Recent advances in environmentally friendly structural colored fabrics

Abstract

Colors originating from the way that light is scattered and diffracted by random or periodic structures are called structural colors. Photonic crystals that are periodic at the scale of the wavelength of visible light exhibit structural colors, so that they have been studied as supplements of dyes to dye fabrics. Compared with dyes, photonic crystals show excellent material diversity and environmental friendliness. However, their structural colors usually exhibit two drawbacks, i.e. low saturation and poor colorfastness. This review focused on structural colored fabrics. The color saturation and colorfastness are two important aspects of structural colored fabrics and their improvement strategies are first summarized. Then, the dyeing methods, and applications of structural colored fabrics are discussed in turn. This tutorial review aims to provide insight into structural colored fabrics with high saturation and colorfastness, further promote the research progress in their functionalization, and ultimately broaden their applications in intelligent wear, anti-counterfeiting and camouflage, energy storage and conversion, and other fields.

Keywords

Structural colored fabrics photonic crystal color saturation colorfastness

Color in the nature can be divided into pigmentary color and structural color according to their generation mechanism. Pigmentary colors are chemical in origin, stemming from the selectively absorption of visible light through the transition of electrons between molecular orbitals. Structural colors are physical in nature, originating from the interaction between random or periodic structures and visible light. Because of the difference in generation mechanisms, structural colors usually show better environmental friendliness and chemical stability compared to pigmentary colors.^1,2

Structural color exists extensively in the animate and the inanimate, such as butterflies, birds, fishes and gem opals. For the animate, the structural colors usually come from the so-called photonic crystals in their wings, feathers, and scales. They not only endow the animate with a beautiful appearance, but also give a way to deliver signals and protect themselves.^3,4 Photonic crystals show vivid colors when lights interact with their microstructures that are periodic at the scale of the wavelength of visible light.^5,6

Structural colors can be divided into iridescent structural color and non-iridescent structural color, which depend on the order degree of microstructure of photonic crystals. The iridescent structural color generates from the long-range ordered array. The relationship between wavelength of structure color (λ) and structure parameters of photonic crystals follows Bragg formula

(λ = 2 d \sqrt{(n_{eff}^{2} - {\sin α}^{2})})

where d is the lattice distance, n_eff is the refractive index, and α is the incident angle.^7,8

Thus, different colors can be observed at different observation angles, that is to say, these structural colors show angle-dependence. Different from iridescent structural color, the non-iridescent structural color is angle-independent or low angle-dependent, because it is produced by amorphous structure with short-range order but long-range disorder. When the light is scattered by several close spheres possessing the same phase, the coherent scattering will occur and structural color will appear.⁹ Because natural light is incident from all angles, the coherent scattering occurs in all directions, so that the structural color shows low angle dependence.^10,11 By controlling the order of colloidal spheres array, the iridescent or non-iridescent structural colors can be obtained, and they can satisfy different needs of fabrics, such as information storage, intelligent wear and other fields. Inspired by the nature, artificial photonic crystals have been widely constructed to generate structural colors. They are composed of different dielectric constant materials that are periodically arranged. According to the number of dimensions that the dielectric constant periodically varies, they are divided into three types, i.e. one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) photonic crystals.^12,13

Fabrics are flexible products woven from fibers and yarns, which show certain mechanical properties and thickness. Various dyes were utilized to endow monotonous fabrics with beautiful colors, including azo dyes, reactive dyes, arylmethane dyes, anthraquinone dyes, and others.^14–16 Traditional dyes combine with fibers through chemical or/and physical interactions, and the dyed fabrics have good colorfastness. And the rich variety of dyes can realize the dyeing of most natural and synthetic fabrics. Meanwhile, their colors cover the visible spectrum, so that pigmentary colors occupy a dominant position in colorful fabrics. However, the pollution in the process of dyeing fabrics with dyes is inevitable, and appropriate methods need to be adopted for further treatment, such as precipitation, adsorption, ion exchanger, membrane filtration.^17–20 Compared with dyes, photonic crystals show excellent material diversity, chemical stability, and environmental friendliness, and they can further broaden the sources of fabric to be dyed. Moreover, utilizing photonic crystals to dye fabrics can endow them with not only iridescent or non-iridescent structural color, but also additional functions, such as responsiveness and hydrophobicity. Thus, structural colored fabrics show great potential to meet different application requirements.^21,22

Dyeing fabrics with structural color is a process to obtain photonic crystals on the surface of fabrics.^23,24 Color saturation and colorfastness are key factors that should be considered to obtain high-quality structural colored fabrics. The inevitable structure defects usually result in dim and white colors, and the weak bonding force between photonic crystal and fabrics usually result in poor colorfastness.²⁵ Many research articles have reported how to improve the color saturation and colorfastness of structural colored fibers and fabrics. However, the existing reviews are mainly focused on structural colored fibers,^26–28 and very few of them are focused on structural colored fabrics. This review provides a comprehensive perspective on structural colored fabrics, as shown in Figure 1, and includes the strategies to enhance color saturation and colorfastness, dyeing methods, and applications of structural colored fabrics. Based on the summary of recent advances in structural colored fabrics, this tutorial review aims to further promote the research progress in their functionalization, and ultimately broaden their applications in intelligent wear, anti-counterfeiting and camouflage, energy storage and conversion, and other fields.

Figure 1.

Schematic diagram of the main contents of this review.

Strategies to enhance color saturation and colorfastness

Enhancing color saturation

Assembling colloidal spheres on the surface of fabrics can easily obtain structural colored fabrics, and this method is almost suitable for all fabrics. Polystyrene (PS), polymethyl methacrylate (PMMA), and silicon dioxide (SiO₂) spheres are typical materials utilized to obtain structural color. Structural colored fabrics dyed by polymer photonic crystals have certain requirements for the working environment due to the limitations of glass transition temperature and solvent resistance of polymer materials. Both the temperature higher than the glass transition temperature and the solvent with strong dissolvability can destroy the structural color of polymer photonic crystals, while structural colored fabrics dyed by inorganic photonic crystals are unaffected. According to the mechanism of structural color generation, it can be effectively adjusted by controlling the diameter of spheres, which is much easier than synthesize new dye molecules.²⁹ Shao et al. assembled the above-mentioned spheres on polyester fabrics, and beautiful fabrics with different structural colors were obtained by assembling spheres with different diameters (Figure 2(a)).^30–32

Figure 2.

(a) Optical photos of structural colored polyester with different diameters of silicon dioxide (SiO₂) photonic crystals, the diameter are 321 nm, 301 nm, 280 nm, 267 nm, 241 nm, 226 nm, and 206 nm from (i) to (vii), respectively.³¹ (b) The dyed polyester fabric with structural color patterns.³⁶ and (c) The reflectance spectra of structural colored white fabrics (i) and black fabrics (ii) dyed by SiO₂@polystyrene (PS) photonic crystals.³⁷PCs: Photonic crystals.

