Search Results (21)

Hangzhou was the political and economic center of the Southern Song Dynasty (1127–1279 AD) and also the southern end of the Beijing-Hangzhou Grand Canal during the Ming and Qing Dynasties (1368–1644 AD). This historical position allowed the city’s economy to develop rapidly and influenced the form of its polychrome paintings with the imperial official style of the north China. However, due to the high temperature and rainy natural preservation conditions, southern polychrome paintings have always been a weak link in Chinese architectural polychrome painting craftsmanship. This study focuses on two well-preserved official-style architectural polychrome paintings in the grand halls from the late Qing period in Hangzhou. Through multi-techniques such as optical microscopy (OM), scanning electron microprobe with energy dispersive X-ray spectroscopy analysis (SEM-EDX), micro-Raman spectroscopy, micro-Fourier Transform Infrared spectroscopy (μ-FTIR), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), it was found that there is a significant difference from the reported common non-ground architectural paintings in the south, typically having four-layer structures with a white base and ground plaster layer in preparation for painting. The appearance of pigments such as artificial ultramarine (Na₆Al₄Si₆S₄O₂₀) and emerald green (Cu(C₂H₃O₂)₂·3Cu(AsO₂)₂) indicates that the paintings were made at least after the 1830s, and the use of malachite green dye and copper phthalocyanine blue (PB 15:X) suggests that unrecorded restorations were also performed after the 20th century. All samples are coated with a layer of alkyd resin, which may have been added during the repairs in the latter half of the 20th century, leading to the black discoloration of the present paintings, especially in areas where emerald green was used. This study provides an important case for the study of the official style of polychrome painting craftsmanship in the southern region of China and also offers important references for the future protection and restoration of traditional architectural polychrome painting. Full article

Cellulose nanocrystals (CNCs) prepared by sulfuric acid hydrolysis were added to phthalocyanine green colour pastes with a surfactant to improve stability. The particle size, zeta potential, absorbance, and microstructure of the colour pastes were analyzed and characterized. The mechanism of CNCs to enhance the stability of hydrophobic phthalocyanine green in water was investigated. The functionalized application of the colour pastes was explored by mixing colour pastes with coating-forming substances to prepare phthalocyanine green paint. The results show that CNCs could enhance the stability of phthalocyanine green in water and form a binary system with non-ionic surfactants in colour pastes. The system could make phthalocyanine green colour pastes have very good dispersion and stability and mix well with coating-forming substances. The phthalocyanine green paint had excellent performance. As a renewable and naturally degradable biomass resource, CNCs have the potential to be applied for the dispersion and stabilization of hydrophobic pigments by compounding with surfactants. Full article

Tattoos have been a ubiquitous phenomenon throughout history. Now, the demand for tattoo removal for aesthetic or practical reasons is growing rapidly. This study outlines the results of field investigations into the chemical and biological removal of tattoo inks (Hexadecachlorinate copper phthalocyanine—C₃₂Cl₁₆CuN₈—CAS no° 1328-53-6). FTIR, Py-GC/MS, and NMR analyses yielded intriguing profiles pertaining to the primary chemical constituents, along with others of an ambiguous nature. A bioremoval protocol was developed on a pork rind surface to simulate human tattooing. Two previously studied microbial strains were included in this analysis: (i) a bacterial culture of Pseudomonas stutzeri 5190 DSMZ viable cells and (ii) a fungal culture of Alternaria infectoria strain NIS4, the latter already isolated and identified. A combination of physical, chemical, and microbiological analyses, along with microscopic observations, was conducted. In our experimental conditions, inocula from environmental samples (soil and compost) were capable of inducing changes in even trace organic matter (glycerin and additives in pigments) used as a binder in emulsifiers in tattoo inks. Furthermore, the two microbial strains demonstrated promising potential for removing green tattoo ink. Finally, wastewater effluents containing green ink were recovered via electrochemical treatment, and the environmental impact in terms of the CO₂ equivalent of our experiments was assessed. The results are promising and warrant further investigation into the innovative biological and chemical removal of tattoo inks from human skin and wastewater, respectively. Full article

