Super aligned annular ring patterns of self-assembled nanomaterials

Cellulose nanocrystals (CNCs) offer great potential as a matrix for plasmonic metasurfaces composed of anisotropic gold nanorods (GNRs) due to their renewability, biodegradability, non-toxicity, and low cost. However, precise control over CNC positioning and orientation on substrates remains still challenging. In this talk, we presented a one-step fabrication method for a homogeneous quadrant CNC matrix film by integrating two interfacial phenomena: (i) spontaneous and rapid self-dewetting, and (ii) evaporation-induced self-assembly (EISA). By optimizing the composition of the CNC ink and determining the coating parameter, we achieved a balance between these two mechanisms, resulting in the alignment of CNCs in an annular shape and the production of coffee-ring-less CNC films. The hydrophilic surface of CNCs facilitated the continuous movement of the contact line without stick-slip motion during the drying process, enabling CNC films to exhibit a consistent annular ring pattern. Moreover, through the co-assembly of GNRs onto the CNC matrix, we created uniformly dried CNC-GNR films. This high level of uniformity and alignment improved their plasmonic performance. This work proposes a new physicochemical pathway for advancing the field of next-generation nanomaterials based on CNC control.