Styrene-methyl Methacrylate-acrylic Acid Research Articles

A new strategy for structural color fabrics: Transfer of photonic crystal coatings from slides to fabrics

The construction of three-dimensional photonic crystals on textile surfaces has emerged as a highly effective method to create fabrics with structural color, generating significant interest among researchers. However, the strict requirements of the substrate fabrics and the challenges associated with patterning coatings for bright structural colors have hindered the widespread application of photonic crystal materials in the textile industry. In this study, we present a strategy for obtaining patterned structural color coatings on fabrics made of different materials. Pre-crystallized poly(styrene-methyl methacrylate-acrylic acid) (P(St-MMA-AA)) liquid photonic crystals (LPCs) are used as raw material for the rapid preparation of solid photonic crystals (SPCs). These SPCs with structural colors are used as templates and transferred to various fabrics through transfer printing techniques. Importantly, the SPCs maintain an ordered face-centered cubic structure both before and after transfer. Such a feature ensures that the processed structural color fabrics exhibit vibrant and iridescent structural colors. This result is achieved by modification of the substrate fabric with viscous polymer and the intact retention of SPCs. The sandwich structure formed by the adhesive polymer on the base fabric and the encapsulation of the film-forming material on the SPCs imparts good stability to the structural color fabric. It is worth noting that patterned photonic crystal coatings can be easily obtained on the fabrics made of different materials (cotton, linen, wool, and silk fabrics) by manipulating the shape of the viscous polymer. Additionally, a wide range of common materials, such as paper, wood, steel, and others, can be used as target substrates. This novel dyeing strategy not only offers new ideas for preparing patterned structural color fabrics but also further promotes the application of photonic crystal materials in textile printing or display.

Iridescence Mimicking in Fabrics: A Ultraviolet/Visible Spectroscopy Study.

Poly(styrene-methyl methacrylate-acrylic acid) photonic crystals (PCs), with five different sizes (170, 190, 210, 230 and 250 nm), were applied onto three plain fabrics, namely polyamide, polyester and cotton. The PC-coated fabrics were analyzed using scanning electronic microscopy and two UV/Vis reflectance spectrophotometric techniques (integrating sphere and scatterometry) to evaluate the PCs' self-assembly along with the obtained spectral and colors characteristics. Results showed that surface roughness of the fabrics had a major influence on the color produced by PCs. Polyamide-coated fabrics were the only samples having an iridescent effect, producing more vivid and brilliant colors than polyester and cotton samples. It was observed that as the angle of incident light increases, a hypsochromic shift in the reflection peak occurs along with the formation of new reflection peaks. Furthermore, color behavior simulations were performed with an illuminant A light source on polyamide samples. The illuminant A simulation showed greener and yellower structural colors than those illuminated with D50. The polyester and cotton samples were analyzed using scatterometry to check for iridescence, which was unseen upon ocular inspection and then proven to be present in these samples. This work allowed a better comprehension of how structural colors and their iridescence are affected by the textile substrate morphology and fiber type.

Study on the subjective brightness of photonic crystal structural colored wood products

ABSTRACT Photonic crystal structural color is a novel method in the field of colored coating on the surface of wood products. However, the subjective brightness of photonic crystal structural colored wood products under different color temperature light sources has not been studied. In this study, poly(styrene-methyl methacrylate-acrylic acid) latex microspheres with different diameters were used to construct photonic crystal coatings on wood surface. The subjective brightness psychological quantity under different color temperature light sources was obtained. Combined with the optical properties of the coatings, the correlation between the physical optical properties of the photonic crystal coating, the color temperature of the light source and the subjective brightness of the coating was obtained. The photonic crystal coating in the near red visible light wavelength range had higher subjective brightness under low color temperature light source, and coating in the near purple visible light wavelength range had higher subjective brightness under high color temperature light source. The subjective brightness of the photonic crystal coating was very closely related to the light source color temperature and closely related to the reflectivity of the coating. This study expands the research on the optical properties of photonic crystal structure colored wood products.

