Kinds Of Pigments Research Articles

New glass-based coatings coloured with red pigments for Foamglas® panels

Abstract This work describes the design and development of new coloured glass-based coatings for Foamglas ® substrates. Four kinds of pigments were added in different proportions (1 and 5 wt% respectively) to a borate glassy matrix (labelled as G7) by two different mixing techniques; the chosen pigments were goethite (α-FeOOH), acicular hematite (Fe 2 O 3 ) spherical hematite and TiO 2 coated hematite. No interaction occurred between the selected pigments and the G7 matrix and consequently no new phases were formed in the reported experimental conditions. Coatings on the Foamglas ® substrates were sintered at 560 °C for 1 h and showed different porosity, pigment dispersion in the matrix and colour development, depending on the mixing technique. The porosity was exploited to add TiO 2 coated hematite into the coating, for photo-catalytic purposes. Each coating was deposited without affecting the Foamglas ® substrate porous structure.

Fotoproteksi Kurkumin terhadap β-Karoten pada Berbagai Nisbah Molar serta Aktivitas Antioksidannya

Curcumin and β-carotene are two kinds of pigments serve as antitumor, anticancer and antioxidant agents. Theantioxidant activity of curcumin is stronger and more stable as compared to β-carotene, so it can protect β-carotene degradation from light and oxygen. Therefore curcumin has higher antioxidant activity as well. Theresearch was conducted by mixing curcumin and β-carotene in several molarity ratios followed by iradiation usingvolpi lamp for 0, 10, 30, 60, and 90 minutes. The result shows that curcumin has photoprotection effect because itcan protect photooxidation of β-carotene. Mixing of curcumin and β-carotene 1:1 was the most stable ratio forprotecting β-carotene.

Discriminating Amino Resin Paints From Alkyd Resin Paints with Two Kinds of Pigments in Automotive Coatings in Forensic Analysis by FTIR Spectroscopy

The analysis of automotive coatings is important to forensic scientists, especially in the investigation of hit-and-run accidents. Amino resin paints, alkyd resin paints, and polyurethane paints are all popular automotive coatings. In this study, FTIR was employed to investigate these coatings, particular in amino resin paints. IR spectra were tentatively interpreted. The indicative peaks distinguishing amino resin paints (1550 cm−1) and alkyd resin paints (1600 cm−1/1580 cm−1) were summarized. Two kinds of alkyd resin paints (with the Pigment Scarlet Powder and with the Toluidine Red), which were frequently confronted in cases and might readily be read as amino resin paints in IR spectra, were studied and interpreted. The indicative peaks (1619 cm−1, 776 cm−1 and 1674 cm−1, 1494 cm−1) were selected to discriminate these two kinds of alkyd resin paints from amino resin paints and avoid an incorrect certificate of authenticity. The data in this study can help the forensic scientists identify these three paints accurately, especially in the cases with the interference of the pigments.

Extraction and characterization of some natural plant pigments

Antioxidant activities, total polyphenols and flavonoids, and antimicrobial effects in some plant pigments were determined in order to use these natural materials for cosmetics. The DPPH (1,1-diphenyl-2-picryl hydrazyl radical scavenging activity, % of control at maximum plants extract concentrations of 2500mg/L) in the thirteen natural plant pigments (black rice, purple sweet potato, yellow bitter melon, yellow paprika, red cabbage, yellow gardenia, blue gardenia, Chinese foxglove, mulberry leave, onion peel, grape peel, mulberry and red beet) ranged from 88.9% for red cabbage to 18.0% for blue gardenia. The highest total polyphenol content (404.2μg/ml) was measured in the onion peel pigment, and the lowest was in Chinese foxglove pigment (11.4μg/ml). The red cabbage had the highest total flavonoid amount which was 95.5μg/ml. The antimicrobial activities of the natural plant pigments were evaluated using the agar diffusion method. Most of the natural pigments for Bacillus subtilis, Micrococcus luteus, Escherichia coli, and Vibrio parahaemolyticus showed the clear zone formation of growth inhibition. Purple sweet potato, mulberry, mulberry leaf, grape peel, and blue gardenia showed high antimicrobial activities. These findings suggest that the pigments derived from natural plants had high biological activities, and exhibited different properties depending on each kind of pigments. Therefore these plant resources, having active functional components, can be used as excellent materials for natural cosmetics and food supplements.

