Pigmented Coatings Research Articles

Plants accumulate key metabolites as a response of biotic/abiotic stress conditions. In seed coats, anthocyanins, carotenoids, and chlorophylls can be found. They have been associated as important antioxidants that affect germination. In wheat, anthocyanins can impart the seed coat color which have been recognized as health-promoting nutrients. Transcription factors act as master regulators of cellular processes. Transcription complexes such as MYB-bHLH-WD40 (MBW) regulate the expression of multiple target genes in various plant species. In this study, the spatiotemporal accumulation of seed coat pigments in different developmental stages (10, 20, 30, and 40 days after pollination) was analyzed using cryo-cuts. Moreover, the accumulation of phenolic, anthocyanin, and chlorophyll contents was quantified, and the expression of flavonoid biosynthetic genes was evaluated. Finally, transcriptome analysis was performed to analyze putative MYB genes related to seed coat color, followed by further characterization of putative genes. TaTCL2, an MYB gene, was cloned and sequenced. It was determined that TaTCL2 contains a SANT domain, which is often present in proteins participating in the response to anthocyanin accumulation. Moreover, TaTCL2 transcript levels were shown to be influenced by anthocyanin accumulation during grain development. Interaction network analysis showed interactions with GL2 (HD-ZIP IV), EGL3 (bHLH), and TTG1 (WD40). The findings of this study elucidate the mechanisms underlying color formation in Triticum aestivum L. seed coats.

Pumpkin seed coat pigments affected aqueous enzymatic extraction processing through interaction with its interfacial protein

Fluorescence analysis of materials used as binders and coatings in artworks is often hampered by numerous factors, leading to uncertainties in data interpretation. Fluorescence lifetime (FL) measurements enable improvement of the specificity with respect to steady-state measurements by resolving the decay dynamics of the fluorophore emissions. In this work, layers of natural resin, oil, and wax—in pure form, pigmented, in mixtures, and spread on different substrates—were analyzed using a compact, portable, fiber-based FL instrument. FL data were processed via the phasor method and integrated with Raman spectroscopy to obtain complementary chemical information on the different substances. It was observed that the τ-phase of the mixtures is affected by both the pigments and the dispersing medium, and that the presence of the metal substrate contributes to changes in the FL of mixtures. The results obtained with our portable FL system combined with Raman spectroscopy pave the way for a systematic study of a larger number of materials for future in situ applications on works of art.

Applying organic coating is an important and effective approach for the protection of metal from corrosion. Weathering degradation and under-film corrosion are the two major important factors that cause the failure of organic coatings. In this work, the degradation investigation of two epoxy coatings (clear and pigmented coatings) was carried out under the dry–wet circulation of three different water fog solutions (deionized water, 0.5 wt% NaCl, 0.05 wt% NaCl + 0.35 wt% (NH4)2SO4) in 35 days. The apparent performance (pull-off adhesion and surface potentials) and electrochemical features [electrochemical noise and electrochemical impedance spectroscopy (EIS)] of the coating samples were monitored after dry–wet fog exposure. In our three accelerating systems of the fog atmosphere, the time that the detectable defects appeared on the surface of coating samples was far ahead in the mixed salt solution than that in the deionized water or 0.5 wt% NaCl solution. For a defective or damaged coating surface, the derived results by using the standard deviation method (SDM) or Fourier power spectrum (FPS) were rather higher than those obtained from EIS as a whole, while for the same coating, the degradation trend with time derived from EIS, SDM, FPS, and scanning Kelvin probe was consistent with each other.

Two types of cinnamoyl-CoA reductase function divergently in accumulation of lignins, flavonoids and glucosinolates and enhance lodging resistance in Brassica napus

Sheep (Ovis aries) is one of the important livestock with diverse phenotypic traits. However, little is known about the molecular mechanism of diverse phenotypic traits in domestic sheep. Using the genome-wide high-density SNP data (600K) in 253 samples from 13 populations, we conducted the tests of selective sweeps (i.e., pairwise F ST and XP-CLR) associated with several important phenotypic traits (e.g., tail types, horn morphology, prolificacy, coat pigmentation, ear size, milk production, meat production, body size and wool fineness). We identified strong selective signatures in previously reported (e.g., T, RXFP2, BMPR1B, TYRP1, MSRB3, TF, CEBPA, GPR21 and HOXC8) and novel genes associated with the traits, such as CERS6, BTG1, RYR3, SLC6A4, NNAT and OGT for fat deposition in the tails, FOXO4 for fertility, PTCH1 and EMX2 for ear size, and RMI1 and SCD5 for body size. Further gene annotation analysis showed that these genes were identified to be the most probable genes accounting for the diverse phenotypic traits. Our results provide novel insights into the genetic mechanisms underlying the traits and also new genetic markers for genetic improvement in sheep and other livestock.