Efficient preparation of single-sided structural color fabrics with asymmetric wettability, angle-dependence and patternability based on liquid photonic crystals

Liquid photonic crystals (LPCs) with structural colors have become the most promising materials for preparing structural color fabrics, which have received extensive attention in textile printing and dyeing. However, the tedious and uncontrollable preparation process for LPCs and its expensive equipment for structural color fabrics with asymmetric wettability limit the practical application of structural color materials. Herein, inspired by the Janus wettability of the unidirectional moisture transport fabric, a simple and efficient approach is reported to fabricate single-sided structural color fabrics (SSCFs) with asymmetric wettability and angle dependence. To obtain asymmetrically wetted substrate fabrics, a low-cost, high-temperature assisted spraying strategy is used to build a hydrophobic layer on one side of the fabric. The ready-to-use LPCs with target mass fraction are accurately prepared by re-dispersing the dry poly(styrene-methyl methacrylate-acrylic acid) (P(St-MMA-AA)) microsphere powder and are uniformly scraped onto the hydrophilic side of the fabric to prepare SSCFs. The as-prepared samples show a brilliant and iridescent structural color, and their color is adjusted by varying the size of the P(St-MMA-AA) microspheres. The water contact angle of the front side (with structural colors) of SSCFs treated by sintering and water bath is 37°, which facilitates further encapsulation to improve the color fastness of SSCFs. Meanwhile, the photonic crystals on the fabric remain ordered. This work provides an alternative, low-cost and practical preparation scheme for the structural coloring of textiles based on LPCs.

Facile and binder-free fabrication of deep colors on cotton fabrics with hand-feel enhancement via screen printing

Screen printing with pigments features its superiority and versatility and has shown promising applications in color-related fields, whereas pigments have clear advantages among colorants owing to their wide color-range, extensive applicability, and green characteristics such as water and energy saving. However, it requires massive, inevitable addition of binders to improve the affinity and dispersity of pigments during printing, which results in undesired rigidity of printed fabrics. Here, we synthesized an anionic poly (styrene-methyl methacrylate-acrylic acid) absorbed Rhodamine B (RB@PSMA) nanosphere via soap-free emulsion polymerization for printing the cotton fabrics without binders. The prepared color nanospheres RB@PSMA show the good size stability (PDI=0.018) and dispersity (< 299.4 nm). Notably, the strong electrostatic attraction from PSMA nanosphere enables the saturated adsorption of Rhodamine B dyes with ionic bonding. The printed fabrics with RB@PSMA were thus endowed with enhanced color performance (X 2.3 in K/S value) and soft hand feel without binders, differing from original RB printed ones that are usually stiff due to the crosslinking-induced rigidity. This approach may carve a practical avenue in binder-free pigment coloring and provide new prospects for the facile and versatile design of other printing and dyeing technology.

Magnetic-Fluorescent Responsive Janus Photonic Crystal Beads for Self-Destructive Anti-counterfeiting.

In this study, we fabricate magnetic-fluorescent responsive Janus photonic crystal beads (JPCBs) based on poly(styrene-methyl methacrylate-acrylic acid) (p(St-MMA-AA)) colloidal nanoparticles, Fe3O4, and photobase generators used for self-destructive anti-counterfeiting. We synthesize two kinds of photobase generators that can react with fluorescamine to produce various fluorescence colors. A microfluidic method is used to obtain the Janus photonic crystal beads. The upper portions of the JPCBs are photonic crystals assembled with colloidal spheres, whereas the Fe3O4 settles down to the bottom of the JPCBs due to its higher density. Photobase generators are distributed in photonic crystal gaps. Because of the magnetism of the Fe3O4, the JPCBs could be flipped from one side to the other in the presence of a magnet. After being exposed to UVC light and fluorescamine, the JPCBs can fluoresce under UVA light. Then, we create Janus microbeads arrays with various types of beads and apply them to the visitor card, bracelet, and box label to provide irreversible and self-destructive anti-counterfeiting. The JPCBs are capable of being encoded and angle-independently displayed, which are crucial to their applications in anti-counterfeiting, information coding, and array display.

