| Full text | |
| Author(s): |
Silva, Gustavo Thalmer M.
[1]
;
Silva, Karen Magno
[1, 2]
;
Silva, Cassio P.
[1]
;
Goncalves, Josue M.
[1]
;
Quina, Frank H.
[1]
Total Authors: 5
|
| Affiliation: | [1] Univ Sao Paulo, Inst Quim, BR-05508000 Sao Paulo - Brazil
[2] Inst Fed Educ Ciencia & Tecnol Sao Paulo, BR-01109010 Sao Paulo - Brazil
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | ACS OMEGA; v. 5, n. 41, p. 26592-26600, OCT 20 2020. |
| Web of Science Citations: | 0 |
| Abstract | |
Flavylium cations are synthetic analogues of anthocyanins, the natural plant pigments that are responsible for the majority of the red, blue, and purple colors of flowers, fruits, and leaves. Unlike anthocyanins, the properties and reactivity of flavylium cations can be manipulated by the nature and position of substituents on the flavylium cation chromophore. Currently, the most promising strategies for stabilizing the color of anthocyanins and flavylium cations appear to be to intercalate and/or adsorb them on solid surfaces and/or in confined spaces. We report here that hybrid pigments with improved thermal stability, fluorescence, and attractive colors are produced by the cation-exchange-mediated adsorption of flavylium cations (FL) on two synthetic clays, the mica-montmorillonite SYn-1, and the laponite SYnL-1. Compared to the FL/SYn-1 hybrid pigments, the FL/SYnL-1 pigments exhibited improved thermal stability as judged by color retention, better preferential adsorption of the cationic form of FL1 at neutral to mildly basic pH (pH 7-8), and lower susceptibility to color changes at pH 10. Although both clays adsorb the cationic form on their external surfaces, SYnL-1 gave more evidence of adsorption in the interlayer regions of the clay. This interlayer adsorption appears to be the contributing factor to the better properties of the FL/SYnL-1 hybrid pigments, pointing to this clay to be a promising inorganic matrix for the development of brightly colored, thermally more stable hybrid pigments based on cationic analogues of natural plant pigments. (AU) | |
| FAPESP's process: | 18/16896-7 - Development of amperometric and impedimetric sensors based on double hydroxides of nickel and vanadium (alpha-NixV1-x(OH)2) and their nanocomposites with expandable graphite/graphene |
| Grantee: | Josué Martins Gonçalves |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |