Characterization of Fly Ash Modified with Vinyltriethoxysilane

Area of Science:

• Materials Science
• Surface Chemistry
• Nanotechnology

Background:

• Fly ash (FA) is a byproduct of coal combustion with potential applications in materials science.
• Unmodified FA often suffers from poor dispersibility and particle agglomeration, limiting its utility.
• Surface modification is a key strategy to overcome these limitations and enhance FA properties.

Purpose of the Study:

• To modify fly ash (FA) using vinyltriethoxysilane (VTES) to improve its dispersibility and prevent agglomeration.
• To investigate the effect of VTES grafting on the surface properties and thermal stability of FA.
• To control the particle size distribution and assess the optimal VTES loading for monodispersity.

Main Methods:

• Fly ash was pre-treated with nitric acid followed by modification with vinyltriethoxysilane (VTES).
• Characterization involved Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), and particle size distribution analysis.
• VTES loading was varied from 1 to 2 wt.% to study its effect on FA properties.

Main Results:

• Successful grafting of VTES onto the FA surface was confirmed, altering surface properties.
• Modified FA (MFA) exhibited significantly higher thermal stability compared to FA treated solely with nitric acid.
• Particle size control was achieved between 0.2–1.5 µm with 1–2 wt.% VTES loading, showing high monodispersity and low agglomeration.
• Agglomeration increased when VTES content exceeded 2 wt.%.

Conclusions:

• VTES modification is an effective method to enhance the dispersibility and thermal stability of fly ash.
• Optimal VTES loading (1–2 wt.%) allows for controlled particle size and reduced agglomeration.
• Surface-functionalized fly ash shows promise for advanced material applications requiring improved dispersion characteristics.