Polymer-hybrid silica composite for the azo dye removal from aqueous solution

The article presents a cost-effective approach to the preparation of polymer-hybrid silica composites in the form of spherical beads, a micrometer in size, which are easy to handle and completely water wettable. Taking into account the swelling phenomenon of the Amberlite XAD7 HP resin, tetramethoxysilane and [3-(2-aminoethylamino)propyl]trimethoxysilane were introduced into polymeric particles with different molar fractions, which was followed by their hydrolysis and condensation in the vapor phase; as a result polymer-amino-functionalized silica systems were formed. The article discusses the characteristics of the composites and their performance on the Cochineal Red A (Ponceau 4R) adsorption and desorption. The composite azo dye adsorption capacity is much higher (up to x100) than for the parent polymer and reaches about 46 mg g(-1). The desorption of azo dye from composites can be enhanced by the modification of the pH of the release medium. Thus, the described materials may be regarded as effective adsorbents for the colorant removal.