Coarse graining in block copolymer films

Coarse graining

Multiscale simulations For nearly all systems of interest to us, the most transferrable and fundamental description of matter is one that invokes quantum mechanics. At the highest level of accuracy, this amounts to solving Schrodinger’s equation for all of the subatomic particles in a system. Computationally, many approximations need to be made in order to use ab initio methods, and even these ...

Salt Complexation in Block Copolymer Thin Films

Ion complexation within cylinder-forming block copolymer thin films was found to affect the ordering process of the copolymer films during solvent annealing, significantly enhancing the long-range positional order. Small amounts of alkali halide or metal salts were added to PS-b-PEO, on the order of a few ions per chain, where the salt complexed with the PEO block. The orientation of the cylind...

Predictive coarse-graining

Brute-force molecular dynamics simulations are limited by the exuberant number of degrees of freedom and the relatively small time-steps. As a result, only relatively small assemblies of molecules over small time spans are accessible with current and foreseeable computational capabilities. In order to overcome this limitation, coarse-grained models have been proposed which employ a much smaller...

Shape-Based Coarse Graining

Coarse-graining quivers

We describe a block-spin-like transformation on a simplified subset of the space of supersymmetric quiver gauge theories that arise on the worldvolumes of D-brane probes of orbifold geometries, by sequentially Higgsing the gauge symmetry in these theories. This process flows to lower worldvolume energies in the regions of the orbifold moduli space where the closed string blowup modes, and there...