Journal articles on the topic 'Surface modified pigments'
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Hájková, T., and A. Kalendová. "The anticorrosion properties of pigments based on molybdates and tungstates surface-modified with conducting polymers." Koroze a ochrana materialu 61, no. 1 (March 1, 2017): 7–18. http://dx.doi.org/10.1515/kom-2017-0001.
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Abstract The objective of this work was to examine the properties of molybdate or tungstate based pigments whose surface has been coated with a conductive polymer, viz. either polyaniline phosphate (PANI) or polypyrrole phosphate (PPY), if used as pigments in organic coating materials. The anticorrosion pigments were prepared by high-temperature solid-state synthesis from the respective oxides, carbonates. The composite pigments (pigment/conductive polymer) were dispersed in a solvent-type epoxy-ester resin binder to obtain a series of paints whose anticorrosion properties were assessed by means of corrosion tests in accelerated corrosion test and by the linear polarisation method. Focus was on the anticorrosion properties of the paints depending on the pigment surface treatment, initial pigment composition, and pigment volume concentration (PVC) in the paint. The surface-treated pigment particles were expected to have a favourable effect on the anticorrosion and the mechanical properties of epoxy-ester resin based paints.
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Zhang, Yong, Xuening Fei, Lu Yu, Lingyun Cao, and Baolian Zhang. "Preparation and characterisation of silica supported organic hybrid pigments." Pigment & Resin Technology 43, no. 6 (November 3, 2014): 325–31. http://dx.doi.org/10.1108/prt-10-2013-0087.
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Purpose The purpose of the work reported in this paper is to prepare hybrid pigments fabricated by depositing pigment yellow 12 (PY12) on the surface of silica gel to improve the application performance of the resulting pigments. The particle size distribution, optical properties, thermal stability, water dispersibility and flowability of the pigments with and without silica gel modification were studied. Design/methodology/approach The hybrid pigments were synthesised with different amount of silica gel. The modified pigments were characterised by Fourier transforms infrared spectroscopy, X-ray diffraction, thermal analysis, scanning electron microscopy and transmission electron microscopy. Findings The particle size distribution of the modified pigments was found to have been altered significantly. This can be explained by the interaction between pigments and silica gel, which prevented self-aggregation of pigment particles and hence improved the properties of pigments. Research limitations/implications Only silica supports and pigment yellow 12 were evaluated. Other pigments could also be studied. Practical implications Modification of pigment particles with smaller particle size can increase the efficiency of the modified pigment, in terms of colour shade and tinting strength, due to better particle size distribution. Originality/value The paper demonstrates that inorganic core can prevent self-aggregation of pigment particles, and the application properties of such pigment depend on the resulting degree of dispersion of pigment particles.
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Sun, Cui, Bao Zhang, Xiang Gao Li, and Ya Qing Feng. "Synthesis and Characterization of Surface Modified Red Pigment 48:2 for Electrophoretic Display." Advanced Materials Research 683 (April 2013): 73–76. http://dx.doi.org/10.4028/www.scientific.net/amr.683.73.
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Red Pigment 48:2 (PR 48:2) was coated with polyethylene (PE). The chemical constitution of the modified pigments was identified by fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and field-emission scanning electron microscopy (FE-SEM). The modified particles have good dispersity and high electrophoretic mobilities. For a simple EPD device, the contrast ratio of red-white electrophoretic fluid reached 2.60.
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M. Ahmed, Nivin, Walaa M. Abd El-Gawad, Elham A. Youssef, and Eglal M. Souaya. "Employment of new modified ferrite pigments in anticorrosive alkyd-based paints." Pigment & Resin Technology 43, no. 4 (July 1, 2014): 201–11. http://dx.doi.org/10.1108/prt-10-2013-0106.
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Purpose – The purpose of this work is to prepare new core-shell pigments based on silca fume waste as core and ferrite pigments in the shell. Silica fume is a byproduct of the smelting process in the ferrosilicon industry. The reduction of high-purity quartz to silicon at temperatures up to 2,000°C produces SiO2 vapours which then oxidize and condense at low-temperature zones to tonnage amounts of tiny particles consisting of non-crystalline silica that is collected and sold rather than being land-filled because nowadays there is increasing environmental concern with regard to excessive volumes of solid waste hazards accumulation. Silica has no direct effect in protecting metals from corrosion, but on precipitating an effective anticorrosive pigment like ferrite on its surface with low concentrations, this can bring out new core-shell pigment with good anticorrosive performance and low cost. The new pigments will be constructed on a waste silica fume core comprising 80-85 per cent of its chemical structure and the ferrite shell that will be only about 20-15 per cent. These pigments are represented as efficient, economically feasible and eco-friendly. Design/methodology/approach – The different ferrites and ferrites/SiO2 pigments were characterized using different analytical and spectro-photometric techniques, such as X-ray diffraction, scanning electron microscopy/energy-dispersive X-ray and transmission electron microscopy (TEM). Evaluation of these pigments was done using international standard testing methods american standard testing methods (ASTM). After evaluation, the pigments were incorporated in solvent-based paint formulations based on medium oil-modified soya-bean-dehydrated castor oil alkyd resin. The physico-mechanical properties of dry films and their corrosion properties using accelerated laboratory test in 3.5 per cent sodium chloride for 28 days were determined. Findings – The results of this work revealed that ferrite/SiO2 core-shell pigments were close in their performance to that of the ferrite pigments in protection of steel, and at the same time, they verified good physico-mechanical properties. Practical implications – As silica fume has a large array of uses, these pigments can be applied in various industries such as painting, wooding coating, anti-corruption coating, powder coating, architectural paint and waterproof paints. Originality/value – Ferrite, ferrite/SiO2 are environmentally friendly pigments which can impart high anticorrosive behaviour to paint films with concomitant cost savings.
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Kalendová, A., E. Halecká, K. Nechvílová, and M. Kohl. "Anticorrosive efficiency of alkyd resin-based coatings containing Mg–Zn–Fe mixed oxide-based pigments." Koroze a ochrana materialu 61, no. 2 (April 1, 2017): 39–53. http://dx.doi.org/10.1515/kom-2017-0005.
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Abstract Mixed oxide-based pigments Mg–Zn–Fe with different particle morphologies were prepared by high-temperature solid phase reactions. The core shell pigments containing ferric oxide and non-isometric particles of layered silicates were also prepared. The pigments were tested in paints, the pigment volume concentrations in the modified alkyd resin based binder being 5%, 10%, and 15%. The paint properties were examined by accelerated corrosion tests and by physico-mechanical tests. The effect of the pigment particle morphology on the surface hardness of the paint films was also studied. The influence of pigment volume concentration on the coating properties, and the optimum concentrations providing the most efficient anticorrosive protection were processed. A higher anticorrosion efficiency was observed for the paints with pigments possessing the lamellar particle shape.
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Aranzabe, Estíbaliz, Miren Blanco, Amaia M. Goitandia, Karmele Vidal, María Casado, and Jose Cubillo. "Preparation and characterisation of photocatalytic pigments for architectural mortar based on ultramarine blue." Journal of Sol-Gel Science and Technology 93, no. 3 (September 11, 2019): 714–21. http://dx.doi.org/10.1007/s10971-019-05116-x.
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Abstract Architectural mortar is used in the building sector when aesthetic surface value is required and therefore, these surfaces present a great potential to be used as a solution for the reduction of atmospheric pollution. In the present work, an inorganic ultramarine blue pigment has been modified to provide the mortars with colour and photocatalytic properties, simultaneously. To modify the pigment, a sol–gel coating based on titanium n-butoxide precursor has been applied on its surface. The influence of different parameters affecting the coating formation, such as the pH and titanium weight content of the sol–gel reactants, has been studied. Moreover, the formation of a coating on the pigment’s surface with several amounts of TiO2 anatase nanoparticles has also been explored. A pigment with better photocatalytic properties has been obtained at pH = 12 applying a coating based on titanium n-butoxide precursors (Ti precursor/pigment weight ratio = 0.5) with 2 wt.% of titania anatase nanoparticles, maintaining the original pigment colour. Moreover, mortars with the new pigment present higher flexural strength and similar compressive strengths than non-modified mortars ensuring the applicability of the pigment in the building sector.
