Co-assembly of cellulose nanocrystals and gold nanorods: insights from molecular dynamics modelling

A coarse-grained molecular dynamics model is developed to explore the co-assembly of cellulose nanocrystals (CNCs) and gold nanorods (AuNRs) under sedimentation conditions with varying volumetric concentration and particle-size ratios. Simulations and statistical analysis reveal a noticable preferential attachment of AuNRs on the surface of CNC clusters as the solid fraction of AuNRs was increased when the volumetric fraction of the AuNRs was low. Density-driven self-assembly under sedimentation forces is primarily driven by the AuNRs. This shift in the dominant mechanism from CNCs to AuNRs reveals the limits of multi-particle interactions and formation of ordered structures in binary particle systems. The fundamental insights provided in this work into the self-assembly process in complex particle systems are valuable for the design and control of the physical conditions to achieve desired ordered structures. A molecular dynamics model for binary self-assembly, indicating a preferential localisation due to density differences under sedimentation conditions.