Colloidal silica is a surface-modified synthetic amorphous silica that is differentiated from standard synthetic amorphous silica (e.g Colloidal silicon dioxide) in having its surface-based silanol groups bonded to dimethyl silyl groups making it hydrophobic in character.
Colloidal silica occurs as a light, fine, white or almost white amorphous powder, not wettable by water.
Colloidal silica refers to a suspension of fine, solid particles of silicon dioxide (SiO2) in a liquid medium.
CAS Number: 112945-52-5
Molecular Formula: O2Si
Molecular Weight: 60.08
EINECS Number: 231-545-4
SILICON DIOXIDE, Silica, Dioxosilane, Quartz, 7631-86-9, Silica gel, Cristobalite, Silicic anhydride, Tridymite, 14808-60-7, Sand, 112945-52-5, 61790-53-2, 112926-00-8, KIESELGUHR, Diatomaceous silica, Wessalon, Aerosil, Silicon(IV) oxide, Zorbax sil, 60676-86-0, Silica, amorphous, 14464-46-1, Dicalite, Ludox, Nyacol, Amorphous silica, QUARTZ (SIO2), Cristobalite (SiO2), Cab-O-sil, Sillikolloid, Extrusil, Santocel, Sipernat, Superfloss, Acticel, Carplex, Neosil, Neosyl, Porasil, Silikil, Siloxid, Zipax, Aerosil-degussa, Silicon oxide, Aerosil 380, Synthetic amorphous silica, Quartz sand, Rose quartz, Silica particles, 91053-39-3, Cab-o-sil M-5, Silica, fumed, Snowtex O, Silica, colloidal, Tokusil TPLM, Dri-Die, SILICA, VITREOUS, Manosil vn 3, Colloidal silicon dioxide, Ultrasil VH 3, Ultrasil VN 3, Aerosil bs-50, Carplex 30, Carplex 80, Snowtex 30, Zeofree 80, Aerosil K 7, Cabosil N 5, Syton 2X, Amorphous silica gel, Positive sol 232, Siliziumdioxid, Aerogel 200, Aerosil 300, Chalcedony, Diatomite, Ludox hs 40, Silanox 101, Silica (SiO2), Vitasil 220, Agate, Positive sol 130M, Silica vitreous, Silicon dioxide (amorphous), Aerosil A 300, Aerosil E 300, Aerosil M-300, colloidal silica, Fused silica, Quartz glass, Silica slurry, Silicon dioxide, fumed, Silicone dioxide, 68855-54-9, Nalfloc N 1050, Quso 51, Silica, amorphous fused, Nalco 1050, Quso G 30, Hydrophobic silica 2482, Kieselsaeureanhydrid, Min-U-Sil, 15468-32-3, SiO2, CCRIS 3699, Silica Gel, 40-63 Micron Particles, Silica aerogel, (SiO2)n, UNII-ETJ7Z6XBU4, ETJ7Z6XBU4, Silicon Dioxide, Amorphous, Silica 2482, hydrophobic, Silicon dioxide, chemically prepared, EINECS 231-545-4, CAB-O-SIL N-70TS, EPA Pesticide Chemical Code 072605, CI 7811, Aerosil 200, 99439-28-8, CHEBI:30563, AI3-25549, Crystalline silica, N1030, U 333, Silica gel 60, 230-400 mesh, Glass, Silicon dioxide, colloidal, 15723-40-7, ENT 25,550, [SiO2], Silica, crystalline - fused, Silicagel, Silica gel, pptd.,cryst.-free, 13778-37-5, 13778-38-6, 17679-64-0, Christensenite, Crystoballite, Silica gel desiccant, indicating, Celite, INS-551, Calcined diatomite, MFCD00011232, MFCD00217788, Silica, amorphous,fumed, cryst.-free, Silica, mesostructured, Amethyst, Aquafil, Cataloid, Crysvarl, Flintshot, Nalcoag, Novaculite, Silikill, Vulkasil, Cherts, Snowit, Imsil, Metacristobalite, Quartz silica, alpha-Quartz, Fossil flour, Fumed silica, Quartz dust, Rock crystal, Silica dust, White carbon, SIMETHICONE COMPONENT SILICON DIOXIDE, Chromosorb P, Tiger-eye, E-551, Vulkasil S, Celite superfloss, Cristobalite dust, Corasil II, Silver bond B, Cab-O-sperse, alpha-Cristobalite, alpha-Crystobalite, Gold bond R, (SiO2), Cabosil st-1, Silica Standard: SiO2 @ 100 microg/mL in H2O, Sil-Co-Sil, Silica Standard: SiO2 @ 1000 microg/mL in H2O, Siderite (SiO2), Tridymite 118, Cab-O-grip II, Tridimite [French], HI-Sil, Amorphous silica dust, Silicon Oxide Hollow Nanospheres, Nyacol 830, Sibelite M 3000, Sibelite M 4000, Sibelite M 6000, Quazo puro [Italian], SILICA, AMORPHOUS (IARC), SILICA, AMORPHOUS [IARC], Caswell No. 734A, Sicron F 300, Sikron F 100, Spectrosil, Accusand, Coesite, Fuselex, Nalcast, Nyacol 1430, Optocil, Quartzine, Quarzsand, Rancosil, Suprasil, Tridimite, Siltex, Vitreous quartz, Vitreous silica, Tridymite dust, W 12 (Filler), beta-Quartz, Fused quartz, MIN-U-sil alpha quartz, Quartz-beta, Amorphous quartz, Dri-Die insecticide 67, Quazo puro, Silica, amorphous, fumed, Vitrified silica, Pyrogenic colloidal silica, Silica, fused, Suprasil W, Vitreosil IR, Borsil P, Dioxide, Silicon, Silane, dioxo-, Crystallized silicon dioxide, Optocil (quartz), CP-SilicaPLOT, Sand, Sea, Silicon oxide, di- (sand), Quarzsand [German], S-Col, Admafine SO 25H, Admafine SO 25R, Admafine SO 32H, Admafine SO-C 2, Admafine SO-C 3, Cristobalite asbestos, Keatite (SiO2), Sg-67, Tridymite (SiO2), Fumed silica, crystalline-free, Stishovite (SiO2), ED-C (silica), Fuselex ZA 30, As 1 (silica), CCRIS 2475, DQ12, Agate (SiO2), Celite 