15 documents found, page 1 of 2
Poly(ionic liquid)-based aerogels for continuous-flow CO2 upcycling
Barrulas, Raquel V.; Tinajero, Cristopher; Ferreira, Diogo P. N.; Illanes-Bordomás, Carlos; Sans, Victor; Ribeiro Carrott, ManuelaThe atmospheric concentration of CO2 is rising at an alarming pace, creating a pressing need for new and sustainable materials capable of capture and conversion. Poly(ionic liquid)s (PILs) are particularly effective catalysts for processes at or near atmospheric pressure. PILs industrial application poses challenges due to the low porosity of PIL, the limited batch conversion capacity, and the difficulties in r...
The AEROPILs Generation: Novel Poly(Ionic Liquid)-Based Aerogels for CO2 Capture
Barrulas, Raquel; López-Iglesias, Clara; Zanatta, Marcileia; Casimiro, Teresa; Mármol, Gonzalo; Ribeiro Carrott, Manuela; García-González, Carlos A.CO2 levels in the atmosphere are increasing exponentially. The current climate change effects motivate an urgent need for new and sustainable materials to capture CO2. Porous materials are particularly interesting for processes that take place near atmospheric pressure. However, materials design should not only consider the morphology, but also the chemical identity of the CO2 sorbent to enhance the affinity to...
Tuning the 1H NMR paramagnetic relaxation enhancement and local order of [Aliqu...
Cordeiro, Rui; Beira, Maria; Cruz, Carlos; Figueirinhas, João; Corvo, Marta C.; Almeida, Pedro L.; Rosatella, Andreia; Mateus Afonso, Carlos AlbertoUnderstanding the behavior of a chemical compound at a molecular level is fundamental, not only to explain its macroscopic properties, but also to enable the control and optimization of these properties. The present work aims to characterize a set of systems based on the ionic liquids [Aliquat][Cl] and [Aliquat][FeCl4] and on mixtures of these with different concentrations of DMSO by means of H-1 NMR relaxometr...
Designing silica xerogels containing RTIL for CO2 capture and CO2/CH4 separatio...
Dos Santos, Leonardo; Bernard, Franciele L.; Polesso, Barbara B.; Pinto, Ingrid S.; Frankenberg, Claudio C.; Corvo, Marta C.; Almeida, Pedro L.CO2 separation from natural gas is considered to be a crucial strategy to mitigate global warming problems, meet product specification, pipeline specs and other application specific requirements. Silica xerogels (SX) are considered to be potential materials for CO2 capture due to their high specific surface area. Thus, a series of silica xerogels functionalized with imidazolium, phosphonium, ammonium and pyridi...
Enhancement of CO2/N2 selectivity and CO2 uptake by tuning concentration and ch...
Duczinski, Rafael; Polesso, Barbara B.; Bernard, Franciele L.; Ferrari, Henrique Z.; Almeida, Pedro L.; Corvo, Marta C.; Cabrita, Eurico JImidazolium-based ionic liquids (ILs) with different cation alkyl chain ([i-C5mim] or [C4mim]) and inorganic anions ([Cl−], [Tf2N−], [PF6−] and [DCA−]) were synthesized and immobilized in commercial mesoporous silica. The synthesized supported ILs (SILs) were characterized using NMR, FTIR, TGA, BET, SEM and TEM. CO2 sorption capacity, reusability and CO2/N2 selectivity were assessed by the pressure-decay techniq...
On the influence of imidazolium ionic liquids on cellulose derived polymers
Paiva, Tiago; Echeverria Zabala, Coro; Godinho, Maria Helena; Almeida, Pedro L.; Corvo, Marta C.The demand for better cellulose solvents has driven the search for new and improved materials to enable the processing of this polysaccharide. Ionic liquids have been debated for a long time as interesting alternatives, but the molecular details on the solubilization mechanism have been a matter of controversy. Herein, for the first time, the structure and dynamics of hydroxypropylcellulose (HPC) liquid crystal...
Influence of chain length of prepolymers in permanent memory effect of PDLC ass...
Mouquinho, Ana; Corvo, Marta C.; Almeida, Pedro L.; Feio, Gabriel; Sotomayor, JoaoThe relationship between linear chain (ethylene oxide units) length of polymerisable monomers with morphology, electro-optical properties and C-13 nuclear magnetic resonance (NMR) spectroscopy of the corresponding polymer-dispersed liquid crystal (PDLC) films was investigated. The preferred liquid crystal molecule alignment and permanent memory effect of PDLC were greatly influenced by the length of the molecul...
Molecular order and dynamics of water in hybrid cellulose acetate-silica asymme...
Beira, Maria Jardim; Condesso, Miguel; Pereira Da Silva, Miguel; Cosme, Pedro; Almeida, Pedro L.; Corvo, Marta C.; Sebastião, Pedro J.In this work 2H NMR spectroscopy and 1H NMR relaxometry and diffusometry were used to characterise water order and dynamics in cellulose acetate/silica asymmetric membranes. Two hydrated membranes were characterised allowing the identification of extra ordering of the water molecules and the presence in each membrane of up to two spectral components with different degrees of order and different T1 values. The m...
Waterborne polyurethane/Fe3O4-synthetic talc composites: synthesis, characteriz...
Dos Santos, Leonardo; Ligabue, Rosane; Dumas, Angela; Le Roux, Christophe; Micoud, Pierre; Meunier, Jean-François; Martin, François; Corvo, Marta C.Nano-Fe3O4-synthetic talc gel was used as filler in the synthesis of waterborne polyurethane/Fe3O4-synthetic talc nanocomposites. This filler presents numerous edges (Si-O and Mg-O) and OH groups easily forming hydrogen bonds and polar interaction with water conferring hydrophilic character, consequently improving filler dispersion within a water-based matrix. Yet, the use of waterborne polyurethane (WPU) as ma...
Efficient heterogeneous polyoxometalate-hybrid catalysts for the oxidative desu...
Mirante, Fátima; Dias, Luís; Silva, Mariana; Ribeiro, Susana; Corvo, Marta C.; De Castro, Baltazar; Granadeiro, Carlos; Balula, SaleteThe heterogenization of the highly active monovacant polyoxotungstate ([PW11O39](7-), abbreviated as PW11) was achieved by preparing the corresponding long chain quaternary ammonium salt (ODA(7)PW(11), ODA = CH3(CH2)(17)(CH3)(3)N). The complete cation exchange confers total heterogeneity to the monovacant catalyst while keeping its oxidative catalytic activity. In fact, the heterogeneous catalyst allowed for th...