top

We investigate the effects of entanglement on polymer crystallization using atomistic molecular dynamics simulations of linear and cyclic polyethylene (PE). While linear chains entangle with their neighbors, unlinked rings adopt compact conformations and do not exhibit conventional entanglements. By isotropically compressing linear chains, we also systematically reduce the entanglement density in PE melts without enhancing any local order that may promote crystallization. After demonstrating tha

We apply molecular dynamics simulations to quantify the effects of free surfaces and interfacial regions on crystallization in freestanding and bilayer polymer films. We show that enhanced crystal nucleation in polymer thin films is quantitatively correlated to faster local segmental dynamics induced by free surfaces. When a second layer is deposited onto a semicrystalline film, we observe rapid primary nucleation near the free surface, secondary nucleation near the semicrystalline interface, an

We investigate the effects of entanglement on polymer crystallization using atomistic molecular dynamics simulations of linear and cyclic polyethylene (PE). While linear chains entangle with their neighbors, unlinked rings adopt compact conformations and do not exhibit conventional entanglements. By isotropically compressing linear chains, we also systematically reduce the entanglement density in PE melts without enhancing any local order that may promote crystallization. After demonstrating tha

We investigate the effects of entanglement on polymer crystallization using atomistic molecular dynamics simulations of linear and cyclic polyethylene (PE). While linear chains entangle with their neighbors, unlinked rings adopt compact conformations and do not exhibit conventional entanglements. By isotropically compressing linear chains, we also systematically reduce the entanglement density in PE melts without enhancing any local order that may promote crystallization. After demonstrating tha

We investigate the effects of entanglement on polymer crystallization using atomistic molecular dynamics simulations of linear and cyclic polyethylene (PE). While linear chains entangle with their neighbors, unlinked rings adopt compact conformations and do not exhibit conventional entanglements. By isotropically compressing linear chains, we also systematically reduce the entanglement density in PE melts without enhancing any local order that may promote crystallization. After demonstrating tha

In this paper, we introduce a geometric structure called top, which is a trivialized bundle of plane pencils over a Riemannian 3-manifold, defined as the set of kernels of a circle of 1-forms (e.g. of contact and integrable forms) with particular properties with respect to the metric. We classify the manifolds which admit tops and we describe the associated metrics.