Preparation of Janus structural color sheets with flexibility, stability and low angle dependence based on textile

Structural colors with low angle dependence arising from photonic crystals are of increasing interest in various fields, such as sensing and display. In this study, the composite Poly(styrene-methyl methacrylate-acrylic acid) photonic crystals consisting of amorphous, simple cubic and face-centered cubic structures were facilely constructed by vacuum-assisted filtration self-assembly. Interestingly, this method enables microspheres to be assembled on flexible fabrics in a "bottom-up" manner, and different types of structural color sheets (single-sided coloring, double-sided homochromy or heterochromatic) can be obtained by controlling the dosage and particle size of the microspheres. In particular, the prepared structural color sheets are exceptionally bright and have low angle dependence. Subsequently, the photonic crystals in the flexible fabric were reinforced by the introduction of Poly(methyl methacrylate-butyl acrylate), which resulted in a significant improvement in the mechanical stability, the performance of which was demonstrated by water-rinsing, friction and folding tests. This study provides a novel way to prepare new structural color materials with bright and low angle dependence. In addition, this double-sided heterochromatic structural color sheet has potential applications in the display field.

Cracking enabled unclonability in colloidal crystal patterns authenticated with computer vision.

Colloidal crystals with iridescent structural coloration have appealing applications in the fields of sensors, displays, anti-counterfeiting, etc. A serious issue accompanying the facile chemical self-assembly approach to colloidal crystals is the formation of uncontrolled and irregular cracks. In contrast to the previous efforts to avoid cracking, the unfavorable and random micro-cracks in colloidal crystals were utilized here as unclonable codes for tamper-proof anti-counterfeiting. The special structural and optical characteristics of the colloidal crystal patterns assembled with monodisperse poly(styrene-methyl methacrylate-acrylic acid) core-shell nanospheres enabled multi-anti-counterfeiting modes, including angle-dependent structural colors and polarization anisotropy, besides the physically unclonable functions (PUFs) of random micro-cracks. Moreover, by using the random cracks in the colloidal crystals as templates to guide fluorescent silica nanoparticle deposition, an fluorescent anti-counterfeiting mode with PUFs was introduced. To validate the PUFs of the fluorescent micro-cracks in the colloidal crystals, a novel edge-sensitive template matching approach based on a computer vision algorithm with an accuracy of ∼100% was developed, enabling ultimate security immune to forgery. The computer-vision verifiable physically unclonable colloidal crystals with multi-anti-counterfeiting modes are superior to conventional photonic crystal anti-counterfeiting materials that rely on angle-dependent or tunable structural colors, and the conventional PUF labels in the aspect of decorative functions, which will open a new avenue for advanced security materials with multi-functionality.

A Diverse Micromorphology of Photonic Crystal Chips for Multianalyte Sensing.

The diversity by nano/microstructural material or device constructing can provide the exciting opportunity for sensitivity and selectivity to achieve facile and efficient multianalyte recognition for clinical diagnosis, environment monitoring, etc., in complex system analysis. Colloidal poly(styrene-methyl methacrylate-acrylic acid) (poly(St-MMA-AA)) nanoparticle-assembled photonic crystals (PCs) can achieve manipulative 3D structural colors and approach PC sensor chip for high-efficient multianalysis utilizing simple dye. Focusing on the morphology effects of structural color, a PC microchip is designed and constructed with various geometrical micromorphologies. Based on the angle dependence of colloidal-crystal structural color, the stopband distribution is explored on various morphological PC pixels. Selective fluorescent enhancement is realized for stopband-matched PCs, which approach the successful discrimination of metal ions and complex multianalysis of groundwater. Meanwhile, printed droplet-shaping manipulation can achieve a large-scale structural-color sensor array of chips with designable nano/microstructures via colloidal assembly. It will be the critical puzzle piece between macromorphology and microstructure for the structural-color researches.

