by Silica is one of the most abundant compounds found on Earth and comprises approximately 60% of the Earth’s crust. Silicon dioxide or silica is an oxide of silicon with the chemical formula SiO2. While silica occurs naturally in many forms, developments in processing technologies have enabled the production of high purity silica suitable for specialized industrial applications. In this article, we explore the key properties and uses of high purity silica across various industries.
Properties of High Purity Silica
High purity silica refers to silica powder or granules that have been processed to remove impurities and achieve a purity level of at least 99.5%. This level of purity gives silica some unique material properties that make it well-suited for performance-critical applications.
– Purity – The high level of purity allows silica to perform consistently without interference from impurities. Even trace amounts of other elements can affect the optical, electrical or chemical behaviors of silica.
– Thermal Stability – Silica exhibits excellent thermal stability and can withstand temperatures up to 1200°C without undergoing structural changes. This thermal endurance enables its use in applications involving high heat.
– Chemical Inertness – Silica is highly chemically inert and resistant to corrosion from acids, bases as well as organic solvents. This resistance to chemical degradation extends the lifespan of silica-based products.
– Optical Properties – High purity amorphous silica demonstrates low absorption in the visible and near infrared range. It also has a relatively high refractive index of about 1.5, making it suitable for applications involving light transmission.
– Electrical Properties – Silica is an excellent electrical insulator with a resistivity of about 1016 ohm-cm. It does not conduct electricity making it ideal for applications requiring electrical insulation.
Use in Electronics Industry
One key application of high purity silica is in the electronics industry where its properties enable critical functions. Some uses of silica in electronics include:
– Fibre Optics – Silica glass optical fibres form the backbone of telecommunications systems worldwide. The fibres transmit light signals over long distances with minimum loss due to silica’s transparency and high purity.
– Semiconductors – Amorphous silica in the form of SiO2 is widely used as the gate dielectric material in MOSFET semiconductors. It provides electrical insulation on transistor gates to control current flow.
– Integrated Circuits – Silica substrates serve as the base layers on which integrated circuits with millions of transistors are constructed. Its chemical inertness allows for clean processing of circuit components.
– Optoelectronics – Devices like LEDs and optical sensors utilize high-index silica to focus and guide light signals. It forms windows, lenses and encapsulants in optoelectronic packages.
– MEMS Sensors – Micro-electro-mechanical systems (MEMS) integrate silica as the structural material for microscopic movable parts in sensors and actuators.
– Display Panels – Thin film transistor LCD panels employ transparent silica as the dielectric insulator in each pixel circuit to switch on individual pixels.
Use in Pharmaceutical Industry
Maintaining High Purity Silica is critical in the pharmaceutical industry where even minor contaminations can impact drug efficacy and safety. Some applications of purified silica include:
– Excipients – Pharmaceutical grade silica is used as an excipient in tablet and capsule formulations to improve flow properties and facilitate processing. Its chemical inertness preserves drug stability.
– Adsorbents – High surface area silica gels are effective at absorbing moisture thereby protecting sensitive pharmaceutical ingredients, intermediates and final products from degradation due to humidity.
– Desiccants – Indicating silica gel desiccants maintain low moisture levels in packaging to prevent caking and preserve a long shelf life for medications prone to hydrolysis.
– Coatings – Anti-adherent silica coatings on production and processing equipment maintain a non-sticky surface that minimizes residue buildup and cross-contamination between product batches.
– Filtration – Silica membranes offer precise pore size control for microfiltration and are employed to clarify active pharmaceutical ingredients and remove particulates from raw materials, solvents, and final drug products.
Use in Other Industrial Sectors
Beyond electronics and pharmaceuticals, high purity silica finds diverse applications in other industries due to its versatile properties:
– Chemicals – As a catalyst support for petrochemical cracking; filler for silicone and epoxy resins and sealants; abrasive in cleaners.
– Personal Care – As a thickening agent in toothpaste; exfoliating agent in facial/body scrubs; anti-caking agent in powders.
– Construction – As aggregate in lightweight concrete; filler in sealants, coatings, and plasters; additive to improve workability of cement.
– Automotive – As anti-abrasive additive in brake pads, wear-resistant coatings; filler/reinforcement in plastic components; desiccant in AC systems.
– Food – As a flowing agent/anti-caking additive in table salt and seasonings; carrier for food supplements; filtering aid in beverages.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
