Tough and smart: physically cross-linked double polymer networks

Investigating mechanical and structural properties of composite networks of bio-inspired (protein)-polymers, to get a better understanding of important fundamental properties of natural structures and combinations thereof (e.g. collagen, silk and elastin). This understanding should pave the way for new design strategies for synthetic composite networks with superior mechanical properties. For my research I use a broad range of techniques: rheology, cryo-(TEM), cryo-(SEM), AFM and scattering techniques.

Enhanced rigidity and rupture strength of composite hydrogel networks of bio-inspired block copolymers

We study self-assembled composite networks consisting of silk-like protein fibres dispersed in a soft gel matrix formed by collagen-like block copolymers. Rheological analysis shows that the composite networks have significantly higher storage moduli than either of the single networks. This is caused by bundling of the fibrils due to depletion attraction induced by the collagen-like polymers. Moreover, the soft background network significantly modifies the non-linear response of the fibrillar network: the strain-hardening disappears almost completely and the stress and strain at which the gel breaks increase strongly, resulting in tougher hydrogels.

Rombouts, W. H.; Colomb-Delsuc, M.; Werten, M. W. T.; Otto, S.; de Wolf, F. A.; van der Gucht, J. Soft Matter 2013, 9, 6936-6942