Terracotta polychrome sculptures examined before and after their conservation work: contributions from non-invasive in situ analytical techniques

The potential of non-invasive in situ analytical techniques such as portable Raman, portable X-ray fluorescence, portable optical microscope and fibre optics reflectance spectroscopy has been shown studying painted layers of Renaissance terracotta polychrome sculptures belonging to the statuary of Santo Sepolcro Church in Milan. The results obtained allowed pointing out the contribution of these techniques to the compositional diagnostic, providing complete information, in some cases, better than micro-destructive techniques, on the kind of pigments used on the external painted layers. Moreover, a comparison with the results obtained before the last conservation work (2009) with micro-destructive techniques allowed ascertaining the removal of the external painted layers during the conservation operations.

Preparation, Characterization and Properties of CaZn<sub>2</sub>(PO<sub>4</sub>)<sub>2</sub>-BaB<sub>2</sub>O<sub>4</sub> Hybrid Nanopowders as Ecological Anticorrosive Pigment

CaZn2(PO4)2and β-BaB2O4nanopowders were firstly synthesized by an ultrasonic-aid chemical precipitation method. Then BaB2O4was mixed with CaZn2(PO4)2to prepare CaZn2(PO4)2-BaB2O4nanopowder ecological anticorrosive pigment. The TG-DTA, XRD and TEM measurements were used to characterize the structure and morphology of products. The activation of pigment has been improved by two ways: one is the synthesis of well-dispersed nanometer-sized powder with narrow distribution; the other way is to mix the two kinds of pigment together to generate a hybrid ecological pigment. Finally, the anticorrosive experiments of the product were investigated in aqueous alkyd paints. The result of anticorrosive performance indicates that the as-obtained hybrid pigments exhibit more excellent properties than commercial zinc phosphate and ZPA from Germany.

식물유래 천연색소의 항산화 활성

Abstract - The objective of this study was to determine the effect of antioxidant enzyme activity and radical scavenging activities of thirteen kinds of natural plant pigments. The analytic method of antioxidant activities were measured by estimating DPPH free radical scavenging and nitrite scavenging ability activity. The free radical scavenging activity by method using stable free radical DPPH was the highest in the red cabbaged pigment. Addition of ethanol extract 1㎎/㎖ from onion peel pigment displayed remarkable effect on nitrite scavenging ability about 91.9%. Antioxidative enzyme activity was evaluated in terms of superoxide dismutase(SOD), catalase(CAT), and ascorbate peroxidase(APX) activity. The bitter melon pigment had the highest SOD activity of 87.3%. The activities of CAT and APX were higher in the mulberry leave pigment compared with other natural plant pigments. In contrast, CAT activity of plant pigment samples were unaffected. These results suggest that natural plant pigment had the potent biological activities such as antioxidant enzyme activities, and that their activities exhibited differently depending on each kind of pigments.

<i>In Vitro</i> Antioxidant Activity of Pigment Extracted from Fruits of <i>Padus racemosa</i> and <i>Padus virginiana</i>

The total anthocyanin content (TAC) of pigment extracted from fruits of Padus racemosa and Padus virginiana was determined by pH-differential method. TAC in pigment from fruits of Padus racemosa was higher than that in Padus virginiana. The vitro antioxidant activity of the two kinds of pigment was evaluated by different assays, including DPPH• assay, ABTS•+assay, OH• assay and reducing power assay. The results showed that except for reducing power, pigment from fruit of Padus racemosa showed stronger ABTS•+, DPPH• and OH• radical scavenging activity than pigment from fruit of Padus virginiana. The study concluded that pigment extracted from fruit of Padus racemosa and Padus virginiana can be used as a source of natural antioxidants instead of synthetic antioxidants.