545, Fumed synthetic amorphous silica, Silica, crystalline - tridymite, FB 5 (silica), Fuselex RD 120, Corning 7940, Microcrystalline quartz, Synthetic amorphous silica, fumed, Denka F 90, Denka FB 30, Denka FB 44, Denka FB 74, Dri-Die 67, Silica gel spherical, 40-75 mum particle size, WGL 300, Cryptocrystalline quartz, FB 20 (silica), Elsil 100, F 44 (filler), D & D, SF 35, Elsil BF 100, F 125 (silica), F 160 (silica), Fuselex RD 40-60, Silica, amorphous, fused, Silica; Silica colloidal anhydrous; Silicium dioxide, EINECS 238-455-4, EINECS 238-878-4, EINECS 239-487-1, 43-63C, HK 400, TGL 16319, Silica, crystalline quartz, Silicon dioxide (vitreous), Silica, amorphous, fumed, cryst.-free, Silica, crystalline, quartz, Silica, crystalline: quartz, tripolite, GP 7I, Precipitated amorphous silica, Chrysoprase, Ronasphere, Silica, crystalline tridymite, Speriglass, Carneol, Citrine, Kieselgel, NaturasilScars, Sandstone, Silica, crystalline - quartz, Silicea, Spherica, AF-SO 25R, Quartz [Silica, crystalline], Siilca, Zorbax, quartz-glass, silica sand, Silicom dioxide, Silica flour (powdered crystalline silica), Silica marina, Silica, crystalline: tridymite, silica-gel, Fused-silica, pyrogenic silica, Silica,fumed, GP 11I, RD 8,FT-0700917, NS00096378, S0822, Silica gel, with 1-4 mm moisture indicator, Silica, amorphous, fumed (crystalline free), Silicon dioxide Nanopowder KH550 processing, Silicon dioxide Nanopowder KH570 processing, Silicon(IV) oxide, 99.0% (metals basis), Celite(R) 110, filter aid, flux calcinated, Celite(R) 512 medium, filter aid, calcined, Chromosorb(R) G/AW-DMCS, 100-120 mesh, Chromosorb(R) W/AW-DMCS, 120-140 mesh, K-411 Glass microspheres, NIST SRM 2066, Silica gel, technical grade 40, 6-12 mesh, C18 Silica Gel, Endcapped, 60A, 40-63um, D05839, D06521, D06522, D78143, Dr. Zenni GGOGGOMA ToothpasteRaspberry flavor, Sand, white quartz, 50-70 mesh particle size, Silica, mesostructured, MSU-F (cellular foam), SILICON DIOXIDE COMPONENT OF SIMETHICONE, Silicon Dioxide, Amorphous Gel, 15% In Water, Silicon Dioxide, Amorphous Gel, 40% In Water, Celite(R) 209, filter aid, natural, untreated, Celite(R) Analytical Filter Aid II (CAFA II), Glass sand, NIST(R) SRM(R) 165a, low iron, Silica gel spherical, 75-200 mum particle size, Silica gel, Davisil(R) grade 922, -200 mesh, Silica gel, large pore, P.Vol. ca. 1.65cc/g, Silicon Oxide (Silica, Silicon dioxide, quartz), Silicon oxide powder, 99.5% Nano, 15-20 nm, Q116269, Sand for sand sieve analysis, NIST(R) RM 8010, Silica gel, GF254, for thin layer chromatography, Silica gel, HF254, for thin layer chromatography, Silica gel, Type III, Indicating, for desiccation, Silica, mesostructured, MCM-41 type (hexagonal), Silicon dioxide, purum p.a., acid purified, sand, Standard Super Cel(R) fine, filter aid, calcined, Celite(R) 500 fine, filter aid, dried, untreated, Collodial Silica in Aqueous Solution (nanoparticles), Glass sand, NIST(R) SRM(R) 1413, high alumina, J-002874, Sand, white quartz, >=99.995% trace metals basis, Silica gel, large pore, P.V. ca. 1cc/g, 8 mesh, Silica gel, technical grade, 1-3 mm particle size, Silica gel, technical grade, 3-6 mm particle size, Silica gel, with moisture indicator (blue), coarse, Celpure(R) P65, meets USP/NF testing specifications, Micro particles based on silicon dioxide, size: 2 mum, Micro particles based on silicon dioxide, size: 3 mum, Micro particles based on silicon dioxide, size: 4 mum, Micro particles based on silicon dioxide, size: 5 mum, Silica gel 60, 0.060-0.2mm (70-230 mesh), Silica gel desiccant, indicating, <1% Cobalt chloride, Silica gel, -60-120 mesh, for column chromatography, Silicon(IV) oxide, 15% in H2O, colloidal dispersion, Silicon(IV) oxide, 30% in H2O, colloidal dispersion, Silicon(IV) oxide, 50% in H2O, colloidal dispersion, Celpure(R) P100, meets USP/NF testing specifications, Celpure(R) P1000, meets USP/NF testing specifications, Celpure(R) P300, meets USP/NF testing specifications, Micro particles based on silicon dioxide, size: 0.5 mum, Micro particles based on silicon dioxide, size: 1.0 mum, Silica Dispersion (SiO2, Aqueous Dispersion, Amorphous), Silica gel 60, 0.032-0.063mm (230-450 mesh), Silica gel 60, 0.036-0.071mm (215-400 mesh), Silica gel 60, 0.040-0.063mm (230-400 mesh), Silica gel desiccant, indicating, -6+16 mesh granules, Silica gel, with moisture indicator (blue), -6-20 mesh, Silica, mesostructured, MSU-H (large pore 2D hexagonal), Silica, mesostructured, SBA-15, 99% trace metals basis, Silicon Dioxide (Silica) Nanodispersion Type A (20nm), Silicon Dioxide (Silica) Nanodispersion Type B (20nm), Silicon dioxide, -325 mesh, 99.5% trace metals basis, Silicon dioxide, washed and calcined, analytical reagent, Silicon(IV) oxide, amorphous fumed, S.A. 85-115m2/g, Synthetic - fused silica: Trade Names: Suprasil; TAFQ, Zeolite - Mesoporous Silica Nanopowder (SBA-15 Type), Chromosorb(R) W, AW-DMCS, 100-120 mesh particle size, Micro particles based on silicon dioxide, size: 0.15 mum, Silica gel, high-purity grade (15111), pore size 60 ??, Silica Slurry (SiO2, Purity: 99%, Diameter: 15-20nm), Silica, mesoporous, 1 mum particle size, pore size ~2 nm, Silica, mesoporous, 1 mum particle size, pore size ~4 nm, Silica, mesoporous, 2 mum particle size, pore size ~2 nm, Silica, mesoporous, 2 mum particle size, pore size ~4 nm, Silica, mesoporous, 3 mum particle size, pore size ~2 nm, Silica, mesoporous, 3 mum particle size, pore size ~4 nm, Silica,fumed, hydrophilic, specific surface area 200 m2/g, Silica,fumed, hydrophilic, specific surface area 400 m2/g, silicon dioxide; synthetic amorphous silicon dioxide (nano), Silicon(IV) oxide, amorphous fumed, S.A. 350-420m2/g, Amorphous silica: Vitreous silica, quartz glass, fused silica, LUDOX(R) AM colloidal silica, 30 wt. % suspension in H2O, LUDOX(R) CL colloidal silica, 30 wt. % suspension in H2O, LUDOX(R) CL-X colloidal silica, 45 wt. % suspension in H2O, LUDOX(R) LS colloidal silica, 30.
Usually they are suspended in an aqueous phase that is stabilized electrostatically.
Colloidal silicas exhibit particle densities in the range of 2.1 to 2.3 g/cm3.
Most colloidal silicas are prepared as monodisperse suspensions with particle sizes ranging from approximately 30 to 100 nm in diameter.
Polydisperse suspensions can also be synthesized and have roughly the same limits in particle size.
Smaller particles Colloidal silicas are difficult to stabilize while particles much greater than 150 nanometers are subject to sedimentation.
Colloidal silicas are most often prepared in a multi-step process where an alkali-silicate solution is partially neutralized, leading to the formation of silica nuclei.
The subunits of colloidal silica particles are typically in the range of 1 to 5 nm.
Whether or not these subunits are joined depends on the conditions of polymerization.
Initial acidification of a water-glass (sodium silicate) solution yields Si(OH)4.
If the pH is reduced below 7 or if salt is added, then the units tend to fuse together in chains.
Colloidal silicas are often called silica gels. If the pH is kept slightly on the alkaline side of neutral, then the subunits stay separated, and they gradually grow.
Colloidal silicas are often called precipitated silica or silica sols.
Hydrogen ions from the surface of colloidal silica tend to dissociate in aqueous solution, yielding a high negative charge.
Substitution of some of the Si atoms by Al is known increase the negative colloidal charge, especially when it is evaluated at pH below the neutral point.
Because of the very small size, the surface area of colloidal silica is very high.
The colloidal suspension is stabilized by pH adjustment and then concentrated, usually by evaporation.
The maximum concentration obtainable depends on the on particle size.
For example, 50 nm particles can be concentrated to greater than 50 wt% solids while 10 nm particles can only be concentrated to approximately 30 wt% solids before the suspension becomes too unstable.
The term "colloidal" indicates that the particles are finely divided and dispersed evenly throughout the liquid, resulting in a stable and homogeneous mixture.
In the case of colloidal silica, the solid particles are typically in the nanometer range.
Colloidal silica is a submicroscopic fumed silica with a particle size of about 15 nm.
Colloidal silica is a light, loose, bluish-white-colored, odorless, tasteless, amorphous powder.
Colloidal silica is prepared by the flame hydrolysis of chlorosilanes, such as silicon tetrachloride, at 18008℃ using a hydrogen–oxygen flame.
Rapid cooling from the molten state during manufacture causes the product to remain amorphous.
Silicon dioxide is a silicon oxide made up of linear triatomic molecules in which a silicon atom is covalently bonded to two oxygens.
Fumed silica may be synthesized by high temperature hydrolysis of SiCl4 in O2(N2)/H2 flame.
Colloidal silica is amorphous in nature and possesses very high specific area.
The micro droplets of amorphous silica fuse into a branch and form a chain like agglomerate.
Colloidal silicas are produced in a variety of grades that range in a number of factors.
