Extensional flow mixer for polymer nanocomposites

Relaxation of dilute polymer solutions following extensional flow 1

The relaxation of dilute polymer solutions following stretch in uniaxial extensional flow is investigated via Brownian dynamic simulations of a flexible freely-draining bead-rod chain. The bead-rod chain simulations are compared to Brownian dynamic simulations of a FENE dumbbell and numerical calculations of a FENE-PM chain. A universal relaxation curve for the stress decay from steady-state is...

Entangled chain dynamics of polymer knots in extensional flow.

We formulate a coarse-grained molecular-dynamics model of polymer chains in solution that includes hydrodynamic interactions, thermal fluctuations, nonlinear elasticity, and topology-preserving solvent mediated excluded volume interactions. The latter involve a combination of potential forces with explicit geometric detection and tracking of chain entanglements. By solving this model with numer...

The rheology of polymer solution elastic strands in extensional flow

Observation of polymer conformation hysteresis in extensional flow.

Highly extensible Escherichia coli DNA molecules in planar extensional flow were visualized in dilute solution by fluorescence microscopy. For a narrow range of flow strengths, the molecules were found in either a coiled or highly extended conformation, depending on the deformation history of the polymer. This conformation hysteresis persists for many polymer relaxation times and is due to conf...

Graphene-Based Polymer Nanocomposites

Materials science continues to occupy a central place in our lives primarily through the design and creation of new materials, and our quality of life has improved over time thanks to the discovery of new materials. Major milestones in the advancement of our society are intimately associated with materials throughout history: the stone age, bronze age, iron age, steel age (industrial revolution...