Papers by Keyword: Pigment

Abstract: In fulfilling its pigment material needs for industrial purposes, Indonesia still relies on imports, whose value continues to rise. This shows that the abundance of local raw materials has not been utilized optimally. Iron, as one of the pigment materials, can be obtained from the refining of metal waste. One of the metal wastes with a high Fe content (up to 97.11% w/w) is used in the manufacture of dishwashing wire. The manufacture of pigments from metal waste has the potential for sales value and commercial-scale development. The pigments synthesized are Prussian blue (iron (III) ferrocyanide or Fe₄[Fe(CN)₆]₃) and oxide red (iron (III) oxide or Fe₂O₃). Iron recovery is carried out using the leaching method with acids, specifically HCl and H₂SO₄. After the iron is dissolved in the acid and the dregs are filtered, the process continues with the oxidation stage, using H₂O₂ as the oxidizing agent. The precipitation stage is carried out using NaOH and K₃Fe(CN)₆. After undergoing filtration and washing, the pigment is heated in an oven until a crystalline powder is obtained. Prussian blue and oxide red pigments were successfully synthesized, with coloring tending towards a Prussian blue hue. This is because the synthesized Prussian blue is more easily dispersed in CMC solution than the oxide red pigment. Several samples were found to change their tendency to oxidize red after sieving >90 mesh, indicating the influence of grain size on pigment mixing. FTIR testing revealed the presence of CN, Fe-O, and Fe-CN functional groups, confirming the presence of these groups in the pigment. This finding was reinforced by EDX testing, which showed the presence of Fe, C, N, and O atoms. From the SEM test of the pigment sieving >90 mesh, irregular angular crystal particles were produced with a size of 0.9-23.6 µm.

Abstract: Non-traditional colour solutions used by designers in the design of building exteriors and interiors are driving a rapid increase in demand for locally produced decorative building materials. The modern pigments market offers a wide range of products, but not all of them satisfy consumer requirements, particularly regarding colour range. Inorganic pigments are characterised by high resistance to light and weather conditions, but organic pigments provide the greatest variety and brightness. Due to the significant rise in energy costs, which in turn has increased the price of Portland cement, more attention in Ukraine is being given to the research and application of magnesia-based binders. One of the advantages of these binders is that they require significantly less energy for production compared to lime and Portland cement.

Abstract: The article considers methods of manufacturing non-toxic films of a given color that meet technological requirements. The problem of reducing the shrinkage of the colored polymer in the casting mould during cooling and maintaining its technical characteristics is experimentally solved. To this end, the influence of the nature of pigments on the degree of polymer coloring is studied, and ways to improve the quality of color are investigated. The object of the study was selected pigment concentrate based on high pressure polyethylene brand 15803-003. The pigment has chosen technical carbon grades N220, P803. Surfactants were modifying additives. Tests of samples to determine the light fastness of dye, migration resistance, the number of agglomerates of pigments, toughness and strength, physical and mechanical properties showed that the most effective additive to improve the coloring properties of soot pigment brand N220 and improve the appearance of finished products introduced into the superconcentrate calcium stearate, which at the stage of mixing in the extruder acts as a surfactant and prevents the adhesion of the pigment and the formation of agglomerates in the polymer melt.

Abstract: The (Zn_0.5Cu_0.5)Al₂O₄ pigments were synthesized by solid state processing with an aim to examine the kinetics of phase formation. The calcining temperature was 1100 °C with firing times of 2, 12, 24, 48 and 96 hours during which intermediate grinding was carried out. All five obtained pigment samples appeared to be single-phase as probed by XRD. However, lattice refinement revealed differences in the lattice constant which kept decreasing and reached constancy after 24 hours of firing. Such reduction in the lattice constant was associated with incorporation of smaller copper cations into the Zn-sites. FTIR spectra also supported this result as the relevant peaks still got broadened and shifted for the calcination times of less than 48 hours. Elemental analysis of the 2-hour sample showed small presence of starting precursor particles, though not detected by XRD, suggesting an incomplete reactivity at a minute scale. These structural changes were resultantly reflected by small but significant alterations in the color parameters. A higher degree of solid solution for the samples fired for longer times, as judged by lowering in the lattice constant, resulted in detectable changes in both a and b parameters. Longer calcination times yielded a brighter (higher L values) brownish tone likely due to both diminution in the averaged particle size from pulverizing and completion of solid solution. The first would be useful for good dispersion in glazes whereas the latter could be directly related to the degree of cationic substitution, confirming the expected “true” color for this specific doping level at a particular calcination temperature.

