Modification of external surface of laponite by silane grafting

Silylation of montmorillonite surfaces: Dependence on solvent nature

“…As reported in the literature, all internal surface, external surface, and broken edge of expandable clay minerals are possible sites for silane grafting [15][16][17][18][19]. 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].…”

“…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].…”

Synthesis and characterisation of clay-supported titania photocatalysts

“…suggest that at a pH of 11.7 the rim charge is neutralised [44,45], thus edge-to-face aggregation is expected below this pH; increasing as the pH decreases. Additionally, TiO 2 colloids are stable at low pH (below 5.9, the isoelectric point for TiO 2 ), where the electrostatic repulsion occuring between positively charged TiO 2 particles is greater than the forces of van der Waals attraction occuring in the system.…”

Silylation of clay mineral surfaces

“…Park (2004) successfully grafted octylsilane onto Laponite surface. The successful grafting did not increase the basal spacing, excluding the possibility of internal surface silylation.…”