In the process of assembling colloidal spheres, it is inevitable that defects are formed, such as point defects, line defects, and surface defects. These defects will lead to strong light scattering and hence make the structural colors milky white. To improve the color saturation, using black fabrics is a good choice.^33,34 For example, Yavuz et al. used P(St-MMA-AA) spheres to dye the black cotton fabric.³⁵ Li et al. assembled hollow SiO₂ spheres on black polyester fabric, and structural color patterns were obtained with the help of polyurethane acrylate (Figure 2(b)).³⁶ Zhou et al. studied the influence of intrinsic color of fabrics on their structural color. Black fabrics can highlight the structural color to the greatest extent, whereas white fabrics can weaken the structural color. As shown in Figure 2(c), the white fabrics only absorb a little incident light (Figure 2(c)(i)), while the black fabrics can absorb almost all light (Figure 2(c)(ii)). As a result, black fabrics facilitate an increase in the relative intensity of reflection peak coming from structural color. Results also show that the saturation of structural color decreases if the intrinsic color and the structural color are complementary, and it is not affected if they are similar.³⁷ Moreover, the characteristics of fabrics have a great impact on their optical properties. Gao et al. proved that smooth substrate is important to obtain structural color with high contrast and uniformity.³⁸

The black fabric is beneficial to improve color saturation, but it limits the application of structural color in dying fabrics with other colors. Introducing black materials to the ordered array and endowing spheres with light absorption properties are typical methods to improve color saturation of structural colored fabrics.^25,39 Meng et al. mixed the PS emulsion with carbon black and polyacrylate (PA), and utilized it to dye the voile polyester fabric. Through the absorption of background stray light and incoherent scattered light by carbon black, the color saturation was visibly improved.⁴⁰ As a known melanin-like material, polydopamine (PDA) is widely used to enhance the color saturation of structural colored fabrics. For example, Zhu et al. prepared PDA spheres and utilized them to dye silks, and the dyed silks exhibited non-iridescent structural colors with high saturation.⁴¹ Wang et al. fabricated the PS@PDA spheres and assembled them into ordered array to dye polyester fabrics. Owing to the absorption of scattered light by PDA, the structural color saturation was visibly enhanced (Figure 3(a)(i)). By contrast, the fabrics dyed by PS spheres showed low color saturation (Figure 3(a)(ii)).⁴² Zhu et al. assembled PS@PDA spheres into amorphous array to dye cotton fabrics, and the dyed fabrics showed vivid non-iridescent structural color. Compared with the fabrics dyed by amorphous PS spheres array, their color saturation was visibly improved (Figure 3(b)).⁴³ Li et al. also utilized SiO₂@PDA spheres to dye polyester fabrics, and the dyed fabrics exhibited highly saturated structural colors.⁴⁴ Shen et al. co-assembled the PS@PDA spheres and chitosan on the cotton fabrics, and the dyed cotton fabrics with non-iridescent structural colors are shown in Figure 3(c).⁴⁵ The colloidal spheres can also be modified by black disperse dyes and black reactive dyes, so that they can endow the structural colored fabrics with high color saturation.^46,47 Shi et al. prepared dopamine prepolymer, which was used to coat the fabrics and infiltrate into the voids of assembled colloidal spheres, and the obtained PDA successfully improved the color visibility (Figure 3(d)).⁴⁸ Yavuz et al. used a disperse dye, C.I. Disperse Red 343, to modify poly(styrene-methyl methacrylate-acrylic acid) (P(St-MMA-AA)) spheres, and then assembled them on the polyamide fabrics dyed by the same disperse dye to endow the fabrics with high-saturation structural colors.⁴⁹ Song et al. dyed the cotton fabric with spheres modified by a C.I. Reactive Red 218 dyes.⁵⁰ Li et al. designed polysulfide spheres with inherent light-absorbing characteristics (Figure 3(e)).²⁹ And Meng et al. applied polysulfide spheres to endow silk, steel, and PVC substrates with high-saturation structural colors without the help of black materials and dyes (Figure 3(f)).⁵¹

Figure 3.

(a) Schematic diagram of melanin-like spheres enhancing structural color saturation.⁴² (b) Optical photos of structural colored fabrics dyed with photonic crystals fabricated by polystyrene (PS) spheres (i) and amorphous photonic structure fabricated by PS@polydopamine (PDA) spheres (ii).⁴³(c) Optical photos (i) and reflection spectra (ii) of fabrics dyed with non-iridescent structural color.⁴⁵ (d) Optical photos of structural colored fabrics with enhanced saturation achieved by polymerizing dopamine in the voids of spheres.⁴⁸ (e) Optical photos of light-absorbing photonic crystals.²⁹ and (f) Different materials dyed by light-absorbing spheres.⁵¹PCs: Photonic crystals.

Both the use of black fabrics and the addition of black materials can enhance the color saturation. These methods are simple and convenient. Using black fabric as a substrate is direct, but it limits the background color of fabrics. In contrast, the introduction of black materials has no limitation on fabrics. And the color saturation can be greatly improved by adjusting the dosage of black materials. But the size of black materials needs to be adjusted to avoid the damage to the structure of photonic crystals. Meanwhile, the introduction of black material can also enhance the colorfastness.

Enhancing colorfastness

The colorfastness of structural colored fabrics is determined by the adhesion not only between spheres and fabrics but also between spheres and spheres. The adhesions between them are weak, and results in poor colorfastness. Thus, it is very important to improve colorfastness of structural colored fabrics to applied them in practical applications.

Introducing binder materials is a common and effective method to improve colorfastness, because they can bond spheres to spheres and bond spheres to fabrics.^52,53 The polymers with low glass transition temperature are good binder candidates. Meng et al. co-assembled PS spheres with PA and carbon black to dye voile fabrics with the help of interface transfer technology. PA easily softens owing to its low glass transition temperature. And then it fills the gap of the spheres uniformly and locks the spheres spatially, which makes the structural colored fabrics show good fastness to rubbing (Figure 4(a)).⁴⁰ Kong et al. also prepared free-standing structural colored film by co-assembling polysulfide spheres with PA, and further applied it into fabric printing.⁵⁴ Zeng et al. sprayed the mixture of P(St-MMA-AA) spheres, PA, and carbon black on cotton fabrics to dyed fabrics with angle-independent and robust structural colors, the color kept unchanged after standard and expedited machine laundry from 1 to 10 cycles (Figure 4(b)).⁵⁵ Li et al. used poly(methylmethacrylate-butylacrylate) P(MMA-BA) latex as adhesive binder and successfully improved the adhesive strength between the photonic crystal and fabrics. The structural color remained basically intact after kneading 20 times (Figure 4(c)).⁵⁶ In addition, co-assembly of small-sized P(MMA-BA) particles with colloidal spheres can effectively reduce the defects of photonic crystals.⁵⁷ Poly(vinyl alcohol) (PVA) can also be used as binder to improve the colorfastness of structural colored fabrics.⁵⁸ Yuan et al. prepared a viscous solution by blending P(St-MMA-AA) colloidal dispersion and PVA solution in a certain proportion, and prepared the composite fibers via electrospinning. Due to the adhesion of PVA, the colloidal spheres are closely arranged on fibers and stacked into films (Figure 4(d)(i) and (ii)). After transferring it to black substrate and removing PVA, the free-standing structural colored films were obtained (Figure 4(d)).⁵⁹ Materials with low glass transition temperature can also be used as the soft shell of core-shell colloidal spheres. The colorfastness of the structural colored fabrics can be effectively enhanced by softening the soft shell. Yuan et al. assembled the core-shell poly[styrene-co-(butyl acrylate)-co-(acrylic acid)] (P(St-BA-AA)) spheres on poly(ethylene terephthalate) (PET) fiber, and the softened shells can connect with each other tightly to achieve the structural colored fibers with robust colorfastness (Figure 4(e)).⁶⁰

Figure 4.

(a) The optical photos and SEM of the structural colored fabric before and after washing process.⁴⁰ (b) Reflection spectra of the structural colored fabric with standard machine laundry (i) and expedite machine laundry (ii) from 1 to 10 cycles, and the optical photos under expedite machine laundry with different cycles (iii).⁵⁵ (c) The optical photos of the structural colored fabric before, during, and after kneading 20 times.⁵⁶ (d) The optical photo of membrane obtained by electrospinning (i), the scanning electron microscopy (SEM) images of fiber before (ii) and after (iii) water treatment, optical photos of colorful films obtained after water treatment (iv-vi).⁵⁹ and (e) SEM images of the structural colored PET fiber (i), the surface image and inserted enlarged structure (ii), and the SEM of the knot of structural colored fiber (iii).⁶⁰PET: Poly(ethylene terephthalate).

