title: Rheology of reconstituted silk fibroin protein gels: the epitome of extreme mechanics.
abstract: In nature, silk fibroin proteins assemble into hierarchical structures with dramatic mechanical properties. With the hope of creating new classes of on demand silk-based biomaterials, Bombyx mori silk is reconstituted back into stable aqueous solutions that can be reassembled into functionalized materials; one strategy for reassembly is electrogelation. Electrogels (e-gels) are particularly versatile and can be produced using electrolysis with small DC electric fields. We characterize the linear and nonlinear rheological behavior of e-gels to provide fundamental insights into these distinct protein-based materials. We observe that e-gels form robust biopolymer networks that exhibit distinctive strain hardening and are recoverable from strains as large as γ=27, i.e. 2700%. We propose a simple microscopic model that is consistent with local restructuring of single proteins within the e-gel network.
authors.affiliation: Georgetown University, Department of Physics, The Institute for Soft Matter Synthesis and Metrology, Washington, DC 20057, USA. Daniel.Blair@georgetown.edu.
authors.forename: A Pasha
authors.initials: AP
authors.lastname: Tabatabai
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Blair
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D012831:Bombyx; D005349:Fibroins / Q000737:chemistry*; D005782:Gels; D055595:Mechanical Phenomena; D012212:Rheology; D033081:Shear Strength; D013314:Stress, Mechanical
chemical_list: D005782:Gels; D005349:Fibroins