Our understanding of canine coat colour genetics and the associated health implications is developing rapidly. To date, there are 15 genes with known roles in canine coat colour phenotypes. Many coat phenotypes result from complex and/or epistatic genetic interactions among variants within and between loci, some of which remain unidentified. Some genes involved in canine pigmentation have been linked to aural, visual and neurological impairments. Consequently, coat pigmentation in the domestic dog retains considerable ethical and economic interest. In this paper we discuss coat colour phenotypes in the domestic dog, the genes and variants responsible for these phenotypes and any proven coat colour-associated health effects.

Quantitative characterization of the spreading and adhesion of styrene-butadiene latex binder in the dried pigment coating layer

The use of TiO2 nanoparticles in organic-based photocatalytic coatings imposes several challenges: poor activity under visible light, binder photo-degradation, need for UV activation and toxicity concerns. Here we present a scalable two-step synthesis route to prepare TiO2-based hollow microspheres (HoS) as alternative photocatalyst to commercial TiO2 nanoparticles. The hollow microspheres of TiO2 or WO3-doped TiO2 (3 mol% WO3) are synthesized via template-assisted spray-drying followed by calcination. The structure and composition of the powders are characterized and their photocatalytic performance is assessed using methylene blue photo-degradation under UV irradiation as model reaction. XRD analysis reveals the presence of anatase and TiO2(B) phases, indicating the heterostructured nature of the samples. The results of the dye photo-degradation tests confirm the photocatalytic functionality of the TiO2-based HoS. Moreover, the introduction of WO3 (TiO2/WO3 HoS) leads to an enhancement of the performance, approaching that of commercial (Aeroxide P25, ~21 nm) nanoparticles. The most active TiO2/WO3 HoS are incorporated into an acrylic formulation and the resulting coatings tested towards pollutant abatement under UV light. A coating containing P25 nanoparticles undergoes an activation process where binder degradation leads to increased TiO2 exposure and a rise in catalytic activity but possibly at the expense of coating stability. By contrast TiO2/WO3 HoS-acrylic coatings exhibit catalytic activity similar to the initial activity of P25 containing coatings, but does not cause the same partial binder photo-degradation.

Optical properties degradation of wollastonite powders under the electron irradiation in vacuum

Titanium dioxide (TiO2) is one of the most commonly used pharmaceutical excipients. It is widely used as a white pigment in tablet and pellet coatings. However, it has recently been under massive criticism as a number of studies suggest a cancerogenic potential. It can therefore no longer be taken for granted that TiO2 will continue to be universally available for drug products. Finding suitable alternatives is hence of special relevance. In this study, a number of different pigments were coated on tablets and their covering potential analyzed. None of the alternative pigments showed comparable effectiveness and efficiency to TiO2, though the CaCO3/CaHPO4-based coating showed the second-best results. Regarding the ability to protect photosensitive active ingredients, ZnO showed a comparable potential as TiO2, while all other pigments failed. Using the alternative pigments as markers for in-line Raman spectroscopy as a process analytical technology was challenging and led to increased prediction errors. Again, the CaCO3/CaHPO4-based coating was the only of the tested alternatives with satisfying results, while all other pigments led to unacceptably high prediction errors.

Agro-industrial waste valorization is an attractive approach that offers new alternatives to deal with shrinkage and residue problems. One of these approaches is the synthesis of advanced carbon materials. Current research has shown that citrus waste, mainly orange peel, can be a precursor for the synthesis of high-quality carbon materials for chemical adsorption and energy storage applications. A recent approach to the utilization of advanced carbon materials based on lignocellulosic biomass is their use in solar absorber coatings for solar-thermal applications. This study focused on the production of biochar from Citrus aurantium orange peel by a pyrolysis process at different temperatures. Biochars were characterized by SEM, elemental analysis, TGA-DSC, FTIR, DRX, Raman, and XPS spectroscopies. Optical properties such as diffuse reflectance in the UV−VIS−NIR region was also determined. Physical-chemical characterization revealed that the pyrolysis temperature had a negative effect in yield of biochars, whereas biochars with a higher carbon content, aromaticity, thermal stability, and structural order were produced as the temperature increased. Diffuse reflectance measurements revealed that it is possible to reduce the reflectance of the material by controlling its pyrolysis temperature, producing a material with physicochemical and optical properties that could be attractive for use as a pigment in solar absorber coatings.

A promising inorganic YFeO3 pigments with high near-infrared reflectance and infrared emission

Chemical and colorimetric analysis for the characterization of degradation forms and surface colour modification of building stone materials

The testing of thin colored coatings based on urethane acrylate composition is a technologically advanced, highly specialized and complex process. For decorative pigmented coatings color stability is crucial quality parameter. The photo chemically curable polymer films were prepared by addition of 3 different radical initiators (KTO, TPO, TPO-L) to aliphatic urethane acrylate composition with various pigments (solid and fluorescent). Coating color change were evaluated in UV chamber (with luminous intensity 130 mw spectrum λmax = 405 nm) after 1 h, 48 h and 72 h. Color measurements were performed according to the CIEL*a*b* color standard to evaluate their stability over time. It was found that pigmented coatings have higher risk of yellowness than clear coatings. Also fluorescent pigments containing red has tendency to yellow after UV light exposure. The influence of the photoinitiator on the color stability were inconsiderable.