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Jiao, Li Yong, Yu Bin Zheng, Ya Jun Liu, Xiao Min Ji, and Lin Lin Li. "Surface Modification of the Light-Storing Pigment by Titanate Coupling Agent and its Application on Print Ink." Applied Mechanics and Materials 200 (October 2012): 708–11. http://dx.doi.org/10.4028/www.scientific.net/amm.200.708.
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A titanate coupling agent, TM-27, was used in surface modification of light-storing pigment to improve its compatibility and stability with the organic system. The surface characteristics of light-storing pigments were reflected by Fourier transform infrared spectroscopy (FT-IR) and scanning electron micrograph (SEM). The result showed that the titanate coupling agent molecular formed a thin layer and binded strongly on the surface of pigments. The modification effect was evaluated on the basis of turbidity and by plotting the afterglow decay curve. The application of light-storing pigment in the printing ink system was also examined. When the dosage of titanate coupling agent was 1.5%, the viscosity of printing ink reached the lowest point. The subsidence rate was reduced from 0.8202 ml/h to 0.5821 ml/h. These results indicated that the modified light-storing pigment had better compatibility and stability with the organic system, and the surface modification did not affect the luminescence properties.
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Sun, Sijia, Hao Ding, Yanpeng Zha, Wanting Chen, and Zhuoqun Xu. "Surface Organic Modification of CaCO3-TiO2 Composite Pigment." Minerals 9, no. 2 (February 15, 2019): 112. http://dx.doi.org/10.3390/min9020112.
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To improve the properties and dispersibility of CaCO3-TiO2 composite pigments (CaCO3-TiO2) in organic matrices, the surface modification of CaCO3-TiO2 was performed with sodium stearate (SS) as an organic modifier by wet ultra-fine grinding in a stirred mill. The pigment properties of modified CaCO3-TiO2 and its dispersibility in organic media were tested and characterized. The binding mechanism between CaCO3-TiO2 and SS was explored by infrared spectrometry (IR) and X-ray photoelectron energy spectroscopy (XPS). The results showed that the mechanical grinding strength and SS dosage had a significant effect on the activation index and sedimentation rate of CaCO3-TiO2. After surface modification, the surface of CaCO3-TiO2 turned from a hydrophilic surface to a hydrophobic surface and the surface free energy was reduced. In addition, the hiding property and dispersibility of CaCO3-TiO2 in the organic medium were significantly improved. IR and XPS results indicated that the modifier SS was adsorbed on the surface of CaCO3-TiO2 by chemical combination.
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Zhang, Baolian, Zhenzhen Zhang, Xuening Fei, Yingchun Gu, and Lu Yu. "Preparation and properties of C.I. Pigment Red 170 modified with silica fume." Pigment & Resin Technology 45, no. 3 (May 3, 2016): 141–48. http://dx.doi.org/10.1108/prt-01-2015-0013.
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Purpose The purpose of the study reported in this paper was to prepare modified C.I. Pigment Red (PR) 170 to reduce production cost and improve application performance. The structure of the modified pigment was characterised. The colour strength, thermal stability, mobility, aqueous dispersability and ultraviolet (UV) resistance of modified pigments were studied. Design/methodology/approach Silica fume was added into the diazonium salt solution under acidic condition, followed by the activation to generate new surface. Subsequently, coupling component was dropwise added to the system to form the modified pigments evenly on the surface of silica fume in situ. The structure and properties of the modified pigment were studied by fourier transform infrared spectoscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravity analysis (TG-DTA), UV-visible diffuse reflectance spectra (UV-Vis DRS), and commission internationale de L‘Eclairage (CIE L*a*b*) colour measurements. Findings The morphology and particle size of the modified pigment were controlled by the modification of the silica fume, and the organic pigment and silica fume formed a core–shell structure. The properties of the modified pigment including colour strength, thermal stability, mobility, aqueous dispensability and UV resistance were improved significantly. Research limitations/implications The effect of the amount of silica fume on the thickness of the organic pigment layer and the effect of the thickness of the organic pigment layer on the properties of the modified pigment need to be studied further. Practical implications This paper shows a feasible method of the modification of the PR170 with the silica fume, and the modification can improve the properties of the PR170. The use of silica fume to modify organic pigment can realise the reuse of solid waste and reduce the production cost of the organic pigment. Social implications This modification method of the organic pigment is adaptive and it can be adjusted to the modification of other species of the organic pigment. Originality/value The modification of the PR170 with the silica fume was carried out in its preparation process, which synchronised the preparation and modification of the organic pigment. The properties of the modified pigment were improved, which were beneficial for their application in inks and coatings.
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Jiang, Wei Hui, Yong Feng, Jian Min Liu, Qing Xia Zhu, and Xia Yi Xu. "Preparation of ZrSiO4/C Inclusion Pigments by Nonhydrolytic Sol-Gel Methed Combined with the Process of Carbon Black Modification." Materials Science Forum 745-746 (February 2013): 545–50. http://dx.doi.org/10.4028/www.scientific.net/msf.745-746.545.
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nclusion pigments of ZrSiO4/C were prepared by nonhydrolytic sol-gel (NHSG) method combined with the process of carbon black modification. The crystalline phases, microstructure, functional groups on the surface of carbon black and chromatic value of the pigments were characterized by XRD, TEM, FTIR and Colorimeter, respectively. The surface structural changes of the carbon black modified by nitric acid and the influences of process parameters on the chromatic value of the pigments were also investigated. The results show that the process of carbon black modification enhances the affinity and binding force between carbon black and ZrCl4 sol, which contributes to improve the effect of carbon black wrapped by ZrSiO4. The ZrSiO4/C inclusion pigment were obtained after calcining at 1000 °C for 8 h, and the L*, a* and b* value is 53.88, 0.74, and 1.88, respectively.
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Athanasiu, Angela Anca, Marian Deaconu, Marian Crudu, Sanda Doncea, Rusandica Stoica, Loti Oproiu, Raluca Senin, Mircea Ruse, Dan Rosu, and Catalin Filipescu. "Synthesis and Characterization of Nanosized Copper(II)-Phthalocyanine Pigment (PBI 15:3) with the Modified Surface. I." Revista de Chimie 68, no. 2 (March 15, 2017): 343–49. http://dx.doi.org/10.37358/rc.17.2.5450.
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The research activity presented in this paper is intended to investigating of certain valuable nanosized blue pigment ( P Bl 15:3) prepared by 3-way synthesis (functionalization reactions) and conditionin(dispersing with or without encapsulation), namely obtaining stable aqueous dispersions of blue pigment with modified surface used in medium nonspecific for pigments. The techniques employed to characterize the structure and properties of blue pigment dispersions with functionalized particles compared to the original powder product were characterized by Fourier transform infrared spectroscopy FT-IR, thermogravimetric analysis (TGA), elemental analysis (EA) and particle size distribution (the distribution and average of particle diameter).In our finding the nano-dispersions obtained contain functionalized blue pigment particles with or without encapsulation in the form of liposomes with the average diameter below 200-300 nm, representing good results.
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Krysztafkiewicz, Andrzej, and Ludwik Domka. "Surface-modified microporous talcs as fillers of polymers and pigments." Journal of Materials Chemistry 7, no. 8 (1997): 1655–59. http://dx.doi.org/10.1039/a700040e.
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KOBAYASHIM, Reijirou, Motohiro YAJIMA, and Koichi KAMEYAMA. "Estimation of Surface Free Energy of Modified Pigments by Gas Chromatography." NIPPON KAGAKU KAISHI, no. 6 (1996): 589–92. http://dx.doi.org/10.1246/nikkashi.1996.589.
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Kalendová, Andrea, David Veselý, Jaroslav Stejskal, and Miroslava Trchová. "Anticorrosion properties of inorganic pigments surface-modified with a polyaniline phosphate layer." Progress in Organic Coatings 63, no. 2 (September 2008): 209–21. http://dx.doi.org/10.1016/j.porgcoat.2008.06.001.