Particle size typically varies from 5nm to 40nm, and particle size distribution can vary from narrow to wide depending on the manufacturing process.
Standard colloidal silica is stable at a pH from 8 - 10.5 and carries an anionic surface charge that is stabilized with sodium or ammonium.
In certain grades, some of the Colloidal silica in the silica particle are replaced with aluminate ions to allow for enhanced stability in a wider pH range, usually 3.5 - 10.5.
Colloidal silica made by DKIC consists of dense silica particles suspended in aqueous medium.
These particles are spherical and uniform in size.
They do not have any internal structure of their own and are totally amorphous.
Colloidal silicas are discrete and non-agglomerated.
Colloidal silica with particle size ranging between 7 to 35 nanometers.
These stable aqueous dispersions of colloidal silica are available in silica concentrations from 20 to 50 weight%.
Colloidal silica can also be produced to carry a positive surface charge that is stable in the acidic pH range.
This is accomplished by modifying the surface of the particle with aluminum and charge stabilizing the particle with a chloride anion.
Colloidal silicas are defined as a stable suspension of microscopic particles or molecules distributed throughout a second substance known as a dispersion medium.
They differ from other types of suspensions in that the colloid is evenly dispersed throughout the suspension, and does not separate or settle.
Colloidal silicas may be any combination of liquid, solid, and gaseous colloids and dispersion media.
Colloidal silicas are prevalent in a variety of common products and produced by various environmental and natural circumstances as well.
Colloidal Silica suspension can produce high-quality mirror polishes.
Colloidal silica is part abrasive, part chemical polisher, which makes it well-suited to polishing materials such as aluminum, stelitte, and cobalt chrome.
Colloidal silicas are made from liquid particles suspended in a gaseous dispersion medium, such as fog, mist, and hairspray.
Colloidal silicas are solids suspended in a gaseous dispersion medium.
Common Colloidal silicas include smoke, dust, and air pollution.
Liquid foams result from gas particles suspended in a liquid dispersion medium, such as whipped cream, shaving cream, and hair-styling mousse.
Emulsion occurs when liquid Colloidal silicas are suspended in a liquid dispersion medium.
Sol refers to Colloidal silicas suspended in a liquid dispersion medium.
Pigmented ink, paint, and blood are common examples of sols.
Colloidal silicas are created when gas particles become suspended in a solid dispersion medium.
Gels are made from Colloidal silicas suspended in a liquid dispersion medium.
Gels are often treated in order to enhance the structure of the solid particles and create a more viscous solution.
Solid sol refers to solid particles suspended in a solid dispersion medium, such as metal alloys, colored glass, and gemstones.
Colloidal silica consists of silica molecules suspended in liquid, thereby forming a liquid sol.
The process of creating colloidal silica is closely monitored to ensure that the silica molecules remain stable and separate within the liquid medium without collapsing into smaller component molecules or collecting into unstable silica gels.
The liquid dispersion medium exhibits greater density than water and must be electrostatically treated for enhanced ionic stabilization.
Colloidal silica’, is a polymeric form of silicon.
The non-toxic, naturally occurring element Colloidal silica is listed in the periodic-table and is widely employed in the industry.
Colloidal silica is abundant in nature because it accounts for a sizeable portion of the Earth's crust and is the second most prevalent element after oxygen.
The water-based suspensions of crystalline Colloidal silicas are known as colloidal silicon dioxide (SiO2).
Colloidal silica nanoparticle surface is then charged, enabling the particles to repel and create a stable dispersion or colloid.
The stable dispersion formed is called colloidal Colloidal silica and has unique properties which can be applied to different applications.
Colloidal silicon dioxide has the physical characteristics of light, loose, bluish-white-colored, flavorless, and amorphous powder.
Conventional colloidal silicon dioxide consists of a negative (anionic) surface charge that is regulated with ammonium or sodium and is stable at a potential hydrogen (pH) range of 8 to 10.5.
Colloidal silica is composed of discrete, amorphous, spherical silica particles dispersed in water that do not exhibit detectable levels of crystallinity or porosity.
Several grades are available in various particle sizes within the range of 5–40 nanometers.
Each grade of LUDOX® colloidal silica has a very tight particle size distribution and varies in pH, silica sol charge, and stabilizing mechanism.
This non-crystallizing Colloidal Silica is made to be user friendly.
Colloidal silica eliminates the problems that are caused by drying or freezing that are associated with other colloidal silica products which are used for chemical/mechanical polishing
Colloidal silica is a first choice silica dispersion for optimizing polishing results such as silicon, fused quartz, fused silica, lithium niobate, YAZ, GGG, alexandrite, sapphire and many others.
Colloidal silica varies from other types of silica in several significant ways.
The most noticeable difference is that Colloidal silica's in liquid form, as opposed to powder.
In addition, Colloidal silica has the widest ranging surface area, and its aggregate size can be as small as the actual size of the primary particle.
Colloidal silica dispersions are fluid, low viscosity dispersions.
There are many grades of colloidal silica, but all of them are composed of silica particles ranging in size from about 2 nm up to about 150 nm Colloidal silicas may be spherical or slightly irregular in shape, and may be present as discrete particles or slightly structured aggregates.
Colloidal silicas may also be present in a narrow or wide particle size range, depending on the process in which they were created.
The maximum weight fraction of Colloidal silica in the dispersion is limited based on the average particle size.
Dispersions with a smaller average diameters have larger overall specific surface areas and are limited to low concentration dispersions.
Conversely, dispersions with larger average diameters have lower overall specific surface areas and are available in more concentrated dispersions.
The appearance of colloidal silica dispersion depends greatly on the particle size.
