Interlamellar Esterification of H-Magadiite with Aliphatic Alcohols

Abstract

Magadiite, a layered sodium polysilicate, was organically modified by esterification of interlayer silanol groups with various aliphatic alcohols. Methanol was directly reacted with H-magadiite (acid-treated magadiite) by refluxing. The methanol-treated product showed an increase in the basal spacing and the 13C NMR signals due to methyl groups. The 2H NMR spectrum of CD3OD-treated H-magadiite showed Pake doublet patterns of quadrupole coupling constants of 43 and 48 kHz and asymmetry factors of 0, indicating the fixation of the C−O axis. When aliphatic alcohols with the carbon chain length longer than 4 were used, an H-magadiite/N-methylformamide (NMF) intercalation compound was used as an intermediate for esterification. The basal spacing of butanol-treated H-magadiite was 1.40 nm, the value of which was smaller than that of H-magadiite/NMF (1.63 nm) and larger than that of H-magadiite (1.15 nm). 13C spin−lattice relaxation times (T 1) of butyl groups showed a low mobility of the α carbon. Other alcohols (C n H2 n +1OH (n = 2−16) and (CH3)3COH) were also reacted with the silanol groups. The differential thermal analysis (DTA) curves of the products showed exothermic peaks. The alkyl chains are apparently lying parallel to the inner surface because almost constant basal spacings were observed despite the variation in the alkyl chain length. The butanol-treated H-magadiite was dispersed in toluene and cast, resulting in the formation of a transparent nanocomposite film.

Dispersion of organically modified clays within n-alcohols

“…6B) ordering of the alkylammonium surfactants and showed that the alkyl chains with n < 9 preferentially remained flat on the silicate surface [17]. Studies of another clay, magadiite, have also shown that the n-alcohol molecules remained parallel to the silicate surface [18].…”

Janus Nanosheets Derived from K4Nb6O17·3H2O via Regioselective Interlayer Surface Modification

“…There have been many reports of surface modification by silane coupling agents for clay minerals [37], layered silicates [38][39][40], and layered transition metal oxides [41,42]. In the case of surface modification by alcohol, there have been reports of polysilicates with ethylene glycol [43] and aliphatic alcohols [44], while layered perovskites have been modified with n-alcohol [45] and alcohol Functional Materials with fluoroalkyl groups [44,46]. Also, layered perovskites were grafted with phenyl or n-alkylphosphonic acids using the aforementioned n-alkoxy derivatives as intermediates [47].…”

Selective C–C Coupling Reaction of Dimethylphenol to Tetramethyldiphenoquinone Using Molecular Oxygen Catalyzed by Cu Complexes Immobilized in Nanospaces of Structurally-Ordered Materials

“…The XRD analysis revealed that the basal spacing of Cu 2+ -magadiite ( d 001 = 13.9 Å) decreased from that of the parent magadiite ( d 001 = 15.1 Å). The d 001 value of Cu 2+ -magadiite was larger than those of proton-exchanged magadiite (H + -magadiite) ( d 001 = 11.5 Å) [ 44 ] and dehydrated magadiite ( d 001 = 12.8 Å) [ 45 ], confirming that Cu species were incorporated within the magadiite interlayer. The interlayer gallery of Cu 2+ -magadiite was estimated as 2.4 Å based on the subtraction of layer thickness of H + -magadiite [ 46 ].…”