Abstract
Bending rigidities of tensionless balanced liquid-liquid interfaces as occurring in microemulsions are predicted using self-consistent field theory for molecularly inhomogeneous systems. Considering geometries with scale invariant curvature energies gives unambiguous bending rigidities for systems with fixed chemical potentials: the minimal surface cubic phase is used to find the Gaussian bending rigidity , and a torus with Willmore energy allows for direct evaluation of the mean bending modulus . Consistent with this, the spherical droplet gives access to . We observe that tends to be negative for strong segregation and positive for weak segregation, a finding which is instrumental for understanding phase transitions from a lamellar to a spongelike microemulsion. Invariably, remains positive and increases with increasing strength of segregation.
- Received 19 July 2017
- Revised 14 October 2017
DOI:https://doi.org/10.1103/PhysRevLett.120.028003
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