SANS Study on the Behaviors of Polymeric Ligands on the Nanoparticle Surfaces

In this work, we employed small angle neutron scattering (SANS) and contrast variation technique to characterize the behaviors of polymer ligands on the nanoparticle (NPs) surfaces. The Janus-type Au NPs were coated with a mixture of two different ligands, PMMA-SH and deuterated PS-SH, and the Au NPs coated only with P(MMA-r-dS)-SH were also prepared for the control case of NPs with homogeneous ligands. From the SANS analysis, it was observed that the ligands become phase separated with increasing the molecular weight of ligands. Furthermore, computational simulation was performed to examine how ligands are phase separated on the curved NPs surfaces.