Dispersions with small silica particles (< 10 nm) are normally quite clear.
Midsize dispersions (10-20 nm) start to take on an opalescent appearance as more light is scattered.
Dispersions containing large colloidal silica particles (> 50 nm) are normally white.
Standard colloidal silica dispersions are stable against gelling and settling in pH range of 8 - 10.5.
Colloidal silica is a synthetic amorphous silica derivative in which the surface of the fumed silica particle has been modified by the addition of dimethyl silyl groups.
The surface modification is achieved via a controlled chemical process that involves the attachment of dimethyl silyl groups, rendering the silica less wettable. It
Colloidal silica is approved for use in pharmaceutical products as an excipient and is supplied as a light, fine, white or almost white amorphous fluffy powder.
Colloidal silica is a water-based, stabilized dispersion of amorphous silicon dioxide (aka silica) nanoparticles.
Manufacturers produce colloidal silicathrough the polymerization of silica nuclei derived from silicate solutions.
Polymerized under alkaline conditions, the silica nuclei convert into silica sols (solid particles) at the nano-scale and with a high surface area.
The process then applies a charge to these silica sols, causing electrostatic resistance between each particle and creating a colloid—a type of stable dispersion.
Colloidal silica, is a stable suspension of spherical silicon dioxide (SiO2) nanoparticles in a liquid, that are hydroxylated on the surface.
Colloidal silica is found in almost all industrial sectors.
The applications range from surface treatment in the paper industry, to use as a polishing agent in the electronics industry and use as an additive for varnishes, coatings and paints to improve weather and abrasion resistance.
Colloidal silica is also a common additive in cosmetics and in the food industry.
The mean particle size and distribution width define the field of application of the SiO2 particles.
Colloidal silica, is a stable suspension of spherical silicon dioxide (SiO2) nanoparticles in a liquid, that are hydroxylated on the surface.
Colloidal silica acid is found in almost all industrial sectors.
Colloidal silica is amorphous silica (oxide of silicon) prepared synthetically by the vapour-phase hydrolysis of a silicon compound.
Colloidal silica has the chemical formula SiO2 but is distinct from other types of silica, such as amorphous or crystalline silica, that exist naturally or otherwise such as silica gel or precipitated silica.
Colloidal silica is supplied as a white or almost white, light, fluffy, and extremely fine powder.
Colloidal silica is commonly used as a binder in the production of ceramic shells for investment casting.
Colloidal silica helps create intricate and detailed molds for casting metal objects.
In the paper and textile industries, Colloidal silica is sometimes used as a coating or finishing agent to improve printability, smoothness, and abrasion resistance.
Colloidal silica can be incorporated into adhesives and sealants to enhance their strength, flexibility, and adhesion properties.
Colloidal silica is employed in the production of anti-reflective coatings for optical applications, such as eyeglasses, camera lenses, and other optical devices.
In some water treatment processes, Colloidal silica can be used to flocculate and remove impurities from water.
Colloidal silica is utilized in certain personal care products, such as toothpaste and skin creams, as a thickening or abrasive agent.
Colloidal silica can be used as a clarifying agent in the production of beer and wine, helping to remove haze-producing particles.
In the oil and gas industry, colloidal silica is sometimes used in drilling fluids and cementing operations to improve wellbore stability.
Colloidal silica is used in the electronics industry for applications like planarization during semiconductor manufacturing.
Melting point: >1600°C
Density: 2.3 lb/cu.ft at 25 °C (bulk density)(lit.)
refractive index: n20/D 1.46(lit.)
solubility: Practically insoluble in organic solvents, water, and acids, except hydrofluoric acid; soluble in hot solutions of alkali hydroxide. Forms a colloidal dispersion with water. For Aerosil, solubility in water is: 150 mg/L at 258℃ (pH 7).
form: powder
Specific Gravity: 2.2
Purification of silica for high technology applications uses isopiestic vapour distillation from concentrated volatile acids and is absorbed in high purity water.
The impurities remain behind. Preliminary cleaning to remove surface contaminants uses dip etching in HF or a mixture of HCl, H2O2 and deionised water.
Colloidal silica, amorphous is a noncombustible solid.
Generally unreactive chemically.
Incompatible with fluorine, oxygen difluoride, chlorine trifluoride.
Soluble in molten alkalis and reacts with most metallic oxides at high temperature.
In a normal abrasive slurry can expect 15-20wt% concentration of abrasive particles, but in a colloidal slurry as much as 50wt% of silica particles can be present.
This greatly increases the amount of Colloidal silicas that work on a substrate making the polishing very uniform and efficient.
Also, the Colloidal silicas are incredibly uniformly spherical, which again, is difficult to match with standard abrasive particles where the shape is far less uniform.
Colloidal silica is a widely used material in industry.
Colloidal Silica is an epoxy thickening additive used to control the viscosity of the epoxy.
Colloidal silica prevents epoxy runoff in vertical and overhead joints. This is a very strong filler.
Colloidal silica creates a smooth mixture, ideal for general epoxy bonding and filleting.
Colloidal silica is also our most versatile epoxy filler.
Often used in combination with other fillers, 406 can be used to improve strength, abrasion resistance, and consistency of epoxy fairing compounds.
The result is a tougher, smoother surface.
Colloidal Silica is the most popular binder used in the precision investment casting industry today.
Colloidal silica offers the investment caster a safe, economical, easy to use slurry component that performs well as either primary or backup slurry.
Colloidal Silica systems are very stable; able to form a long life ceramic slurry with a large range of refractory materials due to the binder’s chemical inertness.