In addition to use of synthetic materials with low glass transition temperature as binders, natural binders can also be used to enhance colorfastness. Natural binders are obtained directly from nature and easy to use, most of them are low in toxicity or non-toxic. In the process of dyeing fabrics with structural color, PDA is the most used natural binder due to its super adhesion. It can directly adhere to the surface of almost any substance through simple physical and chemical action without further grafting modification. And it is also a natural melanin, which can enhance the colorfastness and color saturation at the same time. Zhu et al. assembled PS@PDA into an amorphous array to dye cotton fabric, and the colorfastness was improved due to the high viscosity of the PDA shell.⁴³ Shi et al. directly treated cotton fabrics with dopamine hydrochloride to modify their surface with PDA. Then P(St-MMA-AA) spheres were assembled on the modified surface to realize structural color dyeing with excellent colorfastness. As shown in Figure 5(a)(i) and (ii), the structural colored fabrics possessed water resistance and kept excellent colorfastness after immersion in water for 14 days. They also possessed excellent bending resistance and kept the color unfaded after repeated rubbing or folding 50 times as shown in Figure 5(a)(iii).⁶¹ Dopamine can also be used to modify cotton fabrics through self-polymerization to make them black, but the capillary tension generated during the formation of PDA films will damage the uniformity and interfacial bonding force. Therefore, Yang et al. introduced polyvinylpyrrolidone (PVP)-containing γ-lactam groups, which can form hydrogen bonds with PDA film, to improve the colorfastness (Figure 5(b)).⁶² In addition, Fang et al. introduced poly (glycidyl methacrylate co-polyethylene glycol methyl ether methacrylate) to solve the above-mentioned problem. Due to reactive epoxy groups, covalent bonds were formed between photonic crystal film and cotton to enhance colorfastness.⁶³

Figure 5.

(a) The reflection spectra (i) and transmittance spectra (iii) of the structural colored fabrics immersed into deionized water for different days, and the optical photos of the fabric being folded and rubbed repeatedly 50 times (iii).⁶¹ (b) The optical photos of structural colored cottons before and after friction test.⁶² (c) Schematic diagram of resprayed the waterborne polyurea (WPU) on the surface of structural colored fabric (i) and the optical photos of silks with structural colored patterns (without WPU, with WPU, with WPU/WPU film) before and after friction and simulated washing tests (ii).⁵¹ (d) The optical photos (i) and (ii) and the corresponding reflectance spectra (iii) and (iv) of structural colored fabric before and after mechanical stability test.⁶⁴ and (e) The optical photos of folding and rinsing tests of the structural color pattern on fabric prepared through the hollow silicon dioxide (SiO₂) spheres and polyurethane acrylate (PUA).³⁶ PVP: polyvinylpyrrolidone.

In addition to introducing binder materials and preparing core-shell spheres with soft shell, introducing polymers as protecting layers of the structural colored fabrics is also an effective method to improve colorfastness. Meng et al. co-assembled the waterborne polyurea (WPU) and polysulfide spheres on fabrics by spray coating, and then resprayed the WPU on the surface of amorphous photonic crystals to form a transparent protective film, as shown in Figure 5(c). Because of the adhesion and protection of WPU, the colorfastness was remarkably enhanced (Figure 5(c)(ii)).⁵¹ Wang et al. used waterborne polyurethane as encapsulating agents to improve the colorfastness of structural colored fabrics. The introduction of waterborne polyurethane can not only form a transparent film on the surface of photonic crystals, but also infiltrate into the voids and make the adjacent spheres cohesive. Due to the excellent colorfastness, the colors were not damaged after rinsing with water for 5 min and 20-times folding (Figure 5(d)).⁶⁴ Li et al also used polyurethane acrylate (PUA) as polymer resin “ink” and wrote it on the hollow SiO₂ photonic crystal assembled on the fabric. Thus, the pattern printing of structural color on fiber is realized, and the colorfastness is remarkably improved due to the protection of the flexible cross-linked PUA film. After the 15-times folding and rinsing with high-speed water flow for 3 min, the pattern remained intact and the structural colors were not changed (Figure 5(e)).³⁶ In summary, the colorfastness of structural colored fabrics can be tested by means of the rubbing test, water rinsing test, and repeated bending test. The enhancement of colorfastness ensures that the microstructures of photonic crystals are not damaged and the structural colors keep unfaded. Thus, the enhancement of colorfastness provides a guarantee for the practical application of structural colored fabrics.

Introducing both binder materials and organic layers can enhance the colorfastness. The binder materials can be co-assembled with colloidal spheres or made into the shell of spheres to improve colorfastness. The black binder materials can also improve the color saturation at the same time. Here, PDA shows obvious advantages because it is a natural melanin with high viscosity. This method can also improve the performance of structural colored fabrics by introducing other suitable substances. The introduction of an organic layer can effectively protect the structural color of fabrics, but the organic layer completely covers the photonic crystal and makes the pores completely filled, which makes its performance unable to be further functionalized. This method requires that the organic layers have good transparency to ensure that the structural color can be developed normally.

Methods for dyeing fabrics with structural color

The process of dyeing fabrics by structural color can be regarded as obtaining ordered/disordered arrays on the surface of fabrics (single fiber or the fabrics woven from fibers. Actually, the dyeing process can be seen as using fabric as the substrate to fabricate photonic crystals. And the essence is still to construct photonic crystals. The methods to obtain photonic crystals all can be used to dye fabrics with structural color. Nowadays many methods have been applied to dye fabrics with structural color, such as dip-coating, gravity deposition method, electrophoretic deposition, atomic layer deposition, ink-jet printing, and electrospinning. The selection of dyeing method depends on the properties of colloidal spheres and fabrics.

Dip-coating

Dip-coating is a simple and effective coating method. Fabrics can be dyed with structural color after soaking and pulling out from colloidal emulsions (Figure 6(a)). The drawing rate, concentration of colloidal emulsions, and diameter of fibers all affect the quality of structural colored of the dyed fabrics. Yuan et al. applied dip-coating method to dye glass fibers and PET fibers with PS colloidal spheres, and a different structural color was obtained by changing sphere size (Figure 6(b)). P(St-BA-AA) spheres were co-assembled with SiO₂ by dip-coating method to dye PET fibers with crack-free and robust structural color.⁶⁰ Zhang et al. applied the dip-coating method to assemble the core-shell spheres (PS/PMMA/poly(ethyl acrylate) PEA) onto commercial spandex fibers and further applied it onto fabrics. They proved that the dip-coating method is applicable to fibers with different cross-sectional shapes and various fabrics (Figure 6(c)).⁶⁵

Figure 6.
(a) Schematic diagram of obtaining structural colored fibers by dip-coating.⁶⁰ (b) The microscope images in dark-field (i) and reflection spectra (ii) of structural colored fibers with different sizes of polystyrene (PS) spheres.⁶⁰ (c) Optical photos of cross sections of structural colored fibers with different cross-sectional shapes (i)–(vi) and optical photos of different fabrics (vii) and (viii).⁶⁵ (d) Schematic diagram of dyeing fabrics by vertical deposition.⁷² and (e) Optical photos of structural color pattern on fabrics obtained by spray coating.⁷⁶P(St-MAA): Poly(styrenemethacrylic acid).

