Using Laminar Nanoclays for Phycocyanin and Phycoerythrin Stabilization as New Natural Hybrid Pigments from Microalgae Extraction

Abstract

C-Phycocyanin (PC) and B-phycoerythrin (PE) are light-harvesting water-soluble phycobiliproteins from microalgae that belong mainly to the cyanobaceria and rhodhophytes families. Different methods have been developed for PC and PE extraction and purification from microalgae, and offer a high potential for their use as additives in sectors such as food and cosmetics. However, the main limitations of using these dyes are the sensitivity of their environmental factors, such as light fastness, temperature, and pH. We successfully employed safe lamellar nanoclays such as montmorillonite (M) and Laponite (L) for phycobiliproteins stabilization, as we did before with other natural dyes. We obtained a wide color gamut from blues to pink by combining four different factors under synthesis conditions: three dye concentrations; two laminar nanoclay sizes; a two nanoclay surface modifiers combination with cetylpyridinium bromide (CPB) and a coupling agent (3-Aminopropyl) triethoxysilane. The experimental conditions were defined according to a multilevel factorial design of experiment (DOE) to study the factors interacting in the final hybrid pigment characteristics. In both M and L, the d001 distance (nm) increased due to PC and PE adsorption. The best conditions to increase the basal space depend on the nanoclay structure, and it is better to use the surfactant for M, and silane modification for L. In addition, optical and thermal PE and PC properties significantly improved. We show the optimal synthesis conditions to increase PC and PE adsorption using the high dye concentration, with surfactant and silane depending on the nanoclay. The hybrid pigments from these phycobiliproteins offer the opportunity to perform several industrial applications, including in polymer additives, cosmetics, and packaging.

Adsorption of Dye Molecules and Its Potential for the Development of Photoactive Hybrid Materials Based on Layered Silicates

“…This well-known solvatochromic dye has been considered as a nonluminescent zwitterionic substance with negatively charged phenolate and positively charged pyridinium groups in its aqueous solution. As it was already mentioned earlier, in order to have systems applicable for neutral dyes, it is necessary to modify the surface of the silicate particles through the adsorption of polyelectrolytes , or surfactants . These types of surface functionalization of the silicate substrate can help to achieve such desired properties as the controlled charge density and topography of the surface.…”

“…Further potential applications to be mentioned are the adsorption-induced nonlinear optical properties, photosensitization, , chemiluminescence, and photocatalysis. Chemical stabilization of various types of organic dyes in the hybrid systems with silicates has been reported, which may further broaden their industrial applications. Finally, specific hybrid systems may be applied in the near future in the synthesis of more complex composite materials, such as composites with polymers …”

“…As it was already mentioned earlier, in order to have systems applicable for neutral dyes, it is necessary to modify the surface of the silicate particles through the adsorption of polyelectrolytes 17,18 or surfactants. 49 These types of surface functionalization of the silicate substrate can help to achieve such desired properties as the controlled charge density and topography of the surface.…”