The ordered arrays of colloidal particles (i.e., polystyrene or silica particle) on solid substrates play a crucial role in many applications such as inkjet printings, coatings, films, and lithography. To further develop functions of colloidal arrays such as optical properties, water repellency and biocompatibility, it is crucial to control of arrangements precisely. The evaporation of sessile droplets is one of the simplest and most cost-effective method to produce the ordered colloidal arrays on solid substrates[1-3]. In this study, we found that microspheres of poly ethyl acrylate can form non-close-packed structures on solid substrates after evaporation of water from aqueous sessile droplets without any complex treatment such as an exposure of plasma or heat[4]. Optical microscopy observation of drying process of droplet revealed that these elastomer microspheres adsorbed at the air/water interface and formed an ordered structure at intervals. The arrangements at the interface were transferred onto the solid substrates during drying without disruption (Figure). This result indicates that the deformability of elastomer microspheres is important for formation of non-close-packed structures. Furthermore, tuning of center-to-center distance of non-close-packed arrangement of microspheres were achieved by Langmuir-Blodgett method by adjusting the surface pressure. Our findings of this study would promote further development in arrangement of colloidal particles.

Non-close-packed arrangement of soft elastomer microspheres using self-organization at the air/water interface

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.