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allied
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Journal of Biotechnology and Phytochemistry
Volume 1 Issue 3
Chemistry World 2017
Notes:
Page 22
November 13-15, 2017 Athens, Greece
7
th
World Congress on
Chemistry
Recent Experimental and Theoretical Developments
of Ion Specific "Hofmeister" Phenomena
Andrea Salis
University of Cagliari, Italy
I
on 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 20
th
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. In this presentation
some recent experimental results, based on turbidimetric
and dynamic light scattering measurements of model protein
systems, are shown. These results can be rationalized only by
considering that both approaches are at work.
Biography
Andrea Salis has completed his PhD at the age of 29 years from University
of Cagliari, Italy. He is associated professor of Physical Chemistry and leads
a research team focusing on Biointerfaces and Biocatalysis at the University
of Cagliari. He has published 55 papers in peer review international journals
and serving as an Associate Editor of the journal "Biocatalysis" (De Gruyter
publisher).
asalis@unica.itAndrea Salis, J Biotech and Phyto 2017