Publications

8 Results

Search results

Jump to search filters

Measuring Topological Constraint Relaxation in Ring-Linear Polymer Blends

Physical Review Letters

Vigil, Daniel L.; Grest, Gary S.; Ge, Ting; O'Connor, Thomas C.; Rubinstein, Michael

Polymers are an effective test bed for studying topological constraints in condensed matter due to a wide array of synthetically available chain topologies. When linear and ring polymers are blended together, emergent rheological properties are observed as the blend can be more viscous than either of the individual components. This emergent behavior arises since ring-linear blends can form long-lived topological constraints as the linear polymers thread the ring polymers. Here, we demonstrate how the Gauss linking integral can be used to efficiently evaluate the relaxation of topological constraints in ring-linear polymer blends. For majority-linear blends, the relaxation rate of topological constraints depends primarily on reptation of the linear polymers, resulting in the diffusive time τd,R for rings of length NR blended with linear chains of length Nl to scale as τd,R∼NR2NL3.4.

More Details

Accurate Calculation of Solvation Properties of Lithium Ions in Nonaqueous Solutions

Journal of Physical Chemistry. B

Vigil, Daniel L.; Frischknecht, Amalie L.; Stevens, Mark J.

Here, we perform all-atom molecular dynamics simulations of lithium triflate in 1,2-dimethoxyethane using six different literature force fields. This system is representative of many experimental studies of lithium salts in solvents and polymers. We show that multiple historically common force fields for lithium ions give qualitatively incorrect results when compared with those from experiments and quantum chemistry calculations. We illustrate the importance of correctly selecting force field parameters and give recommendations on the force field choice for lithium electrolyte applications.

More Details
8 Results
8 Results