The Fluorescent Pigment of Mulberry Transferred in the Body of Silkworm, <i>Bombyx Mori</i>

Using silkworm (Bombyx mori, Dazao strain) as material, the fluorescent pigment of mulberry, silkworm blood, silk gland, cocoon shell, silkworm excrement, silkworm urine and moth urine were analyzed by using the technology of thin layer chromatography (TLC). The results indicated that there were 7 bands of fluorescent pigment from the extracts of green cocoon shell after TLC analysis. While, 2 bands in silkworm blood and its urine extracts, 4 bands in the silk gland extracts, as well as 5 bands in moth urine extracts were detected, but no band detection in the silkworm excrement extracts. The blue-violet fluorescent pigment which has the same Rf (0.35) was detected from the extracts of green cocoon shell, silk gland, silkworm urine, moth urine and mulberry after TLC analysis, but it cannot be found in silkworm blood and silkworm excrement. It was revealed that the blue-violet fluorescent pigment may be transferred directly from mulberry leaves, and then accumulated in the silk gland. Most of the pigment remained in the cocoon shell. And only a small amount of this kind of pigment was excreted through urine. There was also some yellow-green fluorescent pigment detected in the silkworm blood, silk gland and cocoon shell extracts, but it cannot be detected in both the mulberry and silkworm urine extracts. It was suggested that yellow-green fluorescent pigment synthesis pathway exist in the body of silkworm (Bombyx mori, Dazao strain).

Preparation and Performance Study of Reflection Heat Preservation Insulation Coating

The influence of film forming matter to heat preservation insulation coating reflectivity was studied. Organosilicon modified styrene-acrylic emulsion was selected as film forming matter through the infrared spectrum test. The influence of several kinds of pigment and filler to reflectivity was studied by orthogonal experimental design . Importance of factors from large to small in turn is: Rutile titanium dioxide> Kaolin> expanded perlite、hollow glass microsphere> iron oxide red, and the formula of pigment and filler was determined .The influence of rutile titanium dioxide to reflectivity was studied, the reflectivity of coating is superior when rutile titanium dioxide grain size is in the range between 0.130 m and 0.136 m. Film thickness has certain influence to reflectivity ,when the thickness is 0.062cm, the reflectivity of coating reaches the highest,is 73.28%.

The identification of the pigments used to paint statues of Feixiange Cliff in China in late 19th century by micro-Raman spectroscopy and scanning electron microscopy/energy dispersive X-ray analysis

The application of micro-Raman spectroscopy (μ-RS) and scanning electron microscopy (SEM)/energy dispersive X-ray spectrometer (EDS) to the research of pigments collected from Statues of Feixiange Cliff No. 67 and No. 69 niche of Tang Dynasty in China is reported. Five kinds of pigments were found in the experimental data, including black (carbon), white (gypsum + quartz), blue (lapis lazuli) and green (Paris green + Barium sulphate). After synthesized in 1814, Paris green was reported for a large import as a light and bright green pigment to paint architectures in China from the late 19th century. The analyzed blue pigment demonstrated the similar Raman spectra to the Lâjvardina blue glazed ceramics, which indicated lapis lazuli was an artificial product. This confirmed the painting of Feixiange Cliff in the early Republic of China as the historical record, and also reveals that some pigments were imported from abroad.

Ancient Portuguese Ceramic Wall Tiles (“Azulejos”): Characterization of the Glaze and Ceramic Pigments

Ancient ceramic wall tiles, called “azulejo”, firstly used on Portuguese churches, monasteries and palaces (15-18th century) have progressively been used in particular houses till the last century. These tiles and its use in huge decorative panels can be considered as a precious but fragile cultural heritage from Brazil to India, in several countries influenced by Portuguese culture. Morphologically, these tiles are composed by a porous clay-based ceramic body, the terracotta, covered by a protective glassy phase, the glaze. As artistic paintings, these murals incorporated various kinds of pigments in the glaze layer to create a pictorial impact on the walls of rich palaces or churches, real and durable monumental works-of-art. In the 21st century, degradation marks are visible on these ceramic tiles because of their use under corrosive conditions (moisture, atmospheric cycles…) along centuries. In order to promote their conservation and enhance their restoration, the physical-chemical characterization of the azulejos is performed in the present work, using mainly non-destructive processes like micro-Raman spectroscopy or X-Ray diffraction. In particular, Raman spectroscopy allows the detection of some nano/microcrystals present in the amorphous glaze due to pigments or opacifying agents or related to the elaboration process of the azulejo. Based on the observation of various selected fragments, one states that very few pigments have been used as colouring agents in this ceramic art during 17-18th centuries. Thus, the relationship between the different colours, the introduced pigments and the structural aspects of the glass will be focused. Some features related with the ancient ceramic technology will also be discussed.

