Sodium montmorillonite silylation: Unexpected effect of the aminosilane chain length

Silylation of montmorillonite surfaces: Dependence on solvent nature

“…The mass loss at ca. 540°C is assigned to the decomposition of the covalent bonded silane [15,20,26]. The mass loss corresponding to the dehydroxylation of Mt almost disappeared, partly due to the consumption of hydroxyl groups during silylation reaction [20].…”

“…The mass losses at ca. 200°C, 330°C, and 430°C are attributed to the silanes physisorbed on Mt surfaces, covalently bonded at the broken edges and/or adsorbed on the Mt surfaces, and intercalated in the interlayer spaces, respectively [15,16,20]. The mass loss at ca.…”

“…In the cases of internal surface and broken edge grafting, a prominent increase in the basal spacing was observed [15][16][17][18], whereas the external surface grafting showed no influence on the basal spacing of clay minerals [19]. The basal spacing of the silylated products strongly depended on the configuration of the silane used [17], the loaded silane amount in the interlayer spaces [18] and the interactions among silane molecules (e.g., intermolecular hydrogen bonding) and between clay mineral and special group of silane (e.g., -NH 2 group) [20]. The chemical nature of the solvents used in silylation reaction has significant influences on the amount and distribution of the grafted silanes and the structure of the silylated products [16,21,22].…”

Locking effect: A novel insight in the silylation of montmorillonite surfaces

“…4e), the mass loss at around 324 C is attributed to the silane covalently bonded at the broken edges and/or adsorbed on the Mt surfaces, and that at ca. 426 C is due to the intercalated silane [8,12,13]. The broad peak at ca.…”

“…The broad peak at ca. 533 C is assigned to the decomposition of the chemically bonded silane [8,12]. The mass loss corresponding to the dehydroxylation of Mt almost disappeared, partly due to the consumption of hydroxyl groups during silylation [14].…”