INS4-0671
Engineering Colloidal Interactions of Semiconductor Nanoplatelets for Functional Soft Materials
Topic
S4. Colloids, Interfaces, and Molecular Assemblies for Functional Soft Materials
When and Where
Sep 30, 2026
12:05 - 12:20
Room 106
Session Chairs
Sangchul ROH
Presenter(s)
Dahin Kim (University of Seoul)
Co-Author(s)
Abstract
Semiconductor nanoplatelets (NPLs) are two-dimensional colloidal nanocrystals with atomically precise thickness and highly anisotropic geometry. Their unique optical properties make them attractive building blocks for functional soft materials and photonic composites. However, their large, flat surfaces promote strong interparticle interactions, often resulting in aggregation and poor colloidal stability in complex media. Here, I will present our recent efforts to understand and control colloidal interactions of NPLs through interface engineering. We investigate depletion interactions in NPL dispersions and show that depletion attraction is strongly influenced by particle geometry, thickness, and ligand-shell structure. Unlike conventional hard-particle systems, the soft organic ligand shell surrounding NPLs plays a critical role in determining excluded-volume interactions. By tuning ligand-shell compactness, we demonstrate that nanoscale interfacial structures can effectively regulate depletion attraction and significantly improve colloidal stability. Building on this understanding, we develop multi-component ligand architectures that introduce controlled free volume and heterogeneous interfacial environments around NPLs. These engineered ligand shells suppress depletion-induced aggregation and enhance compatibility with surrounding molecular media, enabling stable dispersions in liquid-crystalline and polymeric systems. Finally, I will discuss how controlling colloidal interactions enables the fabrication of uniform NPL-based soft composites with improved structural homogeneity and optical functionality. These studies establish a general framework for engineering colloidal interactions in anisotropic nanocrystals and highlight the importance of interface design for the development of next-generation functional soft materials.
