BEGIN:VCALENDAR
METHOD:PUBLISH
PRODID:www-camp-eam-fau-eu//Events//EN
VERSION:2.0
BEGIN:VEVENT
SUMMARY:Guest Lecture: Kostas Steiakakis - Walking on the Potential En
 ergy Landscape: Mapping Degradation Pathways in Polymeric Solids
UID:040000008200E00074C5B7101A82E00800000000A5D32462E6CCDC010000000000
 000000100000001A57E4CA209B0244A03B053526FBB176
DESCRIPTION:The kinetics of chemical ageing in most commercial plastic
 s remains long-debated\, since the nature of dense polymeric solids in
 hibits the in-situ experimental investigation of complex degradation p
 aths\, while traditional computational techniques fail to reach the ti
 mescales associated with slow-progressing degradative reactions. We in
 troduce a new mechanistic framework in which the infrequent reaction e
 vents that govern the long-time-scale evolution of the chemistry of an
 y macromolecular solid are described as successive elementary transiti
 ons of its atomistic configuration between local minima on its energy 
 landscape. For each elementary reaction event\, the corresponding tran
 sition state is identified\, allowing the estimation of the free-energ
 y barrier and\, thereby\, of the transition rate constant by means of 
 transition state theory. The result is a network of states populated b
 y the stationary states that are visited by the system along the chemi
 cal paths\, thus describing its chemical space. We demonstrate the app
 licability of the presented approach for the study of complex reaction
  schemes by applying it to the study of the autoxidation of glassy pol
 ystyrene. The introduction of an appropriately trained reactive forcef
 ield\, tailored for the accurate description of the reactions propagat
 ing polymers oxidation\, i.e.\, peroxy radical and hydroperoxide forma
 tion\, in the glassy state\, allows the large-scale sampling of potent
 ial reaction paths in-situ. From the created network of states\, the e
 nergetics and rates of the elementary reactions in the glassy state ca
 n be extracted\, motivating a discussion over the impact of stereochem
 ical properties of the matrix on the oxidation thermochemistry and kin
 etics.
DTSTART:20260505T120000Z
DTEND:20260505T130000Z
DTSTAMP:20260711T183750Z
END:VEVENT
END:VCALENDAR