Van der Waals Colloidal Crystals

• Published in: Advanced materials (Weinheim) Vol. 36; no. 23; pp. e2312748 - n/a
• Main Authors: Cho, YongDeok, Park, Sung Hun, Kwon, Min, Kim, Hyeon Ho, Huh, Ji‐Hyeok, Lee, Seungwoo
• Format: Journal Article
• Language: English; Catalan
• Published: Weinheim Wiley Subscription Services, Inc 01.06.2024
• Subjects: Colloids; Crystallization; Enthalpy; gold nanoparticles; pair potentials; Photonic band gaps; photonic crystals; van der Waals forces
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202312748

A general guiding principle for colloidal crystallization is to tame the attractive enthalpy such that it slightly overwhelms the repulsive interaction. As‐synthesized colloids are generally designed to retain a strong repulsive potential for the high stability of suspensions, encoding appropriate attractive potentials into colloids has been key to their crystallization. Despite the myriad of interparticle attractions for colloidal crystallization, the van der Waals (vdW) force remains unexplored. Here, it is shown that the implementation of gold cores into silica colloids and the resulting vdW force can reconfigure the pair potential well depth to the optimal range between −1 and −4 kBT at tens of nanometer‐scale colloidal distances. As such, colloidal crystals with a distinct liquid gap can be formed, which is evidenced by photonic bandgap‐based diffractive colorization. The van der Waals (vdW) force has been regarded as a versatile and universal potential. Nevertheless, whether vdW force can be used as an attractive potential for the crystallization of colloids remains to be proven. Here, it is shown that the implementation of gold cores into silica colloids can reconfigure vdW force to optimal range in terms of colloidal crystallizations.