Alkylammonium derivatives of layered alkali silicates and micro- and mesoporous materials: I. Lithium sodium silicate (silinaite)

Thiesen, Peter; Beneke, K.; Lagaly, G.

doi:10.1039/a910216g

Cited by 15 publications

(11 citation statements)

References 39 publications

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“…Thus, at pH~9±9.5, at which they carried out their cation exchange, kanemite dissolves, but not as a result of the alkalinity of the medium, rather because the silicate layers are reorganized thanks to the ability of the surfactant molecules to change from a bilayered structure to a cylindrical micelle-like aggregate. Thiesen et al, 19 who carried out their experiments in similar conditions to ours (the pH was adjusted to 12.5 and the dispersion was held at 70 ³C for 3 h; after cooling to room temperature, the pH was adjusted to 8.5), have explained the dissolution process as a partial destruction of the silicate structure by alkylammonium ions which then carry the fragments of the silicate layers and ®nally aggregate to cylindrical forms. In our case, the partial dissolution of kanemite during the stirring of the suspension at 70 ³C for 3 h occurs mainly because of the high basicity of the medium.…”

Section: Discussionmentioning

confidence: 63%

“…Chen et al 18 proposed the dissolution mechanism in the course of which the loss of structural integrity of the kanemite layers in combination with the ability of the surfactant molecules to change from a bilayered structure to a cylindrical micelle-like aggregate drives the reorganization of the organic±inorganic composite material. More recently, Thiesen et al 19 proposed another dissolution mechanism in the course of which partial destruction of the silicate structure by long-chain alkylammonium ions occurs, followed by aggregation of the alkylammonium ions and fragments of the silicate layers leading to the formation of meso-and micro-pore frameworks during calcination.…”

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confidence: 99%

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Transformation of kanemite into silicalite 1: parameters affecting the cation exchange reaction

et al. 2000

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The optimum crystallization conditions for the transformation of kanemite into silicalite 1 have been determined by X-ray powder diffraction, thermal analysis and 29 Si NMR spectroscopy. The synthesis of silicalite 1 was favored by the use of a TPAOH template, in preference to a TPABr template, highly basic conditions during stirring of the suspension at 70 ³C and the adjustment of the pH to 8.5 after stirring. The more the layered structure of kanemite disintegrated after the cation exchange reaction, the higher the amount of incorporated template and the higher the crystallinity of silicalite 1 after the solid-state transformation. The dissolution process that occurs during the cation exchange reaction with short-chain alkylammonium cations was different from that which occurs in the case of long-chain alkylammonium cations which are used for the synthesis of mesoporous materials.

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Section: Discussionmentioning

confidence: 63%

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confidence: 99%

Transformation of kanemite into silicalite 1: parameters affecting the cation exchange reaction

et al. 2000

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“…3(a), there are the peaks positioned at 2852 and 2925 cm À1 corresponding to the symmetric and asymmetric stretching vibrations of the methylene groups of CTAB, which confirms the presence of CTAB molecules in the intercalated compounds. As mentioned previously [22], Namontmorillonite also has a characteristic IR absorption band at 1043 cm À1 , which can be attributed to an asymmetric stretching vibration of SiO 4 . And the symmetric Si-O-Si stretching vibrations yield the bands between 800 and 600 cm À1 .…”

Section: Characterizationmentioning

confidence: 89%

Magnetic fluids for synthesis of the stable adduct -Fe2O3/CTAB/Clay

Ma¹,

Xu²,

Chen³

et al. 2005

Journal of Crystal Growth

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“…FSM-16-type mesoporous silica can be obtained from silinaite (NaLiSi 2 O 5 Á 3H 2 O). [65] The reaction of KHSi 2 O 5 with alkylamines was reported as a sort of intercalation chemistry process, suggesting interlayer crosslinking, which is based on 29 Si magic-angle spinning NMR (MAS NMR) data. [83] If the optimal synthetic conditions were chosen, the silicate will also produce highly ordered mesophases.…”

Section: Mesoporous Silicas Derived From Layered Silicatesmentioning

confidence: 99%

“…It has been believed so far that kanemite is the unique layered silicate affording ordered mesoporous silica (KSW-1 and FSM-16), but the formation of ordered mesoporous silica from other layered silicates has been discovered recently. [65][66][67][68] Those research works give us further information on the surfactantlayered silicate systems. Research on the kanemite-surfactant systems reported recently have not been discussed by the reviews published previously.…”

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confidence: 99%

Ordered Mesoporous Silica Derived from Layered Silicates

Kimura

Kuroda

2009

Adv Funct Materials

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Here, the development of ordered mesoporous silica prepared by the reaction of layered silicates with organoammonium surfactants is reviewed. The specific features of mesoporous silica are discussed with relation to the probable formation mechanisms. The recent understanding of the unusual structural changes from the 2D structure to periodic 3D mesostructures is presented. The formation of mesophase silicates from layered silicates with single silicate sheets depends on combined factors including the reactivity of layered silicates, the presence of layered intermediates, the variation of the silicate sheets, and the assemblies of surfactant molecules in the interlayer spaces. FSM‐16‐type (p6mm) mesoporous silica is formed via layered intermediates composed of fragmented silicate sheets and alkyltrimethylammonium (CnTMA) cations. KSW‐2‐type (c2mm) mesoporous silica can be prepared through the bending of the individual silicate sheets with intralayer and interlayer condensation. Although the structure of the silicate sheets changes during the reactions with CnTMA cations in a complex manner, the structural units caused by kanemite in the frameworks are retained. Recent development of the structural design in the silicate framework is very important for obtaining KSW‐2‐based mesoporous silica with molecularly ordered frameworks. The structural units originating from layered silicates are chemically designed and structurally stabilized by direct silylation of as‐synthesized KSW‐2. Some proposed applications using these mesoporous silica are also summarized with some remarks on the uniqueness of the use of layered silicates by comparison with MCM‐type mesoporous silica.

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Alkylammonium derivatives of layered alkali silicates and micro- and mesoporous materials: I. Lithium sodium silicate (silinaite)

Cited by 15 publications

References 39 publications

Transformation of kanemite into silicalite 1: parameters affecting the cation exchange reaction

Transformation of kanemite into silicalite 1: parameters affecting the cation exchange reaction

Magnetic fluids for synthesis of the stable adduct -Fe2O3/CTAB/Clay

Ordered Mesoporous Silica Derived from Layered Silicates

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