Search papers, labs, and topics across Lattice.
We introduce quadratic-connectivity entropic (QCE) and adaptive QCE (AQCE) density functionals to improve the quantitative accuracy of phase-field models for block copolymer phase behavior, addressing limitations in predicting domain structure and phase diagrams. QCE incorporates quadratic nonlocal connectivity and a nonlinear relative-entropy term, while AQCE adds bounded interfacial stiffness, leading to significantly reduced errors in lamellar profile and period predictions compared to existing methods. AQCE successfully reproduces the complex topology of SCFT phase diagrams for AB diblocks and generalizes to ABA architectures, demonstrating its broad applicability.
Block copolymer phase-field models now predict domain structure and phase behavior with over fivefold reduction in errors, matching SCFT accuracy for complex topologies.
Phase-field models offer an efficient alternative to self-consistent field theory (SCFT), but quantitative predictions of block-copolymer phase behavior remain challenging. We develop a quadratic-connectivity entropic (QCE) density functional and its adaptive extension (AQCE). QCE combines quadratic nonlocal connectivity with a nonlinear binary relative-entropy term, while AQCE adds bounded interfacial stiffness that preserves the homogeneous response. In lamellar benchmarks, QCE gives the lowest mean profile error among the tested models and AQCE the lowest mean period error. Compared with the optimized phase-field (OPF) model fitted to SCFT force and stress data, AQCE reduces strong-segregation period and profile errors by more than fivefold and sixfold, respectively. AQCE further reproduces the topology of the SCFT phase diagram for AB diblocks, a more demanding test of free-energy rankings among competing morphologies. Because architecture enters through ideal-chain correlations, the same nonlinear construction extends to other A/B architectures. We demonstrate this transfer for symmetric linear ABA lamellae, accurately predicting their profiles, periods, and ordering threshold.
