Color Pigments Research Articles

Ecoprint Techniques as An Environmentally Friendly Fashion Product

The textile industry is one of the contributors to the highest amount of waste in the world. One of the wastes produced by the textile industry is liquid waste which comes from the remains of synthetic dyes which contain several dangerous chemicals. An alternative that can be done to reduce liquid waste from synthetic dyes is to switch to using natural dyes that come from plants. One technique that can be used to color textiles is the ecoprint technique. The ecoprint technique is a process for transferring color and shape to fabric through direct contact. The ecoprint technique uses materials from plant parts that contain color pigments such as leaves, flowers, bark, etc. Products produced from ecoprints can be a business opportunity because ecoprints have artistic value and high selling value. The research method used is literature study by taking reference sources in the form of international journals and national journals. The purpose of writing this article is to describe ecoprint as a business opportunity that can be generated by fashion.

Thermal Treatment and Fermentation of Legume Flours with Leuconostoc citreum TR116 for the Development of Spreadable Meat Alternatives

The demand for meat alternatives in different forms is increasing due to consumers’ awareness of climate change and the health benefits of plant-based ingredients compared to animals. However, current alternatives on the market do not fulfil consumers’ acceptance for taste and texture. Hence, different physical and biological processes, such as thermal treatment and fermentation, need to be investigated. This study reveals that the thermal treatment of legume flours (soy, pea and lentil) prior to single-strain fermentation with Leuconostoc citreum TR116 has a major impact on acidification, colour, texture and sensory properties due to the pregelatinisation of starch and denaturation of proteins. The thermal treatment of soy flour resulted in liquification, and it could not be used as a fermentation substrate. However, non-heat-treated soy flour was fermented for comparison. The highest total titratable acidity (TTA) was determined in fermented pea flour (PF) and fermented lentil flour (LF) after 48 h with 24.35 ± 0.29 mL 0.1 M NaOH/10 g and 24.98 ± 0.33 mL 0.1 M NaOH/10 g, respectively. Heat treatment prior to fermentation led to a reduction in TTA by 20 mL 0.1 M NaOH/10 g for both PF and LF. The loss of colour pigments during thermal treatment led to a lighter colour of the spreadable alternatives. Moreover, a harder texture (+13.76 N in LF; +15.13 N in PF) and a lower adhesiveness (−0.88 N in LF; −0.43 N in PF) were detected in spreadable meat alternatives that were treated with heat prior to fermentation. Cohesiveness was decreased by thermal treatment, and fermentation did not impact it. Fermentation without pre-heat treatment increased adhesiveness by 4.37 N in LF and by 2.36 N in PF—an attribute typical for spreadable meat. Descriptive sensory analysis showed that thermal treatment significantly decreased bitterness but increased crumbliness and reduced juiciness. On the other hand, fermentation without pre-heat treatment mainly influenced flavour by increasing fruitiness and decreasing beaniness, earthiness and off-flavours. In summary, thermal treatment prior to fermentation is powerful in reducing legume-typical off-flavours but is not suitable for the development of spreadable meat alternatives due to texture changes. However, this process can be very beneficial when producing sausage-like alternatives.

Optimisation of TiO2 synthesis from ilmenite sand and its application in the photocatalytic process

ABSTRACT Iron sand, a mineral, can be extracted to produce titanium dioxide (TiO2). TiO2 is a semiconductor material that is commonly used in photocatalytic applications, as well as electronics, colour pigments, paint manufacturing, and semiconductors. In this study, TiO2 was extracted from Banten ilmenite sand using caustic fusion and hydrometallurgical methods. The TiO2 extraction process was carried out by varying the mole ratio of ilmenite sand to NaOH, which was 1:0, 1:3, and 1:5, and the fusion temperatures were 700°C and 850°C, with time variations of 30, 60, and 90 min. XRF analysis revealed that the highest TiO2 composition was 91.64% in samples with a mole ratio of 1:3 during 30 min of fusion time and 91.14% in samples with a mole ratio of 1:5 during 90 min of fusion time. The XRD data revealed that TiO2 has a rutile phase with a tetragonal structure, while scanning electron microscopy (SEM) analysis revealed that the particle distribution in the sample is not uniform. The UV-Vis measurements revealed that TiO2 has a band gap of 3.10 at 700°C and 3.13 at 850°C. Furthermore, TiO2 degraded Rhodamine B dyes at a rate of 28.266%.

