Stability of n-Butylammonium Vermiculite in Powder and Flake Forms

Abstract

Abstract--Interaction between n-butylammonium (BA) chloride and vermiculite from Santa Olalla (Spain) has been studied in large flake (5 • 5 • 0.1 ram) or ground powder (~<80 txm) samples. The differences in adsorption and decomposition of BA ions in both particle sizes have been established. In the interlamellar space, the BA ion remains unaltered in powder samples, but is degraded in flakes. The experimental results suggest decomposition of the BA in the interlamellar space of vermiculite flakes by breaking of the C-N bond. The degradation of BA takes place over a short period. The variety with BA in the interlamellar space is transformed into a new one, due to the degradation of alkylammonium. The transformation occurs through an interstratified phase formed between BA-vermiculite and NH:vermiculite, and finally a phase appears in which only ammonium is present in the interlamellar space. Due to the many industrial applications of alkylammonium-clays, determination of the stability of alkylammonium in the interlamellar space of clay minerals is of great importance.

Adsorption of Acid Red 57 from aqueous solutions onto surfactant-modified sepiolite

“…The band at 1652 cm −1 corresponds to the OH deformation of water, because the OH stretching band at 3390 cm −1 suggests the presence of some interlamellar water [25] and the stretching vibrations obtained at 1635, 1612, and 1461 cm −1 could be characteristics of reversibly adsorbed carbonate on the oxide surfaces for both of samples and this result was [27] and the band at 883 cm −1 conducted with bending vibration of carbonate and two peak at 690 cm −1 is represent the bending vibration of Mg 3 OH both of samples. The bands at 530 and 471 cm −1 due to Si O Al (octahedral) and Si O Si bending vibrations respectively, natural sepiolite and surfactant-modified sepiolite [28].…”

Híbridos inorgânico-orgânicos derivados da reação de filossicatos com organossilanos

“…Normalmente, os compósitos são formados por duas ou mais fases em escala micrométrica, enquanto que nanocompósitos são materiais obtidos por uma formulação em escala molecular ou nanométrica de, pelo menos, uma das fases, o que permite um aumento da especificidade desses compostos 37 . Os minerais argilosos formam um grupo de matrizes que têm a capacidade de inserir espécies, daí a denominação de hospedeiros, os quais favorecem a química de intercalação de várias moléculas orgânicas, como aminas alifáticas ou aromáticas [39][40][41][42][43] , organocátions [44][45][46][47][48][49] , metaloporfirinas 50 , complexos 51-57 ou polímeros [58][59][60][61][62][63][64][65][66][67] . A importância desses derivados está na sua utilização como materiais precursores para pilarização, adsorventes, catalisadores e eletrodos [68][69][70][71] .…”

Organic intercalation of structure modified vermiculite

“…Because of isomorphous replacement in the tetrahedral and octahedral layers, which resulting in a residual negative charge of the structure unit, natural vermiculite has charge balancing inorganic cations, like Na + , Ca 2+ , Mg 2+ , and water molecules in the interlayer space, which can be mutually exchanged or exchanged by organic cations [7][8][9].This feature of vermiculite makes it possible for organic species to be intercalated into the interlayer space, obtaining organic vermiculite. The electric charge of vermiculite sheet, which affects its interaction with interlayer cations, can be changed by structural modification.…”