Sepiolite functionalized with N-[3-(trimethoxysilyl)propyl]-ethylenediamine triacetic acid trisodium salt. Part I: Preparation and characterization
Natural sepiolite from Andrici (Serbia) was functionalized by covalent grafting of N-[3-(trimethoxysilyl)propyl]ethylenediamine triacetic acid trisodium salt to the Si-OH sepiolite groups. The functionalized material, MSEAS, was characterized by determination of phase composition by X-ray diffraction (XRD) analysis, analysis of morphological characteristics by scanning electron microscopy (SEM), using Fourier transform infrared (FTIR) spectroscopy, differential thermal analyses (DTA), determination of specific surface areas and pore size distribution using B.E.T. method and point of zero charge (pHpzc) determination. The crystal structure of sepiolite does not change significantly upon surface modification. FT-IR and DTA analysis confirmed that the modified sample maintained the basic structure of sepiolite and also the presence of organic groups in functionalized sepiolite sample. The point of zero charge of MSEAS in KNO3 solutions of different concentrations determination by the batch technique from was at pH 7.0 ? 0.1.