Physical Properties, Nutritional Composition and Sensory Acceptance of Eggless Pumpkin Muffin Prepared using Plant-Based Ingredients

Eggs play a crucial role in the production of muffins by contributing to their moistness and tenderness. However, several issues arise with using eggs in muffin formulation, such as egg allergies and the sustainability of egg supply in the market. Therefore, this study aimed to determine the effect of incorporating plant-based ingredients (chia seeds, flaxseeds and mashed banana) in eggless pumpkin muffin formulations on physical properties, nutritional composition and sensory acceptance. Four samples were prepared as follows: Control (muffin with egg), F1 (muffin with chia seeds), F2 (muffin with flaxseeds) and F3 (muffin with mashed banana). The samples were analysed for batter density, muffin height, texture profile analysis, muffin crumb colour, nutritional composition and sensory preference using a nine-point hedonic scale. Generally, muffins prepared with plant-based ingredients showed a decrease in height (3.97–3.83 cm) and water activity (0.88–0.89) compared to the control muffins (4.37 cm and 0.90, respectively). On the contrary, the batter density of wet batter eggless pumpkin muffins increased compared to those prepared with egg. The replacement of egg with plant-based ingredients resulted in muffins with a harder texture, as indicated by the increased hardness values compared to the control muffin. The use of plant-based ingredients in pumpkin muffin formulations produced muffins with a lighter colour due to the absence of colour pigments in chia seeds, flaxseeds and mashed banana. The inclusion of plant-based ingredients in eggless pumpkin muffin formulations increased the ash, fibre and carbohydrate content while decreasing the fat content. Overall, the preference test revealed that eggless pumpkin muffins prepared using chia seeds (6.93) and mashed banana (7.58) rated higher for overall acceptance attribute as compared to the control pumpkin muffin.

Perbandingan efektivitas senyawa logam alkali sebagai zat cabut warna golongan reaktif pada batik

In making batik, the color dyeing method sometimes produces colors that are not as desired. One way to remove color pigment is by unpluging color. Apart from that, unplug color can be used as a technique to produce decorative variations on fabric. Unplug color is used to take or remove color pigments that are already on the fabric to obtain the previous color. The use of color removal agents affects the color removal results. The aim of this research is to determine the appropriate level of cleanliness for the application of scrub on fabric that is removed using calcium hypochlorite, sodium hypochlorite, sodium hydrosulfite and potassium permanganate. The research method used is field observations carried out in areas that have color removal facilities, then from the results of the data obtained an experiment will be carried out with a recipe for a removal agent of 10 grams/liter with a removal time of 10 minutes. The experimental results showed that the removal agents for calcium hypochlorite, sodium hypochlorite and sodium hydrosulfite had a color that was lighter than the original color. Meanwhile, the potassium permanganate dissolving agent produces a color that is different from the direction of the original color.

Why are the inner and outer sides of many flower petals differently coloured?

The flower perianth has various, non-mutually exclusive functions, such as visual signalling to pollinators and protecting the reproductive organs from the elements and from florivores, but how different perianth structures and their different sides play a role in these functions is unclear. Intriguingly, in many species there is a clear colour difference between the different sides of the perianth, with colour patterns or pigmentation present on only one side. Any adaptive benefit from such colour asymmetry is unclear, as is how the asymmetry evolved. In this viewpoint paper, we address the phenomenon of flowers with differently coloured inner and outer perianth sides, focusing on petals of erect flowers. Guided by existing literature and our own observations, we delineate three non-mutually exclusive evolutionary hypotheses that may explain the factors underlying differently coloured perianth sides. The pollen-protection hypothesis predicts that the outer side of petals contributes to protect pollen against UV radiation, especially during the bud stage. The herbivore-avoidance hypothesis predicts that the outer side of petals reduces the flower's visibility to herbivores. The signalling-to-pollinators hypothesis predicts that flower colours evolve to increase conspicuousness to pollinators. The pollen-protection hypothesis, the herbivore-avoidance hypothesis, and the signalling-to-pollinators hypothesis generate largely but not entirely overlapping predictions about the colour of the inner and outer side of the petals. Field and laboratory research is necessary to disentangle the main drivers and adaptive significance of inner-outer petal side colour asymmetry.