Sol-gel, hydrothermal, and chemical vapor deposition (CVD) methods have been used to fabricate Colloidal silica.
The sol-gel process is widely utilized to make pure Colloidal silicas because of its capacity to regulate the physical appearance by methodical monitoring of reaction variables under ambient temperature.
The ion-exchange procedure is a part of the technique used to produce Colloidal silica using sodium silicate through the sol-gel method.
With this technique, particle size and distribution of colloidal silicon dioxide may be easily controlled.
The technique also provides improved electric charge and high zeta for cColloidal silica particles.
This makes the solution more stable, repelling aggregation and preventing agglomeration between particles.
These colloidal silica particles can achieve additional anionic charge stability when as aluminosilicate sites are formed by incorporation of aluminum into the surface layer of the silica particles.
Low pH versions of colloidal silica are also available by the adsorption of cationic aluminum oxide onto the surface of the particles.
This results in a cationic particle that is stabilized with anionic species - commonly this is chloride.
These dispersions are stable below a pH of 4.
Low pH grades can also be obtained by completely deionizing the dispersion.
These grades do not require the presence of stabilizing ions and are also stable below a pH of 3.
Colloidal silicas can be modified to several configurations including but not limited to: adjustments to pH, stabilization ions, surface charge and surface modification.
Colloidal silica consists of silica molecules suspended in liquid, thereby forming a liquid sol.
The process of creating colloidal silica is closely monitored to ensure that the silica molecules remain stable and separate within the liquid medium without collapsing into smaller component molecules or collecting into unstable silica gels.
The liquid dispersion medium exhibits greater density than water and must be electrostatically treated for enhanced ionic stabilization.
Colloidal silica is highly fluid with low viscosity.
Uses for colloidal silica vary depending on the size of the silica particles in the solution and the modifiable pH, ionization, and surface charge.
Colloidal silica is extensively used as a rheological additive in personal care products to control flowability.
In the most general terms colloidal silica is a dispersion of amorphous silicon dioxide (silica) particles in water.
These amorphous silica particles are produced by polymerizing silica nuclei from silicate solutions under alkaline conditions to form nanometer sized silica sols with high surface area.
A charge is then induced on the silica nanoparticle surface that allows the silica particles to repel one another and form a stable dispersion, or colloid.
Colloidal silica is a stable suspension of spherical silicon dioxide (SiO2) nanoparticles in a liquid, that are hydroxylated on the surface.
Colloidal silica is found in almost all industrial sectors.
The applications range from surface treatment in the paper industry, to use as a polishing agent in the electronics industry and use as an additive for varnishes, coatings and paints to improve weather and abrasion resistance.
Colloidal silica is also a common additive in cosmetics and in the food industry.
The mean particle size and distribution width define the field of application of the SiO2 particles.
Typical sizes range from 1 nm to 100 nm.
Colloidal silicas are typically aqueous suspensions in the range of 30 – 500 nm in diameter.
Colloidal silicas are usually stabilized electrostatically and have densities in the range of 2.1 to 2.3 g/cm3.
Applications for colloidal silicas include fillers, binders, abrasives, catalysts, and absorbants.
Most size measurements of colloidal silica are performed using dynamic light scattering (DLS) instruments such as the SZ-100 Nanoparticle Analyzer.
Colloidal silica is used in many applications including catalysis, pharmaceuticals, and coatings.
Although naturally formed silica materials are widely available, they are often in forms that are difficult to process or are even harmful to health.
Therefore, uniform colloidal silicas are generally manufactured using synthetic chemical processes.
While established high temperature gaseous synthesis methods fall out of favor in our energy conscious society, liquid synthesis methods are current industrial leaders.
The precipitated Colloidal silica method provides the majority share of commercially produced specialty silicas with its economic advantages predicted to continue to grow in the future.
Colloidal silica products are stable dispersions of non-agglomerated, amorphous, nanometer-size, and spherical particles of silica.
The good stability, adjustable particle size distribution and mechanical properties have made colloidal silica a preferred abrasive for many CMP applications.
Recently, research and analytical efforts have focused on the development of colloidal products with tunable physical and chemical properties to open up new opportunities in the CMP industry segment.
Colloidal silicas are most often prepared in a multi-step process where an alkali-silicate solution is partially neutralized, leading to the formation of silica nuclei.
The subunits of colloidal silica particles are typically in the range of 1 to 5 nm.
Whether or not these subunits are joined together depends on the conditions of polymerization.
Initial acidification of a water-glass (sodium silicate) solution yields Si(OH)4.
If the pH is reduced below 7 or if salt is added, then the units tend to fuse together in chains.
Colloidal silicas are often called silica gels.
If the pH is kept slightly on the alkaline side of neutral, then the subunits stay separated, and they gradually grow.
Colloidal silicas are often called precipitated silica or silica sols.
Hydrogen ions from the surface of colloidal silica tend to dissociate in aqueous solution, yielding a high negative charge.
Substitution of some of the Si atoms by Al is known increase the negative colloidal charge, especially when it is evaluated at pH below the neutral point.
Because of the very small size, the surface area of colloidal silica is very high.
The Colloidal silica is stabilized by pH adjustment and then concentrated, usually by evaporation.
The maximum concentration obtainable depends on the on particle size.
For example, 50 nm particles can be concentrated to greater than 50 wt% solids while 10 nm particles can only be concentrated to approximately 30 wt% solids before the suspension becomes too unstable.
Uses:
Colloidal silica has interesting thickening and thixotropic properties, and an enormous external surface area.
Colloidal silica is produced by a vapor phase hydrolysis process using chlorosilanes or substituted silanes such as, silicon tetrachloride in a flame of hydrogen and oxygen.
