(477a) Bioinspired Folding of Flexible Colloidal Polymers into Colloidal Materials

In self-assembly, building blocks rearrange, stick to each other in programmed ways, and finally assemble themselves into a material. When making a complex material, there are many different ways to put these pieces together. The self-assembly of complex materials is a search in high-dimensional space for the desired structure. We reduce the dimensionality of the problem by folding 1-D colloidomer chains into compact architectures, analogous to a polypeptide folding into a protein. Folding is triggered by tunable DNA-mediated interactions along the length of the colloidal polymer. Colloidal polymers can be assembled with either a single homogeneous interaction or with an alternating set of interactions. The strength of these interactions is temperature-dependent; we can trigger different interactions in sequence by careful design of a temperature protocol. We show that, even with simple alternating sequences, we can prune the possible folding pathways of a heptamer to produce one single final structure. We will also show how equilibrium folding structures differ from kinetically trapped folding structures. This work will enable us to synthesize programmable colloidal polymers that will fold to a unique stable structure of a functional complex material that has unique photonic or material properties. This work was supported by the NSF MRSEC Program (DMR-0820341).