25Hybrid pigments have attracted great interest due to their stability and physicochemical 26 properties that can be used in paintings, artworks and in the field of cultural heritage. The 27 study of new materials includes the search for new pigments by immobilization of the dyes in 28 resistant substrates such clays minerals to get new color fonts and materials with high 29 stability. Organic-inorganic based lake pigments, at different pH, have been prepared. Al-pillared montmorillonite were synthesized and loaded with carminic acid (CA) and alizarin 31 (Aliz) organic dyes. The pillaring process was investigated by X-ray diffraction, textural 32 analysis, transmission electronic microscopy and solid state nuclear magnetic resonance of 33 27 Al. The interactions between the organic guest and the inorganic host were highlighted by 34 infrared, 13 C and 27 Al solid state magnetic nuclear resonance and time resolved fluorescence 35 spectroscopies. The spectra support complex formation between the chromophores and the 36 inorganic matrix. The colours of the pigments prepared were pH dependent. Lake pigments 37 based on Al-Pillared Mt were more stable under light than Ti-based hybrid, even in oil 38 painting formulations. 39 Photoaging. 41 42 43 44 48 aspects. However, the poor stability of the colours used against acids, light or temperature has 49 been a serious problem that has affected works of art and aspects of their cultural heritage as 50 result of their public exposure. Thus, designs for stable pigments are desired in order to 51 prepare/restore paintings and overcome the problem of degradation [1]. It has been expected 52 that the surface where pigments are applied is a preponderant factor in determining the 53 efficiency/stability of colours, and the perfection of paintings. Although there are many 54 sources, there is a necessity to find combinations of raw materials for use as colouring 55 agents/colourants in ink formulations. In fact, hybrid pigments have wide applications not 56 only in works of art, but also in the fields of optics, food processing, cosmetics or plastics [2-57 4]. Hybrid based on organic dye-inorganic compounds are chemically obtained by a strong 58 interaction between organic chromophores and inorganic matrices aiming to obtain stable 59 pigments [8] or removing anionic dyes from wastewater [5]. In this context, a growing 60 application of inorganic dyes-based hybrids are established [6-8]. 61 Anthraquinones are classified as the natural organic dyes most resistant to light-induced 62 deterioration used since prehistoric times [9]. These red colourants may be extracted from the 63 roots of a diversity of plants from the Rubiaceae family (madder family). Alizarin and 64 purpurin are the principal occurring dyes in Rubia tinctoria L. (maddergenus) [2,9]. Lakes are 65 pigments formed from a dye-inorganic hybrid. Several other guest dyes have been reported in 66 the literature to obtain lake pigments, such as carminic acid [1,8], fluorescein [8], betalain 67 [10] and eosin [11].68 4 ...

23Hybrid materials based on montmorillonite, a cationic polymer and carminic acid were 24 prepared. The surface charge of montmorillonite was inversed thanks to the cationic polymer, 25 polydiallyldimethylammonium chloride. Samples were characterized by a set of different 26 techniques including Infrared (IR) and Nuclear Magnetic Resonance (NMR) spectroscopies to 27 highlight the nature of the interactions between the organic and inorganic parts. The photo-28 stability of the samples was tested for different durations, and L*a*b* parameters were 29 measured. It was possible to propose an approach for the degradation mechanism of the 30 supported dye thanks to EPR (electron paramagnetic resonance) spectroscopy. The 31 experimental data were in agreement with the theoretical periodic DFT calculations where a 32 molecular scheme of the adsorption complex was proposed, and the importance of hydration 33 on the stability of the adsorption complex highlighted.34 2

26Organoclays have been applied as efficient adsorbents for pharmaceutical pollutants from 27 aqueous solution. In this work, dodecylpyridinium chloride (C 12 pyCl) and 28 hexadecylpyridinium chloride (C 16 pyCl) cationic surfactants were used for the preparation of 29 organobentonites destined for diclofenac sodium (DFNa) adsorption, an anionic drug widely 30 detected in wastewater. The organofunctionalization of the clay samples was performed under 31 microwave irradiation at 50 °C for 5 min with surfactant amounts of 100% and 200% in 32 relation to the cation exchange capacity (CEC) of the pristine bentonite. The amount of 33 incorporated ammonium salts based on CHN elemental analysis was higher for all samples 34 prepared with 200% of the CEC. The basal spacings of the organoclays ranged from 1.54-35 2.13 nm, indicating the entrance of organic cations into the interlayer spacing of the clay 36 samples, and the spacing depended on the size of the alkyl organic chain. The hydrophobic 37 character of the organobentonites was verified by thermogravimetry and infrared 38 spectroscopy (FTIR). The adsorption isotherms showed that the drug capacity adsorption was 39 influenced by the amount of surfactant incorporated into the bentonite, the packing density 40 and the arrangement of the surfactants in the interlayer spacing. Zeta potential measurements 41 of the organobentonites and FTIR analysis after drug adsorption suggested that electrostatic 42 and nonelectrostatic interactions contributed to the mechanism of adsorption. 43 44 45 46

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TiO 2 immobilized in Sepiolite (TiO 2 /Sep) was successfully prepared by the sol-gel technique, with titanium isopropoxide as the precursor for the formation of TiO 2 in the anatase phase calcined at 400 °C. The prepared samples were characterized by X-ray diffraction, Fourier Transform Infrared spectroscopy, Scanning Electron Microscopy coupled to energy dispersive spectroscopy, and thermogravimetric analysis. The results showed that TiO 2 /Sep structure was identified in all characterizations, showing the specific peaks, bands, mass loss, and morphology after the impregnation process. Photocatalytic experiments were performed under UV irradiation with various photocatalyst concentrations and pH effects in the reaction. The prepared samples presented 72% photocatalytic efficiency for eosin (EA) dye discoloration after 150 min under UV light. This efficiency was attributed to the radicals generated from the TiO 2 and the high specific surface area, showing that TiO 2 /Sep is promising candidate in the degradation of organic pollutants.

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Wine chemistry inspires and challenges with its complexity and intriguing composition. In this context, the composites based on the use of a model protein, a polyphenol of interest and montmorillonite in a model hydroalcoholic solution have been studied. A set of experimental characterization techniques highlighted the interactions between the organic and the inorganic parts in the composite. The amount of the organic part was determined by ultraviolet-visible (UV-VIS) and thermal analysis. X-ray diffraction (XRD) and transmission electronic microscopy (TEM) informed about the stacking/exfoliation of the layers in the composites. Vibrational and nuclear magnetic resonance spectroscopies methods stressed on the formation of a complex between the protein and the polyphenol before adsorption on the clay mineral. The mobility/rigidity of the organic parts were determined by fluorescence time resolved spectroscopy. Changes in the secondary structure of the protein occured upon complexation with polyphenol on clay mineral due to strong interactions. Although not representating faithfully enological conditions, these results highlight the range and nature of mechanisms possibly involved in wine fining.