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Hakeim, O. A., A. A. Arafa, M. K. Zahran, and L. A. W. Abdou. "UV-curable encapsulation of surface—Modified organic pigments for inkjet printing of textiles." Colloids and Surfaces A: Physicochemical and Engineering Aspects 447 (April 2014): 172–82. http://dx.doi.org/10.1016/j.colsurfa.2014.01.075.
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Tenhunen, Tiia-Maria, Tiina Pöhler, Annaleena Kokko, Hannes Orelma, Patrick Gane, Michel Schenker, and Tekla Tammelin. "Enhancing the Stability of Aqueous Dispersions and Foams Comprising Cellulose Nanofibrils (CNF) with CaCO3 Particles." Nanomaterials 8, no. 9 (August 23, 2018): 651. http://dx.doi.org/10.3390/nano8090651.
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In this work, stability of dispersions and foams containing CaCO3-based pigments and cellulose nanofibrils (CNF) was evaluated with the aim to reveal the mechanisms contributing to the overall stability of the selected systems. The utmost interest lies in the recently developed hydrocolloid hybrid CaCO3 pigments and their potential to form bionanocomposite structures when incorporated with CNF. These pigments possess a polyelectrolyte layer deposited on the surface of the particle which is expected to enhance the compatibility between inorganic and organic components. Stability assessment of both dispersions and foams was conducted using turbidity profile scanning. In dispersions, CNF provides stability due to its ability to form a firm percolation network. If surface-modified pigments are introduced, the favourable surface interactions between the pigments and CNF positively influence the stability behaviour and even large macro-size pigments do not interfere with the stability of either dispersions or foams. In foams, the stability can be enhanced due to the synergistic actions brought by CNF and particles with suitable size, shape and wetting characteristics resulting in a condition where the stability mechanism is defined by the formation of a continuous plateau border incorporating a CNF network which is able to trap the inorganic particles uniformly.
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Nechvílová, Kateřina, and Andréa Kalendová. "PROPERTIES OF ORGANIC COATINGS CONTAINING PIGMENTS WITH SURFACE MODIFIED WITH A LAYER OF ZnFe2O4." Advances in Science and Technology Research Journal 9, no. 28 (2015): 51–55. http://dx.doi.org/10.12913/22998624/60783.
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Oliveira, André F. do A., Pollyana Trigueiro, Dihêgo H. L. Damacena, Luzia M. C. Honorio, Josy A. Osajima, and Edson C. Silva-Filho. "Hybrid Pigments from Bixin Dye and Inorganic Matrices." Environmental Sciences Proceedings 6, no. 1 (March 2, 2021): 21. http://dx.doi.org/10.3390/iecms2021-09382.
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Annatto dye is a natural organic dye belonging to carotenoids, whose main components are bixin and norbixin. Due to its low stability, it is convenient to protect the dye molecules with other materials. The use of clay minerals is an alternative, which are phyllosilicates with attractive physico-chemical properties, such as high specific surface area, cation exchange capacity, mechanical/chemical stability and non-toxicity. The main purpose of this work was to develop hybrid materials, using annatto dye and clay mineral modified with different inorganic cations, and then, to evaluate the stability of the new pigments. The process of preparing the modified clay minerals involved mixing a synthetic montmorillonite in solutions containing the precursor salts of the metal cations. Subsequently, the dye was dissolved in a solution containing water and alcohol, followed by filtration and mixed with the modified clay, giving rise to the hybrid pigments. Through the characterizations, it was noted that a variety of colors were obtained, and the sample containing aluminum was the one that most adsorbed the dye and showed a significant increase in stability at high temperatures. This hybrid material was better to dye than its pure form. Therefore, the bixin/montmorillonite pigments are promising for replacing artificial colors in practical applications such as in the cosmetics, food or pharmaceutical industries.
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Oliveira, André F. do A., Pollyana Trigueiro, Dihêgo H. L. Damacena, Luzia M. C. Honorio, Josy A. Osajima, and Edson C. Silva-Filho. "Hybrid Pigments from Bixin Dye and Inorganic Matrices." Environmental Sciences Proceedings 6, no. 1 (March 2, 2021): 21. http://dx.doi.org/10.3390/environsciproc-1256578.
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Annatto dye is a natural organic dye belonging to carotenoids, whose main components are bixin and norbixin. Due to its low stability, it is convenient to protect the dye molecules with other materials. The use of clay minerals is an alternative, which are phyllosilicates with attractive physico-chemical properties, such as high specific surface area, cation exchange capacity, mechanical/chemical stability and non-toxicity. The main purpose of this work was to develop hybrid materials, using annatto dye and clay mineral modified with different inorganic cations, and then, to evaluate the stability of the new pigments. The process of preparing the modified clay minerals involved mixing a synthetic montmorillonite in solutions containing the precursor salts of the metal cations. Subsequently, the dye was dissolved in a solution containing water and alcohol, followed by filtration and mixed with the modified clay, giving rise to the hybrid pigments. Through the characterizations, it was noted that a variety of colors were obtained, and the sample containing aluminum was the one that most adsorbed the dye and showed a significant increase in stability at high temperatures. This hybrid material was better to dye than its pure form. Therefore, the bixin/montmorillonite pigments are promising for replacing artificial colors in practical applications such as in the cosmetics, food or pharmaceutical industries.
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He, Lihua, Yan Zhao, Liying Xing, Pinggui Liu, Youwei Zhang, and Zhiyong Wang. "Low Infrared Emissivity Coating Based on Graphene Surface-Modified Flaky Aluminum." Materials 11, no. 9 (August 22, 2018): 1502. http://dx.doi.org/10.3390/ma11091502.
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A low infrared emissivity coating was prepared using graphene surface-modified flaky aluminum complex powders (rGO-FAl) as fillers. The flaky aluminum powders were coated with graphene through chemical bonding. Compared with pure flaky aluminum, the Vis-NIR diffuse reflectance of rGO-FAl complex powders was significantly decreased, which was beneficial to the low glossiness of the coating. After the modification, the glossiness at 60° of the coating with 40% (mass fraction) pigments decreased from 12.8 to 6.7, while the coating maintained low infrared emissivity (0.238~0.247) at a spectral range of 8–14 μm. In the electrochemical impedance spectroscopy (EIS) measurement, at the lowest frequency, the impedance of the Al-rGO test plate was at least two orders of magnitude greater than that of the control Al test plate, and the graphene layer significantly increased the bandwidth of the maximum phase angle, which indicates a good protective effect of the ultra-thin graphene layer on metal in a corrosive environment. The coating with 40% rGO-FAl complex powders can maintain its appearance after 500 h of salt spray corrosion testing. In contrast, the color of the coating with the original aluminum powders changed after only 300 h.
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Tawiah, Benjamin, Liping Zhang, Anli Tian, and Shai Shao Fu. "Coloration of aluminum pigment using SiO2 and γ-glycidoxypropyltrimethoxysilane with dichlorotriazine reactive dye." Pigment & Resin Technology 45, no. 5 (September 5, 2016): 335–45. http://dx.doi.org/10.1108/prt-07-2015-0063.
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Purpose The purpose of this paper is to colour aluminium pigment to the highest chroma using SiO2 and organic silane with dichlorotriazine reactive dye and investigate its reaction mechanism, chemical stability and thermal properties to improve its applicability in surface coatings. Design/methodology/approach Aluminium pigment was encapsulated by the catalysed sol-gel method using SiO2, followed by modification with γ-glycidoxypropyltrimethoxysilane (GPTMS). Purified reactive dye (1-Amino-4-[3-(4,6-dichlorotriazin-2-ylamino)-4-sulfophenylamino]anthraquinone-2-sulfonic acid (X-BR)) was covalently immobilized onto modified SiO2 to obtain coloured aluminium pigment. The reaction mechanism, chemical stability and thermophysical properties were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscope, transmission electron microscope and thermogravimetric analyses (TGA). Findings The results showed that X-BR was covalently attached to modified Al/SiO2 with maximum colour grafting of 95 per cent when the dosage of GPTMS and X-BR per weight of modified Al/SiO2 was 25 and 15 per cent, respectively, at pH 8.5 and a temperature of 40°C. The coloured aluminium pigment had good chemical stability with excellent anti-migration properties in many solvents. Research limitations/implications The organic silane used required a careful control of pH to ensure maximum colour grafting efficiency meanwhile other silanes with amine groups could also be used effectively with different kinds of colorants besides reactive dyes. Practical implications The method used is less cumbersome and provides a simple route to preparing coloured aluminium pigment. Originality/value The use of organic-inorganic SiO2/γ- GPTMS with purified reactive dye to covalently colour aluminium pigment to the highest chroma is novel and will help advance the frontiers of knowledge on coloration of aluminium pigments.
