Fig 1. Lattice model for phase separation by polymers with one-to-one interacting motifs.
(a) Each polymer is defined by its sequence of motifs, which come in types “A” (red) and “B” (blue). The class of sequences shown consists of repeated blocks of As and Bs, labeled by their block size ℓ. (b) In lattice simulations, an A and a B motif on the same lattice site form a specific, saturating bond (green) with binding energy ϵ. Monomers of any type on adjacent lattice sites have an attractive nonspecific interaction energy J = 0.05ϵ. A-A and B-B overlaps are forbidden. (c) Polymer number distribution P(N) at the phase boundary of the ℓ = 3 sequence (βϵ = 0.9287, μ = −9.9225ϵ). At fixed μ the system fluctuates between two phases. Inset: Snapshots of the GCE (fixed μ) simulation at ϕdilute and ϕdense.