Studio, sintesi e caratterizzazione di nuovi materiali microporosi funzionalizzati per la realizzazione di processi reattivi e separativi in sistemi dinamici

Abstract

This PhD program has focused on the study, preparation and characterization of new functionalized microporous materials for applications in chromatographic and chromatographic-like flow systems, including the possibility of performing chemical transformations in flow-mode (flow chemistry). The work has been multidisciplinary in nature, including elements of analytical and organic chemistry, material science and process modeling. The materials prepared in this work have been used for different purposes. They have been employed, on the one hand, for the preparation of packed-bed microreactors to perform advanced stereoselective chemical transformations by means of organocatalysts anchored to solid supports (polystyrene and silica gel based) and, on the other, as new stationary phases for chromatographic separations. In the case of organocatalyst-functionalized silicon packed-bed microreactors, we followed the idea that mechanisms of chiral induction due to organocatalysts (asymmetric synthesis) might be exploited for chiral discrimination (chiral chromatography) with their immobilized counterparts. The new materials have been thoroughly characterized in terms of chemico-physical, geometric and thermodynamic properties by investigating the mass transfer phenomena in packed beds, by measuring the adsorption isotherms of different substrates on different porous materials and by characterizing some of their fundamental properties such as porosity, superficial area, functionalization degree, etc. In addition, their dynamic behavior in reactive systems has been studied and modeled to understand not only the thermodynamics but also the kinetics of the process and to optimize, based on this information, the experimental conditions as to maximize production yield. Microreactors and the possibility of performing flow-chemistry through them satisfy the fundamental criteria of green chemistry, allowing for the realization of sustainable processes in terms of environmental impact and cost. The activities of my work have produced seven papers on international peer-reviewed journals. These publications are included at the end of my dissertation. One additional paper is in preparation.