Search

Your search keyword '"da Costa Lopes, André M."' showing total 31 results
Start Over Author "da Costa Lopes, André M."
31 results on '"da Costa Lopes, André M."'

8. Sustainable Tailoring of Lignin Nanoparticles Assisted by Green Solvents.

Author

Almeida, Fábio, Margarida, Ana, Seixas, Nalin, Pinto, Ricardo J. B., Silvestre, Armando J. D., and Da Costa Lopes, André M.

Subjects
LIGNIN structure, LIGNINS, NANOPARTICLES, SOLVENTS, ETHYLENE glycol, ZETA potential, MACROMOLECULES, CENTRIFUGATION
Abstract

This work aimed at studying the self‐assembly of lignin macromolecules towards lignin nanoparticles (LNPs) with green solvents and shedding light on a tailor‐made production of LNPs through a meticulous study of different variables. The methodology (antisolvent to lignin solution – method A; or lignin solution to antisolvent – method B), the lignin solvent, the flow rate of solvent/antisolvent addition, the lignin solution loading and the washing step (centrifugation vs dialysis) were examined. Remarkably, method B enabled achieving desired LNPs (127.4–264.9 nm), while method A induced the formation of lignin microparticles (582.8–7820 nm). Among lignin solvents, ethanol allowed the preparation of LNPs with the lowest hydrodynamic diameter (method B=127.4 nm), while the largest particles (method A=7820 nm) were obtained with ethylene glycol. These latest particles were characterized as heterogeneous, irregular, and highly aggregated when compared for instance with γ‐valerolactone counterparts, which showed the most homogeneous (PDI=0.057–0.077) and spherical particles. Moreover, decreasing lignin solution loading enabled the reduction on LNP size and Zeta potential. Dialysed samples allowed the formation of LNPs with lower hydrodynamic size, reduced aggregation, and higher homogeneity. Furthermore, dialysis provided high stability to LNPs, avoiding particle coalescent phenomenon. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

10. ABS Constituted by Ionic Liquids and Carbohydrates

Author

da Costa Lopes, André M., Bogel-Łukasik, Rafał, He, Liang-Nian, Series editor, Rogers, Robin D., Series editor, Su, Dangsheng, Series editor, Tundo, Pietro, Series editor, Zhang, Z. Conrad, Series editor, and Freire, Mara G., editor

Published
2016
Full Text
View/download PDF

24. Unveiling Modifications of Biomass Polysaccharides during Thermal Treatment in Cholinium Chloride : Lactic Acid Deep Eutectic Solvent.

Author

Morais, Eduarda S., Da Costa Lopes, André M., Freire, Mara G., Freire, Carmen S. R., and Silvestre, Armando J. D.

Subjects
CHOLINE chloride, HEMICELLULOSE, LACTIC acid, POLYSACCHARIDES, ACYL chlorides, ANALYTICAL chemistry, BIOMASS
Abstract

A deep analysis upon the chemical modifications of the cellulose and hemicelluloses fractions that take place during biomass delignification with deep eutectic solvents (DES) is lacking in literature, being this a critical issue given the continued research on DES for this purpose. This work intends to fill this gap by disclosing a comprehensive study on the chemical modifications of cellulose (microcrystalline cellulose and bleached kraft pulp) and hemicelluloses (xylans) during thermal treatment (130 °C) with cholinium chloride/lactic acid ([Ch]Cl/LA) at molar ratio 1 : 10, one of the best reported DES for biomass delignification. The obtained data revealed that [Ch]Cl/LA (1 : 10) has a negative impact on the polysaccharides fractions at prolonged treatments (>4 h), resulting on substantial modifications including the esterification of cellulose with lactic acid, shortening of fibers length, fibers agglomeration and side reactions of the hemicelluloses fraction (e. g. humin formation, lactic acid grafting). Wood delignification trials with [Ch]Cl/LA (1 : 10) at the same conditions also corroborate these findings. Moreover, the DES suffers degradation, including the formation of lactic acid derivatives and its polymerization. Therefore, short time delignification treatments are strongly recommended when using the [Ch]Cl/LA DES, so that a sustainable fractionation of biomass into high quality cellulose fibers, isolated lignin, and xylose/furfural co‐production along with solvent recyclability could be achieved. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

27. Pre-treatment and extraction techniques for recovery of added value compounds from wastes throughout the agri-food chain

Author

Arshadi, Mehrdad, primary, Attard, Thomas M., additional, Lukasik, Rafal M., additional, Brncic, Mladen, additional, da Costa Lopes, André M., additional, Finell, Michael, additional, Geladi, Paul, additional, Gerschenson, Lia Noemi, additional, Gogus, Fahrettin, additional, Herrero, Miguel, additional, Hunt, Andrew J., additional, Ibáñez, Elena, additional, Kamm, Birgit, additional, Mateos-Aparicio, Inmaculada, additional, Matias, Ana, additional, Mavroudis, Nikolaos E., additional, Montoneri, Enzo, additional, Morais, Ana Rita C., additional, Nilsson, Calle, additional, Papaioannou, Emmanouil H., additional, Richel, Aurore, additional, Rupérez, Pilar, additional, Škrbić, Biljana, additional, Bodroža Solarov, Marija, additional, Švarc-Gajić, Jaroslava, additional, Waldron, Keith W., additional, and Yuste-Córdoba, F. J., additional

Published
2016
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results