Silica sol-silica gel
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I would like to ask the experienced colleagues: what is the difference between silica sol and silica gel? What is the maximum water content that silica gel can have? Also, if silica gel is used as a catalyst carrier, what is the approximate water content after filtration? Waiting for an answer online, urgently needed, thank you! !
Silica sol is a colloidal solution formed by the uniform dispersion of silica gel particles in water. Due to the small size of these colloidal particles (10-20 nm), they have a large specific surface area; moreover, the particles are colorless and transparent, so they do not affect the color of the substance they cover； Lower viscosity ； When the water in the silica sol evaporates, the colloidal particles adhere firmly to the surface of the object, and silicon-oxygen bonds are formed between the particles ； It can produce gels with a large specific surface area and uniform fine pores, as well as evenly disperse powders to enhance the stability of the suspension ； Wettability can be improved and charging can be prevented through Si—OH groups and adsorbed water ； By uniformly mixing particles, the mechanical, optical, and electrical properties of organic resins can be modified and enhanced ； Homogeneous reactions can be carried out; using silica sol as a substitute for silicon dioxide as the reactant can increase the reaction rate. Uses of silica sol: 1. It is used as an adhesive in various refractory materials, offering strong bonding properties and resistance to high temperatures (1500–1600°C). 2. In the paint industry, it helps to enhance the durability of paints, while also providing properties such as stain and dust resistance, aging resistance, and fire resistance. 3. It is used in precision casting of thin shells, enabling higher strength in the molds and resulting in a higher degree of surface smoothness in the cast products. 4. Silica sols have a high specific surface area, and can be used in catalyst manufacturing and as catalyst carriers. 5. It is used in the paper industry, where it can serve as an anti-sticking agent for cellophane, a pretreatment agent for photographic paper, and an anti-slip agent for cement bags. 6. In the textile industry, it is used as a sizing agent; when used together with oils to treat wool and rabbit fur, it improves the spinnability of these fibers, reduces breakages, prevents fiber loss, increases the yield of finished products, and enhances economic benefits. 7. Used as a treatment agent for silicon steel sheets, a dispersant for cathode ray tubes, and to improve the anti-slip properties of floor waxes.
Silicone gel is a low-viscosity, viscous, gel-like, transparent two-component addition-curing silicone gel that can be cured at room temperature or by heating; the higher the temperature, the faster the curing process. This product generates no by-products during the curing reaction, and can be applied to the surfaces of materials such as PC (Poly-carbonate), PP, ABS, PVC, as well as metals. This gel can maintain its elasticity over a temperature range of -65 to 200°C, and it possesses excellent electrical properties as well as chemical stability. It is water-resistant, ozone-resistant, resistant to weathering, hydrophobic, moisture-proof, shock-resistant, and non-corrosive. It also possesses properties such as physiological inertness, being non-toxic and odorless, being easy to pour, allowing for deep vulcanization, having a low linear shrinkage rate, and being simple to handle. Silicone gels are widely used in the electronics industry as coating and potting materials for moisture protection, theft prevention, and insulation of electronic components; they provide dust protection, moisture resistance, shock protection, and insulating protection for such components and assemblies. When transparent gel is used to encapsulate electronic components, it not only provides shock and water protection but also allows the components to be seen, enabling the use of probes to detect any faults and replace the affected components. The damaged silicone gel can be re-encapsulated for repair. Due to its high purity, ease of use, and certain level of elasticity, silicone gel is an ideal material for internal coating of transistors and integrated circuits, as it can improve the yield and reliability of semiconductor devices ； Silicone gel can also be used as an elastic adhesive for optical instruments. In medicine, silicone gel can be used as implants in the body such as artificial breasts, as well as to repair damaged organs.