The indication of information in materials is widely used in our daily life, and optical encoding materials are ideal for information loading due to their easily readable nature and adjustable ...optical properties. However, most of them could only indicate one type of information, either changing or unchanging due to the mutual interference. Inspired by firefly, we present a non-interfering bipolar information indication system capable of indicating both changing and unchanging information. A photochemical afterglow material is incorporated into the photonic crystal matrix through a high-throughput technique called shear-induced ordering technique, which can efficiently produce large-area photonic crystal films. The indication of changing and unchanging information is enabled by two different utilizations of white light by the afterglow material and photonic crystals, respectively, which overcome the limitations of mutual interference. As a proof of concept, this system is used to indicate the changing photodegradation level of mecobalamin (a photosensitive medicine) and unchanging intrinsic drug information with anti-counterfeiting functionality, which is a promising alternative to instantly ascertain the efficacy of medicine at home where conventional assays are impractical.
The hydrodenitrogenation (HDN) of quinolone (Q) and decahydroquinoline (DHQ) over a Ni
2
P catalyst prepared by the reduction of a conventional phosphate precursor and a surface nickel phosphosulfide ...phase (Ni
2
P–S) obtained by the reduction of Ni
2
P
2
S
6
were studied. A reaction network of the HDN of Q over Ni
2
P was proposed. Both the hydrogenation and C–N bond cleavage activities of Ni
2
P were enhanced after the introduction of sulfur. The surface sulfur species of Ni
2
P–S changed significantly after the HDN of DHQ. The thiolate or thiol species were detected as the major sulfur-containing species in the surface of the spent Ni
2
P–S catalyst.
Graphical Abstract
Due to intermediate hydrophobicity of methyl methacrylate (MMA) monomer in water, it is difficult to prepare its stable water in oil high internal phase emulsion (HIPE). Moreover, the addition of ...fully hydrophilic co-monomer such as 2-hydroxyethyl methacrylate (HEMA) in MMA monomer makes it further troublesome to stabilize these emulsions. This paper addresses the preparation of such type of difficult to prepare emulsions via addition of an amphiphilic fluorinated di-block copolymer (FDB), poly(2-dimethylamino)ethylmethacrylate-b-poly(trifluoroethyl methacrylate) (PDMAEMA-b-PTFEMA) as stabilizer. Interestingly, HEMA and/or HFBA (hexa fluorobutyl acrylate) as co-monomers were successfully added to impart some special properties such as thermodynamic stability, desired amphiphilicity to the final polyHIPEs. Fluorinated blocks in FDB anchored well at oil/water interface of HIPE, offering enough hydrophobicity to the comparatively hydrophilic monomers and in turn providing resistance against coalescence. MMA polyHIPEs were found to be fully hydrophobic just by replacing HEMA co-monomer with HFBA. Due to superb inherent hydrophobic nature of fluorine atoms, MMA-HFBA polyHIPEs showed remarkable water contact angle of 139°. Furthermore, the addition of fluorinated co-monomer in MMA based HIPEs significantly improved thermal stabilities of these materials with improvement in degradation temperature from 305 °C to 360 °C.
Photochromic materials are widely investigated due to their vivid color transformation for many real applications. In this work, a new kind of multiangle photochromic photonic crystal (PC) material ...with high robustness and long durability for smart phone decoration and anticounterfeiting features is fabricated. After thermal mixing of spiropyran powder and monodisperse core-interlayer-shell (CIS) particles, a large-area and high-quality photochromic PC film has been prepared by the self-designed bending-induced ordering technique (BIOT). The spiropyran powder can be well dispersed in the order-structured PC system, so the perfect synergistic combination of photochromism and angle-dependent structure colors can be achieved. The color-switching test for the as-prepared photochromic PC film proved its excellent reversibility and stability. Because of the excellent flexibility of the photo-cross-linked PC films, they can be designed and cut into various shapes with high robustness and long durability. Interestingly, a temperature-controlled photochromic effect was found in this photochromic PC system. Therefore, the as-prepared photochromic PC films can play a significant role in the fields of smart decoration and anticounterfeiting by their unique color switching effects under different stimuli. More importantly, our work verified the feasibility of this route to prepare a series of large-sized advanced smart PC devices by adding versatile functional materials.