This material is formed and collected in a dry state.
Colloidal silica contains no detectable crystalline silica.
Colloidal silica is widely used in pharmaceuticals, cosmetics, and food products.
Colloidal silica is small particle size and large specific surface area give it desirable flow characteristics that are exploited to improve the flow properties of dry powders in a number of processes such as tableting and capsule filling.
Colloidal silica is also used to stabilize emulsions and as a thixotropic thickening and suspending agent in gels and semisolid preparations.
With other ingredients of similar refractive index, transparent gels may be formed.
The degree of viscosity increase depends on the polarity of the liquid (polar liquids generally require a greater concentration of colloidal silicon dioxide than nonpolar liquids).
Viscosity is largely independent of temperature.
However, changes to the pH of a system may affect the viscosity.
In aerosols, other than those for inhalation, Colloidal silica is used to promote particulate suspension, eliminate hard settling, and minimize the clogging of spray nozzles.
Colloidal silica is also used as a tablet disintegrant and as an adsorbent dispersing agent for liquids in powders.
Colloidal silica is frequently added to suppository formulations containing lipophilic excipients to increase viscosity, prevent sedimentation during molding, and decrease the release rate.
Colloidal silica is also used as an adsorbent during the preparation of wax microspheres; as a thickening agent for topical preparations; and has been used to aid the freeze-drying of nanocapsules and nanosphere suspensions.
In papermaking colloidal silica is used as a drainage aid. It increases the amount of cationic starch that can be retained in the paper.
Colloidal silica starch is added as sizing agent to increase the dry strength of the paper.
Colloidal silica hasn't always been the versatile problem solver that it is today.
In fact, early colloidal silicas were not commercially useful because they were too unstable and contained only low levels of silica.
Colloidal silica wasn't until the production of Colloidal silica in the late 1940's that the applications for colloidal silica began to expand.
One of the earliest applications for colloidal silica was in anti-slip coatings for floors.
Colloidal silica is a very common final polishing stage for metallographic sample analysis.
This is because Colloidal silica is generally guaranteed to give a damage free specimen.
These types of samples are viewed under high magnification, so it is important when looking at the structures of a material that damage caused by the preparation processes is not confused with the material make up itself.
For modern material analysis software, a scratch free finish is critical.
Scratches or any other damage on a specimen can confuse the software giving incorrect readings.
This is particularly important with hardness testing software.
For some metallographic samples, the chemical make-up of colloidal silica can be used to etch the surface revealing grain boundaries and other structures.
Colloidal silica hasn't always been the versatile problem solver that it is today.
In fact, early colloidal silicas were not commercially useful because they were too unstable and contained only low levels of silica.
colloidal silica wasn't until the production of LUDOX in the late 1940's that the applications for colloidal silica began to expand.
One of the earliest applications for colloidal silica was in anti-slip coatings for floors.
The 1950's Dupont advertisement below explains how colloidal silica is used in floor wax.
colloidal silica is used in the production of coatings and films due to its ability to form a transparent layer with excellent adhesion properties.
colloidal silica can serve as a support material for catalysts in various chemical processes.
colloidal silica is utilized in the semiconductor and optical industries for polishing and planarizing surfaces.
In the manufacturing of refractory materials, colloidal silica can act as a binder to improve the strength and performance of the final product.
colloidal silica is sometimes added to concrete to enhance its strength and durability.
colloidal silica is used in some dental materials, including composites and impression materials.
In pharmaceuticals, colloidal silica can be employed as a carrier for drug delivery systems.
colloidal silica is highly fluid with low viscosity.
Uses for colloidal silica vary depending on the size of the silica particles in the solution and the modifiable pH, ionization, and surface charge.
Used for final polishing, colloidal silica suspensions are mixtures of abrasive particles dispersed throughout a chemically aggressive liquid carrier.
This combination provides a chemical-mechanical polishing action, resulting in deformation-free surfaces.
The modified pH of these suspensions can provide delineation of grain boundaries and other microstructural features for some sample types.
colloidal silica is used to create thin, transparent coatings and films on surfaces, providing enhanced adhesion, hardness, and durability.
colloidal silica serves as a support material for catalysts in chemical processes, improving their stability and efficiency.
In industries such as semiconductor manufacturing and optics, colloidal silica is used for polishing and planarization to achieve smooth surfaces with high precision.
colloidal silica acts as a binder in the production of refractory materials, improving their strength and resistance to high temperatures.
colloidal silica can be added to concrete to enhance its strength, durability, and resistance to chemical attack.
colloidal silica is used as a binder in ceramic shell molds for investment casting, enabling the production of intricate and detailed metal castings.
colloidal silica is incorporated into adhesives and sealants to improve their adhesive properties, flexibility, and overall performance.
In the production of optical devices, colloidal silica is used to create anti-reflective coatings, reducing glare and enhancing optical performance.
Colloidal silica can aid in water treatment processes by flocculating impurities and facilitating their removal.
colloidal silica is used in some dental composites and impression materials to improve their properties.
colloidal silica is employed in the textile and paper industries for coatings that enhance printability, smoothness, and abrasion resistance.
Found in certain personal care items such as toothpaste and skin creams, acting as a thickening or abrasive agent.
colloidal silica is used as a clarifying agent in the production of beverages like beer and wine to remove haze-producing particles.
In drilling fluids and cementing operations, colloidal silica is used to improve wellbore stability.
Employed in the electronics industry for planarization processes during the manufacturing of semiconductors.
Applications that use colloidal silica vary widely.
colloidal silica can be used to enhance or direct the movement of substances within various processes.
