Solvent-Responsive Invisible Photonic Patterns with High Contrast for Fluorescence Emission Regulation and Anti-Counterfeiting

Abstract

Invisible photonic patterns (IPPs) are photonic materials that can display hidden patterns under external stimulation and are attractive in anti-counterfeiting devices and information storage. In this work, we report a solvent-responsive invisible photonic pattern (SRIPP) with high contrast by polymerizing two monomers of acrylamide (AAm) and poly(ethylene glycol) methacrylate (PEGMA) with different solubility parameters in different regions of poly(hydroxyethyl methacrylate) photonic gels. The two regions with different solvent responsiveness can shrink and swell in the same environment, thus causing the colors of different regions of photonic gel to shift in opposite directions from the initial state. As a result, the contrast of photonic patterns is significantly improved, increasing naked-eye visualization. In addition, by introducing fluorescent substances into the photonic gel and adjusting the photonic band gap (PBG) of photonic gels, we realize the regulation of fluorescence emission and display of fluorescence patterns by utilizing different PBGs on the SRIPP. Dynamic solvent responsiveness patterns and fluorescence patterns are integrated into a photonic gel, showing great potential in information storage and multiple-mode anti-counterfeiting applications.

Bio‐inspired photonic crystals: Tailoring the dielectric building blocks to control the light propagation

“…Taking advantage of a swelling and deswelling process, it has been proved that the periodicity of spatially ordered structures can also be effectively manipulated by certain solvent. [175][176][177][178] Xia's group developed a solvent responsive PDMS/PS colloidal crystal film by utilizing a swelling process. [179] When organic solvent was applied on the surface of the film with a patterned stamp, PDMS matrix in the area contact with the solvent pattern swelled, leading to the increase in interparticle distance and redshift of the reflection peak.…”

“…Taking advantage of a swelling and deswelling process, it has been proved that the periodicity of spatially ordered structures can also be effectively manipulated by certain solvent [175–178] . Xia’s group developed a solvent responsive PDMS/PS colloidal crystal film by utilizing a swelling process [179] .…”

Shape memory photonic materials: fabrication and emerging applications

“…4,19,20 In particular, inspired by the dynamically responsive coloration strategies that natural organisms (i.e., chameleon and brown alga) make to perceive and adapt to the variations in their surroundings, PCs with variable structures and precisely tunable structural color have attracted increasing attention. [21][22][23][24][25][26] Responsive PCs (RPCs) are composite materials constructed by embedding colloidal crystal arrays into stimuli-responsive polymers. 27,28 Current advances in This journal is © The Royal Society of Chemistry 2023 will respond to external stimuli, macroscopically manifested as the variations in the structural color and reflection peak of RPCs.…”

“…, chameleon and brown alga) make to perceive and adapt to the variations in their surroundings, PCs with variable structures and precisely tunable structural color have attracted increasing attention. 21–26 Responsive PCs (RPCs) are composite materials constructed by embedding colloidal crystal arrays into stimuli-responsive polymers. 27,28 Current advances in RPCs exhibit dynamic, reversible, and stable responses to a wide range of external stimuli, including deformation, solvent, vapor, pH, temperature, electromagnetic fields, etc.…”

Rewritable Structurally Colored Paper Based on Hollow SiO2–Polyurethane Composite Photonic Crystal Film

“…By tuning the lattice constant or refractive index, full spectral ranged reflected colors are easily achieved on a responsive photonic crystal film. Such a stimuli-sensitive photonic crystal has been widely used in structure color display, , chemical and physical colorimetric sensor, − anti-counterfeiting, ,− encryption, , and green printing. − It is worth noting that rewritable photonic crystal paper as a kind of green printing material, in which the structural colored pattern can be reversibly printing and erase under external stimuli, has recently become prevalent, since paper is still the most important media for mankind to record information and spread the civilization. Moreover, photonic crystal paper with dye free character is more durable than traditional pigments and dyes, which can lessen the heavy environmental burden brought about by traditional paper industry.…”