Conventional Dyes Research Articles

Solvent-Free Synthesis of Fluorescent Carbon Dots: An Ecofriendly Approach for the Bioimaging and Screening of Anticancer Activity via Caspase-Induced Apoptosis.

Ecofriendly and highly fluorescent carbon dot nanoassemblies have gained prominence for their diverse biological applications, with a focus on combating environmental and human health problems. In this study, we prepared highly fluorescent nitrogen-doped carbon dots from the persimmon fruit (termed as "PCDs"), which was used as a carbon source, via a one-step hydrothermal reaction without any solvent. It is interesting to note that the as-prepared PCDs were highly water-soluble because of the numerous polar functional groups, such as hydroxyl (-OH), amine (-NH2), and carboxylic acid (-COOH) groups, as confirmed by ultraviolet-visible, Fourier-transform infrared, and X-ray photoelectron spectral analysis. These polar functional groups enabled the production of nanohybrids by immobilization of the anticancer drugs doxorubicin and gemcitabine on the surface of the PCDs (PCDs@Dox and PCDs@Gem, respectively) through the 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide coupling reaction. Unlike other reports, as-prepared PCDs@Dox and PCDs@Gem nanohybrids were successfully employed for bioimaging and caspase-induced apoptosis applications. The neat PCDs exhibited significant pH-induced cytotoxicity because of the presence of surface carboxylic acid and phenolic moieties. Thus, PCDs@Dox and PCDs@Gem effectively inhibited the proliferation of HeLa cells in a dose-dependent manner, and the cytotoxicity of the nanohybrids in fibroblasts was significantly lower than that of cancerous cells at the same dose. In addition, it is quite certain that promising boi-imaging results were identified from PCDs like as conventional dyes, which may account for the synthesis of high-fluorescent PCDs without using any solvent. The results demonstrate that the nanohybrids mediate the production of reactive oxygen species (ROS), and this mediation is followed by a decrease in the mitochondrial membrane potential through the activation of caspase-3. These results appear to be promising for anticancer drug delivery and bio-imaging engineering applications.

Detection of tannic acid exploiting carbon dots enhanced hydrogen peroxide/potassium ferricyanide chemiluminescence

Recently, ultra-weak chemiluminescence (CL) systems have become one of the focuses of increasing attention. As one of them, H2O2-K3Fe(CN)6 system had also been studied. However, no attempts had been made to investigate the analytical applications of this system based on carbon dots (CDs). In this paper, nitrogen-doped carbon dots (FNCDs) were synthesized using formaldehyde as a coreactant, and it acted as a new fluorophore instead of conventional fluorescent dyes to enhance the CL signal of H2O2-K3Fe(CN)6 system, in which the excited-state FNCDs was the final emitting species, and was probably produced by the electron transfer and energy from reactive oxygen species. Interestingly, tannic acid (TA) could dramatically suppress the CL intensity of FNCDs-H2O2-K3Fe(CN)6 system. Under the optimum conditions, a linear relationship existed between reduced CL intensity and logarithm of TA concentration in range between 0.2 and 10.0 μM with a detection limit of 39.3 nM. The method was applied to the quantitative analysis of TA concentration in red wine.

Solvent assisted reactive dyeing of cotton with high exhaustion in the absence of salt

Conventional reactive dyeing generates colored effluents with large amounts of salt. Herein, an ethanol (EtOH)-carbon tetrachloride (CCl4)-water (H2O) solvent-assisted dyeing system was proposed for the reactive dyeing of cotton. In detail, cotton yarns were firstly pretreated with alkali solution, followed by dyeing in a 55:40:5 (v/v) EtOH–CCl4–H2O solvent system without the addition of salt. To validate the developed salt-free dyeing approach, six kinds of representative reactive dyes were selected for the experiments according to their color hues and reactive groups. The effects of dyeing temperature and time on the exhaustion and total fixation of the investigated reactive dyes were studied. The influences of the EtOH–CCl4–H2O solvent system on the morphology, particle size, zeta potential, contact angle, and penetration time of the dye solutions were also determined to elucidate the dyeing mechanism detailly. Compared with the samples dyed with conventional method, the cotton yarns dyed in the EtOH–CCl4–H2O solvent system exhibited significantly higher K/S values, exhaustion, and total fixation. More importantly, the excellent permeability, satisfactory colorfastness, and acceptable color uniformity were also achieved on the samples dyed in the EtOH–CCl4–H2O solvent system. Despite that the developed salt-free dyeing method may consume slightly higher material costs, it can significantly reduce chemicals consumption and wastewater discharge. Therefore, this dyeing method can be a promising approach for the cleaner production of cotton. Future studies in this direction will mainly focus on its industrial applications and the reuse of solvents.

