Academic literature on the topic 'Clay-dye pigments'

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.

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.

Interest in applications of natural dye applications has increased because of their antibacterial properties and the possibility of extracting them from nature and residues. Using nanoclays as hosts to reinforce natural dye properties has been successfully demonstrated. However, no one has attempted to optimize the polymer matrix and hybrid pigment properties at the same time to ensure the best final properties for bio-composite applications. Using a statistical design for experiments, we propose the best combination of modifiers with the best nanoclay as the host of three natural dyes: chlorophyll, β-carotene, and betanine. Using the L9 Taguchi designs, we learned both the influence of the nanoclay structure, and the addition moment of surfactant, mordant salt, and silane modifiers. FTIR, XRD, DTG, integration sphere spectrophotometer, and UV-aging tests were used to characterize the hybrid pigments and epoxy bioresin composites. The degradation temperatures of the three natural dyes rose and the reinforcement of the stability of three natural dyes to UV–Vis radiation exposure was demonstrated, which avoided the migration of these dyes from bioresin to wet ribbing. Optimal results were obtained with hydrotalcite clay (calcined or not) by using surfactant and mordant before the natural dye, and before or after silane.

ABSTRACTMaya blue is an organic / inorganic pigment which is composed principally by two elements: a white clay known as palygorskite (in the Mayan dialect Sakalum), and a blue dye called indigo, this dye is extracted from the plant Indigofera suffruticosa. The mixture and the warming of these two elements produce the Maya blue, which exhibits unusual features such as: resistance to the assault of the acids in warm or high temperatures, his persistent color in spite of having been exposed to different climatic conditions as a result of the passage of time and the specific chemical composition that this pigment presents.In the present investigation natural indigo, palygorskite and synthetic maya blue were analyzed with a new implementation technique called photoacoustic analysis, which detects the structural changes that happen in the material under a controlled increase of temperature. Due to the fact that this technology detects with clarity where the structural changes happen but not that type of changes happen, it used as base termogravimetric analysis. One of the important findings, it was that in the spectrum of the synthetic maya blue were detected the structural changes of the clay and the dye, something that with other used technologies had not been achieved to observe.