For example, colloidal silica is used in the paper manufacturing process to draw liquid from the finished paper quickly, thereby allowing the paper to dry faster while retaining its strengthening starch.
Similarly, colloidal silica can be used to absorb moisture in industrial settings where moisture levels are high.
Depending on the size of its constituent particles, colloidal silica may be used to enhance the movement of materials or to increase surface friction.
Colloidal silica is used in many applications including catalysis, pharmaceuticals, and coatings.
Although naturally formed silica materials are widely available, they are often in forms that are difficult to process or are even harmful to health.
Therefore, uniform colloidal silicas are generally manufactured using synthetic chemical processes.
While established high temperature gaseous synthesis methods fall out of favor in energy conscious society, liquid synthesis methods are current industrial leaders.
Colloidal silica can be used to enhance or direct the movement of substances within various processes.
For example, Colloidal silica is used in the paper manufacturing process to draw liquid from the finished paper quickly, thereby allowing the paper to dry faster while retaining its strengthening starch.
Similarly, colloidal silica can be used to absorb moisture in industrial settings where moisture levels are high.
Colloidal silica dioxide is also used to stabilize emulsions and as a thixotropic thickening and suspending agent in gels and semisolid preparations.
With other ingredients of similar refractive index, transparent gels may be formed.
The degree of viscosity increase depends on the polarity of the liquid (polar liquids generally require a greater concentration of Colloidal silica dioxide than nonpolar liquids).
Viscosity is largely independent of temperature.
However, changes to the pH of a system may affect the viscosity.
In aerosols, other than those for inhalation, Colloidal silica dioxide is used to promote particulate suspension, eliminate hard settling, and minimize the clogging of spray nozzles.
colloidal silica is also used as a tablet disintegrant and as an adsorbent dispersing agent for liquids in powders.
colloidal silica is frequently added to suppository formulations containing lipophilic excipients to increase viscosity, prevent sedimentation during molding, and decrease the release rate.
colloidal silica is also used as an adsorbent during the preparation of wax microspheres; as a thickening agent for topical preparations; and has been used to aid the freeze-drying of nanocapsules and nanosphere suspensions.
Depending on the size of its constituent particles, colloidal silica may be used to enhance the movement of materials or to increase surface friction.
Colloidal silica can also be used as a reference material for both particle size and zeta potential.
colloidal silica is a well known and characterized colloidal material that has been studied using various particle size analysis techniques including acoustic spectroscopy, laser diffraction and dynamic light scattering.
Colloidal silica is usually used in combination with a polyurethane polishing pad which has voids within the structure of the pad to hold the colloidal silica.
Colloidal silica is applied using a peristaltic pump and a constant drip feed similar to a conventional abrasive lapping process.
Colloidal silica’s important to maintain the wetness of the process so there is no drag out of material.
Colloidal silica dioxide is widely used in pharmaceuticals, cosmetics, and food products.
Colloidal silicas small particle size and large specific surface area give it desirable flow characteristics that are exploited to improve the flow properties of dry powders in a number of processes such as tableting and capsule filling.
Colloidal silica can be employed as a carrier in drug delivery systems, allowing for controlled release and improved bioavailability of pharmaceuticals.
colloidal silica is used in the formulation of abrasive pastes and polishes for applications such as metal polishing and glass grinding.
colloidal silica is sometimes used in the production of fireproofing materials, contributing to the thermal resistance of coatings and structures.
In the manufacturing of batteries, colloidal silica may be utilized to enhance electrode materials and improve battery performance.
Colloidal silica nanoparticles can be employed in photocatalytic processes, such as water purification and air treatment, due to their unique surface properties.
colloidal silica is used in some environmental remediation processes, aiding in the removal of contaminants from soil and water.
colloidal silica can be used in agriculture to improve soil structure and water retention, promoting better plant growth.
In the emerging field of printed electronics, colloidal silica is utilized in the formulation of conductive inks and coatings.
colloidal silica nanoparticles are investigated for potential biomedical applications, including imaging, drug delivery, and therapeutics.
In addition to batteries, colloidal silica may be explored for use in energy storage systems, contributing to advancements in renewable energy technologies.
colloidal silica can be employed in wastewater treatment processes to remove suspended solids and contaminants.
colloidal silica is used in certain formulations of paints and coatings to improve their adhesion, durability, and resistance to environmental factors.
colloidal silica nanoparticles are studied for their potential in enhanced oil recovery processes in the oil and gas industry.
In the production of solar cells, colloidal silica can be used to create anti-reflective coatings and improve the efficiency of light absorption.
Found in some cosmetic products, colloidal silica may contribute to formulations such as foundations and powders.
Safety Profile:
Poison by intraperitoneal, intravenous, and intratracheal routes.
Moderately toxic by ingestion.
Much less toxic than crystalhe forms.
Questionable carcinogen with experimental carcinogenic data.
Mutation data reported.
colloidal silica is widely used in oral and topical pharmaceutical products and is generally regarded as an essentially nontoxic and nonirritant excipient.
However, intraperitoneal and subcutaneous injection may produce local tissue reactions and/or granulomas.
colloidal silica should therefore not be administered parenterally.
Storage:
colloidal silica is hygroscopic but adsorbs large quantities of water without liquefying.
When used in aqueous systems at a pH 0–7.5, colloidal silica is effective in increasing the viscosity of a system.
However, at a pH greater than 7.5 the viscosityincreasing properties of colloidal silica are reduced; and at a pH greater than 10.7 this ability is lost entirely since the silicon dioxide dissolves to form silicates.
colloidal silica powder should be stored in a well-closed container.