A novel approach for dyeing of polyester using non-aqueous deep eutectic solvent as a dyeing medium

PurposeTextile industry is considered to be one of the largest consumers of water. There needs to be an alternative for water in textile wet processing. Solvent dyeing can be an approach to replace the use of water in dyeing for water conservation.Design/methodology/approachIn this study, the dyeing of polyester was carried out using conventional and solvent dyeing methods. The solvent used was non-aqueous, deep eutectic solvent (DES) prepared using choline chloride and urea. Dyeing parameters such as time, temperature and pH were optimized for a concentration of dye using the solvent and were compared with the conventional dyeing.FindingsThe prepared solvent was characterized in terms of Fourier-transform infrared resonance and1H and13C nuclear magnetic resonance to analyze the reaction between choline chloride and urea. Dyeing performance in terms of K/S and fastness properties of dyed fabrics were evaluated and found to be at par against conventional dyeing.Originality/valueUse of DES as a dyeing medium is a novel approach in the textile industry.

Non-cytotoxic photostable monomethine cyanine platforms: Combined paradigm of nucleic acid staining and in vivo imaging

Cyanine based chemosensing platforms have successfully been employed over the past couple of decades in various fields of biomolecular sciences. Still a substantial number of recent advances and improvements on this class of compounds are reported in the art. This paper presents our latest work on the improved synthetic approach, study on photophysical properties, and biosensing applicability of monomethine cyanine dyes. The series of mono-, di- and tricationic dyes showed up to 5-fold enhanced resistance against photobleaching compared to the commercially available Thiazole Orange (TO). The title compounds were studied as potential molecular probes for the detection of deoxyribonucleic acid, demonstrating their capacity as excellent fluorescent labeling agents. Depending on the dye chemical structure, current Cl-TO compounds exhibit up to 834-fold enhanced fluorescence emission and form stable complexes with Calf Thymus-DNA. The calculated binding constants were found to be higher than several conventional fluorogenic dyes for nucleic acid detection. All studied derivatives appeared as less cytotoxic than the Thiazole Orange. IC50 concentrations in human fibroblasts MRC5 cell line were calculated up to 50 μM for the synthesized Cl-TO dyes, and 0.5 μM for the parental Thiazole Orange. Two of the dyes were found very competent in post-electrophoretic visualization of DNA. As demonstrated by the agarose gel electrophoresis, the staining efficiency and detection limits of the dyes were comparable to the widely used Ethidium Bromide. The tricationic dye revealed great potential for cell cycle analysis in G1, S and G2 phases. The chlorinated TO derivatives readily stain human cells in vivo, while they can effectively be applied for eukaryotic and microbial cell staining.

Studies on the Dyeing Properties of Cotton and Antimicrobial Activity of Natural Colourant Extracted from Beta vulgaris (Beetroot)

Natural colourant was extracted from beetroot (Beta vulgaris) with Soxhlet apparatus using water, ethanol, ethyl acetate and aqueous methanol (50%). Methanol (50%) gave a higher yield of dyestuff than the other solvent. The stability of the dye on pH and temperature was best found to be 4.5 and 50ºC respectively. The purification and separation of the extract was done using TLC and micro column, the better Rf values were found to be 0.47, 0.36 and 0.24 when methanol and hexane (4:1) were used as the solvent. FTIR was used to characterize the extract and it showed that active component in the dye was present. Analysis of the dye was done with UV/visible spectrophotometry at a 538 λmax. The cotton fabrics were dyed with crude extract and a mordant (ferrous sulphate and alum) under conventional dyeing techniques; pre-mordanting and meta-mordanting, adopting a well-known vat dyeing method. The dyed fabric possessed very good fastness to light, rub and press but fair wash fastness. Ferrous sulpate as a mordant gave a better % exhaustion on dyed cotton and the dyeing was best achieved with pre-mordanting techniques. The antimicrobial activity test showed that, the extract was active against Staphylococcus aureus, Escherichia coli, and Aspergillus niger but non-active against Candida albican.