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•Monodisperse colloidal particles were synthesized with average output of 240 g/h.•Photonic crystal film was fabricated with vivid structural color at room temperature.•Based on ...self-designed machine, large-area (over 100 m2) PC film was fabricated.
Polymer photonic crystals have drawn a lot of interest due to cost-effective fabrication. Although tremendous efforts are tried, almost no large-size photonic crystal (PC) films can be obtained due to different kinds of reasons. The main issues are the tedious process and strict preparation conditions (like high temperature and solvents), sometimes the limitation of the machinery equipment, accordingly they are not conducive to preparation of subsequent large-scale PC films. Hence, there is an urgent desire to develop a technique that can assemble polymer PC films in a large scale at low temperature without solvent.
Through semi-continuous emulsion polymerization, core-interlayer-shell (CIS) colloidal particles (PS@PEA@P2EHA) were synthesized with the output of 240 g/h. After the successful production of polymer PC films in the laboratory at room temperature, industrial roll-to-roll process was used for large-scale production of the PC films.
By introducing poly(2-ethylhexyl acrylate) which has quite low glass transition temperature (Tg) into the shell, we have successfully developed an energy-efficient technique for fabrication of large-area (over 100 m2) polymer PC films at ambient temperature for the first time. This technique has great potential to promote the industrial application of PC films, such as display, sensors, anti-counterfeiting and so on.
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•Photonic crystal (PC) films are fabricated by bending-induced ordering technique.•Thermochromism PC (TCPC) films possess switchable vivid color and transparency.•TCPC films can be ...designed and tailored to stickers and tags with various shapes.•TCPC films can be used for anti-counterfeiting and information encryption.
Thermochromic photonic crystal (TCPC) has attracted wide interests for the easy change in vivid colors by external stimuli. In this article, a new type of polychromic photonic crystal film with switchable colors is fabricated by a self-designed bending-induced ordering equipment. After addition of micron-sized heat-sensitive pigment microcapsules into the photonic crystal (PC) system, the ordered and hierarchical structure of the uniform TCPC film can be formed, which is confirmed by USAXS and FESEM. The color-switchable performance after 1000-cycle testing proves its potentials for multi-level anti-fake applications. Meanwhile, the appearance of the TCPC film can quickly transform from opaque to transparent for encryption with mild heating. By using low glass transition temperature copolymer as matrix, the TCPC film can be designed as colorful tags and stickers with different shapes. The as-prepared polychrome TCPC stickers have great application potentials in anti-counterfeiting, information encryption, color display, decorations and so on. Significantly, this new preparation technique opens a powerful route to fabricate the large-sized stimuli-responsive PC films without change of the intrinsic crystal structure through adding different functional nanomaterials, which is beneficial for design of various advanced colorful smart PC devices.
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•Co-localization of structural and pigmentary elements gives color complexity and vividness.•Electro- and thermochromic materials endows PC films with smart ways for light ...modulation.•Large-sized PC films can be fabricated with the shear-induced ordering technique.•The smart window system can serve as interior mood regulators.
Many reptiles, such as Phelsuma geckos, skillfully employ both structural and pigmentary elements to generate versatile colors. Meanwhile, they can also modulate skin brightness through the dispersion and aggregation of pigment-containing cells. Inspired by this amazing biological process, the thermochromic pigments and viologen-based electrochromic materials were ingeniously integrated into colloidal photonic crystals to fabricate multi-responsive photonic crystal films for the first time. Through modulating the reflection and absorption of light, i.e., structural and pigmentary components, the as-prepared photonic crystal films could display RGB colors under different environmental temperatures and tune the color brightness in response to external electric field, mimicking the versatile color variation of geckos. The introduction of viologen resulted in a more vivid color thanks to its absorption of incoherent scattering light inside the colloidal particles aggregates. Furthermore, we employed a new strategy called shear-induced technique to assemble monodisperse microspheres into ordered nanostructure, which could produce large-sized photonic crystal films. As a demonstration, the multi-responsive photonic crystal films were used as a prototype of new generation smart windows, fusing both active (electrochromic) and passive (thermochromic) ways for light modulation, which could serve as interior mood regulator for the person in car.
