Role of particle shape and bond-bending flexibility in nucleation pathways

Determine whether the difference between direct nucleation in triblock ellipses and two-step nucleation in spherical triblock particles is primarily caused by the higher bond-bending flexibility of triangle bonding motifs in elongated particles, including how the resulting changes in bonding entropy, lattice stiffness, defect-loop accommodation, and relative equilibrium-phase stabilities influence the nucleation pathway.

Background

The paper finds that triblock ellipses nucleate directly from the vapor into kagome-like structures, whereas spherical triblock particles have previously been reported to nucleate through an intermediate chain-dominated state. The authors attribute this difference speculatively to the greater bond-bending flexibility of triangle motifs in the elongated particles.

The proposed mechanism is that enhanced flexibility increases the bonding volume and entropy, alters the stiffness of the kagome lattice, changes its ability to accommodate five- and seven-membered defect loops, and thereby modifies the relative stability of equilibrium phases and the pathway followed during nucleation. Establishing this mechanism would require a systematic comparison of particle shape, bonding flexibility, entropy, phase stability, and nucleation kinetics.

References

As the patchy ellipses studied in this contribution can be viewed as an elongated version of the triblock patchy spheres, this leads us directly to speculate about the role that particle shape plays in these nucleation scenarios: we hypothesize that the differences in phenomena originates largely from a higher bond-bending flexibility of the triangle bonding motifs compared to that of the patchy triblock spheres.

— Networks of triblock ellipses: from kagome order to disordered porous networks  (2610.08522 - Wagner et al., 6 Oct 2026) in Conclusion and Discussion, Section 4