Natural dyes developed by microbial-nanosilver to produce antimicrobial and anticancer textiles

Developing special textiles (for patients in hospitals for example) properties, special antimicrobial and anticancer, was the main objective of the current work. The developed textiles were produced after dyeing by the novel formula of natural (non-environmental toxic) pigments (melanin amended by microbial-AgNPs). Streptomyces torulosus isolate OSh10 with accession number KX753680.1 was selected as a superior producer for brown natural pigment. By optimization processes, some different pigment colors were observed after growing the tested strain on the 3 media. Dextrose and malt extract enhanced the bacteria to produce a reddish-black color. However, glycerol as the main carbon source and NaNO3 and asparagine as a nitrogen source were noted as the best for the production of brown pigment. In another case, starch as a polysaccharide was the best carbon for the production of deep green pigment. Peptone and NaNO3 are the best nitrogen sources for the production of deep green pigment. Microbial-AgNPs were produced by Fusarium oxysporum with a size of 7–21 nm, and the shape was spherical. These nanoparticles were used to produce pigments-nanocomposite to improve their promising properties. The antimicrobial of nanoparticles and textiles dyeing by nanocomposites was recorded against multidrug-resistant pathogens. The new nanocomposite improved pigments' dyeing action and textile properties. The produced textiles had anticancer activity against skin cancer cells with non-cytotoxicity detectable action against normal skin cells. The obtained results indicate to application of these textiles in hospital patients’ clothes.

Ring and flower in the eye – An incidental finding of Wilson disease in a case of diabetic retinopathy: A case report

This is to report a rare case of Wilson disease (WD) with Kayser–Fleischer (KF) ring with sunflower cataract along with diabetic retinopathy. A 43-year-old male patient presented to the comprehensive clinic with a chief complaint of diminution of vision of both eyes since 8 months. On ocular examination, the cornea showed golden brown color pigment deposition in the Descemet membrane, indicative of KF ring, which is a pathognomonic feature of WD. There was brown plaque or spoke-like radial opacities on the anterior lens capsule in both eyes, which gives sunflower appearance, which is also a feature of WD. The posterior segment revealed diabetic retinopathy in both eyes. Serum ceruloplasmin was reduced, and the bilirubin level was mildly raised. Liver function test was mildly altered. Urine excretory copper levels were raised. Ultrasonography of the abdomen and pelvis revealed liver cirrhosis with portal hypertension, splenomegaly, gross ascites, and gall bladder calculi. This is a rare case of WD with KF ring with sunflower cataract with diabetic retinopathy in both eyes. Slit lamp examination is mandatory to diagnose it as WD in the presence of KF ring.

Workshop on The Use of Miana Leaf Juice (Coleus Scutellarioides (L) Benth) as An Alternative to Safranin Dye in Bacterial Gram Staining

One of the commonly used stains in bacterial identification is gram staining, this staining is used to distinguish the physical properties of the cell wall and the chemical properties of bacteria, this dye will distinguish bacteria into gram-positive bacteria with the result of the bacteria will be purple and gram negative with the result of red bacteria. The use of safranin is effective in working on bacteria because it is alkaline, this can cause binding between the chromophore component in the dye and the cytoplasm of bacteria that are basophilic. However, the use of safranin also has a negative impact on health and the environment. Therefore, the need to use materials that are safer for health and the environment, miana leaf juice (Coleus Scutellarioides (L) Benth) can be used as a natural dye to replace safranin. Minana leaves are very easy to find in gardens and are usually ornamental plants, the anthocyanin content in this plant can be used as a color pigment to replace safranin, anthocyanins will produce red to dark red pigments in an acidic atmosphere. The purpose of this community service activity, the community service organized a workshop for students of the Medical Laboratory Technology Study Program, Lubuk Pakam Medical Health Institute, aiming to provide information on the use of miana leaf juice (Coleus scutellarioides (L) Benth) as an alternative to safranin dye in bacterial gram staining. From the results of the service, it can be concluded that the participants can understand the material and the demonstration, this can be seen from the increase in the percentage of understanding both from before 61% to 87% after being given the demonstration and material.

