There’s more to cork than sealing wine
Dissolving cork
Oeiras, 15.01.10
When mentioning cork, most of us think of a bottle of wine. But beyond cork stoppers lies a complex material with exceptional properties made of molecules valuable per se. Discouragingly, most compounds in cork are not extractable by conventional strategies and these include suberin, its major component. Resorting to a class of biocompatible and biodegradable ionic liquids, ITQB researchers (from the Applied and Environmental Mycology Lab and the Molecular Thermodynamics Lab) and co-workers have been able to devise a process to specifically dissolve suberin. The work is published in Green Chemistry.
The new technique relies on the versatility of designing ionic liquids, basically liquid salts, to meet specific requirements – in this case dissolving cork biopolymers. The candidate list was shortened by two criteria: previous experience in dissolving lignocellulosic materials and toxicological data of ionic liquids anions and cations. Three cations and six anions were tested in 9 different combinations.
Ionic liquids are remarkable solvents with negligible vapour pressure that clearly surpass traditional organic solvents in environmental friendliness. Moreover, in this study cork was dissolved at a temperature that avoids degradation. To top it all, the tailored ionic liquids are derivatives of commonplace things like vinegar and Vitamin B. Hence, anticipating a wide range of applications, a truly green process for extracting either suberin itself (or molecules trapped inside it) has been uncovered.
Original Article
Green Chem., 2010, DOI: 10.1039/b922553f
Dissolution of cork biopolymers in biocompatible ionic liquids
Helga Garcia, Rui Ferreira, Marija Petkovic, Jamie L. Ferguson, Maria C. Leitão, H. Q. Nimal Gunaratne, Kenneth R. Seddon, Luís P. N. Rebelo and Cristina Silva Pereira