The anticorrosion environmentally friendly pigments based on synthetic zeolite and zinc and calcium phosphates were prepared by mechanochemical method. The surface morphology and chemical composition of the obtained pigments were determined by scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively. It was established that the modification of zeolite by phosphates of divalent metals causes a decrease in the particle size and an increase in the specific surface area of the obtained composite pigments. It was shown that the use of zeolite/phosphate pigments increases the corrosion resistance of the aluminium alloy in 0.1% aqueous NaCl solution. The addition of complex zeolite/phosphate pigments to the sodium chloride solution decelerates the anodic process of electrochemical corrosion, which indicates the formation of a protective film on the metal surface. The composite pigment zeolite/Zn(H2PO4)2 exhibited the highest anticorrosive effect. A gradual release of the inhibitory components from these environmentally friendly pigments provides their long-term action to protect metal products.

BackgroundNellore cattle (Bos indicus) are well-known for their adaptation to warm and humid environments. Hair length and coat color may impact heat tolerance. The Nellore breed has been strongly selected for white coat, but bulls generally exhibit darker hair ranging from light grey to black on the head, neck, hump, and knees. Given the potential contribution of coat color variation to the adaptation of cattle populations to tropical and sub-tropical environments, our aim was to map positional and functional candidate genetic variants associated with darkness of hair coat (DHC) in Nellore bulls.ResultsWe performed a genome-wide association study (GWAS) for DHC using data from 432 Nellore bulls that were genotyped for more than 777 k single nucleotide polymorphism (SNP) markers. A single major association signal was detected in the vicinity of the agouti signaling protein gene (ASIP). The analysis of whole-genome sequence (WGS) data from 21 bulls revealed functional variants that are associated with DHC, including a structural rearrangement involving ASIP (ASIP-SV1). We further characterized this structural variant using Oxford Nanopore sequencing data from 13 Australian Brahman heifers, which share ancestry with Nellore cattle; we found that this variant originates from a 1155-bp deletion followed by an insertion of a transposable element of more than 150 bp that may impact the recruitment of ASIP non-coding exons.ConclusionsOur results indicate that the variant ASIP sequence causes darker coat pigmentation on specific parts of the body, most likely through a decreased expression of ASIP and consequently an increased production of eumelanin.

The effect of hydrophilic bentonite incorporation on the curing performance of pigmented ultra violet (UV) curable polyurethane acrylate (PUA) coating was investigated. To the best of our knowledge, crock fastness and gloss properties of pigmented bentonite incorporated UV curable PUA coating have been examined for the first time. Fourier Transform Infrared (FTIR) spectroscopy analysis of the cured films showed that addition of both bentonite and pigment decreased the conversion of C=C. However a more significant drop was observed with the addition of pigment into the formulation. The drop of conversion with the incorporation of bentonite did not adversely affect the hardness and crock fastness values and hence the UV curing performance of the films. Bentonite particles were efficiently distributed in the film and intercalation was achieved owing to the ball milling process. Hardness of the cured films increased with the increase in energy levels. On the other hand, hardness decreased at higher pigment concentrations however, was not affected adversely by bentonite incorporation. Gloss was found to be enhanced with the addition of bentonite in both pigmented and unpigmented films. Significant improvement in crock fastness could not achieved with the addition of bentonite.

Soybean has undergone extensive selection pressures for seed nutrient composition and seed color during domestication, but the major genetic loci controlling seed coat color have not been completely understood, and the transcriptional regulation relationship among the loci remains elusive. Here, two major regulators, GmMYBA2 and GmMYBR, were functionally characterized as an anthocyanin activator and repressor, respectively. Ectopic expression of GmMYBA2 in soybean hairy roots conferred the enhanced accumulation of delphinidin and cyanidin types of anthocyanins in W1t and w1T backgrounds, respectively, through activating anthocyanin biosynthetic genes in the reported loci. The seed coat pigmentation of GmMYBA2-overexpressing transgenic plants in the W1 background mimicked the imperfect black phenotype (W1/w1, i, R, t), suggesting that GmMYBA2 was responsible for the R locus. Molecular and biochemical analysis showed that GmMYBA2 interacted with GmTT8a to directly activate anthocyanin biosynthetic genes. GmMYBA2 and GmMYBR might form a feedback loop to fine-tune seed coat coloration, which was confirmed in transgenic soybeans. Both GmTT8a and GmMYBR that were activated by GmMYBA2 in turn enhanced and obstructed the formation of the GmMYBA2-GmTT8a module, respectively. The results revealed the sophisticated regulatory network underlying the soybean seed coat pigmentation loci and shed light on the understanding of the seed coat coloration and other seed inclusions.

The effect of structure-property relationships on the formability of pigmented polyester coatings