Pengaruh Penambahan Pigmen Warna pada Filamen PLA SUNLU Colors dan SUNLU Natural

3DP technology is experiencing rapid development and is widely used in various fields. PLA material is widely used as a material for making filaments used in 3D printing (3DP). PLA filament in 3DP is widely used because it has many advantages, including biocompatible, biodegradable, and non-toxic. When compared with other filament materials, PLA material is easier and safer to use because the temperature used is relatively lower so it is more energy efficient compared to other filament materials. SUNLU is a well-known manufacturer that provides various types of quality filaments, including PLA Colors and PLA Natural, where each type of SUNLU PLA filament has its characteristics and advantages. The choice of PLA filament type is adjusted to the desired printing needs, including the desired color and visual effect. The use of color pigments in PLA filaments with various color choices is used to produce objects that are more attractive and more flexible in their use in various fields. This experimental research was carried out to determine the effect of adding color pigments to SUNLU PLA Colors and SUNLU PLA Natural 1.75 mm filament samples with predetermined sample manufacturing variables. This research uses the ASTM D638 type V standard tensile test so that the tensile strength value of each sample can be determined and the maximum value from the tensile test can be determined. The results of this research will show a comparison of the tensile strength between SUNLU PLA Colors filament samples and SUNLU PLA Natural 1.75 mm. The tensile test results of the SUNLU PLA Natural sample had a higher value, namely 53.98 MPa, and for the SUNLU PLA Colors Orange and Gray samples, each had a tensile strength value of 46.58 MPa and 46.63 MPa. These results show that adding color pigments to the filament affects the strength of the resulting 3D-printed samples

Pencucian Crude Palm Oil (CPO) untuk Mitigasi Penurunan 3-MCPDE dan GE pada Pemurnian Minyak Sawit

Crude palm oil (CPO) purification aims to remove or degrade unwanted components such as free fatty acids (FFA), phospholipids, impurities, color pigments, metals, and odors. The CPO purification generally consists of degumming, bleaching, and deodorization process. During the stages, some undesirable compounds are formed, including 3-monochloropropane-1,2-diol ester (3-MCPDE) and glycidyl ester (GE). The main precursors responsible for formation of the two compounds are chlorides and acyl glycerol fractions, especially diacylglycerol (DAG) and this occurs high temperatures in the deodorization process. Therefore, it is necessary to reduce their precursors in order to supress the contaminants. To cope with the problem, a washing process of CPO was proposed as an extra process before a purification stage. The washing process was carried out in two ways, namely wet washing by using water, and dry washing by using bleaching earth (BE) by 2 types of commercial BE (natural and acid activated). Washing processes using wet and dry washing (natural and activated BE) showed comparable effectiveness in reducing 3-MCPDE and GE levels in refined palm oil. As a result, the process successfully reduced 3-MCPDE content to comply with a standard Commission Regulation (EU) 2020/1332, but GE content did not conform to standard.

A review on improving the sensitivity and color stability of naturally sourced pH-sensitive indicator films.

