Sepiolite-based materials for the photo- and thermal-stabilization of pesticides

Influence of clay mineral structure and surfactant nature on the adsorption capacity of surfactants by clays

“…The equilibrium concentration at which this plateau was reached differed from one mineral to another, although for all the clay minerals it was completely attained for an initial concentration below the cmc of the surfactant (120 g/mL) [43,44]. This type of isotherm has also been reported by other authors in the adsorption of other cationic surfactants by different clay minerals [45][46][47].…”

Removal of 2,4-dichlorophenoxyacetic acid from aqueous solutions by partially characterized organophilic sepiolite: thermodynamic and kinetic calculations

“…The cross section of sepiolite tunnels is about 11 × 4 Å. The tunnels shelter two types of water molecules: (a) coordinated water molecules bonded to Mg +2 ions located at the edges of the octahedral sheet, and (b) zeolitic water bonded to the coordinated water molecules through hydrogen bonding [15,16]. Ruiz-Hitzky [15] proposes a preferential molecular arrangement of pyridine molecules in the tunnels with the ring lying parallel to the (d 100 ) plane of the sepiolite crystal.…”

Fe2O3–palygorskite nanoparticles, efficient adsorbates for pesticide removal

“…It is a magnesium aluminum non-planar hydrous 2:1 phyllosilicate with modulated structure, showing a fibrous morphology resulting from the 180°inversion occurring every four silicon tetrahedra, which produces a structure of chains aligned parallel to the "a" axis, each of which has a 2:1 type structure, with exchangeable cations and reactive Si-OH groups on its surface (Bradley, 1940;Serratosa, 1978;Suarez Barrios et al, 1995) that may be involved in interactions with many different compounds. The alternation of these building blocks creates structural cavities (zeolitic channels) that lead palygorskite to have great internal surface (Casal et al, 2001). The width of the block structure is 0.64 to 0.37 nm (Fernández-Saavedra et al, 2004).…”