Abstract

In the last decade DNA has become routinely used to drive the self-assembly of Brownian objects, including colloids an nanoparticles. In these systems, the particles are coated with DNA tethers, that bind to each other via selective and reversible Watson-Crick be pairing. Recently the same approach has been applied to more compliant units, including emulsion droplets and lipid vesicles. In these systems, the deformability of the substrates couples with the already complex statistical mechanics of multivalent interactions. Moreover, due to the liquid nature of the interfaces, DNA tethers can diffuse and rearrange, giving rise to nontrivial entropic contributions to the free energy. We recently investigated the emergent thermal response of systems of networks of DNA -functionalised lipid vesicles, leading to tuneable porosity and negative thermal expansion [Nature Communications 6:5948 2015]. I will discuss experimental findings and compare them with the predictions of a detailed analytical model. The results highlight the importance of entropic contributions to the coupling between the DNA tethers and the morphology of the substrates.