Synergistic Hydrophilic and Electrostatic Induction for Liquid Photonic Crystals of Poly (Acrylic Acid)‐block‐Polystyrene Colloidal Nanospheres From RAFT‐Mediated Emulsion Polymerization

Abstract Liquid Photonic Crystals (LPCs) represent a distinctive category of photonic materials that merges the ordered structure of colloidal photonic crystals with the dynamic nature of liquids, allowing for flexibility in tuning their assembly and optical properties in response to external stimuli. However, the requirement of high solid content and high stability of these LPCs continue to pose a significant challenge in their controlled synthesis, efficient assembly, and system stabilization. Herein, highly charged poly (acrylic acid)‐ b ‐polystyrene (PAA‐ b ‐PS) colloidal nanospheres are synthesized using RAFT‐mediated emulsion polymerization. Under the hydration and electrostatic interactions induced by selected polymeric inducers, PAA‐ b ‐PS colloidal nanospheres with a uniform carboxylate anion surface are synthesized, capable of forming iridescent LPCs at an overall low solid content (20 wt%) containing localized areas of high solid content. Furthermore, carboxymethyl cellulose (CMC), one of the polymeric inducers, undergoes photosensitive modification to facilitate the digital light processing (DLP) 3D printed LPCs hydrogel models. This strategy offers innovative approaches for the synthesis, assembly, and 3D‐printed LPC materials, promising applications in smart displays, sensory systems, and optical devices.