Novel, sustainable and water efficient nano bubble dyeing of cotton fabric

Textile is one of the basic human needs and almost all the textile fabrics are colored. Unfortunately, the extensive amounts of clean water, petrochemical based dyes, and chemicals are used for textile dyeing. After dyeing, these substances are discharged as pollutants. The disposal of this discharge is a serious issue which pollutes the natural environment. Therefore, there is a dire need to develop the novel dyeing processes with extremely low consumptions of water, dyes and chemicals. Nevertheless, the technologies with the low liquor ratios bring several challenges such as uneven dyeing, poor fastness, limited colors, lack of skills, and complicated processes. To address such challenges, this research achieves the extremely low liquor ratio of 1:1 using nano bubble technology. For the first time, this research describes novel, sustainable, and water efficient nano bubble dyeing of cotton with 11 different reactive dyes. The fabric dyeing performance properties of shade depth, dry rubbing fastness, wet rubbing fastness, and washing fastness were assessed for the liquor ratio of 1:1. The performance of 1:1 dyeing was compared with the conventional dyeing having liquor ratios of 1:5 and 1:10 for the same dyes. All the 11 reactive dyes, dyed at liquor ratio of 1:1 exhibited the uniform dyeing, acceptable fastness properties, and superior air permeability along with zero liquid discharge in the main dyeing cycle. Therefore, this research confirms the effectiveness of the newly developed dyeing process at extremely low liquor ratio of 1:1 for reactive cotton dyeing with significant saving of water, energy, dyes, chemicals and effluent load.

Effect of Vectashield-induced fluorescence quenching on conventional and super-resolution microscopy

Finding the right combination of a fluorescent dye and a mounting medium is crucial for optimal microscopy of fixed samples. It was recently shown that Vectashield, one of the most commonly used mounting media for conventional microscopy, can also be applied to super-resolution direct stochastic optical reconstruction microscopy (dSTORM). dSTORM utilizes conventional dyes and starts with samples in a fluorescent “ON” state. This helps in identifying structures of interest. Subsequently, labelled samples are induced into blinking, which is necessary for determining the position of single molecules and reconstruction of super-resolution images. This is only possible with certain fluorescent dyes and imaging buffers. One of the most widely used dyes for dSTORM, Alexa Fluor 647 (AF647), blinks in Vectashield. However, after preparing immunocytochemical samples in Vectashield, we noticed that the fluorescence intensity of AF647 is quenched. This is particularly evident for dimmer immunostainings, such as stainings of some components of neuronal cytoskeleton and axonal initial segment. Because structures of interest cannot be identified in quenched samples, loss of fluorescence intensity hinders imaging of AF647 in Vectashield. This has consequences for both conventional and dSTORM imaging. To overcome this, we provide: 1) a quantitative analysis of AF647 intensity in different imaging media, 2) a quantitative analysis of the suitability of Vectashield for dSTORM imaging of high and low-abundance AF647-labelled targets. Furthermore, for the first time, we quantitatively analyse the performance of Alexa Fluor Plus 647, a new variant of AF647-conjugated antibody, in dSTORM imaging.

Dynamic colour in textiles: combination of thermo, photo and hydrochromic pigments

Colour Change Materials are a class of smart materials that present distinct characteristics relative to conventional pigments and dyes. When exposed to a given stimulus, these materials exhibit reversible chromatic changes, allowing the introduction of dynamic and interactive qualities to textiles. Currently, the combination of various chromic materials presents an under-developed area. The objective of this research is to study the integration and combination processes of different types of dynamic colourants in textiles, namely thermo, photo and hydrochromic pigments. The experimental work conducted demonstrates the effect of screen printing variables in textile chromatic qualities, being the variables set: screen mesh count, magnetic field of the screen printing table, printed layers (number and process) and pigments’ combination method – overprinting and combination in the screen printing paste. The results attained also highlight design possibilities to further research colour change effects and outline a methodology to explore and design screen printed textiles with multi-sensitive qualities.