Octa-methylpyridiloxy-substituted Zn(II)- and Ga(III)-phthalocyanines (ZnPc1 and GaPc1) were studied on human pigmented melanoma (SH4) and keratinocyte (HaCaT) cell lines. The efficacy of ZnPc1 and GaPc1 against melanoma cells was compared to the results in the presence of a proteaseα-chymotrypsin (ChT). The synthesis and characterization of compounds were carried out using well-known approaches. The formation of physical conjugates due to the addition of ChT was studied via absorption and fluorescence. The proteolytic activity of ChT was verified with casein as a substrate. The photosafety of compounds was proven on embryonal cells (BALB 3T3) under solar exposure (LED 360–1100 nm). The photodynamic activity of GaPc1 and ZnPc1 was studied for a concentration range of irradiation (LED 660 nm). The reduction of the proteolytic activity of ChT was observed only for the irradiation of ZnPc1 or GaPc1. GaPc1 and ChT and their conjugates, except ZnPc1 (PIF ~6), were evaluated as photo-safe to solar light (PIF < 2). The efficiency of GaPc1 was shown to be much higher than that of ZnPc1 in their individual applications. The phototherapeutic index of GaPc1 (PI = 1.71) on SH4 cells was higher for the conjugate. α-Chymotrypsin and phthalocyanine have the advantages of reducing high toxicity and increasing the phototherapeutic index. Full article

Polypropylene color masterbatches containing modified layered double hydroxides, LDHs, were created. The simple, industry-acceptable method of LDH surface modification with quinacridone and phthalocyanine pigments using the pulverization method in ball mills was applied. It was reported that the modification parameters such as time and rotational speed affected the tendency to create the aggregates for modified fillers. TGA analysis of the modified LDH showed that modification with phthalocyanine pigment shifted the temperature at which 5%, T_5%, and 10% of mass loss, T_10%, occurred compared with that for unmodified LDH. The viscoelastic properties of prepared masterbatches were investigated. The incorporation of the modified fillers instead of neat pigments led to an increase in the loss shear modulus, G″, indicating a stronger influence on the dissipation of energy by the melted masterbatch. The similar values of tan, δ, were determined for melted masterbatches containing phthalocyanine pigment and green modified LDH filler. The incorporation of both LDHs modified by phthalocyanine and quinacridone pigment fillers slightly increased the zero-shear viscosity, η₀, compared with that of the masterbatches based on the neat pigments. The Cole–Cole plots and the analysis of the Maxwell and continuous relaxation models showed that modified colored LDH fillers facilitated the relaxation of the melted masterbatch, and shorter relaxation times were observed. The phthalocyanine-modified LDH filler improved the thermal stability of the masterbatches. Additionally, the impact of pigments and modified, colored LDH on the crystallization of polypropylene was investigated. Full article

Phthalocyanine pigments have many problems in waterborne coating applications because of their low polarity, poor dispersion in water, and easy agglomeration properties. In order to solve these problems, the phthalocyanine pigments were encapsulated with a copolymer of methyl methacrylate (MMA) and butyl acrylate (BA) by a mini-emulsion polymerization method. The pigments are effectively dispersed in water and have good compatibility with the resin. Concerning the bacterial reproduction and growth problem for the waterborne system, the resin-encapsulated phthalocyanine pigments were further grafted with antibacterial polymer poly(N-(2-hydroxyethyl) acrylamide) (PHEAA) on its surface using the photoemulsion polymerization technique. Comprehensive properties, including centrifugal stability and chromaticity change, were studied. The polymer encapsulation improved the centrifugal stability of the pigment. The thermogravimetric results showed that the residual mass of C.I. Pigment Green 7 (52.30%) was higher than that of C.I. Pigment Blue 15:3 (30.06%), and the sublimation fastness of PG7 was higher. The TEM results revealed that the shape of the PG7 after encapsulation and grafting was more regular than that of PB15:3. The L* of the pigment decreased after encapsulation but then increased after further grafting. The phthalocyanine pigment composite latex had good antibacterial properties after the grafting of PHEAA. Full article

