Partículas Minerais Sílico-Metálicas Sintéticas (SSMMP) como cargas em membranas de matriz mista para separação de CO2 de gases pós-combustão

Abstract

Mixed Matrix Membranes (MMMs) are designed to combine the properties of a polymeric matrix with a selective inorganic filler, enhancing mechanical and chemical properties as well as CO2 separation. In this study, polysulfone, a polymer with good CO2 selectivity, was combined with synthetic silico-metallic mineral particles (SSMMPs), produced in a preliminary process to synthetic talc. The chemical structure of SSMMP presents a large number of hydroxyl groups, making it an attractive material for compatibility with polymers and the production of membranes with high selectivity to the CO2/N2 mixture. SSMMPs were also combined with ionic liquids (Im(nBu)Tf2N e Im(nBu)I), know from the literature for the ability of increasing affinity with CO2. MMM were synthesized and characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and atomic force microscopy (AFM). Permeability analyses were measured in triplicate, at a temperature of 25°C and pressure of 0.4MPa. The results demonstrate that after adding bare SSMMP and SSMMP/Im(nBu)Tf2N, the selectivity of the membranes increased at all concentrations used. Using SSMMP/Im(nBu)I, selectivity was reduced, while permeability was increased at all concentrations studied. The best result corresponds to the sample with 2% by mass of SSMMP/Im(nBu)Tf2N, whose selectivity was 71,9, a value 4 times higher than the pure polysulfone sample. The results suggest that the manufactured MMMs have potential for use in CO2 separation applications.