John Kieffer

Professor

kieffer@umich.edu

2018 HH Dow

T: (734) 763-2595

Bio

Projects

Publications

Facilities

Group

Openings

CV


Multiscale Simulations of Crosslinked Polymers

We are exploring a computational methodology to understand self healing properties of a new class of smart materials developed by Scott White and coworkers at UIUC. This system uses DCPD (Dicyclopentadiene) monomer in conjunction with a Ruthenium based Grubbs catalyst to provide self healing capabilities to a PMMA (poly-methyl-metha-acrylate) polymer matrix.
Self Healing allows a polymer matrix to to regain almost full mechanical strength after the formation of defects and subsequent healing. This property can be used to increase the toughness of polymers and extend service life. The main focus of my research is the computational simulation of stress induced defects/cracks in amorphous cross-linked polymers and their simultaneous healing by catalytic reactions with free monomers forming networks that "heal" the defects and stop further propagation. This research explores mechanical network properties of cross-linking polymers created from elementary monomer liquids.
The research involves 2 major thrust areas 1) a Coarse grained model that allows efficient simulation of reactions using a probabilistic reaction step incorporated within classical MD simulations. 2) conversion of these coarse grained structures to atomistic detail, creating molecular structures that allow better mechanical analysis. It is also envisaged that a seamless transfer between these 2 modes can allow faster and more efficient simulations of large sizes in complicated systems.