This work documents the complete scientific journey of the PVS-R (Variational Principle of the Serpentine) model, from its abstract philosophical origins to its rigorous experimental validation. The research began with the premise of the "Five Laws of the Serpentine," which was formalized into a robust computational framework based on the conserved Cahn-Hilliard equation to predict pattern formation in block copolymers .
This publication serves as the critical second chapter, detailing the model's confrontation with real-world experimental data. The process began with a crisis: a validation audit revealed that the reference scattering data for a key hexagonal system (F21-PAA20) was erroneous . This paper narrates the resolution of this issue through meticulous bibliographic verification and the subsequent correction of the pipeline, leading to the definitive Version 21.1 of the PVS-R code.
The results from the corrected model led to two major conclusions:
1. Successful Validation: For the hexagonal system, the calibration was an immediate success, perfectly matching the experimental scattering peak and reproducing the correct morphology, thus validating the model's physical accuracy .
2. Scientific Discovery: For the lamellar system, the model unexpectedly produced a hexagonal pattern instead of lamellae. This was not a failure, but a crucial scientific insight. We demonstrate that this outcome is a physically plausible result driven by the chosen average composition (ψavg ≈0.3), which places the simulation in a composition regime where hexagonal phases are thermodynamically favored .
This research transforms an apparent "error" into a discovery, underscoring that morphological fidelity in phase-field models requires not only matching scattering data but also respecting the underlying physical constraints, such as composition.