Naturally sourced pH-sensitive indicator films are of interest for real-time monitoring of food freshness through color changes because of their safety. Therefore, natural pigments for indicator films are required. However, pigment stability is affected by environmental factors, which can in turn affect the sensitivity and color stability of the pH-sensitive indicator film. First, natural pigments (anthocyanin, betalain, curcumin, alizarin, and shikonin) commonly used in pH-sensitive indicator films are presented. Subsequently, the mechanisms behind the change in pigment color under different pH environments and their applications in monitoring food freshness are also described. Third, influence factors, such as the sources, types, and pH sensitivity of pigments, as well as environmental parameters (light, temperature, humidity, and oxygen) of sensitivity and color stability, are analyzed. Finally, methods for improving the pH-sensitive indicator film are explored, encapsulation of natural pigments, incorporation of a hydrophobic film-forming matrix or function material, and protective layer have been shown to enhance the color stability of indicator films, the addition of copigments or mental ions, blending of different natural pigments, and the utilization of electrospinning have been proved to increase the color sensitivity of indicator films. This review could provide theoretical support for the development of naturally sourced pH-sensitive indicator films with high stability and sensitivity and facilitate the development in the field of monitoring food freshness.

Interpretation of Hue Diversity and Coloring Pigment Analysis onto the Wooden Ksitigarbha Bodhisattva Triad and Clay Ten Underworld Kings in Namwon Seonwonsa Temple, Korea

The Wooden seated Ksitigarbha Bodhisattva triad and Clay Statues of Ten Underworld Kings within the Myeongbujeon Hall of Namwon Seonwonsa Temple are known to have clear creators, and documented to be in 1610. The Statues serve as significant academic resources for examining the morphological changes in the statues that were actively produced in the late Joseon period. However, various damages such as exfoliation of pigment layer, cracks and breakages occurred in the studied Statues, and the pigments showed complex chemical composition. In particular, large amounts of Ca and P were detected in the white basement layer, which suggesting the existence of a whitewashed at the time of creation. The blue pigments on the Clay Statues of Ten Underworld Kings generally shows the characteristics of Sinamchae, a mixture of colored metal oxides and glassy powder. The studied Statues have been recorded in multiple repairing, and various coloration components were detected even in pigments of similar colors, indicating that were toned. Based on the coloring techniques such as over and filler paintings, it is interpreted that there was a supply and demand of materials reflected the period and social situation of the time. The results of this study can be utilized as basic data for future conservations on the Statues in Seonwonsa Temple.

Antibacterial activity of pigment extracted from bacteria isolated from soil samples

The purpose of this study was to evaluate antibacterial activity of pigment extracted from bacteria, isolated from soil samples. During the study, 20 soil samples were collected from different areas (forest, agriculture fields, river sides and dumping sites) of Kathmandu and Lalitpur districts which were processed for isolation of pigment producing bacteria by spread plate technique. The pigmented bacterial isolates were identified and enriched in nutrient broth. Then, pigment was extracted in 95% methanol as solvent, which was further characterized using UV-Vis Spectrophotometric and TLC analysis. The obtained crude pigment extract was processed to carry out the antimicrobial susceptibility assay using agar well diffusion method. Out of 13 total pigmented bacteria isolates, four different colored pigmented bacterial isolates (S4O, S11Y, S14P and S17G) which produced efficient pigment on nutrient agar were chosen and they were further processed. Among these isolates, S4O was identified as Staphylococcus aureus, S11Y was identified as Micrococcus luteus, S14P was identified as Micrococcus roseus and S17G was identified as Pseudomonas aeruginosa respectively. On characterization using UV-Vis Spectrophotometric and TLC analysis, the pigment extracted from isolates S4O, S11Y and S14P were found to be Carotenoids and from isolate S17G was found to be Pyocyanin in nature. The maximum antibacterial activity was shown against Staphylococcus aureus from all the four pigments extracts. The green color pigment extract from isolate S17G was found to be most effective against all the Gram-positive and Gram-negative test bacteria. This study suggests that these pigment extracts from pigmented bacteria may have beneficial antibacterial roles that can be exploited in controlling unwanted bacterial growth.