Graphene-based composites have received a great deal of attention in recent year because the presence of graphene can enhance the conductivity, strength of bulk materials and help create composites with superior qualities. Moreover, the incorporation of metal oxide nanoparticles such as Fe3O4 can improve the catalytic efficiency of composite material. In this work, we have synthesized a composite material with the combination of reduced graphene oxide (rGO), and Fe3O4 modified tissue-paper (mGO-PP) via a simple hydrothermal method, which improved the removal efficiency of the of methylene blue (MB) in water. MB blue is used as the model of contaminant to evaluate the catalytic efficiency of synthesized material by using a Fenton-like reaction. The obtained materials were characterized by SEM, XRD. The removal of materials with methylene blue is investigated by UV-VIS spectroscopy, and the result shows that mGO-PP composite is the potential composite for the color removed which has the removal efficiency reaching 65% in acetate buffer pH = 3 with the optimal time is 7 h. Keywords Graphene-based composite, methylene blue, Fenton-like reaction. References [1] Ma Joshi, Rue Bansal, Reng Purwar, Colour removal from textile effluents, Indian Journal of Fibre & Textile Research, 29 (2004) 239-259 http://nopr.niscair.res.in/handle/123456789/24631.[2] Kannan Nagar, Sundaram Mariappan, Kinetics and mechanism of removal of methylene blue by adsorption on various carbons-a comparative study, Dyes and pigments, 51 (2001) 25-40 https://doi.org/10.1016/S0143-7208(01)00056-0.[3] K Rastogi, J. N Sahu, B. C Meikap, M. N Biswas, Removal of methylene blue from wastewater using fly ash as an adsorbent by hydrocyclone, Journal of hazardous materials, 158 (2008) 531-540.https://doi.org/10.1016/j.jhazmat.2008.01. 105.[4] Qin Qingdong, Ma Jun, Liu Ke, Adsorption of anionic dyes on ammonium-functionalized MCM-41, Journal of Hazardous Materials, 162 (2009) 133-139 https://doi.org/10.1016/j.jhazmat. 2008.05.016.[5] Mui Muruganandham, Rps Suri, Sh Jafari, Mao Sillanpää, Lee Gang-Juan, Jaj Wu, Muo Swaminathan, Recent developments in homogeneous advanced oxidation processes for water and wastewater treatment, International Journal of Photoenergy, 2014 (2014). http://dx. doi.org/10.1155/2014/821674.[6] Herney Ramirez, Vicente Miguel , Madeira Luis Heterogeneous photo-Fenton oxidation with pillared clay-based catalysts for wastewater treatment: a review, Applied Catalysis B: Environmental, 98 (2010) 10-26 https://doi.org/ 10.1016/j.apcatb.2010.05.004.[7] Guo Rong, Jiao Tifeng, Li Ruifei, Chen Yan, Guo Wanchun, Zhang Lexin, Zhou Jingxin, Zhang Qingrui, Peng Qiuming, Sandwiched Fe3O4/carboxylate graphene oxide nanostructures constructed by layer-by-layer assembly for highly efficient and magnetically recyclable dye removal, ACS Sustainable Chemistry & Engineering, 6 (2017) 1279-1288 https://doi.org/10.1021/acssuschemeng.7b03635.[8] Sun Chao, Yang Sheng-Tao, Gao Zhenjie, Yang Shengnan, Yilihamu Ailimire, Ma Qiang, Zhao Ru-Song, Xue Fumin, Fe3O4/TiO2/reduced graphene oxide composites as highly efficient Fenton-like catalyst for the decoloration of methylene blue, Materials Chemistry and Physics, 223 (2019) 751-757 https://doi.org/ 10.1016/j.matchemphys.2018.11.056.[9] Guo Hui, Ma Xinfeng, Wang Chubei, Zhou Jianwei, Huang Jianxin, Wang Zijin, Sulfhydryl-Functionalized Reduced Graphene Oxide and Adsorption of Methylene Blue, Environmental Engineering Science, 36 (2019) 81-89 https://doi. org/10.1089/ees.2018.0157.[10] Zhao Lianqin, Yang Sheng-Tao, Feng Shicheng, Ma Qiang, Peng Xiaoling, Wu Deyi, Preparation and application of carboxylated graphene oxide sponge in dye removal, International journal of environmental research and public health, 14 (2017) 1301 https://doi.org/10.3390/ijerph14111301.[11] Yu Dandan, Wang Hua, Yang Jie, Niu Zhiqiang, Lu Huiting, Yang Yun, Cheng Liwei, Guo Lin, Dye wastewater cleanup by graphene composite paper for tailorable supercapacitors, ACS applied materials & interfaces, 9 (2017) 21298-21306 https://doi.org/10.1021/acsami.7b05318.[12] Wang Hou, Yuan Xingzhong, Wu Yan, Huang Huajun, Peng Xin, Zeng Guangming, Zhong Hua, Liang Jie, Ren MiaoMiao, Graphene-based materials: fabrication, characterization and application for the decontamination of wastewater and wastegas and hydrogen storage/generation, Advances in Colloid and Interface Science, 195 (2013) 19-40 https://doi. org/10.1016/j.cis.2013.03.009.[13] Marcano Daniela C, Kosynkin Dmitry V, Berlin Jacob M, Sinitskii Alexander, Sun Zhengzong, Slesarev Alexander, Alemany Lawrence B, Lu Wei, Tour James M, Improved synthesis of graphene oxide, ACS nano, 4 (2010) 4806-4814 https://doi.org/10.1021/nn1006368.[14] Zhang Jiali, Yang Haijun, Shen Guangxia, Cheng Ping, Zhang Jingyan, Guo Shouwu, Reduction of graphene oxide via L-ascorbic acid, Chemical Communications, 46 (2010) 1112-1114 http://doi. org/10.1039/B917705A [15] Gong Ming, Zhou Wu, Tsai Mon-Che, Zhou Jigang, Guan Mingyun, Lin Meng-Chang, Zhang Bo, Hu Yongfeng, Wang Di-Yan, Yang Jiang, Nanoscale nickel oxide/nickel heterostructures for active hydrogen evolution electrocatalysis, Nature communications, 5 (2014) 4695 https:// doi.org/10.1038/ncomms5695.[16] Wu Zhong-Shuai, Yang Shubin, Sun Yi, Parvez Khaled, Feng Xinliang, Müllen Klaus, 3D nitrogen-doped graphene aerogel-supported Fe3O4 nanoparticles as efficient electrocatalysts for the oxygen reduction reaction, Journal of the American Chemical Society, 134 (2012) 9082-9085 https://doi.org/10.1021/ja3030565.[17] Nguyen Son Truong, Nguyen Hoa Tien, Rinaldi Ali, Nguyen Nam Van, Fan Zeng, Duong Hai Minh, Morphology control and thermal stability of binderless-graphene aerogels from graphite for energy storage applications, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 414 (2012) 352-358 https://doi.org/ 10.1016/j.colsurfa.2012.08.048.[18] Deng Yang, Englehardt James D, Treatment of landfill leachate by the Fenton process, Water research, 40 (2006) 3683-3694 https://doi.org/ 10.1016/j.watres.2006.08.009.

This thesis is concerned with an experimental study of clay intercalation by organic dye molecule which is crucial for the successful development of a stable clay-dye pigment with combined advantages of organic dye and inorganic clay. Clay-dye pigments were prepared by two different methods. Two different organic dyes were used with unmodified clay and modified clay to study the intercalation. Characteristics of clay-dye pigment have been investigated using X-Ray Diffraction, Thermo-gravimetric Analysis and Transmission Electron Microscopy. In this thesis it is shown that the absorption of cationic dye by unmodified clay in aqueous medium mainly takes place in the interlayer clay surface. More likely the dye molecules with aromatic quaternary ammonium cation intercalate the clay layer and strongly interacts with the clay interlayer oxygen plane, where solvent dye (which is hydrophobic in nature) adsorption by unmodified clay mainly takes place on outer surface of the clay. Dye molecules are weakly interacted with outer surface oxygen plane by hydrogen bonding or Vander Waals forces. Modified clay enabled the solvent dye to intercalate inside the clay interlayer surface with the suitable non-aqueous medium (because of its expanded structure). The modified clay suspension in the selected non-aqueous medium shows only partial desorption of alkyl ammonium molecule from the clay layer with the presence of both cationic dye and solvent dye. Therefore the penetrated dye molecules must have weakly interacted with the interlayer oxygen plane as well as the remaining alkyl ammonium molecule present inside the clay layer. It is believed that the thermal and UV stability of organic dye can only be facilitated by a specific interaction (Ĉ-interactions) between aromatic alkyl ammonium cation of organic dye molecule and the interlayer oxygen plane of clay minerals. This interaction possibly enables the high thermal energy or the energy of the UV radiation to transmit immediately into the clay layer. Therefore organic dye molecules are protected from high energy loading and hence thermal and UV stability are improved.