The functionalization of PES/SAPO-34 mixed matrix membrane with [emim][Tf2N] ionic liquid to improve CO2/N2 separation properties

• Autor(a) principal: Cardoso, Jonathan
• Data de Publicação: 2023
• Outros Autores: Lin, Zhi, Brito, Paulo, Gando-Ferreira, Licínio M.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10198/28931
• topic: Gas separation; Mixed matrix membranes; Ionic liquid; Polyethersulfone; SAPO-34

The use of ionic liquid [emim][Tf2N] as an additive in polyethersulphone (PES) and nanosized silico-aluminophosphate-34 (SAPO-34) mixed matrix membrane was studied through the incorporation of different amounts of [emim][Tf2N] in the membrane composition, as presented in this work, varying from 10 to 40 wt%. Through gas permeation tests using CO2 andN2, the membrane composition containing 20 wt% [emim][Tf2N] led to the highest increase in CO2 permeability and CO2/N2 selectivity. The use of low concentrations of additive (10–20 wt%) promoted a state called antiplasticization; in this state, the permeability was even more regulated by the kinetic diameter of the species which, in this work, permitted achieving a higher CO2/N2 selectivity while increasing the CO2 permeability until an optimal condition. [emim][Tf2N] also promoted a better dispersion of SAPO-34 particles and an increase in the flexibility of the polymeric matrix when compared to a film with the same composition without [emim][Tf2N]. Moreover, the characterizations corroborated that the inclusion of [emim][Tf2N] increased the zeolite dispersion and improved the polymer/zeolite compatibility and membrane flexibility, characterized by a decrease in glass transition temperature, which helped in the fabrication process while presenting a similar thermal resistance and hydrophilicity as neat PES membrane, without affecting the membrane structure, as indicated by FTIR and a contact angle analysis.