Phototuning Energy Transfer in Self‐Organized Luminescent Helical Superstructures for Photonic Applications

AbstractStimuli‐triggered changes in the emission color of functional materials are in demand for a variety of potential applications. Herein, a strategy to reversibly phototune fluorescence color in cholesteric liquid crystal (CLC) with self‐organized luminescent helical superstructure via fluorescence resonance energy transfer (FRET) is developed. This dynamic FRET system is constructed by doping with 1,2‐dithienyldicyanoethene‐based chiral fluorescent photoswitch (switch 7) as an acceptor and a conventional coumarin dye C6 as a donor into a nematic liquid crystal (LC) host. The efficient energy transfer from C6 to switch 7 in the LC media, which is evidenced by both of emission color shift and enhanced circularly polarized luminescence, can be modulated on the basis of reversible trans–cis photoisomerization of switch 7 upon visible/UV light irradiations, leading to the emission color change from orange to green. Noteworthily, the FRET efficiency can be significantly improved when CLCs are confined in the polymer microtubes. Preliminary demonstrations of the LC film and LC microtubes array for information display and encryption with ease of electrical operation between planar, homeotropic, and focal conic states or light manipulation are described.

A novel imaging tool; fluorescent organosilica nanoparticles

The new type of silica nanoparticles as a novel imaging tool, organosilica nanoparticles, has been developed by Nakamura and colleagues. The nanoparticles can be synthesized in a few of simple reactions and have a good size and dispersibility. Organosilica nanoparticles contain fluorescent dyes and are superior in fluorescence intensity to the conventional dye. These nanoparticles have SH groups on their surface, which makes it possible to conjugate them with antibodies and other protein molecules. We synthesized organosilica nanoparticles whose diameter is 100 nm including fluorescein isothiocyanate (FITC) or Rhodamine B and then conjugate these nanoparticles with an anti‐mouse IgG antibody and so on. We applied these conjugated antibodies to immunofluorescence staining to mouse brain sections. We also discuss this novel imaging tool to detect many biomolecules.

Quantum Dot Bioconjugates for Diagnostic Applications.

Quantum dots (QDs) are a special type of engineered nanomaterials with outstanding optoelectronic properties that make them as a very promising alternative to conventional luminescent dyes in biomedical applications, including biomolecule (BM) targeting, luminescence imaging and drug delivery. A key parameter to ensure successful biomedical applications of QDs is the appropriate surface modification, i.e. the surface of the nanomaterials should be modified with the appropriate functional groups to ensure stability in aqueous solutions and it should be conjugated with recognition elements capable of ensuring an efficient tagging of the BMs of interest. In this review we summarize the most relevant strategies used for surface modification of QDs and for their conjugation to BMs in preparation of their application in nanoplatforms for luminescent BM sensing and imaging-guided targeting. The applications of conjugations of photoluminescent QDs with different BMs in both in vitro and in vivo chemical sensing, immunoassays or luminescence imaging are reviewed. Recent progress in the application of functionalized QDs in ultrasensitive detection in bioanalysis, diagnostics and imaging strategies are reported. Finally, some key future research goals in the progress of bioconjugation of QDs for diagnosis are identified, including novel synthetic approaches, the need for exhaustive characterization of bioconjugates and the design of signal amplification schemes.

Green dyeing of weld on corona discharge treated wool fabric

Atmospheric pressure plasma treatment as a dry and environment-friendly process can modify the textile surface and improve wettability, adhesion and dye uptake. In this study, the effect of corona discharge treatment was investigated on wool dyeing with weld as a natural dye. Wool fabrics were treated by corona discharge treatment in different times. Then they were dyed with weld in acidic pH. For comparing to conventional dyeing method, untreated wool fabrics were dyed with weld in presence of tannic acid as mordant. The color data (L*, a*, b*) and fastness properties were determined. Furthermore, the corona treated samples were evaluated by scanning electron microscope (SEM) and Fourier transform-infrared spectroscopy (FTIR). The results show that the corona treatment was caused to improve color strength as compared to conventional method without changing the fastness properties. It means that the corona treatment can be replaced with mordant in wool dyeing. SEM pictures showed that the cracks on the surface of wool fiber have increased and the cuticle scales have partially etched.