Gravitational sedimentation and vertical deposition

Deposition methods are important methods to assemble colloidal spheres into the 3D photonic crystal, among which the gravitational sedimentation and vertical deposition are suitable for dyeing fabrics. In the dying process, the spheres gradually assemble into periodically ordered structure on substrates under the action of gravity with the evaporation of solvent. Liu et al. studied the dyeing process of gravitational sedimentation. Results showed that the colloidal spheres started assembling from the gap between fibers, and gradually deposited on the surface of polyester to form a long-range ordered array.⁶⁶ Li et al. found that the flat and compact fabrics are conducive to the self-assembly of spheres.⁶⁷ Gao et al. proposed that the structural color of fabrics generated from both the Bragg diffraction of an ordered structure and the Mie scattering of a disordered structure.⁶⁸ Fernandes et al. applied gravitational sedimentation to assemble P(St-MMA-AA) spheres on polyamide 6,6 fabrics and endowed them with structural colors.⁶⁹ Although gravitational sedimentation is a convenient dyeing method with low-cost, it usually takes a long time due to the small sizes of spheres, which usually have diameters of 100–200 nm. The modified methods based on gravitational sedimentation method, such as thermal-assisted gravity deposition and interface-gravity joint self-assembly, can shorten the dyeing time to a certain extent.^70,71 Different from gravitational sedimentation, vertical deposition can concurrently achieve the dyeing of both sides of fabrics. The liquid level slowly drops as the solvent evaporates, and the spheres assemble into ordered arrays on the surface of fabrics under the interaction of capillary force and gravity (Figure 6(d)).^72,73 Zhang and Liu pointed out that the brightness of structural color of plain fabrics is brighter than that of satin fabric dyed by vertical deposition.⁷⁴

Rapid spray coating

Rapid spray coating is an effective method to dye fabrics to endow them with non-iridescent structural colors. Different from self-assembly methods, this method can accelerate the volatilization rate of solvent and greatly reduce the assembly time, thus breaking the “crystallization” trend to obtain amorphous structure. The wettability of fabrics, volatility of solvents, spraying pressure and working distance affect the aggregation state and morphology of the as-sprayed spheres.⁷⁵ Fu et al. endowed fabrics with iridescent structural colors by the spray coating of P(St-MMA-AA) spheres, and the soft shell endowed the structural colored fabrics with high colorfastness (Figure 6(e)).⁷⁶ Yu et al. applied the spray coating method to dye the thermoplastic polyurethane (TPU)/Fe₃O₄ fiber networks, which is obtained through microfluidic blow-spinning, and the obtained structural colored films can respond to a magnetic field.⁷⁷

Ink-jet printing

Ink-jet printing is a technique that combines self-assembly with direct writing. It can directly achieve the fabric printing without the help of mold.^78,79 Similar to traditional ink-jet printing on paper, the photonic crystal ink is a key part to dye fabrics. The ink should have good fastness on fabrics, storage stability, appropriate viscosity, and other properties. With the help of the ink-jet printer, the photonic crystal can assemble on fabrics and endow it with patterned structural colors.^34,46 Liu et al. used the mixture of P(St-MAA) colloidal spheres and formamide as ink, and successfully endowed the polyester fabrics with structural color patterns by ink-jet printing (Figure 7(a)).⁸⁰

Figure 7.
(a) The photos of patterned structural colored fabrics dyed by ink-jet printing.⁸⁰ (b) Schematic diagram of dyeing fabrics by colloidal electrospinning.⁵⁹ (c) Schematic diagram of dyeing fabrics by microfluidic-spinning process.⁸² (d) Optical microscope of Janus fibers obtained by adjusting the proportion of silicon dioxide (SiO₂) with two sphere sizes.⁸³ (e) Schematic diagram of dyeing fabrics by electrophoretic deposition.⁸⁵ (f) Schematic diagram of mechanical rubbing test (i) and laundering test (ii), the optical photos and reflection spectra of structural colored fabrics before and after rubbing test (iii) and laundering test (iv).⁹² and (g) The thickness of TiO₂ coatings on fabrics and corresponding photos obtained by different deposition cycles of atomic layer deposition (ALD), the patterned structural colored fabrics with different color and the corresponding Commission Internationale de l’Eclairag (CIE) chromaticity.⁹³ PVA: poly(vinyl alcohol).

Electrospinning and microfluidic spinning technique

Directly fabricating novel fibers with structural colors is another strategy to obtain structural colored fabrics. In the electrospinning and microfluidic spinning process, the assembly of colloidal spheres and the fabrication of fibers can be completed almost at the same time. Then the obtained novel fibers can be further woven into fabrics. Electrospinning is a powerful fiber manufacturing technology realized by electrostatic atomization of polymer fluid. Under the action of a strong electric field, the droplets of polymer solution at the needle tip changes from a sphere to a cone and spray out. The polymer solution is further stretched and solidified in the flying process, and then form fibers, which finally form non-woven fabrics. Yuan et al. were able to electrospin the viscous solution of P(St-MMA-AA) colloidal dispersion and poly(vinyl alcohol) (PVA) into non-woven fabrics. As shown in Figure 7(b), after transferring it on black substrates and removing PVA in water solution, the structural colored fabrics were obtained.⁵⁹ Yuan et al. adopted the same method to fabricate fibers, and then they utilized water as the ink and carried out the inkjet printing process on the fabrics. The printed water dissolved PVA, so that the fabrics with structural color patterns were directly obtained.⁸¹ Structural colored fibers can also be obtained by microfluidic spinning technique. Li et al. used the mixed viscous solution of SiO₂ spheres and PVP to prepare fibers via the microfluidic spinning technique, and obtained structural colored fibers after removing PVP by calculation (Figure 7(c)).⁸² Kim et al. combined the microfluidic spinning technique with in-situ photocuring to continuously prepare the mechanochromic structural colored fibers. They even fabricated Janus photonic fibers by using two kinds of silica spheres with different sizes (Figure 7(d)).⁸³ Honaker et al. adopted the microfluidic wet spinning method to fabricate core-shell fibers with structural colors, of which the core and shell were composed of liquid crystal material and rubber, respectively.⁸⁴

Electrophoretic deposition

Electrophoretic deposition method shows great advantages in dyeing conductive fabrics. The charged spheres can be driven by an electric field to assemble into an ordered array, thus endowing fabrics with structural color. Liu et al. used conductive metal tubes and carbon fibers to form the circinate electric field to drive PMMA spheres to assemble on carbon fibers, and endowed carbon fibers with structural colors (Figure 7(e)).⁸⁵ Sun et al. used the electrophoretic deposition method to assemble PS spheres onto carbon nanotubes wound on the surface of poly(dimethylsiloxane) (PDMS) fiber, and then covered the colloidal spheres with PDMS to protect them. The obtained fibers were mechanochromic, and the structural color could be changed by stretching and releasing.⁸⁶

Magnetic field assisted dyeing

Under the action of an external magnetic field, magnetic spheres can be assembled into an ordered array and hence endow fabrics with structural color. Wang et al. utilized this method to construct novel structural colored fibers. Different polymer monomers mixed with the superparamagnetic Fe₃O₄@C spheres were injected into a Teflon tube, and then polymerized under the action of a magnetic field, and thus the structural colored fibers were directly obtained.^87–89 The structural colored fibers have excellent mechanical and strain-responsive properties, and show great potential for application.

Atomic layer deposition

Different from the above above-mentioned methods, atomic layer deposition (ALD) is a dyeing method based on chemical reactions. The dyeing process of ALD is achieved by alternate deposition of different materials on the fabric surface. The thickness and composition of materials can be accurately controlled because of the unique self-limited growth process. ALD can effectively solve the strength problem because it is realized by covalent bonding instead of non-covalent bonding such as hydrogen bond, electrostatic force, and van der Waals force.⁹⁰ ALD can be carried out under medium pressure and low temperature, and can even achieve the growth of metal oxides at room temperature, thus providing great convenience for dyeing temperature sensitive materials.⁹¹ ALD has been widely used for dyeing carbon fabrics. Niu et al. applied ALD to alternately deposit Al₂O₃ and ZnO layers on carbon fiber, and endowed the fibers with structural colors generated from one-dimensional photonic crystals. The structural colored carbon fibers showed excellent tensile strength and washing resistance (Figure 7(f)).⁹² Chen et al. dyed carbon fabrics with structural colors by depositing TiO₂ coating. As shown in Figure 7(g), the structural color was controlled by the thickness of TiO₂ coating, which depended on the number of ALD cycles. With the help of a mask, the structural color printing was further realized by controlling the cycle numbers.⁹³ Khan et al. also alternately deposited Al₂O₃ and ZnO to dye e-textiles via ALD, and the structural colored textiles showed great potential for wearable electronic products.⁹⁴ ALD can not only dye fabrics with structural color, but also keep or endow fabrics with other properties, such as chemical stability and photostability.⁹⁵