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Hakeim, O. A., A. A. Arafa, M. K. Zahran, and L. A. W. Abdou. "Effect of process conditions on the properties of surface-modified organic pigments encapsulated by UV-curable resins." Coloration Technology 134, no. 1 (November 7, 2017): 44–58. http://dx.doi.org/10.1111/cote.12318.
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Mihelčič, Mohor, Vojmir Francetič, Pavli Pori, Helena Gradišar, Janez Kovač, and Boris Orel. "Electrochromic coatings made of surface modified rutile and anatase pigments: Influence of trisilanol POSS dispersant on electrochromic effect." Applied Surface Science 313 (September 2014): 484–97. http://dx.doi.org/10.1016/j.apsusc.2014.06.010.
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Pereira, G. J., Douglas Gouvêa, and S. M. Hiraoka. "Influence of Tin Oxide Addition in the Morphologic Characteristics of Zinc Oxide Powders Synthesized by Pechini's Method." Materials Science Forum 498-499 (November 2005): 704–9. http://dx.doi.org/10.4028/www.scientific.net/msf.498-499.704.
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Zinc oxide is widely used in semiconductors fabrication, pigments and mainly in varistors. The electrical properties of ZnO based varistors are related to the grain boundary characteristics, and it can be modified using additives. In this work, zinc oxide based powders were prepared by chemical route derived from the Pechini’s method, and small amounts of tin ions were added to the system. The XRD measurements showed that the tin oxide not forming solid solution in the bulk, and it was observed that the increasing of tin concentration causes an increasing of the surface area at isothermal conditions of calcination. Once the isoelectric point was dislocated to more acid values, the hypothesis of segregation onto surface was considered.
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Lin, Ruya, Zhijie Liang, Chun Yang, Zhiwei Zhao, and Fuyi Cui. "Selective adsorption of organic pigments on inorganically modified mesoporous biochar and its mechanism based on molecular structure." Journal of Colloid and Interface Science 573 (August 2020): 21–30. http://dx.doi.org/10.1016/j.jcis.2020.03.112.
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Zhao, Yanan, Cathleen Schlundt, Dennis Booge, and Hermann W. Bange. "A decade of dimethyl sulfide (DMS), dimethylsulfoniopropionate (DMSP) and dimethyl sulfoxide (DMSO) measurements in the southwestern Baltic Sea." Biogeosciences 18, no. 6 (March 25, 2021): 2161–79. http://dx.doi.org/10.5194/bg-18-2161-2021.
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Abstract. Dimethyl sulfide (DMS), dimethylsulfoniopropionate (DMSP) and dimethyl sulfoxide (DMSO) were measured at the Boknis Eck Time Series Station (BE, Eckernförde Bay, SW Baltic Sea) during the period February 2009–December 2018. Our results show considerable interannual and seasonal variabilities in the mixed-layer concentrations of DMS, total DMSP (DMSPt) and total DMSO (DMSOt). Positive correlations were found between particulate DMSP (DMSPp) and particulate DMSO (DMSOp) as well as DMSPt and DMSOt in the mixed layer, suggesting a similar source for both compounds. The decreasing long-term trends, observed for DMSPt and DMS in the mixed layer, were linked to the concurrent trend of the sum of 19′-hexanoyloxyfucoxanthin and 19′-butanoyloxy-fucoxanthin, which are the marker pigments of prymnesiophytes and chrysophytes, respectively. Major Baltic inflow (MBI) events influenced the distribution of sulfur compounds due to phytoplankton community changes, and sediment might be a potential source for DMS in the bottom layer during seasonal hypoxia/anoxia at BE. A modified algorithm based on the phytoplankton pigments reproduces the DMSPp : Chl a ratios well during this study and could be used to estimate future surface (5 m) DMSPp concentrations at BE.
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El-Sabbagh, Salwa H., and Nivin M. Ahmed. "Enhancement of styrene-butadiene rubber composites using kaolin covered with metal oxide pigments." Pigment & Resin Technology 44, no. 2 (March 2, 2015): 57–73. http://dx.doi.org/10.1108/prt-03-2014-0028.
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Purpose – This paper aims to express in detail the rheological, morphological and thermal properties of unpigmented and pigmented styrene-butadiene rubber composites with new prepared inorganic pigment based on kaolin covered with a thin layer of calcium and magnesium oxides or mixed oxide of both together. These new pigments combine the properties of both their constituents (kaolin and metal oxides), which are a new trend in inorganic pigments called core-shell pigments. The pigments used for comparison are kaolin (K), CaO/kaolin (CaO/K), MgO/kaolin (MgO/K) and CaO.MgO/kaolin (CaO.MgO/K). Design/methodology/approach – The different pigments were characterized using different analytical and spectrophotometric techniques, such as X-ray diffraction, scanning electron microscopy/energy dispersive X-ray and transmission electron microscopy, while rubber vulcanizates' rheological, morphological, swelling and thermal properties were examined using different standard and instrumental testing and methods. Findings – The study revealed that there is a significant effect of the new prepared pigments on SBR properties, where the optimum pigment loading was 40 phr for CaO/kaolin, while it was 2.5 phr for MgO/kaolin. Studying the effect of different ratios of oxides on kaolin (5, 10 and 20 per cent), different loadings of these pigments ranging between 2.5 and 40 phr were done for each pigment. These modified kaolin or core-shell metal oxide/kaolin pigments imparted new and improved reinforcing properties to SBR vulcanizates. Research limitations/implications – No research limitations were found. Practical implications – Core-shell MgO/kaolin pigments are eco-friendly and can replace other expensive pigments that are usually used as fillers in the rubber industry with less expenses and comparable efficiency. Originality/value – These new pigments are cheap and efficient and can be used in different fields other than rubber.
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Parnell, J., P. Lee, C. S. Cockell, and G. R. Osinski. "Microbial colonization in impact-generated hydrothermal sulphate deposits, Haughton impact structure, and implications for sulphates on Mars." International Journal of Astrobiology 3, no. 3 (July 2004): 247–56. http://dx.doi.org/10.1017/s1473550404001995.
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Hydrothermal gypsum deposits in the Haughton impact structure, Devon Island, Canada, contain microbial communities in an endolithic habitat within individual gypsum crystals. Cyanobacterial colonies occur as masses along cleavage planes, up to 5 cm from crystal margins. The crystals are transparent, so allow transmission of light for photosynthesis, while affording protection from dehydration and wind. The colonies appear to have modified their mineral host to provide additional space as they expanded. The colonies are black due to UV-screening pigments. The relative ease with which microbial colonization may be detected and identified in impact-generated sulphate deposits at Haughton suggests that analogous settings on other planets might merit future searches for biosignatures. The proven occurrence of sulphates on the Martian surface suggests that sulphate minerals should be a priority target in the search for life on Mars.
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Kucmanová, Alexandra, and Kristína Gerulová. "Microalgae Harvesting: A Review." Research Papers Faculty of Materials Science and Technology Slovak University of Technology 27, no. 44 (June 1, 2019): 129–43. http://dx.doi.org/10.2478/rput-2019-0014.
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Abstract Microalgae are photosynthetic autotrophic microscopic organisms growing in a range of aquatic and terrestrial habitats. They produce a huge complex of compounds in their surroundings which are of important use to humans. Their commercial use lies in human nutrition, animal and aquatic feed, in cosmetics products, natural pigments, pharmaceutical industry, bio-fertilizer for extracting high-value molecules, stable isotope biochemicals, and for the synthesis of antimicrobial, antiviral, antibacterial and anticancer drugs. Therefore, it is necessary to develop a simple, effective and economically advantageous method for harvesting the algal products. Magnetic separation is a simple separation process. Different synthesis methods have been used by researchers to obtain magnetic particles of varying size and shapes according to the algae to be studied. Chemical co-precipitation method has been the most commonly used method, which helps in synthesizing magnetic particles of the micro to nano range. Naked, coated and surface modified are the general types of magnetic particles used for algal harvesting with its own advantages and disadvantages.
