Nanosilica

Nano silica, also known as nanoscale silica or silica nanoparticles, refers to silica (SiO2) particles with a diameter of 1-100 nanometers (nm).
Properties:
1. High surface area (up to 400 m²/g)

2. High reactivity

3. Small particle size

4. Porous structure

5. Chemical stability
Applications:
Industrial:
1. Concrete and construction: Improves strength, durability, and water resistance

2. Coatings and paints: Enhances scratch resistance, UV protection, and gloss retention.

3. Composites: Reinforces polymers, ceramics, and glass.

4. Ceramics: Increases strength, toughness, and thermal resistance.
5. In waste water: Removes pollutants, heavy metals.

 6. Air purification: Captures particulate matter, pollutants.

 7. Soil remediation: Adsorbs contaminants, improves fertility.

Manufacturing methods:
The nano silica synthesis from sol-gel process using sodium silicate and hydrochloric acid (HCl)
in Distilled water. The first step is the hydrolysis of sodium silicate followed by the acidification with 1M HCl for 15-20min. The next step is the gelation which requires the continuous stirring for 1hr. The mixture later transforms into a gel like substance which was allowed to aged to 4-6hrs and later washed to removed any impurities. The final step is the calcination ( 500-800°C for 2-4 hours)  to improve crystallinity and remove residual water.