For most spheres, such as PS, PMMA, SiO₂, core-shell spheres, the dip-coating, gravitational sedimentation and vertical deposition, rapid spray coating, ink-jet printing methods can be used to dye fabrics. These methods are easy to operate and low cost. And ink-jet printing can directly achieve the fabric printing without the help of a mold. Electrospinning and microfluidic spinning technique are methods can directly fabricate novel fabrics with structural color through colloidal spheres. For the above spheres, the ink-jet printing, electrospinning, and microfluidic spinning technique all require the solution used to have a certain viscosity. But for special spheres and fabrics, these dyeing methods can not satisfy our demand. For conductive fabrics, electrophoretic deposition is more suitable. For the magnetic spheres, the dyeing process needs the assistance of a magnetic field. For the sensitive materials and fabrics, the medium pressure and low temperature operating conditions of ALD show great advantages. And ALD can achieve the dyeing through the precursor liquid instead of colloidal spheres. In addition to the above methods, other methods such as heating evaporation-induced self-assembly,⁹⁶ extrusion method,⁹⁷ electrostatic self-assembly,^98,99 screen printing,⁵³ atomization deposition,⁵⁸ and magnetron sputtering deposition,^100–102 can also be used to dye fabrics to endow them with structural colors. The various dyeing methods provide great convenience to obtain structural colored fabrics with properties that are demanded. The specific dyeing method is mainly selected according to the properties of fabrics and spheres, and it can be optimized to obtain structural colored fabrics with high color saturation and excellent colorfastness.

Applications of structural colored fabrics

The most basic application of structural colored fabrics is to enrich the color of fabrics and hence our life through use of green methods. In addition, structural colored fabrics can also be endowed with different functions. Structural color originates from the physical interaction between the microstructure and visible light, and it can be regulated by changing the lattice parameters and refractive index. Owing to the change of structural color caused by external stimulation, structural colored fabrics can be endowed with response performance and show potential advantages in the sensing field. The response performance is realized by changing the lattice parameters and refractive index of photonic crystals. Namely, the photonic crystal layers act as response layers while the fabrics act as substrates. Yuan et al. dyed carbon fibers with poly(N-isopropylacrylamide)-co- acrylic acid spheres via the electrophoretic deposition method and endowed the fibers with sensing properties. The polar organic solvent gas can permeate into the air-sphere-pores of photonic crystal, and the gap between two spheres and the sphere diameters both increase due to the formed H-bond, thus resulting in the change of structural color (Figure 8(a)).¹⁰³ Malekovic et al. fabricated fibers with multilayer cladding, which was assembled by the films of PDMS and a PS-polyisoprene blockcopolymer and formed distributed Bragg reflectors. Due to physicochemical interaction between the solvent and structural colored fibers, the layers swell and effective refractive index changes, hence resulting in the color changes which are the sensor signals.¹⁰⁴ Zhao et al. fabricated structural colored fabrics with bright colors and enhanced toughness by combining the supramolecular photonic elastomers with hierarchical-fiber-structured conductive polyester fabrics. They achieved properties of optical response and electric response, and these can be used to monitor human joint movements (Figure 8(b)). Taking the movement of wrist as an example, the wrist bending process can be regarded as stretching the fabrics in the horizontal direction, thus the lattice spacing is reduced in the vertical direction, and hence the structural color changes from red to green, and the relative resistance changes at the same time.¹⁰⁵ Nie et al. used two methods, assembling the cellulose nanocrystal (CNC) with different proportions of glucose, or self-assembling CNC in the vertical direction, to dye cotton fabrics. The structural colored fabrics can respond to the relative humidity fluctuation. Therefore, they can be used as a test material to distinguish the water content in ethanol.¹⁰⁶

Figure 8.
(a) Schematic diagram of structural colored fiber sensing to vaper (i), and the color changes from original purple (ii) and (iv) to blue (iii) and (v) for the response to acetone and ethanol vaper respectively.¹⁰³ (b) Schematic diagram of mechanochromic electronic fabric used for monitoring human joint movements (i) and the time-varying signal of reflection spectra and relative resistance variation of wrist bending.¹⁰⁵ (c) The photo of the fabrics dyed by hexadecyltrimethoxysilane (HDTMS)-silicon dioxide (SiO₂) and perfluorodecyltrimethoxysilane (FAS)-SiO₂ spheres dripping with water and oil droplets respectively (i), and the photo of fabrics immersed into water and oil (ii).¹⁰⁹ and (d) Schematic diagram of the thermal measurement and the reflective cooling mechanism under solar irradiation of structural colored carbon fabrics (i) and the infrared thermal images of non-dyed carbon fabrics (top) and structural colored carbon fabrics (bottom) (ii).⁹²

Structural colored fabrics can also be used in self-cleaning materials. The structural colored fabrics can be endowed with hydrophobic properties by using hydrophobic spheres. The spheres attach to the surface of fabrics and occupy the voids of fibers, so as to prevent the infiltration of water and improve the hydrophobic property. The rough structure of spheres can also induce the formation of a double rough structure similar to lotus leaves, and the special “lotus” structure can effectively enhance the hydrophobicity of fabrics. Thus, they are expected to be used in the field of self-cleaning.^107,108 Li et al. modified SiO₂ spheres with hexadecyltrimethoxysilane (HDTMS) and 1H, 1H, 2H, 2H-perfluorodecyltrimethoxysilane (FAS), and used them (HDTMS-SiO₂, FAS-SiO₂) to endow fabrics with superhydrophobic and oleophobic properties, respectively (Figure 8(c)(i)). As shown in Figure 8(c)(ii), the structural colored fabrics dyed by HDTMS-SiO₂ and FAS-SiO₂ can resist water and oil respectively, and their structural colors keeps unchanged after immersion, thus achieving self-cleaning function.¹⁰⁹

In addition to sensing and self-cleaning applications, structural colored fabrics can also be used for thermal management. Niu et al. dyed carbon fabrics with 1D photonic crystals, and endowed the fabrics with vivid structural color and excellent colorfastness. Moreover, the light reflection of the structural colored fabrics in the visible and near-infrared regions was utilized to achieve thermal management. As shown in Figure 8(d), the temperature of structural colored carbon fabrics and non-dyed carbon fabrics both increased under the solar irradiation, but the increase range of structural colored fabrics was smaller, which showed the superior cooling power and capability for thermal management.⁹²

Although structural colored fabrics have been used in the fields of sensing, self-cleaning and thermal management, their application prospects need to be further expanded. Actually, they are potential to be applied in intelligent wear, anti-counterfeiting and camouflage, energy storage and transformation and other fields, and becoming an indispensable part of life.

Summary and outlook

This review focused on structural colored fabrics, which are dyed by photonic crystals. Attention should be paid to two problems of their optical properties, i.e. low color saturation and poor colorfastness. The utilization of black fabrics, the introduction of black materials such as carbon, PDA, and black dyes, and coating of colloidal spheres with a PDA shell all can improve the color saturation of structural colored fabrics via the absorption of visible light. To realize the application of structural colored fabrics, their poor colorfastness is an urgent problem that should be solved. Both co-assembling binder materials with colloidal spheres or making them into core-shell colloidal spheres can effectively improve the adhesion between not only spheres and spheres but also spheres and fabrics. In addition, coating an organic layer on the surface of structural colored fabrics can enhance the adhesion between photonic crystal layer and fabrics, thus effectively protecting their structural colors.

There are various methods for dyeing fabrics with structural colors, which are selected based on the properties of colloidal spheres and fabrics. Methods, such as dip-coating, gravitational sedimentation, vertical deposition, and rapid spraying, are simple to operate and have low requirements for equipment. They are applicable to most spheres, such as PS, PMMA, and SiO₂ spheres, and core-shell spheres. ALD and ink-jet printing can realize the precise control of dyeing and printing of fabrics. Electrospinning and microfluidic spinning can realize fiber dyeing while preparing fiber and the structural colored fibers can be woven into fabrics. For special materials, the dyeing methods can be selected according to their characteristics. For example, electrophoretic deposition is suitable for conductive fabrics, magnetic field assisted dyeing is suitable for magnetic spheres.

