Application of zeolites as matrices for pigments

Color and shade parameters of ultramarine zeolitic pigments synthesized from kaolin waste

“…The methodology adopted for the synthesis of ultramarine zeolite pigments was that described by Kowalak and Jankowska 24 , in which 1 g of zeolite A derived from kaolin waste was mixed with elemental sulfur (S, Synth) and sodium carbonate (Na 2 CO 3 99%, Nuclear) in a porcelain crucible with additive (S/Na 2 CO 3 ) to zeolite ratios varying from 10 to 50% m/m, without reductive agent. A molar ratio of 1 was maintained for the S/Na 2 CO 3 additives.…”

“…Proportions of 20 24,25 , 40 21,22 , or 60 % 17 sulfur relative to the mass of zeolite are commonly used, and the S/Na 2 CO 3 ratio is defined by considering that an excess of sodium carbonate favors the formation of S -3 and an excess of sulfur favors the formation of S -2 . Given this background on the subject, the objective of this study was to obtain ultramarine pigments from zeolite A derived from kaolin waste in the Amazon region and determine the influence of the reagent concentrations and cooling rates after calcination on the color and shade of the final product.…”

Encapsulation of red sulfur chromophores in a zeolitic imidazolate framework (ZIF-8) via solvent assisted linker exchange

“…Use of zeolites is advantageous due to their relatively low cost as well as the lower emission of SO 2 [2]. Moreover the coloration and properties of the product can be varied by varying the zeolite synthesis conditions [8]. During the preparation of zeolitic ultramarine pigments, the zeolite is heated to temperatures varying from 500 to 800 C with sodium carbonate and sulfur [12,13].…”

Synthesis and characterization of amorphous aluminosilicates prepared by sol–gel to encapsulate organic dyes

“…Currently, there is a great interest in the cleaning of streams from industries, such as those involved in the printing and textile processes [6][7][8]. One strategy is to encapsulate the dye molecules in porous matrices such as aluminosilicates via short distance bonding between the functional groups of the dye molecules and those in the cavities of the aluminosilicate [9,10].…”