Bio-inspired soft physical gels
Gels are highly porous disordered solids which play a crucial role in several biological systems. Gels can arise in suspensions of colloidal particles or solutions of macromolecules which organize themselves into a disordered structure as a result of very specific attractive interactions. Within this project we plan to explore new pathways to physical gelation in bio-inspired systems in which the bond strength is comparable to the thermal energy (reversible bonds). Specifically we will focus on DNA-based gelling systems, such as DNA stars, G-quartets and DNA-based vitrimers. The fundamental issues which will be addressed in our investigations concern (i) the structural and dynamical features related to the formation and breaking of reversible bonds in these gels; (ii) the dependence of rheological and mechanical properties of the gel on network topology and on strength and lifetime of reversible bonds and (iii) how to design the DNA particles to encode in the resulting material the desired mechanical and thermal properties, along the lines of DNA-nanotechnology. We will conduct a combined experimental and computational investigation,
merging the potential provided by computational approaches by carrying out simulations of full atom or accurate coarse-grained model with neutrons and light scattering experiments.
By fully characterizing the gelation mechanisms in these systems and the rich and complex dynamics of networks stabilized by reversible bonds we hope (i) to provide a deeper understanding of the factors influencing the gel stability and (ii) to elucidate the connections between the designed gel porous structure and the peculiar rheological and mechanical properties of these soft materials. Finally, we hope to provide new insights in the design of novel DNA based nanoconstructs relevant for material science and biomedical applications.