On the relationship between the plateau modulus and the threshold frequency in peptide gels

• Autor(a) principal: Rizzi, L. G.
• Data de Publicação: 2017
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: https://doi.org/10.1063/1.5012753; http://www.locus.ufv.br/handle/123456789/19321
• topic: Plateau modulus; Peptide gels

Relations between static and dynamic viscoelastic responses in gels can be very elucidating and may provide useful tools to study the behavior of bio-materials such as protein hydrogels. An important example comes from the viscoelasticity of semisolid gel-like materials, which is characterized by two regimes: a low-frequency regime, where the storage modulus G (ω) displays a constant value Geq , and a high-frequency power-law stiffening regime, where G (ω) ∼ ωn . Recently, by considering Monte Carlo simulations to study the formation of peptides networks, we found an intriguing and somewhat related power-law relationship between the plateau modulus and the threshold frequency, i.e., Geq ∼ (ω∗ )∆ with ∆ = 2/3. Here we present a simple theoretical approach to describe that relationship and test its validity by using experimental data from a β-lactoglobulin gel. We show that our approach can be used even in the coarsening regime where the fractal model fails. Remarkably, the very same exponent ∆ is found to describe the experimental data.