Previous studies have shown that the incorporation of sulfonated metallophthalocyanines into sensitive sensor materials can improve electron transfer and thus species detection. Herein, we propose a simple and easy alternative to the use of generally expensive sulfonated phthalocyanines by electropolymerizing polypyrrole together with nickel phthalocyanine in the presence of an anionic surfactant. The addition of the surfactant not only helps the incorporation of the water-insoluble pigment into the polypyrrole film, but the obtained structure has increased hydrophobicity, which is a key property for developing efficient gas sensors with low sensitivity to water. The obtained results show the effectiveness of the materials tested for the detection of ammonia in the range of 100 to 400 ppm. It is shown by comparing the microwave sensor responses that the film without nickel phthalocyanine (hydrophilic) produces greater variations than the film with nickel phthalocyanine (hydrophobic). These results are consistent with the expected results since the hydrophobic film is not very sensitive to residual ambient water and therefore does not interfere with the microwave response. However, although this excess response is usually a handicap, as it is a source of drift, in these experiments the microwave response shows great stability in both cases. Full article

The conjugation of photosensitizer with collagen seems to be a very promising approach for innovative topical photodynamic therapy (PDT). The study aims to evaluate the effects of bovine collagen hydrolysate (Clg) on the properties of gallium (III) phthalocyanine (GaPc) on pigmented melanoma. The interaction of GaPc with Clg to form a conjugate (GaPc-Clg) showed a reduction of the intensive absorption Q-band (681 nm) with a blue shift of the maximum (678 nm) and a loss of shape of the UV-band (354 nm). The fluorescence of GaPc, with a strong emission peak at 694 nm was blue shifted due to the conjugation which lower intensity owing to reduce quantum yield (0.012 vs. 0.23, GaPc). The photo- and dark cytotoxicity of GaPc, Glg and GaPc-Clg on pigmented melanoma cells (SH-4) and two normal cell lines (BJ and HaCaT) showed a slight decrease of cytotoxicity for a conjugate, with low selectivity index (0.71 vs. 1.49 for GaPc). The present study suggests that the ability of collagen hydrolysate to form gels minimizes the high dark toxicity of GaPc. Collagen used for conjugation of a photosensitizer might be an essential step in advanced topical PDT. Full article

The conservation of contemporary art often offers unique occasions to study complex multi-material artworks and understand their creative process and esteem degradation distress. The recent diagnostic campaign on the surrealist artwork Perché le vittime vincano (For the victims to win) (1974–75) by the artist Roberto Sebastian Matta allowed us to characterize the original painting materials (pastels on spolvero paper), never investigated and completely unknown, in order to support the imminent restoration. Due to the great dimensions of the artwork and its conservative issues, non-invasive multispectral imaging (HMI) analyses were done to investigate the whole painted surface, mapping and differentiating original materials and possible degradation patterns. Imaging data supported analytical characterization analyses run through elemental (portable X-ray fluorescence spectroscopy and scanning electron microscopy coupled with energy-dispersive spectroscopy) and molecular spectroscopy (Fourier transform infrared and portable µ-Raman spectroscopy) to identify the original artist’s materials and to support the restoration operations. The analysis revealed that the painting materials used by Matta are pastels characterized by modern pigments and dyes, such as Cu-phthalocyanines, chrome orange, titanium and zinc whites, compacted with kaolin without any organic binder or with a possible minuscule amount of gum. Full article