β-Cyclodextrin assisted simultaneous preparation and dyeing acid dyes onto cotton fabric

Acid dyes are applied onto the cellulosic textiles through the modification of the textile surfaces with cationic groups. The conventional dyeing of the cellulosic textiles with acid dyes is usually performed over two main steps including, the preparation of the acid dyes and then the applying of these prepared dyes onto modified cellulosic textiles. Herein, a new strategy for simultaneous preparation and dyeing of the cotton fabrics with acid dyes in one step was developed. The innovative strategy was involved in two steps. The first step: β-CDs were grafted onto cotton fabrics through citric acid in the presence of sodium hypophosphite as catalyst and subsequently, the β-CDs grafted cotton fabrics were loaded with naphthols. In the second step; the acid dyes were formed directly onto the modified fabrics by the in-situ coupling of the diazonium salt of the different amines with the naphthols/β-CDs grafted cotton fabrics complexes. The amounts of the grafted β-CDs on the cotton fabrics were evaluated by qualitative and quantitative methods. The cotton fabrics were evaluated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Finally, the coloration and fastness properties of the dyed modified cotton fabrics were investigated. The results displayed that, the dyed modified cotton fabrics were shown the different color shades according to the naphthols and amines with remarkable fastness properties.

Extraction and Natural Cotton Dyeing of Valonia Oak and Anatolian Buckthorn by Microwave Irradiation

ABSTRACT In this work, organic cotton fabrics were dyed using Rhamnus petiolaris Boiss, Quercus ithaburansis Decaisne, and Quercus ithaburansis Decaisne + Rhamnus petiolaris Boiss by microwave irradiation and conventional dyeing methods. They were used in equal percentages. The dyed fabrics were analyzed by different analytical and technical methods. Coloring compounds were analyzed in the dye extractions (before dyeing bath and after dyeing bath) and dyed fabrics by RP-HPLC-PAD. Identified coloring compounds based on the coloring compounds analysis were kaempferol, kaempferol derivative, quercetin, rhamnetin, ellagic acid, ellagic acid derivatives, and gallic acid derivative. Color characteristics of all the dyed fabrics were measured by CIEL*a*b* spectrophotometer. SEM-EDX was used for imaging of the dyed organic cotton fabrics. The coloristic and color fastness properties of the dyed fabrics were investigated and compared with each other. No damage was observed in the fabrics dyed by the microwave and conventional dyeing methods. Almost the same color yields were obtained in both dyeings using different processing times. According to the analyzes and test results, microwave irradiation method is very eligible compared to conventional dyeing methods, considering coloristic properties of dyed fabrics, time saving and the cost effectiveness wise for the dye processes.

Dyeing of textiles with natural dyes extracted from Terminalia arjuna and Thespesia populnea fruits

Natural dyes are eco-friendly, non-hazardous and sustainable. But the use of metal mordants such as copper, chromium, tin and zinc could make the application of natural dyes unsustainable since they are heavy metals. Hence, sustainable natural dyeing could be achieved with natural mordanting assistant such as myrobalan, metal mordants like alum and ferrous sulphate which have lesser environmental impacts compared to other metal mordants. The current study aims at extracting natural dyes from the fruits of Terminalia arjuna and Thespesia populnea and their application on textiles such as silk, cotton and nylon. Ultrasonic bath dyeing, an energy-efficient method, has been adopted for the study and the process has been compared with conventional water bath dyeing. It has been observed that ultrasonic dyeing is better both in terms of dye exhaustion and energy conservation compared to water bath dyeing.

Utilizing some synthesized nanostructured materials to improve the functional properties of cotton fabric for possible applications

The potential of the synthesized Copper Oxide (CuO)and Graphene Oxide (GO)nanostructures as an efficient modifier for cotton fabric surface, to enhance its functional properties when dyed with C.I. Reactive Yellow 160 (RY 160) was investigated. For this purpose, Copper Oxide nanoparticles (CuO NPs) and Graphene Oxide nanoparticles (GO NPs) were synthesized and characterized through SEM, and EDX analysis, TEM analysis, FTIR spectrum analysis and X-ray diffraction (XRD) analysis. The cotton fabric was first treated separately with CuO NPs and GO NPs, and then dyed with RY160. The dye exhaustion percentages (E%) of pretreated cotton fabric samples were compared with their corresponding values obtained through conventional dyeing of untreated cotton. Dye adsorption rate constants according to pseudo-first order, pseudo-second order, and intra-particle diffusion kinetic models were calculated. Moreover, the diffusion coefficients and the activation energy of diffusion of RY160 into cotton fabrics were calculated before and after NPs treatment. The activation energy of diffusion of RY160 into pretreated GO NPs-cotton fabric was the lowest value, saving 44.06% of the energy required for conventional dyeing completion. The overall adsorption process follows pseudo-second order kinetics and intraparticle diffusion model. The corresponding thermodynamic parameters, namely enthalpy (∆ H), entropy (∆ S ), and free energy changes (∆ G ), were also calculated for untreated cotton fabric and compared with the data obtained for treated cotton fabrics after surface modification via synthesized nanomaterials, CuO NPs and GO NPs. The NPs treatment produces a cotton fabric with advanced color fastness and antibacterial properties enabling them to improve human health care and decrease the environmental impacts and fabric damage.