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Abd El-Wahab, H., G. El-Meligi, M. G. Hassaan, A. Kazlauciunas, and Long Lin. "New water-based copolymer nanoparticles and their use as eco-friendly binders for industry of flexographic ink, part I." Pigment & Resin Technology 49, no. 3 (January 11, 2020): 239–48. http://dx.doi.org/10.1108/prt-10-2019-0095.
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Purpose The purpose of this paper is to prepare, characterise and evaluate nano-emulsions of copolymers of various compositions as eco-friendly binders for flexographic ink industry. Design/methodology/approach Various nano-emulsions of copolymers were prepared using styrene (St), butyl acrylate (BuAc), acrylic acid (AA) and acrylamide (AAm) monomers by means of a conventional seeded emulsion polymerisation technique, using K2S2O8 as the initiator. The characterisation of the prepared emulsions was performed using Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), gel permeation chromatography (GPC) and transmission electron microscopy (TEM). A selection of copolymers was formulated with pigments and additional ingredients, as water-based flexographic inks. The inks were characterised for their viscosity, pH, degree of dispersion, water resistance and colour density. Findings It was found that the low viscosity of the prepared copolymers may reduce the film thickness of the flexographic inks and may also increase the spreading of the ink on the surface. As a result, stable modified polyacrylate-based latex with improved physico-mechanical properties were obtained. The prepared latexes were showed improving and enhancing in water resistance; gloss values, and the print density that ranged from 2.06 to 2.51 and the maximum gloss values (39 and 48) were also obtained. Also, these binders provide excellent adhesion properties for both the pigment particles and the base paper. Practical implications This study focuses on the preparation of new water-based copolymer nanoparticles and their use as eco-friendly binders for flexographic ink industry. Social implications The ink formulations developed could find use in industrial-scale printing. Originality/value Eco-friendly environment ink formulations for printing on paper substrates are novel.
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Ahmed, Nivin M., Walaa M. Abd El-Gawad, Elham A. Youssef, and Eglal R. Souaya. "New eco-friendly anticorrosive core-shell pigments." Pigment & Resin Technology 44, no. 5 (September 7, 2015): 276–91. http://dx.doi.org/10.1108/prt-10-2014-0085.
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Purpose – The purpose of this paper is to present the preparation of core-shell ferrites/kaolin pigments and comparing their efficiency in protecting metal substrates to original ferrites which were also prepared. Core-shell structured particles are recently gaining lots of importance due to their exciting applications in different fields; these particles are constructed from cores and shells of different chemical compositions which show ultimately distinctive properties of varied materials different from their counterparts. The new core-shell pigment is based on shell of different ferrites that comprises only 10-20 per cent of the whole pigment on kaolin (cores) which is a cheap and abundant ore that comprises 80-90 per cent of the prepared pigment. The new pigments do not only comprise two different components, but they also contain pigment and extender in the same compound; their loadings in the paint formulations ranges from 50 and 75 per cent of the whole pigment. The work showed that these eco-friendly and cheap core-shell pigments are comparable in their efficiency to that of ferrites in protecting steel substrates. Design/methodology/approach – The different ferrites and ferrites/kaolin pigments were characterized using different analytical and spectrophotometric techniques, such as X-ray fluorescence, X-ray diffraction (XRD), scanning electron microscopy/energy-dispersive X-ray (SEM/EDAX) and transmission electron microscopy (TEM). Evaluation of these pigments was done using international standard testing methods (ASTM). After evaluation, the pigments were incorporated in solvent-based paint formulations based on medium oil-modified soya-bean dehydrated castor oil alkyd resin. The physico-mechanical properties of dry films and their corrosion properties using accelerated laboratory test in 3.5 per cent NaCl for 28 days were determined. Findings – The results of this work revealed that ferrite/kaolin core-shell pigments were close in their performance to that of the ferrite pigments in protection of steel, and at the same time, they verified good physico-mechanical properties. Practical implications – Treated kaolin can be applied in many industries beside pigment manufacture and paint formulations; it can be applied as reinforcing filler in rubber, plastics and ceramic composites. Also, it is applied in paper filling, paper coatings and electrical insulation. Originality/value – Ferrite and ferrite/kaolin are environmentally friendly and can replace other hazardous pigments (e.g. chromates) with almost the same quality in their performance; also, they can be used in industries other than paints, for example paper, rubber and plastics composites.
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El‐Sabbagh, Salwa H., Nivin M. Ahmed, and Mohamed M. Selim. "Preparation and characterisation of high performance rubber vulcanizates loaded with modified aluminium oxide." Pigment & Resin Technology 35, no. 3 (May 1, 2006): 119–31. http://dx.doi.org/10.1108/03699420610665148.
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PurposeA new method for modifying the properties of aluminium oxide had been developed which allowed alumina to be used as a white, reinforcing filler in various rubber composites to replace carbon black, producing high performance white rubber vulcanizates comparable to those loaded with carbon black that could be coloured if needed.Design/methodology/approachAlumina was treated with small amounts of ammonium molybdate. Characterisation of modified aluminium oxide was carried out using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Also, evaluation of the pigments prepared, in terms of oil absorption, specific gravity, and bulking value using international standard testing methods was performed. The morphology of the natural rubber composites loaded with the new modified alumina were studied using SEM. Kraus equation was used to analyse the extent of polymer‐pigment interaction, while Mooney‐Rivlin relation was employed to study the near equilibrium stress‐strain behaviour.FindingsThe results showed that, the pigment had a significant effect on the rheological characteristics (scorch, cure time, etc.), mechanical properties, stress and strain at yield and at rupture of white rubber vulcanizates prepared resulting in high performance.Research limitations/implicationsAs concentration of molybdenum oxide increased in the alumina crystals, the reinforcing effect in rubber composites also increased till an optimum concentration where such a reinforcing effect reversed. However, investigation of the application of these pigments in other systems such as an anticorrosive pigment in paint formulations and reinforcing filler in polyester composites could also be interesting.Practical implicationsThe pigments prepared could be used as reinforcing filler in plastic composites and also as anticorrosive pigment in paint formulations.Originality/valueAluminium oxide is a cheap compound. The originality of the work lay in the finding that by adding trace amounts of molybdenym to it, aluminium oxide's properties changed dramatically resulting in more effective action in reinforcing rubber composites filled with such modified alumina, producing white rubber composites with comparable properties to those loaded with carbon black, and may exceed them in some cases. This allowed the preparation of coloured rubber with good rheological and physical properties.
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Djenane, D., L. Martínez, A. Sánchez-Escalante, L. Montañés, D. Blanco, J. Yangüela, J. A. Beltrán, and P. Roncalés. "Effect of Lactic Acid Bacteria on Beef Steak Microbial Flora Stored Under Modified Atmosphere and on Listeria Monocytogenes in Broth Cultures." Food Science and Technology International 12, no. 4 (August 2006): 287–95. http://dx.doi.org/10.1177/1082013206067788.
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Beef steaks were inoculated with one or other of two protective strains of lactic acid bacteria, the bacteriocinogenic Lactobacillus sakei CTC 372 or the uncharacterised Lactobacillus CTC 711. They were stored under modified atmospheres (20–40% CO2). Inoculation of meat with both strains inhibited the growth of the spoilage bacteria. Neither CO2 in the pack atmosphere, inoculation with protective strains, nor a combination of both, affected formation of metmyoglobin or the development of off-odours. The formation of metmyoglobin in meat pigments and the sensory odour scores were compatible to those of fresh meat which had not undergone either oxidative deterioration or microbial spoilage. Listeria monocytogenes were inhibited in broth by meat surface microbiota containing either of the protective strains. With an initial population of 5.6 log cfu/mL, after 7 days incubation at 3°C, Listeria monocytogenes were recovered at log mean population of 2.8 log cfu/mL when neither protective strain was present. At 8°C, the population of Listeria monocytogenes recovered were reduced by about 2.5 or 1.5 log cfu/mL in the presence of Lactobacillus sakei CTC 372 or Lactobacillus CTC 711, respectively. At 25°C, the population of Listeria monocytogenes recovered from broth containing either protective strain were about 5 log cfu/mL less than the population recovered from broth containing Listeria monocytogenes only.
