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Mechanically induced Helfrich-Hurault effect in lamellar systems
Gaetano Napoli1, Andrea Nobili
1Dipartimento di Ingegneria dell'Innovazione, Università del Salento, via per Monteroni, Edificio Corpo O, 73100 Lecce, Italy.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|November 13, 2009
Summary
Soft material layers buckle under strain, forming undulations. A new continuum model provides a critical threshold and amplitude expression, differing from existing theories for thin materials.
Area of Science:
- Soft matter physics
- Materials science
- Continuum mechanics
Background:
- Layered phases are common in self-organizing soft materials.
- These materials exhibit buckling instability under dilatative strain, leading to periodic undulations.
Purpose of the Study:
- To develop a continuum model for layered soft materials under finite deformation.
- To derive expressions for the critical buckling threshold and undulation amplitude.
- To compare model predictions with the Helfrich-Hurault theory.
Main Methods:
- Utilizing a continuum model within a finite deformation framework.
- Analyzing the behavior of layered phases subjected to dilatative strain.
Main Results:
- A novel expression for the critical buckling threshold was derived.
- This expression differs from the Helfrich-Hurault theory but converges in the thick specimen limit.
- An analogous disagreement was found for the undulation amplitude expression.
Conclusions:
- The developed model offers new insights into the buckling instability of layered soft materials.
- Results are particularly relevant for materials with coherence length comparable to cell thickness.
- The findings challenge and refine existing theories for soft material behavior under strain.
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