WIDECARS multi-parameter measurements in premixed ethylene-air flames using a wavelength stable ultrabroadband dye laser.

Width-increased dual-pump enhanced coherent anti-Stokes Raman spectroscopy (WIDECARS) measurements were used to determine the temperature and major species mole fractions in laminar, premixed, ethylene-air flames operating at atmospheric pressure. Conventional ultrabroadband dye lasers for WIDECARS, which use Pyrromethene dyes, have historically suffered from day-to-day wavelength shifting. To overcome this problem, a new ultrabroadband dye laser was developed in this study to provide a stable wavelength and power generation. A new dye laser pumping scheme and a mixture of Sulforhodamine 640, Kiton Red 620, and Rhodamine 640, was used to generate the desired FWHM ${\sim}{15}\;{\rm nm}$∼15nm (${410}\;{{\rm cm}^{ - 1}}$410cm-1) bandwidth. The WIDECARS measured mole fraction ratios of ${{\rm CO}_2}$CO2, CO, and ${{\rm H}_2}$H2 with ${{\rm N}_2}$N2 agreed well with chemical equilibrium calculations.

The effect of liposome on dyeing mohair/wool blends

AbstractThe aim of this study was to examine the use of liposome in the dyeing of wool and mohair fibres with acid dyestuffs. Soybean lecithin and cholesterol were used to form the liposome membrane utilised in the dyebath. Liposome production was performed according to the thin lipid layer method (Bangham Method) using a rotary evaporator. Two different forms of liposome were used for dyeing wool and mohair fibres. In its first form, liposome was utilised as an auxiliary agent, where it was added to a conventional dyebath at the beginning of the process. In its second form, dyes were encapsulated with liposome and then used in dyeing. The effects of these two different forms of liposome were compared with conventional dyeing. Dyeing was carried out at depths of shade of 0.5%, 1.0% and 2.0% using three different concentrations of liposome (0.33%, 0.66% and 1.33%). An analysis of K/S values, fastness to washing, and the alkali solubility of fibres was conducted. The fibre samples dyed in the presence of liposome exhibited very good fastness to light (grade 8). The wash fastness test results of the liposomal‐dyed samples were significantly better (grade 4‐5) than for those samples which were conventionally dyed. In the presence of liposome, the tensile strength of fibres was 20 gf, whereas it was 11 gf without liposomes.

Preparation and properties of black Ti-doped zirconia ceramics

Black zirconia ceramics has many problems, such as uneven color and poor phase stability. The reason for this phenomenon is that the colorant uses a colorant with a complex black spinel structure, and also the application of a dyeing method. To improve the color uniformity and phase stability of black ceramics, TiO2 was introduced to replace the traditional complex black spinel, a high-temperature reduction method (HTR) was employed to prepare a black Ti-doped zirconia ceramic, stead of the conventional dyeing method. After the HTR at 1400 °C, the concentration of Ti3+ and oxygen vacancies increased, and the lightness of the ceramic samples decreased from 93.48 to 44.17. The black ceramic is uniform in color and stable in phase, avoiding the disordered phase of the spinel doped multiphase zirconia ceramic. The results indicate that the overall color of the samples depends on the development mechanism of the color center. The formation of color centers (F+ centers) in this work was related to the electronic transition of Ti 3d states and oxygen vacancies generated during the HTR. F+ centers cause a strong light absorbance over the entire visible light range (400–750 nm), so that the color of the ceramics is black. Based on their good color attributes, black ceramics have great potential in industry, for example as the back plate of mobile phones.