BEGIN:VCALENDAR VERSION:2.0 PRODID:-//jEvents 2.0 for Joomla//EN CALSCALE:GREGORIAN METHOD:PUBLISH BEGIN:VEVENT UID:a1dc121fcb3963e8d915dc4712ea26cd CATEGORIES:Colloquium CREATED:20180117T165134 SUMMARY:Professor Stephen Craig DESCRIPTION:Professor Stephen CraigDuke UniversityTuesday February 6, 2018\n11:00AM, WL 260\n"Stretching the Limits of Chemical Reactivity Through Polymer Mechanoc hemistry”\nThe forces typical of the macroscopic world (for example, those between a baby's fingers) are many orders of magnitude larger than the forc es between the individual atoms of a molecule. It has been known for decade s, for example, that breaking a piece of plastic or shearing a polymer solu tion can lead to homolytic carbon-carbon bond scission along the main chain of an organic polymer and a concomitant reduction in molecular weight. The magnitude of macroscopic forces, in combination with the fact that they ar e directional, creates a spectacular opportunity to direct chemistry that m ight otherwise be effectively impossible. \nThis talk will present studies of reactions under large, directional forces, and their applications in stu dies of fundamental reactivity and new classes of stress-responsive polymer s. Specific outcomes that have been observed include the ability to trap tr ansition states for extended periods of time, molecules that get shorter in response to being pulled, and new classes of self-healing polymers in whic h mechanical activation of chemical reactions leads to improved structure a nd properties under conditions that are typically destructive to both. The emphasis will be on fundamental structure-activity relationships that prov ide insights into the challenges, opportunities, and strategies for next ge neration mechanochemical responses.\n~Coffee/tea will be served prior to le cture~\n X-ALT-DESC;FMTTYPE=text/html:
Tuesday February 6, 2018
"Stretching the Limits of Chemical Reactivity Through Polymer Mechanochemistry”
The forces typical of the macroscopic world (for example, those between a baby's finge rs) are many orders of magnitude larger than the forces between the in dividual atoms of a molecule. It has been known for decades, for example, t hat breaking a piece of plastic or shearing a polymer solution can lead to homolytic carbon-carbon bond scission along the main chain of an organic po lymer and a concomitant reduction in molecular weight. The magnitude of mac roscopic forces, in combination with the fact that they are directiona l, creates a spectacular opportunity to direct chemistry that might otherwi se be effectively impossible.
This talk will present studies of reactions under large, directional forces, and their applications in studi es of fundamental reactivity and new classes of stress-responsive poly mers. Specific outcomes that have been observed include the ability to trap transition states for extended periods of time, molecules that get shorter in response to being pulled, and new classes of self-healing polymers in w hich mechanical activation of chemical reactions leads to improved structur e and properties under conditions that are typically destructive to both.&n bsp; The emphasis will be on fundamental structure-activity relationsh ips that provide insights into the challenges, opportunities, and strategie s for next generation mechanochemical responses.
~Coffee/tea will be served prior to lecture~
DTSTAMP:20240329T103558 DTSTART:20180206T160000 DTEND:20180206T170000 SEQUENCE:0 TRANSP:OPAQUE END:VEVENT END:VCALENDAR