Skip to main content

Metal soaps: physicochemical and structural study, their identification in artworks, and coordination polymers with technological applications based on them. Studies with synchrotron radiation

QUICK INFORMATION
Type
Seminar
Start Date
05-05-2017 09:00
End Date
05-05-2017 10:00
Location
Room 126, Central Building
Speaker's name
Francisco Javier MARTINEZ CASADO
Speaker's institute
Lund University, Sweden
Contact name
Claudine Roméro
Host name
Jonathan Wright
Add event to calendar
iCal | vCal

The metal soaps (or alkanoates) belong to the family of organic salts and are formed by an inorganic cation and an anion from a fatty acid. They are very interesting from the physicochemical point of view, since they present polymorphism and polymesomorphism, that is, different crystalline phases and/or mesophases (solid: rotator, or condis phases, or fluid: liquid crystal phases), apart from the different glass states derived from each of them. They might show luminescence, and behave as lubricants in solid state and surfactants in solution. Besides these properties, the relevance of metal soaps has grown hugely in the last two decades, because they were found as degradation products in historical oil paintings, and it is estimated that more than 70% of them are affected in some way by the formation of these salts.

In this work, a deep analysis in some metal soaps series is presented, especially for lead(II), copper(II) and lithium soaps, thoroughly describing their polymorphism (enantio- and monotropic), solving more than 30 crystal structures, and their mesophases (rotator and liquid crystal). Diffraction and scattering techniques (with synchrotron radiation) and others such as DSC, FTIR, NMR, etc. have been used, all of them as a function of temperature. In particular, diffraction and PDF analysis show fingerprints of the salts in the ordered and disordered phases, respectively, and the latter is here proposed to be used as a new tool in the identification of metal soaps in the initial stages of formation of metal soaps in artworks.

Parallel to this study, new coordination polymers based on metal soaps have been also prepared, using different metals, alkanoate anions and bridging or chelating ligands with the aim of obtaining mixed ligand complexes of different dimensionalities (from 0D to 3D) with potential luminescent, magnetic or fungicide applications.

Visitors from off-site please contact Claudine Roméro tel +33 (0)4 76 88 20 27 to arrange for a gate pass.
Requests made by e-mail will be confirmed.
If you do not receive a confirmation e-mail, please contact us by phone.