Azoic dyes hosted on hydrotalcite-like compounds: Non-toxic hybrid pigments

New multifunctional materials obtained by the intercalation of anionic dyes into layered zinc hydroxide nitrate followed by dispersion into poly(vinyl alcohol) (PVA)

“…Therefore, like layered double hydroxides [19][20][21][22][23][24][25][26][27], layered hydroxide salts such as zinc hy- droxide nitrate, when intercalated with anionic dye molecules and dispersed into polymers such as PVA, can confer new properties on the polymeric matrix and be classified as a new class of multifunctional materials.…”

“…When intercalated with dyes, LDHs act not only as filler materials for synthetic polymers but also as multifunctional materials [19][20][21][22][23][24][25][26][27] that are capable of conferring additional properties on the polymeric matrix, such as color, transparency, photo/UV and thermal stability, and flame-retardant capability. Unlike LDHs, as far as we know, LHSs have never been studied as alternative matrices for multifunctional materials.…”

Formation of photo- and thermo-stable layered double hydroxide films with photo-responsive wettability by intercalation of functionalized azobenzenes

“…Strong bands at 1606 and 1386 cm −1 are characteristic of the antisymmetric and symmetric stretching bands of the carboxylate group, consistent with intercalation of the CF 3 AZO − anion in the LDH interlayer galleries (Xu et al, 2006), although the latter broad peak may also include a contribution from residual nitrate anions. A point worth emphasizing is that incomplete exchange of inorganic precursor anions is commonly observed when large organic anions are intercalated in LDHs (Khan et al, 2001;Tronto et al, 2001;Bauer et al, 2003;Wei et al, 2005;Laguna et al, 2007).…”

“…A wide variety of organic anions have been successfully intercalated into the interlayer gallery regions of powdered LDHs, mainly by coprecipitation or ion exchange (Xu and Braterman, 2003;Singh et al, 2004;Gago et al, 2004). Previous studies have indicated that the stability of organic anions such as pharmaceuticals or organic anionic dyes, as well biological materials such as proteins, can be significantly enhanced through supermolecular host-guest interactions (Khan et al, 2001;Tronto et al, 2001;Bauer et al, 2003;Wei et al, 2005;Laguna et al, 2007). In this work we show that the ability of LDHs to act as a "molecular container" can be utilized to stabilize a photo-sensitive organic species.…”

Preparation of biomorphic Ni–Al LDHs using cotton from discarded T–shirt as a template and the adsorption capability for Congo red

“…Because of their high physicochemical stability and recalcitrant nature, dyes are usually very difficult to biodegrade and they are difficult to eliminate from the natural aquatic environment. Conventional wastewater-treatment methods for removing dyes include physical and/or chemical methods, for example coagulation and flocculation [5], oxidation or ozonation [6], photocatalysis [7,8], adsorption [9,10], membrane separation [11], and electrochemical techniques [12], among others. Among these methods, adsorption is regarded as an attractive option because of its low initial cost and simplicity of operation.…”