Azin Mazloom Jalali - Department of Chemistry, Amirkabir University of Technology, Tehran, Iran
Faramarz Afshar Taromi - Department of Chemistry, Amirkabir University of Technology, Tehran, Iran,Department of Polymer Engineering, Amirkabir University of Technology, Tehran, Iran
Mohammad atai - Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran
laleh solhi - Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran

The purpose of this paper is to investigate the influence of the silanization reaction conditions on surface charge and the colloidal stability of modified particles. Surface modification of nanoparticles was performed using acidic and basic silanization methods. Methacryloxypropyltrimethoxysilane (γ–MPS) was used as silane coupling agent. The silanization reaction was performed in the following conditions: (i) acidic ethanol-water solution with a pH of 5 and (ii) basic cyclohexane with a pH of 9. Zeta Potential analyses were applied to study the surface charge of sepiolite nanoparticles. The colloidal stability of the modified nanoparticles was investigated using a separation analyzer. The results revealed that the basic condition resulted in higher silanization efficiency. The higher hydrophobicity of the silanized nanoparticles decreased their dispersion stability in ethanol.

sepiolite- Zeta Potential- Colloidal stability- Salinization- Coupling agent