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Abd El-Wahab, H., G. A. Meligi, M. G. Hassaan, and L. Lin. "New water-based flexographic ink based on new ter-polymer nano-particles as eco-friendly binders – Part II." Pigment & Resin Technology 49, no. 6 (May 4, 2020): 473–82. http://dx.doi.org/10.1108/prt-12-2019-0111.
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Purpose The purpose of this study is to prepare, characterise and evaluate nano-emulsions of ter-polymers of various compositions as eco-friendly binders for flexographic ink industry. Design/methodology/approach Various nano-emulsions of ter-polymers were prepared based on Vinyl acetate, Vinyl Versatate, butyl acrylate, acrylic acid and acrylamide monomers by means of a conventional seeded emulsion polymerisation technique, using K2S2O8 as the initiator. The characterisation of the prepared emulsions was performed using Fourier transform infrared, thermo-gravimetric analysis, gel permeation chromatography and transmission electron microscopy. A selection of co-polymers and ter-polymers were formulated with pigments and additional ingredients, as water-based flexographic inks. The inks were characterised for their rheological properties, pH, degree of dispersion, water-resistance and colour density. Findings It was found that the low viscosity of the prepared polymers may reduce the film thickness of the flexographic inks and may also increase the spreading of the ink on the surface. As a result, stable modified poly acrylate-based latex with improved physico-mechanical properties was obtained. The prepared latexes showed improved properties such as enhanced thermal stability and better water resistance. The effect of the emulsifier type on the properties of the resulting emulsion latexes and their corresponding films were investigated. Also, as the hydrophobic monomer increases, so does the colour density and increasing the binder ratio enhances the gloss values. The improving in gloss values were obtained and provide excellent adhesion properties for both the pigment particles and the base paper. Research limitations/implications The study focusses on the preparation of new water-based ter-polymer nano-particles and their use as eco-friendly binders for flexographic ink industry. Ink formulations based on other different type emulsion polymers could also be studied to assess the applicability of the ink formulation system found for other binders. Practical implications The ink formulations developed could find use in industrial-scale printing. Originality/value Eco-friendly environment and low-cost ink formulations for printing on paper substrates are novel.
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Yu, Qian, Yong Le Ke, Xu Kun Tan, Gao Dan Luo, Sheng Bo Han, Lin Yu, and Guo Qing Luo. "Study on Surface Modification of Mica Pearl Pigment with Stearic Acid." Materials Science Forum 852 (April 2016): 774–81. http://dx.doi.org/10.4028/www.scientific.net/msf.852.774.
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Using stearic acid as modifier, the surface of mica pearl pigment organic modification technology are discussed in this paper, and the application effect of after modified. X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and Scanning electron microscope (SEM) were used to characterize the effect of surface modification. Electrostatic spraying test (EST) and Chromatism test were used to characterize the application effect of after modified. The results showed that the stearic acid could be successfully grafted on the surface of mica pearl pigment and enhanced hydrophobicity. Besides, it was demonstrated that the mica pearl pigment treated with stearic acid could make the value of chromatism deviation are low, which also could significantly improve the powder spraying ratio at low spray voltages.
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Schrader, Larry E. "Scientific Basis of a Unique Formulation for Reducing Sunburn of Fruits." HortScience 46, no. 1 (January 2011): 6–11. http://dx.doi.org/10.21273/hortsci.46.1.6.
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Sunburn, a major type of solar radiation injury, causes large economic losses of several fruits, vegetables, and ornamentals. Sunburn necrosis occurs in attached apple (Malus domestica Borkh.) when excess solar radiation is converted to heat energy and causes a high fruit surface temperature (FST). When the FST reaches ≈52 °C, thermal death of cells is induced and sunburn necrosis appears later. A second type of sunburn, sunburn browning, is caused by the combination of high FST (46 to 49 °C) and high solar radiation. Cell death is not induced, but several pigment changes occur and the apple peel typically turns yellow or brown. The objective of this study was to develop a unique technology for protection of apples from sunburn necrosis and sunburn browning. Natural waxes in the cuticle and pigments in the upper epidermis of apple, which reflect and absorb ultraviolet radiation, attenuate only part of the harmful ultraviolet radiation. I hypothesized that applying additional wax as a sprayable emulsion would augment natural waxes in the cuticle and that addition of reflective compounds to the wax emulsion would reduce the heat load on the fruit. Synthesis of a formulation of this composition would be unique for plants and would be akin to sunscreens used by humans that generally contain organic (chemical) compounds to absorb harmful ultraviolet radiation and inorganic (physical) compounds to scatter, block, and/or reflect solar radiation. Emulsified carnauba wax, a natural plant wax, decreased transmission of ultraviolet radiation; addition of emulsified, organically modified clay to the wax emulsion enhanced reflectivity. When combined into a sprayable formulation, the carnauba wax and organoclay emulsion was more effective in protecting apples from sunburn browning than from sunburn necrosis. Spraying the unique formulation on apple trees caused no phytotoxicity on either leaves or fruit and did not decrease leaf chlorophyll fluorescence or whole-tree gas exchange, indicating no effect on photosynthesis or transpiration of apple trees. The unique formulation is patented as a sunburn protectant for fruits and vegetables and is marketed in several countries as RAYNOX®.
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Darvish, Abolfazl, Reza Naderi, and Mohammad Reza Mohammadzadeh Attar. "Improvement in polyurethane coating performance through zinc aluminium phosphate pigment." Pigment & Resin Technology 45, no. 6 (November 7, 2016): 419–25. http://dx.doi.org/10.1108/prt-09-2015-0084.
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Purpose This research aims to provide a comparative study of the effect of conventional zinc phosphate (ZP) and zinc aluminium phosphate (ZPA) representing second generation of phosphate-based anticorrosion pigments on the protective performance and physical mechanical properties of a solvent-borne polyurethane (PU) coating. Design/methodology/approach The two pigments were incorporated into the coating at optimum pigment volume concentration. To evaluate the protective performance, electrochemical impedance spectroscopy (EIS) was used. The effect of modification of ZP on the physical–mechanical properties of the coatings was studied through dynamic mechanical thermal analysis. Moreover, Micro Vickers hardness and pull-off tests were used to evaluate the hydrolytic coating degradation. Findings EIS revealed the superior protective function of coatings incorporated with ZPA compared to those formulated with ZP. This behaviour might be attributed to the release of sufficient inhibiting species because of partial dissolving of the anticorrosive pigments when an electrolyte penetrates into the coating. In addition, the effectiveness of modification of ZP on the physical–mechanical properties of coatings was shown. Research limitations/implications As a classical replacement for the toxic chromates, ZP has been widely used in the formulation of protective coatings. However, undesirable inhibitive function of the pigment arising from its low solubility has made modification necessary. Because of the modified solubility, second generation of phosphate-based anticorrosion pigments has been reported to reveal superior performance. Originality/value According to the literature, no report can be found studying the effect of the second generation of phosphate-based anticorrosion pigments on the physical–mechanical properties of PU coatings. The main goal of this work is to study the correlation between physical–mechanical properties and anticorrosion performance of the PU coatings.
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Fragoso, Glaucia M., Alex J. Poulton, Igor M. Yashayaev, Erica J. H. Head, and Duncan A. Purdie. "Spring phytoplankton communities of the Labrador Sea (2005–2014): pigment signatures, photophysiology and elemental ratios." Biogeosciences 14, no. 5 (March 14, 2017): 1235–59. http://dx.doi.org/10.5194/bg-14-1235-2017.
