and reusable catalyst for the one-pot synthesis of 3, 4-dihydropyrimidin-2 (1H)-ones
Salehi P, et al.
Tetrahedron Letters, 44(14), 2889-2891 (2003)
Platinum catalysed aerobic selective oxidation of cinnamaldehyde to cinnamic acid
Durndell LJ, et al.
Catalysis Today, 333(4), 161-168 (2019)
Effect of C/S ratio on morphology and structure of hydrothermally synthesized calcium silicate hydrate
He Y, et al.
Journal of Wuhan University of Technology-Materials Science Edition, 26(4), 770-773 (2011)
Synthesis of nano-structured 3C-SiC by carbothermal reduction of silicon bearing gel and carbon soot
Sharma M, et al.
Materials Letters, 65(14), 2161-2164 (2011)
Organosilane modified silica/polydimethylsiloxane mixed matrix membranes for enhanced propylene/nitrogen separation
Beltran AB, et al.
Applied Surface Science, 258(1), 337-345 (2011)

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