CAPSChain Assembly and Packing Suite

Run · module 18

DPD

Mesoscale dissipative particle dynamics: describe species as bead strings, set χ between bead types, and watch blends and block copolymers segregate into domains.

Open it Modules›Mesoscale (DPD)…

You start with
Species written as bead strings (for example A5B5) and χ parameters between bead types.
You get
The segregation ψ, domain spacing, structure factor and the final domains.
Mesoscale · dissipative particle dynamics: species, χ between bead types and the segregation over the run.

Step by step

  1. Add the species

    Under Species, Add each one with its name, its beads (for example A5B5 for a symmetric diblock) and the number of molecules.

  2. Set χ between bead types

    Under χ between bead types, Add each pair with its Flory–Huggins χ.

  3. Set the run

    Steps (dt 0.04) 20 000, density ρ 3, r_c 6.46 Å. Start from a random mix, or seed lamellae, cylinders or spheres. Chain stiffness k_θ is optional.

  4. Press Run DPD

    Follow Segregation over the run and the structure factor of the first bead type; the result gives ψ, the domain spacing and the domains at the end.

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