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Abstract. The Labrador Sea is an ideal region to study the biogeographical, physiological, and biogeochemical implications of phytoplankton community composition due to sharp transitions between distinct water masses across its shelves and central basin. We have investigated the multi-year (2005–2014) distributions of late spring and early summer (May to June) phytoplankton communities in the various hydrographic settings of the Labrador Sea. Our analysis is based on pigment markers (using CHEMTAX analysis), and photophysiological and biogeochemical characteristics associated with each phytoplankton community. Diatoms were the most abundant group, blooming first in shallow mixed layers of haline-stratified Arctic shelf waters. Along with diatoms, chlorophytes co-dominated at the western end of the section (particularly in the polar waters of the Labrador Current (LC)), whilst Phaeocystis co-dominated in the east (modified polar waters of the West Greenland Current (WGC)). Pre-bloom conditions occurred in deeper mixed layers of the central Labrador Sea in May, where a mixed assemblage of flagellates (dinoflagellates, prasinophytes, prymnesiophytes, particularly coccolithophores, and chrysophytes/pelagophytes) occurred in low-chlorophyll areas, succeeding to blooms of diatoms and dinoflagellates in thermally stratified Atlantic waters in June. Light-saturated photosynthetic rates and saturation irradiance levels were highest at stations where diatoms were the dominant phytoplankton group ( > 70 % of total chlorophyll a), as opposed to stations where flagellates were more abundant (from 40 up to 70 % of total chlorophyll a). Phytoplankton communities from the WGC (Phaeocystis and diatoms) had lower light-limited photosynthetic rates, with little evidence of photoinhibition, indicating greater tolerance to a high light environment. By contrast, communities from the central Labrador Sea (dinoflagellates and diatoms), which bloomed later in the season (June), appeared to be more sensitive to high light levels. Ratios of accessory pigments (AP) to total chlorophyll a (TChl a) varied according to phytoplankton community composition, with polar phytoplankton (cold-water related) having lower AP : TChl a. Polar waters (LC and WGC) also had higher and more variable particulate organic carbon (POC) to particulate organic nitrogen (PON) ratios, suggesting the influence of detritus from freshwater input, derived from riverine, glacial, and/or sea ice meltwater. Long-term observational shifts in phytoplankton communities were not assessed in this study due to the short temporal frame (May to June) of the data. Nevertheless, these results add to our current understanding of phytoplankton group distribution, as well as an evaluation of the biogeochemical role (in terms of C : N ratios) of spring phytoplankton communities in the Labrador Sea, which will assist our understanding of potential long-term responses of phytoplankton communities in high-latitude oceans to a changing climate.
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Hollingshead, Sarah, Sophie Bliss, Patrick J. Baker, and C. Neil Hunter. "Conserved residues in Ycf54 are required for protochlorophyllide formation in Synechocystis sp. PCC 6803." Biochemical Journal 474, no. 5 (February 20, 2017): 667–81. http://dx.doi.org/10.1042/bcj20161002.
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Chlorophylls (Chls) are modified tetrapyrrole molecules, essential for photosynthesis. These pigments possess an isocyclic E ring formed by the Mg-protoporphyrin IX monomethylester cyclase (MgPME–cyclase). We assessed the in vivo effects of altering seven highly conserved residues within Ycf54, which is required for MgPME–cyclase activity in the cyanobacterium Synechocystis. Synechocystis strains harbouring the Ycf54 alterations D39A, F40A and R82A were blocked to varying degrees at the MgPME–cyclase step, whereas the A9G mutation reduced Ycf54 levels by ∼75%. Wild-type (WT) levels of the cyclase subunit CycI are present in strains with D39A and F40A, but these strains have lowered cellular Chl and photosystem accumulation. CycI is reduced by ∼50% in A9G and R82A, but A9G has no perturbations in Chl or photosystem accumulation, whilst R82A contains very little Chl and few photosystems. When FLAG tagged and used as bait in pulldown experiments, the three mutants D39A, F40A and R82A were unable to interact with the MgPME–cyclase component CycI, whereas A9G pulled down a similar level of CycI as WT Ycf54. These observations suggest that a stable interaction between CycI and Ycf54 is required for unimpeded Pchlide biosynthesis. Crystal structures of the WT, A9G and R82A Ycf54 proteins were solved and analysed to investigate the structural effects of these mutations. A loss of the local hydrogen bonding network and a reversal in the surface charge surrounding residue R82 are probably responsible for the functional differences observed in the R82A mutation. We conclude that the Ycf54 protein must form a stable interaction with CycI to promote optimal Pchlide biosynthesis.
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Yang, Xin Yu, Zhao Lun Wang, and Ming Chu Pan. "Preparation and Characterization of Self-Dispersal Nanometer Carbon Black Pigment." Advanced Materials Research 189-193 (February 2011): 3836–39. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.3836.
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The surfaces of carbon black were modified by nitric acid oxidation. The surface structures of the original and oxidized carbon black were investigated by means of FT-IR and XPS, respectively. Furthermore, the oxidized carbon black and distilled water were mixed to form the self-dispersal nanometer carbon black pigment. The particle size distribution and dispersion stability of the carbon black pigment were investigated by means of particle-size analyzer and spectrometer, respectively. The results showed that some highly marked hydrophilic character functional groups on carbon black surfaces were increased greatly by nitric acid oxidation.
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Bulychev, N., E. Kisterev, H. Reimann, C. Schaller, and C. D. Eisenbach. "Ultrasonic Treatment Enhanced Surface Modification of Titanium Oxide by Tailor-Made Surface-Active Polymers." Eurasian Chemico-Technological Journal 11, no. 2 (April 6, 2016): 121. http://dx.doi.org/10.18321/ectj305.
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The surface modification of titanium dioxide in aqueous dispersions of specially tailor-made periodic acrylic acid/isobutylene copolymers, poly(acrylic acid)/polystyrene graft copolymers, and hydrophobically modified polyethyleneoxide urethane (HEUR) by ultrasonic treatment was studied. The pigment surface modification by the above copolymers was comparatively investigated regarding conventional adsorption as contrasted to an ultrasonic treatment assisted procedure. The course and efficiency of the polymer adsorpption onto the pigment surface was quantified by electrokinetic sonic amplitude measurements. The higher efficiency of the pigment surface coating by the copolymers as achieved by ultrasonic treatment varies with the copolymer architecture and is a consequence of ultrasonically induced pigment surface activation.
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Velygodska, A. K., and O. V. Fedotov. "The production and analysis of carotenoid preparations from some strains of xylotrophic Basidiomycetes." Biosystems Diversity 24, no. 2 (July 4, 2016): 290–94. http://dx.doi.org/10.15421/011637.
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The aim of the study was selection of optimal conditions for obtaining carotenoid drugs of mycelium origin from the basidiomycete strains Laetiporus sulphureus Ls-08, Fomes fomentarius Ff-1201 and Fistulina hepatica Fh-18 and the study of antibacterial and total antioxidant activity of these compounds. The strains were surface grown on a glucose-peptone medium modified for each producer. The homogenized pigments of the mycelium strains were extracted with ethanol and the solvent was separated under vacuum at 60 ºC. The absorption spectra of the carotenoid drugs were recorded for alcoholic solutions at 350–500 nm. The antibacterial activity of the carotenoids was determined by the agar diffusion method, and the total antioxidant activity was determined by the DPPH-method. It was found that the optimum temperature for carotenoid extraction is 60 °C. The absorption spectra of carotenoid drugs showed three peaks in 420, 450 and 470 nm. These results respond to the β-carotene absorption spectra. The highest antioxidant activity was noted for carotenoid drugs from F. hepatica Fh-18 and L. sulphureus Ls-08 strains obtained at an extraction temperature of 40 and 60 °C respectively. The antibacterial activity of carotenoid drugs against the test cultures was not species dependent. Carotenoid drugs with a 20% concentrate obtained from the L. sulphureus Ls-08 strain had the highest antibacterial activity against the test cultures Staphylococcus aureus and Escherichia coli. Carotenoids from the mycelium of F. hepatica Fh-18 had the highest antibacterial activity against the test culture Candida albicans. Extraction temperature of 60 °C is optimal for mycelial yield of carotenoids from the studied strains. All preparations of carotenoids exhibited antibacterial activity against the test microorganism cultures. The carotenoid drugs obtained at 40 and 60 °C from the strains F. hepatica Fh-18 and L. sulphureus Ls-08 respectively showed the highest antioxidant activity.
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Aggarwal, L. K., and G. W. Kapse. "Modified iron‐oxide pigment based paints." Pigment & Resin Technology 14, no. 6 (June 1985): 4–11. http://dx.doi.org/10.1108/eb042140.
