title: Anisotropic swelling of thin gel sheets.
abstract: We describe the anisotropic swelling within the Flory-Rehner thermodynamic model through an extension of the elastic component of the free-energy, which takes into account the oriented hampering of the swelling-induced deformations due to the presence of stiffer fibers. We also characterize the homogeneous free-swelling solutions of the corresponding anisotropic stress-diffusion problem, and discuss an asymptotic approximation of the key equations, which allows us to explicitly derive the anisotropic solution of the problem. We propose a proof-of-concept of our model, realizing thin bilayered gel sheets with layers having different anisotropic structures. In particular, for seedpod-like sheets, we observe and quantitatively measure the helicoid versus ribbon transition determined by the aspect ratio of the composite sheet.
authors.affiliation: Sapienza Università di Roma, via Eudossiana 18, Roma, Italy. paola.nardinocchi@uniroma1.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Nardinocchi
authors.forename: Matteo
authors.initials: M
authors.lastname: Pezzulla
authors.forename: Luciano
authors.initials: L
authors.lastname: Teresi
mesh_terms: D016880:Anisotropy; D004058:Diffusion; D005782:Gels / Q000737:chemistry*; D008956:Models, Chemical; D012996:Solutions / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D005782:Gels; D012996:Solutions