Self-assembly of poly(styrene-methyl methacrylate-acrylic acid) (P(St-MMA-AA)) colloidal microspheres on wood surface by thermal-assisted gravity deposition

P(St-MMA-AA) microspheres were used as raw materials to develop photonic crystal coatings with structural color on wood surfaces by thermal-assisted gravity deposition method. Morphologies of the microspheres and photonic crystal coatings as well as the self-assembly of microspheres on wood surface were studied. Microspheres with core–shell morphology were synthesized by emulsion polymerization and their good monodispersity ensured well-ordered arrangement of photonic crystals on the wood surface. The structural color of coatings could be controlled by the particle size of microspheres. Under thermal influence, microspheres aggregated at the emulsion surface and were orderly arranged forming two-dimensional photonic crystals with structural color during the self-assembly process. Due to continuous evaporation of water, the photonic crystals accumulated, thickened and finally formed the colored structural coating with iridescent effect on the wood surface. The results of this study provided an environmentally friendly and novel methodology to improve the color of wood surfaces.

Fabrication of Structural-Coloured Carbon Fabrics by Thermal Assisted Gravity Sedimentation Method.

Structural-coloured poly(styrene-methyl methacrylate-acrylic acid) (Poly(St-MMA-AA)) deposited carbon fabrics (Poly(St-MMA-AA)/PCFs) with fascinating colours (salmon, chartreuse, springgreen, skyblue, mediumpurple) changing with the (Poly(St-MMA-AA) nanoparticle sizes can be facilely fabricated by the thermal-assisted gravity sedimentation method that facilitates the self-assembly of Poly(St-MMA-AA) colloidal nanoparticles to generate photonic crystals. The particle sizes of Poly(St-MMA-AA) copolymer with core/shell structure varying from 308.3 nm to 213.1 nm were controlled by adjusting the amount of emulsifier during emulsion polymerisation. The presence of the intrinsic chemical information of Poly(St-MMA-AA) copolymer has been ascertained by Raman and Fourier Transform Infrared (FT-IR) Spectroscopy analysis. Colour variation of the as-prepared structural-coloured carbon fabrics (Poly(St-MMA-AA)/PCFs) before and after dipping treatment were captured while using an optical microscope. The structural colours of Poly(St-MMA-AA)/PCFs were assessed by calculating the diffraction bandgap according to Bragg’s and Snell’s laws. The Poly(St-MMA-AA) photonic crystal films altered the electrical properties of carbon fabrics with the resistivity growing by five orders of magnitude. The differential electrical resistivity between Poly(St-MMA-AA)/PCFs and wet Poly(St-MMA-AA)/PCFs combined with the corresponding tunable colours can be potentially applied in several promising areas, such as smart displays, especially signal warning displays for traffic safety.

Preparation of Polyaniline/Emulsion Microsphere Composite for Efficient Adsorption of Organic Dyes.

Surface-functionalized polymeric microspheres have wide applications in various areas. Herein, monodisperse poly(styrene–methyl methacrylate–acrylic acid) (PSMA) microspheres were prepared via emulsion polymerization. Polyaniline (PANI) was then coated on the PSMA surface via in situ polymerization, and a three-dimensional (3D) structured reticulate PANI/PSMA composite was, thus, obtained. The adsorption performance of the composite for organic dyes under different circumstances and the adsorption mechanism were studied. The obtained PANI/PSMA composite exhibited a high adsorption rate and adsorption capacity, as well as good adsorption selectivity toward methyl orange (MO). The adsorption process followed pseudo-second-order kinetics and the Langmuir isotherm. The maximum adsorption capacity for MO was 147.93 mg/g. After five cycles of adsorption–desorption, the removal rate remained higher than 90%, which indicated that the adsorbent has great recyclability. The adsorbent materials presented herein would be highly valuable for the removal of organic dyes from wastewater.

Fabrication of Coatings with Structural Color on a Wood Surface

A facile method for the fabrication of colloidal photonic crystal coatings with tunable structural color on a wood surface was presented. The photonic crystal coatings were formed from monodisperse latex spheres composed of poly(styrene-methyl methacrylate-acrylic acid) (P(St-MMA-AA)). The latex spheres with a hard PSt core and elastomeric P(MMA-AA) shell were prepared using the emulsion polymerization method. The sessile drop method, a rapid single-step self-assembly method through simple evaporation of emulsion, was used to form three-dimensional colloidal crystals. Coatings with brilliant colors and uniform Bragg’s diffraction covering the entire visible region were fabricated by controlling the sphere size. This simple method provided new insight into the development of wood color embellishment.