Abstract: The environmental concern of many countries seeking to conserve natural resources is driving the development, production and consumption of biodegradable composites. However, in view of their high cost, adding various fillers to composites (such as, wood flour (WF)) is promising. The advantages of using composites with wood fillers are resistance to weathering, environmental friendliness, ease of mechanical processing, and the possibility of waste disposal. To improve the properties and expand the scope of such composites, it is possible to use thermal modification of the filler, which gives wood such properties as: high hardness, water resistance, chemical and biological resistance. Thermal modification consists in heating wood in the temperature range from 150 to 230 °C without oxygen. At the same time, color properties of the material are changed definitely: an increase in the processing temperature affects darkening of wood, which leads to a change in the color characteristics of the last composite. In this regard, a regression mathematical model is proposed for easy color control prediction of the product, which is obtained as a result of composites color analysis based on polylactide (PLA) and the RGB color code. The proposed mathematical model, setting the processing temperature of wood filler, lets predicting the intensities of red, green and blue components for the subsequent visual representation of the last composition color using standard computer programs.

Abstract: The surface of α-Fe₂O₃ nanoparticles was successfully coated with mesostructured silica templated by surfactant assemblies using cetyltrimethylammonium ions. By repeating the coating operation, it was possible to control the thickness of the mesostructured silica phase. In the sample obtained with ten coatings, in particular, the aggregation and sintering of the α-Fe₂O₃ nanoparticles was suppressed, and the bright red before the heat treatment was maintained even after a heat treatment at 1300 °C.

Abstract: This paper is devoted to research of utilization possibility of tailings of quartzite enrichment. It is shown that quartzitic waste of JSC "Dinur" (Pervouralsk city, Russia) is suitable for obtaining the cement flooring composite material. It was found that the quartzitic waste can be recommended as a fine aggregate and/or filler after additional screening. With the introduction of quartzitic dust in the amount of 30 % by weight of cement and with quartzitic waste as a fine aggregate it is possible to obtain the composite material of the class not less B12.5 (compressive) and В_tb 5.2 (flexural), which also meet the requirements of the Russian standard, namely abradability, adhesion strength, etc.

Abstract: Colouring of folk houses, its variations in time and sorts of pigments used has been very little explored in the region of interest so far. The paper shows the results of the investigation of twenty four coloured plaster and render samples from six object from two ethnographic regions of Moravia, Czech Republic. Polarizing microscopy, powder X-ray diffraction and Raman spectroscopy were the principal analytical methods were. The results show that all the blue colours were due to ultramarine application, red one was caused by industrial by-product of iron processing and the yellow one by ochre. The deep green was due to organic synthetic pigment, whereas the lighter shades due to green earth, a natural glauconite clay in these cases. Based on the examined set of samples, no qualitative difference in the composition of pigments were found between South Eastand Central Moravia. In both the regions not only lime but also plaster or Paris or a mixture of both the material was used to produce plasters and renders in the past.

Abstract: Nowadays, the colouring is used in wide range of architectural concrete. Therefore, determination efficiency of pigments in case of particular combination of input materials is necessary. The research deals with influence of concentration of liquid inorganic pigments on the resulting colour of cement mortars. Two liquid pigments (yellow, red) were used for measurement purposes to verify their optimal ratio to achieve the best colouring of cement specimens. Pigments were mixed in the mortars of two types of cements used for architectural and decorative design. The colour change was determined using Konica Minolta spectrophotometer in colour space CIE Lab (1976). General definition of deviation in the colour space ΔELab was applied for calculating of colour deviation. From the results of the laboratory tests is obvious that significant change of the colour of cement specimens do not show between the concentration of 6% and 9% of the pigment per cement weight yet. Consequently, using of high ratio of pigment than 9% is not profitable neither for purchaser, nor builder. Future research will focus on trials with a more elaborate share of pigment and it will have importance for price optimization in the construction industry.

Abstract: This study examined the chemical stability of malayaite pigments in ceramic glazes containing high amounts of zinc oxide (ZnO). The calcined pigments were embedded in a molten glaze which is basically corrosive glass. Within the glaze, ZnO has been known among potters to be undesirable as some pigments are not stable in glazes containing ZnO. The synthesized pigments’ particle size ranges from 4 to 18 μm without dominant preferential orientation. Their colors were in the red and yellow tones. Chemical stability between the pigments and glazes was tested using X-ray Diffraction (XRD). Slight changes were observed. Increasing amounts of ZnO resulted in an interfacial layer of approximately 50 μm between the crystalline pigment and surrounding amorphous glaze. The a color parameters gradually decreased while the b parameters switched to a negative value. The resulting glazes evolved from maroon to pale violet. The correlation between color and microstructural alterations was discussed.