Details

Autor(en) / Beteiligte

• Beardsley, Thomas M.
• Matsen, Mark W.

Titel

Well-tempered metadynamics applied to field-theoretic simulations of diblock copolymer melts

Ist Teil von

• The Journal of chemical physics, 2022-09, Vol.157 (11), p.114902-114902

Ort / Verlag

Melville: American Institute of Physics

Erscheinungsjahr

2022

Quelle

AIP Journals Complete

Beschreibungen/Notizen

• Well-tempered metadynamics (WTMD) is applied to field-theoretic simulations (FTS) to locate the order–disorder transition (ODT) in incompressible melts of diblock copolymer with an invariant polymerization index of N̄=104. The polymers are modeled as discrete Gaussian chains with N = 90 monomers, and the incompressibility is treated by a partial saddle-point approximation. Our implementation of WTMD proves effective at locating the ODT of the lamellar and cylindrical regions, but it has difficulty with that of the spherical and gyroid regions. In the latter two cases, our choice of order parameter cannot sufficiently distinguish the ordered and disordered states because of the similarity in microstructures. The gyroid phase has the added complication that it competes with a number of other morphologies, and thus, it might be beneficial to extend the WTMD to multiple order parameters. Nevertheless, when the method works, the ODT can be located with impressive accuracy (e.g., ΔχN ∼ 0.01).