Linking Structure and Topology in Single-Chain Nanoparticles using Simulations and Scattering Data

We investigate the structure of single-chain nanoparticles (SCNP) on the basis of small angle neutron scattering (SANS) data. The folding of poly(pentafluorobenzyl- stat-tert-butyl acrylate) precursors in a controlled solvent environment is simulated using a coarse grained Monte Carlo model. Simulation results closely follow the experimental signature of compaction at intermediate wave vectors under variation of crosslinker density. The good agreement allows, vice versa, relating structural features observed in scattering experiments with the underlying topological state that emerged during the crosslinking. By exploring ensembles in sequence space of the crosslinkable monomers, we show that experimental SCNPs were typically in a sparse state when compared to fractal globules. However, a subgroup of SCNPs with highest compaction shows signatures of the form factor expected for a dense sphere. Hence, we enable the predictive design of soft nanoparticles under variation of solvent quality and sequence for the given precursor- and folding chemistry.