Multi-stimuli-responsive elastomeric opal films: processing, optics, and applications

Abstract

A new strategy to build large-scale solvent-responsive elastomeric opal films that are candidates for a wide range of optical sensor applications is reported. Hard-soft core-interlayer-shell (CIS) beads were used to prepare paper-supported elastomeric opal films with remarkably distinct iridescent reflection colors. Extrusion and compression molding of the CIS beads directly on the top of a highly porous paper sheet followed by UV cross-linking led to polymer-paper composite films with a high tensile strength and an outstanding solvent resistivity. Due to the high porosity of the papersheets used, these composites could be easily swollen by various solvents. The swelling changed the crystalline lattice of the opals which provoked a tremendous photonic band gap shift and also enhanced the brilliance of these colors. After deswelling, the original opal structure was totally restored which means that the shift of the photonic band gap was completely reversible. This approach can become the basis for a whole family of polymer-based soft sensors with a fascinating optical response.

Multiple Structural Transitions in Langmuir Monolayers of Charged Soft-Shell Nanoparticles

“…15,17 The monodisperse CIS nanoparticles with a diameter of ca. 250 nm [measured by dynamic light scattering (DLS) 15,17 ] were dispersed in chloroform (CHCl 3 ) and exhibited a zeta-potential of ca. −50 mV for both washed and nonwashed nanoparticles.…”

“…18 Therefore, these materials have been used as electronic inks for rewritable electronic paper technology and were used as active materials in mechano-, thermo-, and solvato-chromic sensors. [13][14][15]18,24,25 spheres are used instead of polymeric cores to increase the Δn values. 12,16,26 To attach the shell-forming polymers permanently to the chains of the hard core, one can introduce an interlayer, which allows for a dense grafting of these shell-forming polymer chains.…”

Cellulose photonic crystal film sensor for alcohols

“…The swelling changed the crystalline lattice of the opals which provoked a tremendous photonic band gap shift and also enhanced the brilliance of these colors. This approach became the basis of a whole family of polymer-based soft sensors with a fascinating optical response [28].…”

Embedding Photoacids into Polymer Opal Structures: Synergistic Effects on Optical and Stimuli-Responsive Features

“…The basic prerequisites of such materials rely on a periodically differing refractive index within domain sizes that fit the wavelength of visible light [ 7 , 8 ]. Through interference with light, photonic crystals show their angle-dependent and vivid structural colors [ 9 , 10 , 11 ]. Since their discovery in the 1980s, many approaches for the fabrication of photonic crystals have been developed, and most of them are based on monodisperse nanoparticles [ 12 , 13 , 14 , 15 , 16 ].…”