The concentrations of polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were determined in soil samples collected around an industrial park in Northwest China, to investigate the potential impacts of park emissions on the surrounding environment. The total concentration ranges of PCBs, PCNs, and PCDD/Fs in the soil samples were in 13.2–1240, 141–832, and 3.60–156 pg/g, respectively. The spatial distribution and congener patterns of PCBs, PCNs, and PCCD/Fs indicated that there might be multiple contamination sources in the study area, so source apportionments of PCBs, PCNs, and PCCD/Fs were performed by a positive matrix factorization model based on the concentrations of all target congeners together. The results revealed that these highly chlorinated congeners (CB-209, CN-75, and OCDF) might be derived from phthalocyanine pigments, the legacy of Halowax 1051 and 2,4-D products, which together contributed nearly half of the total concentration of target compounds (44.5%). In addition to highly chlorinated congeners, the local industrial thermal processes were mainly responsible for the contamination of PCBs, PCNs, and PCDD/Fs in the surrounding soil. The total carcinogenic risk of PCBs, PCNs, and PCDD/Fs in a few soil samples (0.22 × 10⁻⁶, 0.32 × 10⁻⁶, and 0.40 × 10⁻⁶) approached the threshold of potential carcinogenic risk (1.0 × 10⁻⁶). Since these pollutants can continuously accumulate in the soil, the contamination of PCBs, PCNs, and PCDD/Fs in surrounding soil deserves continuous attention. Full article

This research sheds light on the analysis of pigments and adhesives applied on a color painting on wooden architecture in Taiping Heavenly Kingdom Prince Dai’s mansion, located in Changzhou, Jiangsu Province in China. Four samples were collected from the painting above the building beam in the mansion, and the samples were analyzed and identified using a series of techniques, including polarized light microscopy (PLM), scanning electron microscope coupled with an energy-dispersive X-ray spectroscopy (SEM-EDS), micro-Raman spectroscopy (m-RS) and Fourier-transform infrared spectroscopy (FTIR). The results indicate that the red, black, blue, and green pigments were identified to be cinnabar, ivory black, indigo, and phthalocyanine green, respectively. The green pigment was inferred to be a lately repainted pigment based on its production age, suggesting that this ancient building had been refurbished or repaired. Given the good stability and visual effect of this green pigment, it is suggested to be used in future conservation processes. The pyrolysis-gas chromatography/mass Spectrometry (Py-Gc/Ms) results indicate that glue containing protein was used as a binder for the pigment samples, and that walnut oil might have been applied to the wooden architecture as a primer before painting. Our findings can well inform curators and conservators of the selection of appropriate restoration materials if necessary, and also provide data support for conservation of similar ancient buildings in southern China. Full article

Liu Kang (1911–2004) was a Chinese artist who settled in Singapore in 1945 and eventually became a leading modern artist in Singapore. He received academic training in Shanghai (1926–1928) and Paris (1929–1932). Liu Kang’s frequent visits to China from the 1970s to the 1990s contributed to a special artistic subject—the Huangshan and Guilin mountains. This subject matter triggered an uncommon painting approach for his oeuvre. In this context, this study elucidates the artist’s choice of materials and methods for the execution of 11 paintings, dating between 1977 and 1996, depicting Huangshan and Guilin landscapes. The paintings belong to the collection of the National Gallery Singapore. They were investigated with a combination of non- and micro-invasive techniques, supplemented by a wealth of documentary sources and art history research. The obtained results highlight the predominant use of hardboards resembling Masonite^® Presdwood^® without the application of an intermediate ground layer. Commercially prepared cotton and linen painting supports were used less frequently, and their structure and ground composition were variable. This study revealed the use of a conventional colour base for the execution of the paintings—a consistent colour scheme favouring ultramarine, yellow and red iron-containing earths, viridian and titanium white. Less commonly used pigments include Prussian blue, cobalt blue, phthalocyanine blue, phthalocyanine green, naphthol red AS-D, umber, Cr-containing yellow(s), cadmium yellow or its variant(s), Hansa yellow G, lithopone and/or barium white and zinc white and bone black. The documentary sources indirectly pointed to the use of Royal Talens, Rowney and Winsor & Newton, brands of oil paints. Moreover, technical and archival findings indicated the artist’s tendency to recycle rejected compositions, thereby strongly suggesting that the paintings were executed in the studio. Although this study focuses on the Singapore artist and his series of paintings relating to China, it contributes to existing international studies of modern artists’ materials. Full article