Functional structural color dye with excellent UV protection property

With the rapid improvement of people's living quality, the requirements for textiles are not only limited to the basic demands of warmth keeping, florid, fashion and UV protection are also badly needed. Brilliant structural color possesses many unique advantages compared with traditional dyes or pigments and has shown great potential in replacing the traditional dyes and pigments. Besides, the structural color is usually self-assembled by latex spheres with unique diameters and refractive index, therefore the building block has its own advantages to be modified and functionalized, which may have the possibility to solve problems of multiply functional dyes mentioned above. This article reported a kind of functional structure color dye with excellent ultraviolet (UV) rays protection property, which was fabricated through the self assembly of poly-(styrene-methyl methacrylate-acrylic acid)-avobenzone core-shell latex sphere, in which a commonly used UV absorber avobenzone was well encapsulated and sealed. The encapsulation of avobenzone into latex sphere ensured the structure color fantastic UV protection property, and meanwhile avoided the direct contact dermatitis of UV absorber to skin and allergens, meanwhile the as prepared structure color dye possessed good color visibility. The functional structure color dye with excellent UV protection property will provide a new perspective for the next generation functional dyes and pigments.

Direct-writing Structure Color Patterns on the Electrospun Colloidal Fibers toward Wearable Materials

This study presents a direct-writing structure color patterns on electrospun colloidal fibers by inkjet printing. The colloidal fiber was obtained by electrospinning the aqueous mixture of colloidal particles of poly(styrene-methyl methacrylate-acrylic acid) and poly(vinyl alcohol). The pattern was obtained by directly inkjet printing water onto the electrospun colloidal fiber. The pattern formation was attributed to the morphological transition of the colloidal fiber from the fiber aggregation to latex aggregation and the corresponding color change due to the dissolution of poly(vinyl alcohol) by water. Interestingly, a clear and clean image was successfully obtained on the ethanol-treated colloidal fibers film in comparison to a confused and blur image onto the freshly-made film. It is because the treatment process can compact the fiber structure and lower the spreading/wetting behavior of ink on the fiber structure, contributing to the formation of high-quality pattern. Various letters or quick response code were flexibly designed and printed on to colloidal fibers. Furthermore, the pattern can be easily transferred onto flexible substrate, i.e., a flexible printed bracelet. This work will be of great significance for the development of novel wearable functional materials/devices based on electrospun colloidal fibers.

Dyed Poly(styrene-methyl Methacrylate-acrylic Acid) Photonic Nanocrystals for Enhanced Structural Color.

In the present work, we investigated the combined effect of poly(styrene-methyl methacrylate-acrylic acid) [P(St-MMA-AA)] PCs with the disperse dye C.I. Disperse Red 343 on the photonic crystals (PCs) shape, distribution, organization, iridescence, chemical structure, thermal stability, and reflectance. PCs were successfully produced in the form of highly spherical, monodisperse colloidal structures. Presence of dye in the PCs inner core-shell structure was confirmed via Fourier-transformed infrared spectroscopy. The PCs brightness and iridescent effect was enhanced by the presence of the dyestuff, which also promoted the self-assembly of the colloidal nanospheres in the form of arrays. The P(St-MMA-AA) PCs thermal stability did not alter with the introduction of the dye. In a side experiment, dyed PCs were also coated onto dyed polyamide fabrics. Data reported successful coating of the textile fabric and an improvement of its reflectance. Fabric immobilization fostered the self-assembling of the dyed colloidal nanospheres in the form of well-organized face-centered cubic, closed-packed arrays. This is the simplest and most energy favorable organization for PCs. The combination of disperse dyes with PCs is a very recent and challenging idea and could open new ways to understand the influence the PCs photonic-band structure may exert on the photoluminescence properties of the dyes embedded in the PCs inner space, and vice versa.

