Professor Andrea Salis, Laboratory of Biocatalysis and Biointerfaces, University of Cagliari, Italy
The Hofmeister Series: A Chemical History 130 Years Long
‘Ion specific phenomena’ are perhaps the longest unsolved puzzle of chemistry. About 130 years ago Franz Hofmeister observed that egg white proteins solubility was salt specific. He ordered the salts in an efficiency sequence universally known as the ‘Hofmeister series’. During the 20th century a myriad of experiments showed that salt or, better, ion specificity is ubiquitous in chemistry (solution chemistry, colloidal science, electrochemistry) and biology. Unfortunately, our available theories of electrolytes (Debye-Hückel, 1923) and colloid stability (DLVO, 1941-1948) fail to explain and predict ion specificity. That is, LiI, NaCl, and CsF should behave in the same way because they are all 1:1 electrolytes. But they do not. In 1997 Collins proposed a phenomenological set of rules known as the law of matching water affinities (LMWA). LMWA explains and predicts at a qualitative level the order of ion-ion and ion-surface site interactions. The same year Ninham proposed the inclusion of additional quantum mechanical dispersion forces acting on ions which are missing from conventional theories. Ion dispersion forces and LMWA approaches appeared to conflict. Here some recent experimental results are shown. They seem to indicate the way for the reconciliation of the two apparently opposing approaches.
ABOUT THE PRESENTER
Professor Salis is an associate Professor of Physical Chemistry in the Chemical and Geological Department in the University of Cagliari. He obtained his Masters Degree in Chemistry in 1997 in the University of Cagliari. From January 1998 to March 1999, he was Lieutenant in the Engineering Corp of the Italian Army, in the Technical Center for Chemistry, Physics and Biology in Rome. After that he completed a PhD (first class honours) in the same University during which time he was a visiting PhD student in Lund University (Sweden). After his PhD he obtained a postdoc and a research fellowship from the Australian National University in Canberra (Australia) for one year. In 2015 he was appointed Professor of Physical Chemistry and in the same year he received the Italian national qualification to teaching in a University. His scientific interests range from biocatalysis, enzyme immobilization, nanotechnology, biophysics, biodiesel production, Hofmeister effects, enzymes biosensors, electrochemistry, nanomedicine. He collaborates with research groups in Australia, Ireland, Sweden, Germany and Belgium. He is associate Editor of the journal Biocatalysis (Gruyter). He has supervised dozens of bachelor, masters and PhD students. He has published more than 50 peer reviewed papers with more than 1600 citations earning an H-index of 23.
DATE: Monday, 22 February 2015
VENUE: MSG-025 MSSI Building Extension
REFRESHMENTS WILL BE PROVIDED AT 14h45
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