Selective dissolution of value-added compounds from cork using ionic liquids
Field: Biotechnology/Green Chemistry
Laboratory: Applied and Environmental Mycology
Supervisor: Cristina Silva Pereira (spereira@itqb.unl.pt)
(Scientific training will involve Rui Ferreira rferreira@itqb.unl.pt and Helga Garcia hgarcia@itqb.unl.pt)
Ionic liquids are, by definition, salts that are liquid at, or near, room temperature,
completely composed of ions. They can be “designed” to be chemically and thermally
stable, recyclable, and to have tunable physical, chemical and even biological properties.1
Ionic liquids are commonly labeled as “green solvents” due to their negligible vapour
pressure, however many of them present high toxicity and low biodegradability. In
addition, their negligible vapour pressure combined with their outstanding solvent ability
opens doors for numerous industrial and biotechnological applications, 2 e. g. cellulose
dissolution3.
In fact, biomass feed-stocks constitute a source of numerous value-added compounds, such
as biopolymers, biofuels, and building-block chemicals. In the national context, we are
especially interested on the cork industrial wastes arising from the stoppers manufacturing.4
Cork, the outer bark of Quercus suber L., is a remarkable plant composite composed of
very interesting chemical structures (suberin ~50 %, lignin ~20 %, polysaccharides ~20 %
and extractives ~10 %).5,6 Recently, dissolution studies of recalcitrant plant composites by
ionic liquids demonstrated, that some cholinium alkanoates are remarkable solvents. They
can selectively dissolve in situ suberin, some of them efficiently disrupting the recalcitrant
cork composite.7 Moreover, this cholinium family have also shown to be both benign to
eukaryotic organisms and biodegradable,8 reinforcing its potential as an environmental
benign process.
Our vision is to explore ionic liquids with the ability to selectively extract value-added
compounds, namely extractives and/or bio-polyesters. Project execution will involve the
development of new ionic liquids as well as the deep understanding of the dissolution
method. Many different techniques will be used e. g. UPLC, FTIR, NMR, TGA and DSC.
References:
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8.
A. Stark and K. R. Seddon, Kirk-Othmer Encyclopedia of Chemical Technology, Hoboken, New Jersey, USA, 2007.
N. V. Plechkova and K. R. Seddon, Chem. Soc. Rev., 2008, 37, 123-150.
D. A. Fort, R. C. Remsing, R. P. Swatloski, P. Moyna, G. Moyna and R. D. Rogers, Green Chem., 2007, 9, 63-69.
L. Gil, Cortiça: Produção, Tecnologia e Aplicação, Lisboa, 1998.
M. H. Lopes, C. P. Neto, A. S. Barros, D. Rutledge, I. Delgadillo and A. M. Gil, Biopolymers, 2000, 57, 344-351.
M. H. Lopes, A. S. Barros, C. P. Neto, D. Rutledge, I. Delgadillo and A. M. Gil, Biopolymers, 2001, 62, 268-277.
H. Garcia, R. Ferreira, M. Petkovic, J. L. Ferguson, M. C. Leitão, H. Q. N. Gunaratne, K. R. Seddon, L. P. N. Rebelo and C. S.
Pereira, Green Chem., 2010, 12, 367 - 369.
M. Petkovic, J. L. Ferguson, H. Q. N. Gunaratne, R. Ferreira, M. C. Leitão, K. R. Seddon, L. P. N. Rebelo and C. Silva Pereira,
Green Chem., 2010, 12, 643-649