Structural and electrorheological properties of mesoporous silica modified with triethanolamine

In this work, mesoporous silica (MCM-41) was modified by triethanolamine (TEA) by a wet impregnation method. The structure and morphology of modified MCM-41 particles were characterized by X-ray diffraction, N-2 adsorption/desorption, Fourier-transform infrared spectra, scanning electron microscopy, particle size analyzer and thermogravimetric analysis. The results show that the interior channels of MCM-41 are modified by TEA without destroying its mesoporous structure. Further, pure MCM-41 and TEA-modified particles were adopted as dispersed phase in silicone oil for electrorheological (ER) investigation. The TEA-MCM-41 (modified with 7 wt.% TEA)-based ER fluid with a volume fraction of 5% exhibits stronger ER activity than pure MCM-41 fluid. The possible mechanism related to dielectric properties is also provided. (C) 2007 Elsevier B.V. All rights reserved.