Effect of Pigment Kinds on the Solar Heat Reflection Characteristics of Paint Film in Visible and Near-Infrared Ray Area

In recent years, the global warming has been recognized as a serious problem throughout the world. In Japan, various global warming control technologies for slowing the global warming are being applied and verified. The high reflectance surface for structures has got a great deal of public attention as a promising technology that mitigates the heat island phenomenon which is a cause of the global warming. It is considered that the heat island phenomenon is generated by the temperature rise due to the heat release from the buildings which have a high heat absorptance and are warmed by the solar radiation during the daytime. Applying with solar heat high reflectance paint to the exterior surfaces of urban structures would suppress the increase in temperature, and make possible mitigating of the urban heat island. Solar heat high reflectance paint is composed of various raw materials to enhance the reflection in visible and near-infrared ray. This paper describes solar heat reflectance characteristics of the paint film by varying thickness of film, formulation of paint (pigments by binder mass ratio ; P/B) and kinds of pigments which are uesd for colorling structures in white, black, blue, red, and yellow. The conclusions obtained from this study are as follows : 1) With the increase in P/B, solar reflectance of paint films used organic pigments are devided into two groups. One is not influenced with the increase of P/B and the other is increased with the increase of P/B. The solar transmittance of paint films with most organic pigments is decreases with the increase of P/B. The solar reflectance and the solar transmittance of paint films with inorganic pigments are not influenced with the increase of P/B. 2) The solar reflectance is not influenced by the thickness of paint film and the solar transmittance decreases with the increase of thickness of paint film.

THE CHEMICAL COMPOSITION OF BLUE PIGMENT ON CHINESE BLUE‐AND‐WHITE PORCELAIN OF THE YUAN AND MING DYNASTIES (ad 1271–1644)*

The chemical compositions of the glazes and pigments of 39 blue‐and‐white porcelains of Ming Dynasty date and three of Yuan date were examined by SR‐XRF. Both the analysis of the Fe/Mn ratio in the light blue areas of the glaze and a comparison of the Fe/Mn values between light blue, dark blue and clear glaze areas reveals that the samples can be divided into three groups. The results indicate that there are two significant changes of provenance of blue pigment during the Ming Dynasty and that some kinds of pigment were most probably imported from the Middle East. Considering literature records and other scholars’ studies, an outline picture of the pigment used on Chinese blue‐and‐white porcelain produced in Jingdezhen in the Yuan and Ming Dynasties is presented.

Diagnostic and historical-iconographic study on frescos in Palazzo Maioli (Ravenna)

The pictures discovered in Ravenna at Maioli Palace (Ravenna) have been subjected to an analytical survey, both during and after the works of a restoration performed at the Restoration Laboratory. This building, set during the time of the Venetian rule in the town of Romagna (1447-1509), belonged for centuries to the noble Maioli Family, that had come from Faenza. The walls, taken into consideration, show four levels, i.e. four different times about when the four pictures have been performed. The first one refers to the construction period of the building, the second one is the one studied, the third one can be connected to the Seventeenth century, according to the stylistic details of the Pompeian period. While the forth one is dated back to the end of the Eighteenth century, since the is typical of that time (with decorative part we refer to the stencil decorations, i.e. applications of pictures, inks or colours by means of special little masks). The experimental study carried out on two kinds of pictured samples (chosen according to their kind of pigments i.e.: yellow and black) as focused on: the colorimetry, in order to determine the components of the chromaticity; the fluorescence spectrometry to X ray, to characterize the pigments used; the thermal analysis with the goal of finding out the kind of plaster; the video-microscopy to get documentary and cognitive purposes. A systematic analysis of the pictures was justified both by the will of finding the pictorial technique of the painter, and by the wish to be able to date them back to the period of their creation, since at the moment, there is no documentation about these issues.

