Synthesis and adsorption properties of mesoporous silica modified with nickel and copper

Abstract

Interest in the investigation of adsorption and thermodynamic characteristics of mesoporous silica gels is increasing due to a number of advantages of these materials, such as chemical inertness, developed specific surface area, high chemical and mechanical stability, low toxicity and biospecificity. All these prop- erties make them promising for use in medicine, as sorbents and carriers for catalysts of industrially impor- tant processes.

The aim of this work was to synthesize mesoporous silicas modified with nickel and copper and to study their adsorption properties. The synthesis of mesoporous silicas and their modification with nickel and copper nanoparticles were developed. Moreover, textural characteristics of these materials were obtained. In addition, it was shown that the modification leads to a significant decrease in the specific surface area and pore volume. Likewise, the differential heat of adsorption (Ǭ₁) and changes in standard differential molar entropies of adsorption ∆S₁̅ _,с⁰ of test organic compounds with various types of intermolecular interactions were calculated using inverse gas chromatography. In conclusion, it is shown that modification MCM with nickel and copper nanoparticles increases dispersive interactions of organic compounds on this materials comparing to unmodified MCM. Analysis of compensatory thermodynamic dependencies has established that entropy is the determining thermodynamic parameter for adsorption of organic compounds on MCM, MCM (Ni) and MCM (Cu).