Surface Nucleation and the Design of Nucleating Agents by Molecular Simulation

Alexander J. Bourque1, C. Rebecca Locker2, and Gregory C. Rutledge1

1Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge MA, USA
2ExxonMobil Research and Engineering Company, Annandale, NJ, USA

In most cases of practical interest, nucleation of polymer crystallites is believed to occur heterogeneously, through the action of additives or impurities that serve as nucleation agents, significantly reducing the activation barrier to formation of a new phase [1]. The number and activity of these nucleating agents can alter the resulting morphology of the semicrystalline polymer, for example through polymorph selection, the number and size of spherulites or the orientation of individual lamellae; the properties of the polymer can also be controlled as a consequence. The classical theories of polymer crystal growth are similarly predicated on a surface nucleation mechanism, which may proceed through one or more precursor states. We report the results of molecular simulations that examine the phenomenon of 2-dimensional nucleation on both familiar and foreign surfaces. Continue reading Surface Nucleation and the Design of Nucleating Agents by Molecular Simulation