A New Approach in the Determination of Eumelanin in Human Hair Using near Infrared Spectroscopy

Page 10 NIR news Vol. 16 No. 6 (2005) The aetiology of skin cancers is a complex interaction between genetic characteristics (phenotypically expressed by skin complexion) and exposure to sun. These two factors, complexion and exposure to sun, modulate the risk of different tumours in a different way. In detail, for melanoma, risk is associated with fair complexion (light blonde or red hair, high number of naevi and freckles, tendency to sunburn) and with intense and intermittent exposures like those experienced during holidays. Risk profiles are defined by semi-quantitative empiric parameters (scale of hair, eye and skin colour, acute reactivity scale, such as MED, Minimal Erithemal Dose) for the tendency to sunburn. Knowledge of the biochemistry of skin pigments, the melanins, has made it possible to identify a biological marker. Melanins are biopolymers present in the hair and epidermis. There are two distinct types of melanin pigments: the eumelanins, efficient in photo-protection and responsible for black and brown colour and the pheomelanins, bad at photo-protection and responsible for yellow and reddish colour. Most Caucasian populations have intermediate skin and hair colour and present these two kind of pigment in different ratios. This study about the distribution of melanin pigment in the population in general and in groups of subjects with different cutaneous tumours is an original work, starting from results obtained in the biochemical field. The turning point from empirical characterisation to biochemical characterisation of phenotypes by the quantitative determination of melanins in human hair can lead to the selection of groups with an elevated risk of cutaneous tumours. In these groups of people it will be possible to carry out more thorough diagnostic tests (dermatological inspection of skin). A multicentric case-control study was carried out in different European countries. Three groups of about 300 cases were recruited for each cutaneous cancer (cutaneous melanoma, squamous cell carcinoma and basal cell carcinoma) and 300 controls. For each group of people, in addition to data concerning phenotype and sun exposure Eumelanin in Human Hair

Non-destructive and in situ identification of rice paper, seals and pigments by FT-IR and XRD spectroscopy

This paper studied the chemical characteristics of rice paper, pigments and seals on Chinese calligraphies and traditional Chinese paintings. The techniques used here were Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD). FT-IR allows good identification of the substances present in pigments and inkpads and differentiates each era of rice paper. This can be the base of estimating the age of rice paper. Different crystalline phases can be identified by XRD, which is further evidence to separate different kinds of pigments or inkpads. Both of these methods were non-destructive in situ analysis and can be used in the identification in calligraphies and traditional Chinese paintings. These results confirmed that the applied techniques are relatively quicker and more reliable than traditional approaches authenticated by years of experience.

Simple and Easy Solid-State Dye Laser

Perylene orange is a kind of pigment that is not easily photobleached. We doped perylene orange into a 2-mm-thick acrylic plastic monolith as a laser-active medium. Commercially available metalized film tape was affixed to both sides of the acrylic monolith and served as mirrors for a Fabry–Perot resonator. The pump source was a Q-switched frequency-doubled Nd:YAG laser. We obtained a yellow laser beam whose center wavelength was 578.6 nm.

Detection of new pigments related to purple urine bag syndrome

It is well known that participation of two kinds of pigments, indigo blue and indigo red, are concerned with purple urine bag syndrome (PUBS). However, there is no research which describes the participation of other pigments. We separated three new kinds of red pigments, other than indigo blue and indigo red, from four patients with PUBS. One of the pigments was not visible to the naked eye and appeared only when an ultraviolet ray was irradiated. The appearance patterns of indigo blue, indigo red and the three new red pigments were in complete agreement in two cases, but differed in the other two cases. Moreover, bacteria isolated from the urine were cultured in an indican-added alkaline liquid media (pH9), 80% or more bacteria produced purple pigments. In case 1, from deep-colored pigments, each bacterium produced both indigo blue and indigo red, although new pigments could not be observed in the in vitro media.

Thermogravimetric Analysis of Pigments and Fillers for Papermaking

Thermogravimetric analysis was applied to several kinds of pigments and fillers for papermaking to examine exact temperatures from which mass reduction commences. Clay and talc began to reduce mass from about 350°C and 450°C respectively. Clay contained in coated paper began to reduce mass from about 350°C. Therefore, “Other fillers and pigments (than calcium carbonate) such as clay and titanium dioxide are also unaffected by ashing at 525°C.” stated in ISO 1762: 2001, “Paper, board and pulps-Determination of residue (ash) on ignition at 525°C” was found to be apparently wrong. Calcium carbonate began to reduce mass from about 580°C, suggesting no decomposition at 525°C specified in JIS P 8251: 2002. The result also suggests no decomposition even at the ashing temperature 575°C specified in the previous edition of ISO 1762. However, the standard tolerates an accuracy of ±25°C due to technical difficulty in temperature control of muffle furnaces. So, it is appropriate that the ashing temperature was lowered from 575 to 525°C in the revision. There was no mass reduction for titanium dioxide below 1, 000°C.