PRODUCTION OF NANO SILICA USING SOL GEL METHOD BY VARYING THE CONCENTRATION OF SURFACTANT AND TO STUDY ITS BEHAVIOUR IN BLENDED MATERIAL

Abstract

The spherical particles of Nano silica (NS) with controllable size have been synthesized by using
tetraethoxysilane, as a starting material, with ethanol solvent and ammonia as a base catalyst using sol gel method. The
method is carried out as a trial and error process by varying the concentration of surfactants viz., 2.2g, 2.4g, 2.5g, 2.6g,
and 2.8g. The concentration of pH maintained as 8. The result showed that the size of NS increased the concentration
surfactant also increased but the size of NS is lesser for the concentration of surfactant 2.5g comparatively other. The
comparatively study of normal cement paste, silica fume varied contents (0.2%, 0.4%, 0.6%, 0.8%, 1%, 2.5%, 5%, 7.5%
and 10%) and NS varied contents (0.2%, 0.4%, 0.6%, 0.8%, and 1%). The experimental results of these studies showed
that the compressive strength of fresh paste was increased by increasing the content of NS up to 1% in cement paste. The
setting time of cement paste was decreased by increasing the content of NS. The nature and morphology of synthesized
nano silica was investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray
diffraction (XRD).