Smart polymer inverse-opal photonic crystal films by melt-shear organization for hybrid core–shell architectures

Abstract

A feasible strategy to achieve large-area mechano-, thermo-and solvatochromic hybrid opal (OPC) and inverse opal photonic crystal (IOPC) films based on polymer hydrogels is described. Silica core particles featuring surface-anchored stimuli-responsive polymers are prepared and advantageously used for the melt-shear organization technique. By this approach hybrid OPC films with adjustable periodicities for photonic applications can be prepared. The large-area OPC films can be furthermore converted into IOPC structures simply by etching the silica particles while maintaining the excellent order of the entire opal film. This herein developed new process seems to be universal and is successfully applied to two thermo-responsive polymers, poly(N-isopropylacrylamide) (PNIPAM) and poly(diethylene glycol methylether methacrylate) (PDEGMEMA) as particle shell materials. Besides the remarkable mechanical robustness of the hybrid OPC and IOPC films, optical properties upon changes of temperature, mechanical stress and different solvents as external triggers are successfully confirmed. The herein described novel strategy for the preparation of inorganic/organic OPC and IOPC polymer films is feasible for a wide range of applications in fields of sensing and photonic band gap materials. † Electronic supplementary information (ESI) available: TEM images, DLS measurements, table of average particle sizes and standard deviations, DSC measurements and additional UV-Vis reection spectra. See

Functional Polymer Opals and Porous Materials by Shear‐Induced Assembly of Tailor‐Made Particles

“…The step‐wise synthetic approach is depicted in Scheme . As already mentioned in the previous section, PDEGMEMA or copolymers of PNIPAM could be introduced as stimuli‐responsive shell materials and therefore, smart inverse opal structures could be obtained after silica etching …”

“…Much effort has been spent in order to improve the macroscopic arrangement of colloidal spheres for the preparation of large‐scalable porous opal structures. Quite recently, hybrid core/shell particles featuring monodisperse silica cores and surface‐anchored responsive polymer shells were prepared . These inorganic/organic particles can be arranged into highly organized hybrid opal films by using the melt‐shear organization technique.…”

“…(Abbreviations are as follows: TEOS = tetraethoxysilane, DEGMEMA = diethylene glycol methylether methacrylate, MEMO = 3‐methacryloxypropyltrimethoxysilane, EA = ethyl acrylate, ALMA = allyl methacrylate). Reproduced with permission . Copyright 2015, Royal Society of Chemistry.…”

Self-assembly of silica colloidal crystal thin films with tuneable structural colours over a wide visible spectrum

“…One of the most important and interesting properties of natural opals is the tuneable structural colour effect. This provides a novel way of producing colours without colourants [6] and has practical applications such as structurally coloured films [7][8][9], effect pigments [10], photonic papers and inks [11], opal fibres and fabrics [12][13][14].…”

Highly Crystallized Brilliant Polymeric Photonic Crystals via Repulsion‐Induced Precipitation Assembly toward Multiresponsive Colorimetric Films

“…Apart from the above‐mentioned strategies, significant progress has been made in this area recently. For instance, an efficient and easy‐scalable route to self‐supporting elastomeric opal films with excellent optical properties has been developed by Schäfer and co‐workers . Based on a melt‐shear organization technology, this method can easily yield fully reversible large‐area multiresponsive 3D polymeric PC films by employing the special latex spheres with crosslinked core and a rubbery shell.…”