The effect of different temperature rate on sol-gel approach derived M-type hexagonal BaFe12O19 using D-mannose as a fuel: Synthesis, structural, thermal gravimetric and magnetic properties

In this article, we reported that the BaFe12O19 powders were prepared using the effective sol-gel process under different calcination temperatures, i.e., 700–900 °C for 2 h. The structural effects of the temperature rate on the phase formation, morphological and magnetic properties of the as-prepared powders have been analyzed and discussed. The X-ray diffraction pattern confirmed the hexaferrite phase formation at calcined temperature range of 800 °C with no secondary phase and the particles size are about 45 nm–65 nm. The Fourier-transform infrared (FT-IR) spectra show that the intensity frequencies for hexaferrite site stretching were observed at 601 and 443 cm−1 from Fe–O and Ba–O bonds, respectively. The micro-sized flakes morphological structure with particle sizes ranging from 45 to 65 nm by strongly agglomerated powders of the hexaferrite phase is examined through the field emission scanning electron microscopy (FESEM) technique for the good-quality calcined 800 °C. Additionally, the effect of the calcination rates at 800 °C on the material features was analyzed by the energy-dispersive X-ray, X-ray photoelectron spectroscopy (XPS), etc. The magnetic properties, such as saturation magnetization and coercive field of the as-prepared nanomaterials were analyzed using the vibrating sample magnetometry (VSM) technique. The hysteresis loop of the BaFe12O19 nanomaterials calcined at 800 °C for 2 h showed excellent magnetic properties, with a higher saturation magnetization curve of 55.774 emu/g and a coercivity (Hc) of 5079 kOe. The dark brown colored annealed 800 °C nanomaterials can be useful as a ceramic color pigment, which has several industrial applications.

The Chromatin Organization Close to SNP rs12913832, Involved in Eye Color Variation, Is Evolutionary Conserved in Vertebrates.

The most significant genetic influence on eye color pigmentation is attributed to the intronic SNP rs12913832 in the HERC2 gene, which interacts with the promoter region of the contiguous OCA2 gene. This interaction, through the formation of a chromatin loop, modulates the transcriptional activity of OCA2, directly affecting eye color pigmentation. Recent advancements in technology have elucidated the precise spatial organization of the genome within the cell nucleus, with chromatin architecture playing a pivotal role in regulating various genome functions. In this study, we investigated the organization of the chromatin close to the HERC2/OCA2 locus in human lymphocyte nuclei using fluorescence in situ hybridization (FISH) and high-throughput chromosome conformation capture (Hi-C) data. The 3 Mb of genomic DNA that belonged to the chromosomal region 15q12-q13.1 revealed the presence of three contiguous chromatin loops, which exhibited a different level of compaction depending on the presence of the A or G allele in the SNP rs12913832. Moreover, the analysis of the genomic organization of the genes has demonstrated that this chromosomal region is evolutionarily highly conserved, as evidenced by the analysis of syntenic regions in species from other Vertebrate classes. Thus, the role of rs12913832 variant is relevant not only in determining the transcriptional activation of the OCA2 gene but also in the chromatin compaction of a larger region, underscoring the critical role of chromatin organization in the proper regulation of the involved genes. It is crucial to consider the broader implications of this finding, especially regarding the potential regulatory role of similar polymorphisms located within intronic regions, which do not influence the same gene by modulating the splicing process, but they regulate the expression of adjacent genes. Therefore, caution should be exercised when utilizing whole-exome sequencing for diagnostic purposes, as intron sequences may provide valuable gene regulation information on the region where they reside. Thus, future research efforts should also be directed towards gaining a deeper understanding of the precise mechanisms underlying the role and mode of action of intronic SNPs in chromatin loop organization and transcriptional regulation.

Physicochemical analysis of deterioration affecting the darkening of rock art in Maros-Pangkep, South Sulawesi, Indonesia