Owing to the material diversity, chemical stability, and environmental friendliness, the structural colored fabrics exhibit broad application prospects. They are widely used for sensing, where the changes of lattice spacing and refractive index both provide a basis for sensing performance. Nowadays, the structural colored fabrics can be applied to sensing solvent, vapor, pressure, electrical signals, and so on. Structural color dyeing can endow fabrics with superhydrophobic properties, which makes them show application potential on self-cleaning clothes. The structural colored fabrics can also be given other functions and even multi-function, and can be used in many fields.

At present, there are many research studies on structural colored fabrics, but most of them focus on improving basic color properties, i.e. improving the color saturation and colorfastness. Although a large number of studies have been carried out on dyeing fabrics with structural color, they are still limited to the laboratory and far from practical applications. And the research on the functionalization and application of structural colored fabrics is deficient and needs to be further expanded. According to the specific needs of application, the reasonable selection of dyeing methods and materials is critical for realizing the practical applications of structural colored fabrics. At the same time, we can innovate the dyeing methods by learning from other membrane preparation technologies, and we can also try to achieve dyeing through the synergy of multiple methods. In order to endow structural colored fabrics with functions and expand their applications, the functional design of photonic crystals is particularly important. We can design and endow the photonic crystals with fluorescence, temperature sensitivity, photosensitivity, shape memory, and other properties, and use them for dyeing to realize the functionalization of structural colored fabrics, so as to broaden the application fields. It is a definite trend to dye fabrics with structural color and endow them with multi-functions. It is believed that with the deepening of research, structural colored fabrics are expected to be applied to intelligent wear, anti-counterfeiting and camouflage, energy storage and conversion, and other fields, and become an indispensable part of life.

Fabric dyeing by pigmentary color is achieved through the physical/chemical interactions between dye molecules and fabrics, while the essence of structural color dyeing is obtaining an ordered/disordered array on the surface of fabrics. Although the color saturation and colorfastness of structural colored fabrics compared with fabrics dyed by traditional dyes still show a certain gap, the excellent light fastness of structural color is incomparable due to the color generation mechanism. Therefore, structural color has broad application prospects for fabric dyeing. In order to accelerate the application process of dyeing fabrics by structural color in industry, it is necessary to enhance the color saturation and colorfastness, innovate the dyeing methods, and even refer to the research on dyeing fabrics by pigmentary color to establish dyeing models and propose performance indicators for evaluating dyeing performance. With the deepening of research on fabric dyeing by structural color, the findings will eventually be applied in industry to satisfy our needs in life.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the National Natural Science Foundation of China (22108299, 21878043), the Postdoctoral Science Foundation of China (2021M693970), the Science and Technology Innovation Program of Hunan Province (2021RC2066), the Huxiang Young Talent Project (2020RC3033), Innovative Talents of Colleges and Universities in Liaoning Province (LCR2018066), and CFC Key Laboratory Foundation of NUDT (WDZC20205500508).

ORCID iDs

Fangfang Liu

Bingtao Tang

References

Liu

Xiu

Tang

, et al. Dynamic monitoring of thermally assisted assembly of colloidal crystals. J Mater Sci 2017; 52: 7883–7892.

Shang

Zhang

, et al. Bio-inspired intelligent structural color materials. Mater Horiz 2019; 6: 945–958.

Teyssier

Saenko

van der Marel

, et al. Photonic crystals cause active colour change in chameleons. Nat Commun 2015; 6: 6368.

Zhou

Yang

Liu

, et al. Dynamic structural color from wrinkled thin films. Adv Opt Mater 2020; 8: 2000234.

Dong

Schaefer

, et al. Solvatochromism based on structural color: Smart polymer composites for sensing and security. Mater Design 2018; 160: 417–426.

Zhang

Han

Ouyang

, et al. Synthesis of poly(styrene-N-hydroxymethyl acrylamide) microspheres and their application in patterned photonic crystals. Text Res J. Epub before print day month 2022. Published July 28, 2022. DOI: 10.1177/00405175221112661.

Guo

Chen

, et al. Reconfiguration of three-dimensional liquid-crystalline photonic crystals by electrostriction. Nat Mater 2020; 19: 94–101.

Zhu

Electrically tunable liquid photonic crystals with large dielectric contrast and highly saturated structural colors. Adv Funct Mater 2018; 28: 1804628.

Noh

Liew

Saranathan

, et al. How noniridescent colors are generated by quasi-ordered structures of bird feathers. Adv Mater 2010; 22: 2871–2880.

10.

Zhang

Dong

Chen

, et al. Using cuttlefish ink as an additive to produce non-iridescent structural colors of high color visibility. Adv Mater 2015; 27: 4719–4724.

11.

Meng

Umair

Zhang

, et al. Thermal-guided interfacial confinement to fabricate flexible structural color composites for durable applications. J Mater Chem C 2019; 7: 11258–11264.

12.

Kuang

Wang

Jiang

Bio-inspired photonic crystals with superwettability. Chem Soc Rev 2016; 45: 6833–6854.

13.

Leo

Zhang

, et al. Chromogenic photonic crystal sensors enabled by multistimuli-responsive shape memory polymers. Small 2018; 14: e1703515.

14.

Qiu

Xiao

Tang

, et al. Facile synthesis of novel disperse azo dyes with aromatic hydroxyl group. Dyes Pigments 2019; 160: 524–529.

15.

Shan

Tong

Xiong

, et al. A new kind of H-acid monoazo-anthraquinone reactive dyes with surprising colour. Dyes Pigments 2015; 123: 44–54.

16.

Shan

Cui

Zhang

, et al. Synthesis and application of poly(vinylamine-co-acrylic acid) macromolecule dyes with high light fastness. Text Res J 2020; 90: 156–165.

17.

Saruchi, Kumar

Ghfar

, et al. Microwave synthesize karaya Gum-Cu, Ni nanoparticles based bionanocomposite as an adsorbent for malachite green dye: Kinetics and thermodynamic. Front Mater 2022; 9: 827314.

18.

Saruchi, Sharma

Hatshan

, et al. Sequestration of eosin dye by magnesium (II)-doped zinc oxide nanoparticles: Its kinetic, isotherm, and thermodynamic studies. J Chem Eng Data 2021; 66: 646–657.

19.

Saruchi, Verma

Kumar

, et al. Comparison between removal of ethidium bromide and eosin by synthesized manganese (II) doped zinc (II) sulphide nanoparticles: Kinetic, isotherms and thermodynamic studies. J Environ Health Sci Engineer 2020; 18: 1175–1187.

20.

Saruchi and Kumar V. Effective degradation of rhodamine B and Congo red dyes over biosynthesized silver nanoparticles-imbibed carboxymethyl cellulose hydrogel. Polym Bull 2020; 77: 3349–3365.

21.

Yang

Colored cotton fabric with hydrophobicity prepared by monodispersed cationic colored polymer nanospheres. Colloid Polym Sci 2021; 299: 1371–1381.

22.

Yavuz

Zille

Seventekin

, et al. Structural coloration of chitosan-cationized cotton fabric using photonic crystals. IOP Conf Ser: Mater Sci Eng 2017; 254: 102012.

23.

Zhou

Liu

, et al. The synthesis of core-shell monodisperse P(St-MAA) microspheres and fabrication of photonic crystals Structure with Tunable Colors on polyester fabrics. Fiber Polym 2014; 15: 1112–1122.

24.

Zhou

Chai

, et al. Study on the formation of three-dimensionally ordered SiO₂ photonic crystals on polyester fabrics by vertical deposition self-assembly. Text Res J 2016; 86: 1973–1987.

25.

Shen

Shi

You

, et al. Large-scale fabrication of three-dimensional ordered polymer films with strong structure colors and robust mechanical properties. J Mater Chem 2012; 22: 8069–8075.

26.

Huang

S-G

Ren

, et al. Structural coloration and its application to textiles: A review. J Text I 2019; 111: 756–764.