Electrophoretic displays (EPDs) based on photonic crystals show great potential due to their reduced eye fatigue and low power consumption. However, the current image quality and service life of this ...system still face great challenges. In this work, we fabricated a new kind of electrically responsive photonic crystal (ERPC) device based on PSMA@SiO2 liquid colloidal crystals (LCCs) for EPDs. By introduction of the PSMA core with lower density and higher refractive index, the suspension stability and color saturation of PSMA@SiO2 LCCs were greatly enhanced compared with those of bare SiO2 LCCs. The PSMA@SiO2 LCCs showed brilliant colors, wide color tuning range (∼200 nm), and good reversibility under low voltages (<4 V). Interestingly, the transparency of PSMA@SiO2 LCCs could also be obviously regulated by an electric field, which was different from the traditional ways that change the thickness of PCs or contrast of refractive index (Δn) between the nanospheres and matrix. This transparency modulation offered a novel idea for the transmittance control of smart windows. As a proof of concept, we fabricated a new type of patterned ERPC device to demonstrate their potential in electrophoretic displays and smart windows with controllable transmittance under an electric field.
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•Photonic crystal materials with magnetic coupling effect are prepared by non-uniform magnetic nanoparticles.•Strong binding between particles and monomers can efficiently induce the ...formation of quasi-ordered arrays.•Photonic pigments embedding in transparent matrix can form various non-iridescent coatings.•Magnetite quasi-ordered arrays can greatly enhance the magnetic coupling and improve the wave absorption.
Non-iridescent structural color films and pigments with novel enhanced microwave absorption characteristics are successfully fabricated at room temperature for the first time. The quasi-uniform magnetite nanoparticles (CV = 0.10 ∼ 0.20) with high refractive index (n = 2.42) and broad light absorption provide evident low-angle-independent property for the structural color pigments. More importantly, a universal technical protocol is developed for preparation of photonic crystals with inorganic nanoparticles, i.e., through designing of the binding strength between nanoparticles and mediated molecules, the slurry modulus is increased to 105 Pa, which effectively drives the nanoparticles to rapidly assemble into closely packed ordered arrays by our-designed powerful assembly technique. Additionally, the structural color materials are subjected as photonic crystal pigments (∼20 wt%) embedding in a transparent polymer matrix to form color coatings. Remarkably, the photonic crystal pigments exhibit strong magnetic coupling effect and enhanced microwave absorption performance due to the regular arrangement, with superior reflection loss (RLmin) values of −14.97 dB (increase by 65.8 % compared with randomized magnetic nanoparticles), and the effective absorption bandwidth (EAB) of 2.15 GHz. This new kind of photonic crystal pigment, combining visual color and radar wave absorption, provides a novel idea for developing of multi-wave-band high-performance stealth materials.
In this study, we fabricate a new kind of ultrasensitive humidity-responsive photonic crystal (HPC) films based on emulsion polymerization and the open mill and bending-induced ordering technique ...(OM-BIOT) method, which is simple and scalable. The HPC film senses relative humidity (RH) from 9 to 98% for the polymer matrix swells up in high RH and shrinks in low RH, leading to a large reflectance shift (81 nm) and distinct color change. Based on the double-peak reflective spectra of the HPC film, we confirm the gradient swelling hypothesis and find that the thickness is another important factor for controlling the sensitivity and response rate of the HPC film. Except for static humidity, the HPC film can also respond to the dynamic humid flow of blowing and polar solvents, which broadens its application potential. This kind of HPC film shows a vivid structural color, and the humidity-responsive behavior is quick, distinct, energy-free, and reversible, having a great prospect for anticounterfeiting application.
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