CAS 7440-21-3 Silicon Nanopowder - Materials / Alfa Chemistry

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Silicon Nanopowder

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Catalog Number

ACM7440213

CAS Number

7440-21-3

Product Name

Silicon Nanopowder

Structure

Category

Nanopowders

Description

Silicon powder, amorphous appears as a dark brown powder. Insoluble in water and denser than water. Burns readily when exposed to heat or flames, and may be difficult to extinguish. Water may not be effective in extinguishing flames. Used to make computer microchips.;DryPowder; DryPowder, OtherSolid; DryPowder, PelletsLargeCrystals; OtherSolid; OtherSolid, Liquid; PelletsLargeCrystals;STEEL-GREY CRYSTALS OR BLACK-TO-BROWN AMORPHOUS POWDER.;Black to gray, lustrous, needle-like crystals.;Black to gray, lustrous, needle-like crystals. [Note: The amorphous form is a dark-brown powder.]

IUPAC Name

silicon

Molecular Weight

28.085g/mol

Molecular Formula

Canonical SMILES

[Si]

InChI

InChI=1S/Si

InChI Key

XUIMIQQOPSSXEZ-UHFFFAOYSA-N

Boiling Point

4271 °F at 760 mm Hg (NIOSH, 2016);2355 °C;2355 °C;4271°F;4271°F

Melting Point

2570 °F (NIOSH, 2016);1410 °C;1410 °C;2570°F;2570°F

Density

2.33 at 77 °F (NIOSH, 2016);2.33 g/cu cm at 25 °C/4 °C;2.33 g/cm³;2.33 at 77°F;(77°F): 2.33

Solubility

Insoluble (NIOSH, 2016);Soluble in a mixture of nitric and hydrofluoric acids and in alkalis; insoluble in nitric and hydrochloric acid;Soluble in molten alkali oxides; practically insoluble in water;Silicon and germanium are isomorphous and thus mutually soluble in all proportions; molten silicon is immiscible in both molten tin and molten lead.;Solubility in water: none;Insoluble

Color/Form

Black to gray, lustrous, needle-like crystals or octahedral platelets (cubic system); amorphous form is dark brown powder

Complexity

Covalently-Bonded Unit Count

EC Number

231-130-8

Exact Mass

27.976927g/mol

Formal Charge

Heat of Vaporization

16 kJ/g

Heavy Atom Count

ICSC Number

1508

MeSH Entry Terms

Silicon;Silicon 28;Silicon-28

Monoisotopic Mass

27.976927g/mol

Other Experimental

Atomic number: 14; valence: 4, 2; poor conductor of electricity ... lattice constant (25 °C): 5.41987X10-8 cm; compressibility (vol/vol 0) at 25x10+3 kg/sq cm: 0.978; at 100x10+3 kg/sq cm: 0.940; dielectric constant: 13; covalent bond ionization energy at 0 K = 1.2 electron volt; band gap: 1.106 electron volt; impurity atom ionization energy: approx 0.04 electron volt; intrinsic resistivity at 300 K = 0.23 megaohm; average heat capacity (16-100 °C): 0.1774 cal/g/deg C;Electron mobility at 300 K: 1500 sq cm/volt/sec; hole mobility at 300 K: 500 sq cm/volt/sec; intrinsic charge density at 300 K: 1.5x10+10; electron diffusion constant at 300 K: 38; hole diffusion constant at 300 K: 13; attacked by hydrofluoric or a mixture of hydrofluoric and nitric acids; burns in fluorine, chlorine;Elemental silicon transmits more than 95% of all wavelengths of IR from 1.3 to 6.7 um; attacked by halogens and dilute alkali;Temperature of transition: solid = 1683 degree K; liquid = 2750 degree K; Heat of transition: solid = 11.1 kcal/g mole; liquid = 71 kcal/g mole;Mohs hardness: 7; dielectric constant: 12; coordination number: 6;At atm pressure, silicon has a diamond cubic structure, ie, two interpenetrating face-centered cubes displaced 1/4, 1/4, 1/4 from each other. When subjected to about 11 GPa (110,000 atm) hydrostatic pressure, the diamond structure is converted to a body-centered tetragonal lattice ... Silicon produced at temperatures below 500 °C by vapor deposition is generally amorphous; upon reheating to a somewhat higher temp, crystallization will occur.;Total optical emissivity = 0.33 at MP and at 1500 °C; reflectivity at 633 nm = 72% at MP and 70% at 1500 °C /Liquid silicon/;Oxygen forms strong bonds with silicon. ... At room temp, silicon is covered with an oxide layer 2-3 nm thick. This oxide is amorphous. ... Oxidation consumes a silicon thickness equal to about 0.4 times the rate of oxidation. The exact values of oxidation depend on the temp, pressure, oxidant, crystal orientation of the surface being oxidized, and the amt and type of impurity in the silicon.;Oxygen dissolves in the silicon crystal lattice, forming SiOx, which may radically affect the electrical properties of the silicon. ... When oxygen-containing silicon is annealed in the 450 °C range, the OSi complexes become donors and contribute to electrical conductivity.;Critical volume: 232.6 cu cm/mol; atomic density: 5X10+22 atoms/cu cm; Knoop hardness: 950-1150; volume expansion on freezing: 9.5%;Density at melting pt = 2.30 g/cu cm (solid), 2.51 g/cu cm (liquid); Heat of evaporation = 385 kJ/mol; Surface tension at melting pt = 885 mJ/sq m;Bulk is unreactive to oxygen, water, hydrogen halides (except hydrogen fluoride); reactive to halogens: fluoride at room temp, chlorine at 3 °C; acted on by nitrogen at 14 °C; sulfur reacts at 6 °C; phosphorus reacts at 10 °C;Heat of formation: 0.0 kJ/mol; molar entropy: 18.8 J/mol-K; molar heat capacity at constant pressure: 20.0 J/mol-K at 298.15 K /Silicon crystal/;Heat of formation: 450.0 kJ/mol; Gibbs energy of formation: 405.5 kJ/mol; molar entropy: 168.0 J/mol-K; molar heat capacity at constant pressure: 22.3 J/mol-K at 298.15 K /Silicon gas/;Enthalpy of fusion at melting point: 50.21 kJ/mol;Specific heat capacity: 0.712 J/g-K; molar heat capacity: 19.99 J/mol-K at 25 °C and 1 bar

Rotatable Bond Count

RTECS Number

VW0400000

UNII

5J076063R1;Z4152N8IUI

UN Number

1346;1346;1346;1346;1346

Vapor Pressure

0 mm Hg (approx) (NIOSH, 2016);1 Pa at 1635 °C; 10 Pa at 1829 °C; 100 Pa at 2066 °C; 1 kPa at 2363 °C; 10 kPa at 2748 °C; 100 kPa at 3264 °C;0 mmHg (approx);0 mmHg (approx)

Viscosity

Dynamic viscosity = 0.88 cP at MP and 0.7 cP at 1500 °C; kinematic viscosity (calculated) = 0.347 cSt at MP and 0.28 cSt at 1500 °C /Liquid silicon/

MSDS

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COA

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Spec Sheet

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