27.

Kan

C-W.

Review on fabrication of structurally colored fibers by electrospinning. Fibers 2018; 6: 70.

28.

Sun

Peng

Mechanochromic fibers with structural color. Chemphyschem 2015; 16: 3761–3768.

29.

Tang

, et al. Facile synthesis of monodispersed polysulfide spheres for building structural colors with high color visibility and broad viewing angle. Small 2017; 13: 201602565.

30.

Shao

Zhang

, et al. Preparation of monodispersed polystyrene microspheres and self-assembly of photonic crystals for structural colors on polyester fabrics. J Text I 2014; 105: 938–943.

31.

Zhou

Liu

, et al. Fabrication of high-quality silica photonic crystals on polyester fabrics by gravitational sedimentation self-assembly. Color Technol 2015; 131: 413–423.

32.

Chai

Zhou

Liu

, et al. Study on the stability of the photonic crystals under different application environments and the possible mechanisms. J Text I 2018; 110: 234–242.

33.

Liu

Han

Chai

, et al. Fabrication of cotton fabrics with both bright structural colors and strong hydrophobicity. Colloid Surface A 2020; 600: 124991.

34.

Liu

Han

Chai

, et al. Preparation of P(St-NMA) microsphere inks and their application in photonic crystal patterns with brilliant structural colors. Front Mater Sci 2020; 14: 62–72.

35.

Yavuz

Zille

Seventekin

, et al. Structural coloration of chitosan coated cellulose fabrics by electrostatic self-assembled poly (styrene-methyl methacrylate-acrylic acid) photonic crystals. Carbohydr Polym 2018; 193: 343–352.

36.

Wang

, et al. Patterned SiO₂/Polyurethane acrylate inverse opal photonic crystals with high color saturation and tough mechanical strength. Langmuir 2019; 35: 14282–14290.

37.

Zhou

Liu

, et al. Study on the correlations between the structural colors of photonic crystals and the base colors of textile fabric substrates. Dyes Pigments 2016; 133: 435–444.

38.

Gao

Rigout

Owens

The structural coloration of textile materials using self-assembled silica nanoparticles. J Nanopart Res 2017; 19: 303.

39.

Tang

Xiu

, et al. Hydrophilic modification of multi-walled carbon nanotube for building photonic crystals with enhanced color visibility and mechanical strength. Molecules 2016; 21: 547.

40.

Meng

Tang

, et al. Multiple colors output on voile through 3D colloidal crystals with robust mechanical properties. ACS Appl Mater Interfaces 2017; 9: 3024–3029.

41.

Zhu

Yan

, et al. Fabrication of non-iridescent structural color on silk surface by rapid polymerization of dopamine. Prog Org Coat 2020; 149: 105904.

42.

Wang

Zhou

, et al. Structural colouration of textiles with high colour contrast based on melanin-like nanospheres. Dyes Pigments 2019; 169: 36–44.

43.

Zhu

Wei

Mia

, et al. Preparation of PS@PDA amorphous photonic structural colored fabric with vivid color and robust mechanical properties based on rapid polymerization of dopamine. Colloid Surface A 2021; 622: 126651.

44.

Jia

Dong

, et al. Construction of photonic crystal structural colors on white polyester fabrics. Opt Mater 2021; 116: 111115.

45.

Shen

Liang

Song

, et al. Facile fabrication of mechanically stable non-iridescent structural color coatings. J Mater Sci 2019; 55: 2353–2364.

46.

Chai

Hong

Sun

, et al. Preparation of disperse dye@P(St-BA-MAA) microsphere inks and their application on white textile substrates with high color saturation. Dyes Pigments 2021; 193: 109528.

47.

Zhou

, et al. Facile fabrication of reactive dye@PSt photonic crystals with high contrast on textile substrates by ink-jet printing. Mater Chem Phys 2020; 250: 123025.

48.

Shi

, et al. Rapid fabrication of robust and bright colloidal amorphous arrays on textiles. J Coat Technol Res 2020; 17: 1033–1042.

49.

Yavuz

Felgueiras

Ribeiro

, et al. Dyed Poly(styrene-methyl methacrylate-acrylic acid) photonic nanocrystals for enhanced structural color. ACS Appl Mater Interfaces 2018; 10: 23285–23294.

50.

Song

Fang

Bukhari

, et al. Green and efficient inkjet printing of cotton fabrics using reactive dye@copolymer nanospheres. ACS Appl Mater Interfaces 2020; 12: 45281–45295.

51.

Meng

Umair

Iqbal

, et al. Rapid fabrication of noniridescent structural color coatings with high color visibility, good structural stability, and self-healing properties. ACS Appl Mater Interfaces 2019; 11: 13022–13028.

52.

Liu

Guo

Zhou

, et al. Tough, structurally colored fabrics produced by photopolymerization. J Mater Sci 2019; 54: 10929–10940.

53.

Zhou

Zhang

, et al. Rapid fabrication of vivid noniridescent structural colors on fabrics with robust structural stability by screen printing. Dyes Pigments 2020; 176: 108226.

54.

Kong

Meng

Zhang

, et al. Self-supporting structural color films with excellent stability and flexibility through hot-press assisted assembly. Dyes Pigments 2021; 195: 109742.

55.

Zeng

Ding

, et al. Rapid fabrication of robust, washable, self-healing superhydrophobic fabrics with non-iridescent structural color by facile spray coating. RSC Adv 2017; 7: 8443–8452.

56.

Fan

Wang

, et al. Shear-induced assembly of liquid colloidal crystals for large-scale structural coloration of textiles. Adv Funct Mater 2021; 31: 2010746.

57.

Zhou

Liu

, et al. Study on the fabrication of composite photonic crystals with high structural stability by co-sedimentation self-assembly on fabric substrates. Appl Surf Sci 2018; 444: 145–153.

58.

Zhang

Shi

, et al. Additive mixing and conformal coating of noniridescent structural colors with robust mechanical properties fabricated by atomization deposition. ACS Nano 2018; 12: 3095–3102.

59.

Yuan

Zhou

Shi

, et al. Structural coloration of colloidal fiber by photonic band gap and resonant Mie scattering. ACS Appl Mater Interfaces 2015; 7: 14064–14071.

60.

Yuan

Zhou

, et al. Structural color fibers directly drawn from colloidal suspensions with controllable optical properties. ACS Appl Mater Interfaces 2019; 11: 19388–19396.

61.

Shi

Xie

, et al. Photonic crystals with vivid structure color and robust mechanical strength. Dyes Pigments 2019; 165: 137–143.

62.

Yang

Zhou

Duan

, et al. Preparation of structural color on cotton fabric with high color fastness through multiple hydrogen bonds between polyphenol hydroxyl and lactam. ACS Appl Mater Interfaces 2022; 14: 3244–3254.

63.

Fang

Liu

Zheng

, et al. Eco-friendly colorization of textile originating from polydopamine nanofilm structural color with high colorfastness. J Clean Prod 2021; 295: 126523.

64.

Wang

Zhao

, et al. High structural stability of photonic crystals on textile substrates, prepared via a surface-supported curing strategy. ACS Appl Mater Interfaces 2021; 13: 19221–19229.

65.

Zhang

Liu

, et al. The continuous fabrication of mechanochromic fibers. J Mater Chem C 2016; 4: 2127–2133.

66.

Liu

Shao

Zhang

, et al. Self-assembly behavior of polystyrene/methacrylic acid (P(St-MAA)) colloidal microspheres on polyester fabrics by gravitational sedimentation. J Text I 2015; 106: 1293–1305.

67.

Zhou

Zhang

, et al. Study on the effects of the characteristics of textile substrates on the photonic crystal films and the related structural colors. Surf Coat Tech 2017; 319: 267–276.

68.

Gao

Rigout

Owens

Optical properties of cotton and nylon fabrics coated with silica photonic crystals. Opt Mater Express 2017; 7: 341–353.

69.