This study investigates the darkening processes affecting Maros-Pangkep rock art through a comprehensive multianalytical approach. We integrate in-situ color index measurements using Nix color Pro 2 with various physicochemical characterization techniques, including optical microscopy, XRF, SEM-EDS, Raman spectroscopy, and FTIR. By examining microbial, geochemical, and anthropogenic factors on rock art pigment samples, we establish a clear correlation between the formation of blackish-gray layers and reduced chromaticity values, indicating a significant darkening process. The shift in pigment color from vibrant red or purple to a prevailing blackish-gray hue is attributed to surface accumulation. Surface morphology analysis reveals distinct blackish deposits and delicate white fibrous structures on darkened rock art. Elemental composition analysis demonstrates heightened blackish deposit formation and increased phosphorus content in darkened samples. SEM-EDS characterization exposes gypsum morphology, with filament-like structures prevailing in heavily darkened samples, highlighting the role of both geochemical and microbial factors in deposit layer formation. FTIR spectra results confirm the presence of gypsum minerals, which are attributed to the substrate minerals and/or mineral weathering product, and unveil the existence of organic compounds, indicating microbial activity. Additionally, Raman spectroscopy reveals the anthropogenic contribution, notably soot deposition produced by human activities, to the darkening of rock art. This study underscores the need for a holistic preservation approach addressing natural, human, and microbial impacts on cultural heritage sites. Further research is also needed to conduct cross-sectional stratigraphical analysis to understand the accurate mechanism of the deterioration process on the rock art. Moreover, excavation measures regarding the possible relationship of soot deposition with human activities are also important to be carried out at the sites.

Tunable colors from responsive 2D materials

AbstractOne of the long‐sought‐after goals in responsive material development is to generate and tune colors for advanced and emerging applications such as dynamic displays, light‐emitting diodes, lasers, smart windows, chromic fabrics, high‐security encryption, and visual sensors. Benefiting from the atomically thin nature as well as strong optical interaction, two‐dimensional (2D) materials can serve as color‐generating centers for both chemical pigment colors and physical interference colors in solution, gels, films, and matrix interface systems, to offer new promises for color science and applications. Concerning color tunability, 2D material systems have been demonstrated as one of the ideal responsive materials to achieve the desired goals, including the change of composition, layer thickness, strain, magic angle, and thermally/photically/chemically responsive, magnetically‐responsive, electrically‐responsive, mechanically‐responsive. This makes it an attractive prospect for device applications such as optoelectronics, displays, and nanomedicine. However, to the best of our knowledge, no comprehensive review has been reported specifically on color‐centered aspects of 2D materials. In this review, we highlight experimental approaches and related applications for tuning pigment colors, reflective structural colors, and transmissive interference colors, and we refine the challenges and propose opportunities in future studies for the further development of color science in the 2D material system. Eventually, it is anticipated that this review will serve as a resource and source of inspiration for scientists, as well as open up new avenues for the advancement of color science and related fields in responsive 2D material systems.

Enhancing wood coatings with red beetroot-derived pigments: Investigating synergy with UV absorber and composite filler for improved durability and aesthetics

The objective of this study is to assess the synergy among a specific bio-based pigment derived from red beetroot, a composite filler, and a UV absorber as additives for wood paints. The composite filler aims to enhance the mechanical properties of the coating, while the UV absorber is selected to improve the pigment's color stability under solar radiation. The impact of these additives on sample aesthetics is evaluated through color, gloss, and roughness measurements. Mechanical properties are analyzed using Buchholz surface hardness and Taber abrasion resistance tests. The protective role of the UV absorber is further examined through accelerated degradation tests in a UV-B chamber. To ensure that the additives do not compromise the coating's barrier properties, water uptake tests, resistance to liquids, and contact angle measurements are conducted. Overall, the study demonstrates how each additive serves a distinct purpose and their combined application offers benefits such as enhanced color retention and improved mechanical durability of the coating. It highlights the potential of using bio-based pigments to enhance color durability without sacrificing the protective performance of wood coatings.

A smartphone image-based method for the colorimetric characterization of historical pigments in mural paintings

In this article, the detailed description of a smartphone-based analytical method to turn a smartphone into a colorimeter is described and applied to mural painting replicas. The method consists of a camera characterization process, to estimate CIELAB values from RGB camera responses, correcting for potential experimental interferences, like the effect of the lighting/capture geometry or software for color modification and enhancement. Next, the estimated CIELAB descriptors were used to build a chemometric Support Vector Classifier to objectively distinguish among the colors of the different pigments. The method was validated in terms of color reproduction and classification performance.•A smartphone-based method is described to capture mural painting color.•A color gamut-specific camera characterization procedure is developed and the performance of the smartphone-based colorimeter is compared with a spectrophotometer.•A classification method based on the estimated CIELAB descriptors is validated in terms of classification performance.