New pigments based on carminic acid and smectites: A molecular investigation

Abstract

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

Organophilic bentonites obtained by microwave heating as adsorbents for anionic dyes

“…The reusability is one of the important characteristics of any kind of adsorbents and is a critical point on the economy of the process (Salehi et al, 2016). However, in recent years great importance was given to the preparation of new stable pigments based on clay minerals (Fournier et al, 2016;Zhang et al, 2017;Guillermin et al, 2018;Trigueiro et al, 2018). The study of new materials includes the search for new pigments by immobilization of the dyes in resistant substrates such clays minerals to get new color fonts and materials with high stability (Fournier et al, 2016;Trigueiro et al, 2018).…”

Study of the leaching potential in a soil and its depuration capacity: perspectives in a landfill selection

“…Finally, the carminic acid is a degradable substance by biological and physical processes and their stability was not considered in this study [20]. Thus, the carminic acid adsorbed in the porous soil may be degraded by allocthonous microbiota and the delay fractions may be subsequently released.…”

Carminic Acid Linked to Silica Nanoparticles as Pigment/Antioxidant Bifunctional Excipient for Pharmaceutical Emulsions

“…The incorporation of a pigment to inorganic matrices to obtain a hybrid material that improves the resistance and chemical stability of the pigments has been widely studied in several fields of application and different production methodologies [44][45][46][47][48].…”