Application of non-ionic surfactant in modifying the surface of carbon black and its role in the formation of colloidal composite materials

Abstract

In this work, carbon black (CB)/silica colloidal composites were synthesized using a surface adsorption methodology. A unique biocompatible, amphiphilic, non-ionic polysorbetol monoelate easter (Tween 80) surfactant was used to enhance surface activity and wettability of CB aggregates. A metal alkoxide (tetraethoxysilane) was used as precursor for silica precipitation in an acid catalyzed reaction. The precipitated silica gets adsorbed onto surfactant modified CB aggregate via an interactive hydrophilic layer. This results in formation of different configurations of CB/silica colloidal composite, which was characterized by morphological studies. The chemical extraction study was done to quantify, the amount of silica present in CB/silica colloidal composites and observation were further supported by energy dispersive x-ray (EDX) analysis. The x-ray diffraction (XRD) characterizes, the structural arrangement of synthesized materials. The surface-free energies studies by inverse gas chromatography (IGC) were done to understand changes in dispersive and polar component of CB-silica composite compared to conventional filler materials. The distribution of silica in CB/silica composite aggregates was uniform up to adsorption level of 5 wt%. Further, increase in the level of silica adsorption leads to flocculation, causing agglomerated composites. The results obtained encourage adaptation of a simple, low-cost and environmentally friendly process to promote synthesis of CB/silica composite material.