Abstract
High quality opal‐like photonic crystals containing graphene are fabricated using evaporation‐driven self‐assembly of soft polymer colloids. A miniscule amount of pristine graphene within a colloidal crystal lattice results in the formation of colloidal crystals with a strong angle‐dependent structural color and a stop band that can be reversibly shifted across the visible spectrum. The crystals can be mechanically deformed or can reversibly change color as a function of their temperature, hence their sensitive mechanochromic and thermochromic response make them attractive candidates for a wide range of visual sensing applications. In particular, it is shown that the crystals are excellent candidates for visual strain sensors or integrated time‐temperature indicators which act over large temperature windows. Given the versatility of these crystals, this method represents a simple, inexpensive, and scalable approach to produce multifunctional graphene infused synthetic opals and opens up exciting applications for novel solution‐processable nanomaterial based photonics.
Highlights
Introduction for coating applicationsIn other reports,[19,20] chromatic sensors were fabricated using core-shell particles infused withNature offers incredible examples of functional materials
The polymeric latex used in this study produced through emulsion polymerization, is comprised of a random copolymer of methyl methacrylate (MMA), butyl acrylate (BA), and methacrylic acid (MAA) in the form of a charge-stabilized colloidal suspension of polymer spheres
By carefully controlling the self-assembly of the colloidal particles and taking into account the interplay between particle diffusion, inter-particle forces, and settling dynamics,[43] we achieved solids with long-range particle ordering resulting in opal-like crystals containing pristine graphene
Summary
It is worth noting that this simple model ignores the effect of increased particle concentration and its associated effect on slowing the sedimentation velocity Regardless, it is clearly valid in the initial stages of self-assembly when the solids content of the system is still relatively low. For the polymer particles, evaporation significantly dominates over both diffusion and particle sedimentation In this regime, as the air/water interface descends during evaporation, the top of the film sweeps up the polymer particles, accumulating them at the top. As the air/water interface descends during evaporation, the top of the film sweeps up the polymer particles, accumulating them at the top Phase separation and formation of black sediment at the bottom of the vial occurs (Figure S1, Supporting Information)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