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Pham, Maria H., Håvard J. Haugen, and Janne E. Reseland. "Fluoride Modification of Titanium Surfaces Enhance Complement Activation." Materials 13, no. 3 (February 3, 2020): 684. http://dx.doi.org/10.3390/ma13030684.
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Immediately after dental implant insertion, blood will be in direct contact and interact with the implant surface and activates inflammatory responses and complement cascades within seconds. The aim of the present study was to determine the ability of fluoride-modified titanium surfaces to activate complement cascades using the human buffy coat as model. The buffy coats were exposed to hydrofluoric acid-modified surfaces for a short time and its responses were compared to controls. Identification and quantification of complement cascade biomarkers were conducted using ELISA kits and multianalyte profiling using Luminex. A lower level of C3 at 30 min and increased levels of C4, MIP-4, CRP, and pigment epithelium-derived factor at 360 min were found on modified surfaces as compared to controls. We found no significant differences in the levels of C3a, C5a, C Factor H, α2M, ApoA1, ApoC3, ApoE, Prealbumin, α1AT, and SAP in modified surfaces in the buffy coats. We conclude that titanium surfaces treated with hydrofluoric acid modify the levels of specific biomarkers related to the complement cascade and angiogenesis and, thus, tissue growth, remodeling and repair, as this may play a role in the enhanced clinical performance of fluoride-modified Ti dental implants.
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BULYCHEV, Nikolay A., Lev N. RABINSKIY, and Olga V. TUSHAVINA. "INVESTIGATION OF AN AMPHIPOLAR COPOLYMER ADSORPTION ON THE HYDROPHOBIC SURFACE OF COPPER PHTHALOCYANINE NANOPARTICLES." Periódico Tchê Química 16, no. 32 (August 20, 2019): 732–38. http://dx.doi.org/10.52571/ptq.v16.n32.2019.750_periodico32_pgs_732_738.pdf.
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It was presented the data on the thicknesses of the adsorbed polymer layer, which were obtained for copper phthalocyanine (CuPc) pigment dispersions under ultrasonic processing conditions. The thicker adsorption layers, which are observed in ultrasound systems, confirm the fact that the activation of the surface of the pigment occurs under the action of ultrasonic energy. The course and efficiency of adsorption of the polymer onto the pigment surface were quantified by electrokinetic measurements of the amplitude of sound (EIAZ). It became possible to obtain a more detailed picture of the pigment-polymer interactions and the adsorption mechanism of the copolymer based on the data on the dynamic mobility, obtained as a result of electrokinetic measurements of the amplitude of the sound. For aqueous dispersions of CuPc, stabilized with a copolymer of poly (acrylic acid) -poly (isobornyl acrylate) (PiBA-PAA), it was established the saturation concentrations of polymeric surfactant. Thus, the ultrasonic treatment allows to obtain stable, highly dispersed pigment suspensions with a modified pigment surface, which opens up new prospects for a more effective change in the surface of the pigment.
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Schreiber, H. P., M. Y. Boluk, and C. Dufour. "Pigment dispersion in thermally modified polyethylenes." Journal of Applied Polymer Science 39, no. 2 (January 20, 1990): 465–70. http://dx.doi.org/10.1002/app.1990.070390220.
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Tanjaya, Ailen, S. Sudono, Nani Indraswati, and Suryadi Ismadji. "Aktivasi bentonit alam pacitan sebagai bahan penyerap pada proses pemurnian minyak sawit." Jurnal Teknik Kimia Indonesia 5, no. 2 (October 2, 2018): 429. http://dx.doi.org/10.5614/jtki.2006.5.2.4.
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Application of pacitan's bentonite as adsorbent in purification process of palm oil. Bentonite is one of the widely use adsorbent which is usually used in the bleaching process of edible palm oil to remove pigments color and other impurities which can improve the sensory quality and the oxidative stability of the oil. Bleaching capacity from bentonite can be improved by acid activation, to modified the structure as well as to improve the sorptive surface area. The aim of this research was to determine the optimum acid concentration for the activation of bentonite from Pacitan, East Java. The bleaching capacity of activated bentonite was evaluated based on color, free fatty acid (FFA) and peroxide value (PV) contents of bleached palm oil. The activation was carried out using sulfitric acid (HSO) and hydrochloride acid (HCI) as activating agents at a ranges of concentrations from 1 N to 10 N. The bleaching process of crude palm oil was conducted at 100 C for 10 mins. The bleached palm oil were analyzed for its colur, free fatty acid (FFA) and peroxide value (PV) contents. From this study it can be concluded that the activation process using HCl 5 N gave the optimum bleaching capacity.Keywords: Bleaching earth; Acid activation; Bentonite; Color; Free fatty acid; Peroxide value AbstrakBentonit merupakan salah satu jenis adsorben yang sering digunakan pada proses bleaching minyak kelapa sawit untuk menyerap zat warna dan pengotor-pengotor dalam minyak. Kemampuan bleaching dari bentonit dapat ditingkatkan dengan aktivasi dengan asam untuk meningkatkan luas permukaan dan memodifikasi struktur bentonit. Tujuan dari penelitian ini adalah menentukan jenis dan konsentrasi asam yang optimum pada proses aktivasi bentonit Pacitan. Kemampuan bleaching bentonit dievaluasi berdasarkan parameter warna, kadar asam lemak bebas (Free Fatty Acid, FFA) dan bilangan peroksida (Peroxide Value, PV) pada bleached palm oil. Proses aktivasi bentonit dilakukan menggunakan asam sulfat (H2SO4) dan asam klorida (HCl) dengan variasi konsentrasi 1-10 N. Bentonit yang telah diaktivasi digunakan untuk proses bleaching degummed palm oil pad a suhu 100 C selama 10 menit. Bleached palm oil dianalisa warna (dengan lovibond tintometer), kadar FFA dan PV Dari hasil penelitian diperoleh bahwa bentonit Pacitan yang diaktivasi menggunakan HCl 5 N, memberikan hasil bleaching yang optimum.Kata kunci : Bleaching earth; Aktivasi asam; Bentonit; Wama; Asam lemak bebas; Bilangan peroksida
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El‐Saied, Houssni, Snaa M. El‐Sawy, and Altaf H. Basta. "Modified barium metaborate pigment as a paper filler." Pigment & Resin Technology 25, no. 2 (February 1996): 8–17. http://dx.doi.org/10.1108/eb043172.
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Chakvattanatham, K., S. Phattanarudee, and S. Kiatkamjornwong. "Anionically surface‐modified pigment/binder ink jet inks for silk fabric printing." Pigment & Resin Technology 39, no. 6 (November 9, 2010): 327–41. http://dx.doi.org/10.1108/03699421011085821.
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Che Musa, Siti Aisha Na’illa, R. M. Taha, Ummi Nur Ain Abdul Razak, Nordiyanah Anuar, and A. K. Arof. "The effects of different solvent extraction and pH on the stability of carotenoids and chlorophyll in Cucumis melo L. for potential coating technology." Pigment & Resin Technology 47, no. 6 (November 5, 2018): 511–16. http://dx.doi.org/10.1108/prt-11-2016-0105.
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Purpose The purpose of this paper is to evaluate the potential use of natural colorant extracted from fruit flesh and leaves of Cucumis melo L. (C. melo L.) in coating applications. Design/methodology/approach Carotenoids and chlorophylls compounds were extracted from C. melo L. fruit flesh and C. melo L. leaves with the best extraction solvents. Both compounds were tested at various pH for colour stability tests. Then, the most stable pH of both extracts was mixed with 20 per cent poly methyl methacrylate (PMMA) together with tetrahydrofuran and acrylic polyol to form a coating system on glass slides. The coated glass slides were exposed to three different temperatures. The effects of heat on the coated glass slides were evaluated using spectrophotometer at 400-700 nm wavelengths. Findings Results revealed that carotenoids extracted from C. melo L. were less stable to be applied in coating applications since the colour degraded in a very short time; however, the chlorophylls extracted were more stable where the colour retained for longer duration. Originality/value The method of the plant pigment production of C. melo L. with PMMA was a modified method that could give other various applications as natural product based on plant pigments.