Silicon Dioxide, Silica (SiO2) Nanoparticles – Properties, Applications

Topics Covered

Chemical Properties
Physical Properties
Thermal Properties


Silicon dioxide nanoparticles, also known as silica nanoparticles or nanosilica, are the basis for a great deal of biomedical research due to their stability, low toxicity and ability to be functionalized with a range of molecules and polymers.

Nano-silica particles are divided into P-type and S-type according to their structure. The P-type particles are characterized by numerous nanopores having a pore rate of 0.61 ml/g. The S-type particles have a comparatively smaller surface area. The P-type nano-silica particles exhibit a higher ultraviolet reflectivity when compared to the S-type. Silicon belongs to Block P, Period 3 while oxygen belongs to Block P, Period 2 of the periodic table.

Chemical Properties

The following tables list the chemical properties of silicon dioxide.

Chemical Data
Chemical symbol SiO2
CAS No 7631-86-9
Group Silicon 14
Oxygen 16
Electronic configuration Silicon [Ne] 3s2 3p2
Oxygen [He] 2s2 2p4
Chemical Composition
Element Content (%)
Silicon 46.83
Oxygen 53.33

Physical Properties

Silicon dioxide nanoparticles appear in the form of a white powder. The table below provides the physical properties of these nanoparticles.

Properties Metric Imperial
Density 2.4 g/cm3 0.086 lb/in3
Molar Mass 59.96 g/mol -

Thermal Properties

The thermal properties of silicon dioxide nanoparticles are given in the table below:-

Properties Metric Imperial
Melting Point 1600°C 2912°F
Boling Point 2230°C 4046°F


The following are the chief applications of silica nanoparticles:

  • As an additive for rubber and plastics
  • As a strengthening filler for concrete and other construction composites
  • As a stable, non-toxic platform for biomedical applications such as drug delivery and theranostics

Source: AZoNano


  1. Daniel E. Martinez Daniel E. Martinez Mexico says:

    This type of nanoparticles, still has the piezoelctric property

  2. hassan javid hassan javid Islamic Republic of Pakistan says:

    is nano silica harmful as nanofluid in machining setup?

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