Adsorption Properties of Silica Surface Layers Modified with Acetylacetonates of Transition Metals

The purpose of the research was to synthesize sorbents based on Chromaton N--AW with mesoporous silica layers modified with cobalt, nickel and copper acetylacetonates. After the thermal analysis we determined the operating temperature range of the synthesized sorbents: it is possible to use them up to 290 °C without destroying the complex. The adsorption properties of the surface of Chromaton N--AW + SiO₂ and chelate-containing materials based on it were studied by gas chromatography using test compounds of various chemical structures. As test compounds we used n-alkanes (C₆--C₁₀) and the adsorbates whose molecules have different electron-withdrawing and electron donating properties. From the experimental data we calculated the differential molar heat of adsorption change of the standard differential molar entropy and for polar adsorbates we calculated contributions into the total adsorption energy. By the nitrogen porosimetry method we found that when the complexes are applied to the surface of the initial adsorbent, the specific surface area decreases

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