Structural coloration of chitosan coated cellulose fabrics by electrostatic self-assembled poly (styrene-methyl methacrylate-acrylic acid) photonic crystals

The structural coloration of a chitosan-coated woven cotton fabric obtained by glutaraldehyde-stabilized deposition of electrostatic self-assembled monodisperse and spherically uniform (250 nm) poly (styrene-methyl methacrylate-acrylic acid) photonic crystal nanospheres (P(St-MMA-AA)) was investigated. Bright iridescent coatings displaying different colors in function of the viewing angle were obtained. The SEM, diffuse reflectance spectroscopy, TGA, DSC and FTIR analyses confirm the presence of structural color and the glutaraldehyde and chitosan ability to provide durable chemical bonding between cotton fabric and photonic crystal (PCs) coating with the highest degradation temperature and the lowest enthalpy. The coatings are characterized by a mixture of face-centered cubic and hexagonal close-packed arrays alternating random packing regions. For the first time a cost-efficient structural coloration with high washing and light fastness using self-assembled P(St-MMA-AA) photonic crystals was successfully developed onto woven cotton fabric using chitosan and/or glutaraldehyde as stabilizing agent opening new strategies for the development of dye-free coloration of textiles.

Structural coloration of chitosan-cationized cotton fabric using photonic crystals

In this work, poly (styrene-methyl methacrylate-acrylic acid) P(St-MMA-AA) composite nanospheres were deposited onto chitosan-cationized woven cotton fabrics followed by a second layer of chitosan. The deposited photonic crystals (PCs) on the fabrics were evaluated for coating efficiency and resistance, chemical analysis and color variation by optical and SEM microscopy, ATR-FTIR, diffuse reflectance spectroscopy and washing fastness. Chitosan deposition on cotton fabric provided cationic groups on the fiber surface promoting electrostatic interaction with photonic crystals. SEM images of the washed samples indicate that the PCs are firmly coated on the cotton surface only in the chitosan treated sample. The photonic nanospheres show an average diameter of 280 nm and display a face-centered cubic closepacking structure with an average thickness of 10 μm. A further chitosan post-treatment enhances color yield of the samples due to the chitosan transparent covering layer that induce bright reflections where the angles of incidence and reflection are the same. After washing, no photonic crystal can be detected on control fabric surface. However, the sample that received a chitosan post-treatment showed a good washing fastness maintaining a reasonable degree of iridescence. Chitosan fills the spaces between the polymer spheres in the matrix stabilizing the photonic structure. Sizeable variations in lattice spacing will allow color variations using more flexible non-close-packed photonic crystal arrays in chitosan hydrogels matrices.

Process optimization and optical properties of colloidal self-assembly via refrigerated centrifugation

This paper presents a detailed study of the influence of various parameters on refrigerated centrifugation (RC) of polymer colloidal crystals self-assembly. Refrigerated centrifugation could accuracy control the centrifugal temperature. Specifically, an experimental design using poly(styrene-methyl methacrylate-acrylic acid) (P(St-MMA-AA)) nanospheres was implemented to optimize the RC procedure by varying some parameters such as colloidal concentration, rotational velocity, and centrifugal temperature. The obtained colloidal crystals were characterized with respect to their morphology, periodicity, reflectance spectroscopy, and 3D surface roughness. The optimum conditions for RC fell in a narrow window, with which we obtained nearly perfect, crack-free, centimeter-sized, self-supporting, face-centered cubic colloidal crystals. The results demonstrate that the obtained P(St-MMA-AA) process parameters could be used as an operating template for other colloidal self-assemblies via refrigerated centrifugation.

Construction of Hydrogen-Bond-Assisted Crack-Free Photonic Crystal Films and Their Performance on Fluorescence Enhancement Effect

The ability to fabricate high-quality colloidal photonic crystal (CPC) films in large areas is critical in many applications, ranging from flexible displays, security devices to optical enhancement. Herein, a large-scaled CPC film with crack-free structure and uniform optical performance is prepared via a hydrogen-bond-assisted method. The crack-free CPC film is ascribed to the intermolecular hydrogen bonds between carboxyl (COOH) moieties of poly(styrene-methyl methacrylate acrylic acid) microspheres and isocyanate (NCO) moieties of polyurethane. Furthermore, the as-prepared CPC film is applied as a Bragg reflection mirror for fluorescence enhancement. It is demonstrated that a fourfold enhancement of fluorescence signal is achieved when the stopband of CPCs overlaps with the emission wavelength of quantum dots. This simple method of preparing large-area and crack-free CPC film is promising for developing efficient optical devices.