In this work, micro-Raman spectroscopy and micro-energy-dispersive X-ray fluorescence spectroscopy (µ-EDXRF) were applied on microsamples taken from the Plaiko Zubixe footbridge (1927) located in Ondarroa (Basque Country, Spain) in order to investigate the original paint coating and make an evaluation of the conservation state before its restoration. Elemental and molecular images were acquired for the study of the compounds distribution. Some modern pigments such as phthalocyanine blue and green pigments, minium, calcium carbonate, Prussian blue, and hematite were identified. Barium sulfate and titanium dioxide were recognized as opacifier agents. Thanks to the study of the stratigraphies, it has been possible to determine the original paint layer, which includes lead white, ultramarine blue, carbon black, and barium sulfate. In addition, colorimetric analyses made it possible to know the CIELab values of the original layer in order to reproduce the original colour during the planned restoration work. The massive presence of chlorine detected by µ-EDXRF and the corrosion products of the rust layer, in particular akaganeite and hematite, highlighted the atmospheric impact in the conservation of the bridge because they were due to the effect of both marine aerosol and to the presence of acidic components in the environment coming from anthropogenic activity. This work demonstrated the usefulness of a scientific approach for the study of industrial archaeology heritage with the aim to contribute to its conservation and restoration. Full article

Electrophoretic display (EPD) is a popular display technology in recent years. The core of the EPD is electrophoretic particles, and its Zeta potential has an important impact on EPDs. In this work, a method using pyrrolidine mono ionic liquid was proposed to improve the Zeta potential of electrophoretic particles: Copper (II) phthalocyanine pigment was modified with mono ionic liquid 1-Butyl-1-methylpyrrolidinium bromide. The characterization results show that the mono ionic liquid had been successfully coated on pigment particles. At the same time, the dispersion and stability of particles were improved. The modified Copper (II) phthalocyanine pigment could be stably dispersed in tetrachloroethylene for more than 20 days. The Zeta potential increased from 32.42 mV to 49.91 mV, increasing by 53.95%. Finally, the prepared blue electrophoretic particles were compounded with white titanium dioxide to prepare blue and white dual-color electrophoretic dispersion, and then an EPD cell was designed to test its performance. The results show that the prepared electrophoretic dispersion can realize reversible reciprocating motion. Therefore, because of the unique structure and properties of pyrrolidine mono ionic liquids, the blue nanoparticles prepared with pyrrolidine ionic liquids as charge control agents in this study can be used as excellent candidate materials for EPD. Full article

Due to the increasing tattoo practicing in Eastern countries and general concern on tattoo ink composition and safety, the green tattoo inks Green Concentrate by Eternal, for European and “for Asia Market Only” were analyzed, under the premise that only the former falls under a composition regulation. A separation of the additives from the pigment was carried out by successive extraction in solvents of different polarities, i.e., water, acetone and dichloromethane. The solid residues were analyzed by IR and Raman spectroscopies, the liquid fractions by GC/mass spectrometry. The relative pigment load and element traces were also estimated. We found that the European and the Asian inks are based on the same pigment, PG7, restricted in Europe, though at different loads. They have a similar content of harmful impurities, such as Ni, As, Cd and Sb and both contain siloxanes, including harmful D4. Furthermore, they have different physical-chemical properties, the European ink being more hydrophilic, the Asian more hydrophobic. Additionally, the Asian ink contains harmful additives for the solubilization of hydrophobic matrices and by-products of the phthalocyanine synthesis. Teratogenic phthalates are present as well as chlorinated teratogenic and carcinogenic compounds usually associated to the laser treatment for removal purposes, to a larger extent in the European ink. The composition of the inks does not seem to reflect regulatory restrictions, where issued. Full article