Fernandes

RDV

Gomes

Zille

, et al. The influence of chemical reaction conditions upon poly(styrene-methyl methacrylate-acrylic acid) synthesis: Variations in nanoparticle size, colour and deposition methods. Color Technol 2020; 136: 101–109.

70.

Lee

Kan

, et al. Fabrication of structural-coloured carbon fabrics by thermal assisted gravity sedimentation method. Nanomaterials 2020; 10: 1133.

71.

Chai

Zhou

Liu

, et al. Interface-gravity joint self-assembly behaviors of P(St-MAA) colloidal microspheres on polyester fabric substrates. J Mater Sci 2017; 52: 5060–5071.

72.

Liu

Zhou

, et al. The fabrication of full color P(St-MAA) photonic crystal structure on polyester fabrics by vertical deposition self-assembly. J Appl Polym Sci 2015; 132: 41750.

73.

Liu

Zhou

Fan

, et al. The vertical deposition self-assembly process and the formation mechanism of poly(styrene-co-methacrylic acid) photonic crystals on polyester fabrics. J Mater Sci 2015; 51: 2859–2868.

74.

Zhang

Liu

Preparation and self-assembly of photonic crystals on polyester fabrics. Iran Polym J 2017; 26: 107–114.

75.

Yang

, et al. Angle-independent colours from spray coated quasi-amorphous arrays of nanoparticles: Combination of constructive interference and Rayleigh scattering. J Mater Chem C 2014; 2: 4395–4400.

76.

Zhang

Chu

, et al. Rapid fabrication of photonic crystal patterns with iridescent structural colors on textiles by spray coating. Dyes Pigments 2021; 195: 109747.

77.

Zhu

, et al. Fabrication of magnetically driven photonic crystal fiber film via microfluidic blow-spinning towards dynamic biomimetic butterfly. Mater Lett 2021; 291: 129450.

78.

Cui

Wang

, et al. Fabrication of large-area patterned photonic crystals by ink-jet printing. J Mater Chem 2009; 19: 5499–5502.

79.

H-Y

Park

Shin

, et al. Rapid self-assembly of monodisperse colloidal spheres in an ink-jet printed droplet. Chem Mater 2004; 16: 4212–4215.

80.

Liu

Zhou

Zhang

, et al. Fabrication of patterned photonic crystals with brilliant structural colors on fabric substrates using ink-jet printing technology. Mater Design 2017; 114: 10–17.

81.

Yuan

S-J

Meng

W-H

A-H

, et al. Direct-writing structure color patterns on the electrospun colloidal fibers toward wearable materials. Chinese J Polym Sci 2019; 37: 729–736.

82.

G-X

Shen

H-X

, et al. Fabrication of colorful colloidal photonic crystal fibers via a microfluidic spinning technique. Mater Lett 2019; 242: 179–182.

83.

Kim

Lee

, et al. Microfluidic production of mechanochromic photonic fibers containing nonclose‐packed colloidal arrays. Small Sci 2021; 1: 2000058.

84.

Honaker

Vats

Anyfantakis

, et al. Elastic sheath-liquid crystal core fibres achieved by microfluidic wet spinning. J Mater Chem C 2019; 7: 11588–11596.

85.

Liu

Zhang

Wang

, et al. Structurally colored carbon fibers with controlled optical properties prepared by a fast and continuous electrophoretic deposition method. Nanoscale 2013; 5: 6917–6922.

86.

Sun

Zhang

, et al. Mechanochromic photonic-crystal fibers based on continuous sheets of aligned carbon nanotubes. Angew Chem Int Ed Engl 2015; 54: 3630–3634.

87.

Shang

Liu

Zhang

, et al. Facile fabrication of a magnetically induced structurally colored fiber and its strain-responsive properties. J Mater Chem A 2015; 3: 11093–11097.

88.

Liu

Zhang

Wang

, et al. Magnetic field induced formation of visually structural colored fiber in micro-space. J Colloid Interface Sci 2013; 406: 18–23.

89.

Shang

Zhang

Wang

, et al. Facile fabrication of magnetically responsive PDMS fiber for camouflage. J Colloid Interface Sci 2016; 483: 11–16.

90.

Johnson

Hultqvist

Bent

SF.

A brief review of atomic layer deposition: From fundamentals to applications. Mater Today 2014; 17: 236–246.

91.

Guo

, et al. Recent progress of atomic layer deposition on polymeric materials. Mater Sci Eng C Mater Biol Appl 2017; 70: 1182–1191.

92.

Niu

Zhang

Wang

, et al. Multicolored photonic crystal carbon fiber yarns and fabrics with mechanical robustness for thermal management. ACS Appl Mater Interfaces 2019; 11: 32261–32268.

93.

Chen

Yang

, et al. Facile and effective coloration of dye-inert carbon fiber fabrics with tunable colors and excellent laundering durability. ACS Nano 2017; 11: 10330–10336.

94.

Khan

Kim

Park

, et al. Tunable color coating of E-textiles by atomic layer deposition of multilayer TiO₂/Al₂O₃ films. Langmuir 2020; 36: 2794–2801.

95.

Yang

, et al. Facile and effective fabrication of highly UV-resistant silk fabrics with excellent laundering durability and thermal and chemical stabilities. ACS Appl Mater Interfaces 2019; 11: 27426–27434.

96.

Liu

Zhang

Wang

, et al. Structural colored fiber fabricated by a facile colloid self-assembly method in micro-space. Chem Commun (Camb) 2011; 47: 12801–12803.

97.

Finlayson

Goddard

Papachristodoulou

, et al. Ordering in stretch-tunable polymeric opal fibers. Opt Express 2011; 19: 3144–3154.

98.

Zhang

Zhuang

Jia

, et al. Structural coloration of polyester fabrics with electrostatic self-assembly of (SiO₂/PEI)_n. Text Res J 2015; 85: 785–794.

99.

Zhuang

Ping

Zhang

, et al. Optical properties of silk fabrics with (SiO₂/polyethyleneimine)_n film fabricated by electrostatic self-assembly. Text Res J 2016; 86: 1914–1924.

100.

Yuan

Wei

Chen

, et al. Electrical and optical properties of polyester fabric coated with Ag/TiO₂ composite films by magnetron sputtering. Text Res J 2016; 86: 887–894.

101.

Zhang

Jiang

Cai

, et al. Magnetron sputtering deposition of Ag/Ag₂O bilayer films for highly efficient color generation on fabrics. Ceram Int 2020; 46: 13342–13349.

102.

Yuan

Yin

, et al. Properties and application of multi-functional and structurally colored textile prepared by magnetron sputtering. J Ind Text 2020; 51: 1295–1311.

103.

Yuan

Liu

Shang

, et al. Visibly vapor-responsive structurally colored carbon fibers prepared by an electrophoretic deposition method. RSC Adv 2016; 6: 16319–16322.

104.

Malekovic

Urann

Steiner

, et al. Soft photonic fibers for colorimetric solvent vapor sensing. Adv Optical Mater 2020; 8: 2000165.

105.

Zhao

Cao

Alsaid

, et al. Interactively mechanochromic electronic textile sensor with rapid and durable electrical/optical response for visualized stretchable electronics. Chem Eng J 2021; 426: 130870.

106.

Nie

, et al. Chameleon-inspired iridescent structural color textiles with reversible multiple stimulus-responsive functions. Chem Eng J 2022; 433: 134410.

107.

Joshi

Bhattacharyya

Agarwal

, et al. Nanostructured coatings for super hydrophobic textiles. B Mater Scie 2012; 35: 933–938.

108.

Liu

Zhou

Wang

, et al. Study on the high hydrophobicity and its possible mechanism of textile fabric with structural colors of three-dimensional poly(styrene-methacrylic acid) photonic crystals. RSC Adv 2015; 5: 62855–62863.

109.

Chai

Wang

, et al. Facile fabrication of amorphous photonic structures with non-iridescent and highly-stable structural color on textile substrates. Materials 2018; 11: 2500.