POS4-0733
Porous Photonic Papers composed of Non-close-packed Colloidal Crystals Created by Polymerization-Induced Phase Separation
Topic
S4. Colloids, Interfaces, and Molecular Assemblies for Functional Soft Materials
When and Where
Sep 29, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Hae Jung SON
Boseok KANG
Presenter(s)
Hyeonbin Jo (KAIST)
Co-Author(s)
Abstract
Solvent-responsive photonic papers have great potential as rewritable optical media, sensing platforms, and structural-color printing substrates. However, their practical use is often constrained by slow response, low color contrast, or complicated fabrication. Here, we develop a straightforward strategy for porous photonic papers by forming non-close-packed silica colloidal crystals spontaneously within an ethanol-containing photocurable resin, followed by photopolymerization-induced phase separation. Monodisperse silica particles are first organized into ordered arrays via repulsive interparticle interactions. UV curing then fixes the lattice with polymer bridges, while ethanol separation and evaporation create an interconnected air-pore network without compromising crystalline order. The resulting high refractive-index contrast gives the dried films vivid structural colors. The ethanol-to-monomer ratio serves as a parameter for tuning porosity, pore connectivity, stopband position, and reflection bandwidth. In highly porous films, water infiltration induces complete color switching within 2.5 s by stopband shifts, along with repeatable dry–wet state change over multiple cycles. The porous architecture is accessible to various solvents, enabling refractive-index-dependent color tuning. Volatile liquids can be applied by simple handwriting to achieve reversible writing and selective erasure of patterns, whereas dispenser-based printing with photocurable resin enables permanent structural-color patterning. Moreover, the papers are compatible with digital inkjet printing, allowing the fabrication of high-resolution structural-color graphics. This strategy provides vivid, rapidly responsive, rewritable, and permanently printable photonic papers for pigment-free decorative printing, solvent-responsive sensors, and anti-counterfeiting labels.
