resumo
Herein we demonstrate the formation of new stimuli-responsive aqueous biphasic systems (ABS), able to respond simultaneously to temperature and pH, or just to one stimulus, therefore allowing the design of more sustainable separation processes. This dual behavior is achieved with ABS formed by mono- or dicationic protic ionic liquids as phase-forming components, being defined by the ionic liquid cation chemical structure or its basicity. While ABS comprising monocationic ionic liquids only respond to the effect of temperature, systems comprising dicationic ionic liquids are simultaneously affected by both temperature and pH variations. Dicationic ionic liquids are here identified as the key to unlock a double response to stimuli, which is due to the presence of two pKa values afforded by the cation. The reported findings contribute to increase the customizability of double stimuli-responsive ABS based on ionic liquids, whose development was up to date limited to ionic liquids bearing pH-responsive anions, opening the door towards the development of more sustainable separation processes.
palavras-chave
SEPARATION; EXTRACTION; SALTS
categoria
Chemistry
autores
Rufino, AFCS; Capela, EV; Quental, MV; Coutinho, JAP; Vranes, MB; Gadzuric, SB; Silva, FAE; Freire, MG
nossos autores
Ana Filipa Correia Santos Rufino
Estudante de doutoramento
Ana Francisca Osório de Almeida Coelho e Silva
Investigador Júnior
Emanuel V. Capela
Investigador Júnior
Mara Guadalupe Freire Martins
Professor Catedrático
Maria João Quental
Bolseiro de pós-DoutoramentoGrupos
G1 - Materiais Porosos e Nanossistemas
G4 - Materiais Renováveis e Economia Circular
G5 - Materiais Biomiméticos, Biológicos e Vivos
Projectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020), UIDP/50011/2020 (DOI 10.54499/UIDP/50011/2020) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020), financed by national funds through the FCT/MEC (PIDDAC) and EXPL/BII-BTI/0731/2021 (DOI 10.54499/EXPL/BII-BTI/0731/2021), financed by national funds (OE), through FCT/MCTES. The NMR spectrometers are a part of the National NMR Network (PT NMR) and are partially supported by the Infrastructure Project No. 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL, and FCT through PIDDAC). A.F.C.S. Rufino and F.A. e Silva acknowledge FCT for the PhD grant SFRH/BD/138997/2018 and for the researcher contract CEECIND/03076/2018/CP1559/CT0024 (DOI 10.54499/CEECIND/03076/2018/CP1559/CT0024) under the Scientific Employment Stimulus-Individual Call 2018, respectively.