Nanomaterials From Mixed-Layer Clay Minerals: Structure, Properties, and Functional Applications

Physical-Chemical Properties of Nano-Sized Phyllosilicates: Recent Environmental and Industrial Advancements

“…Fida et al [76] showed that the low pH is favorable to the Cr 6+ removal with nano-sized kaolinite and the removal rate of Cr 6+ reached high adsorption capacity (87%) at low pH (pH ≤ 3.0). Nano-sized mixed-layer illite/smectite clay adsorption in aqueous solution for Cu 2+ and Cd 2+ ions increased (adsorption Cu 2+ = 95.15% and adsorption Cd 2+ = 91.53%) with increasing pH values pH ≥ 4 [24]. The adsorption properties of mixed-layered clays for Pb 2+ and Th 4+ were observed to be enhanced by the presence of humic and fulvic acids which increase adsorption of Pb 2+ and Th 4+ at low pH but decreased adsorption of mixed-layered clays at a basic pH [24,77,78].…”

“…Common intermediate products involving pure end-member clays are mixed-layer clay minerals. Mixed-layer clay minerals are abundant in nature and applied as adsorbents for the removal of heavy metals in aqueous solution owing to their large surface area and exceptional ion-exchange capacity [24]. Montmorillonite/vermiculite is a common swelling component in most mixed-layer clays.…”

“…Kaolinite can be exfoliated into few-layered nanosheets and reassembled into functional materials with macroscopic controllable size and thus unique physical and mechanical properties [23]. Mixed-layer clay minerals (e.g., montmorillonite/illite/chlorite) can be dispersed into polymer matrices forming nanocomposites used for drug delivery carrier, food packaging, advanced rubber and polymers [24]. Nano-sized clay minerals are mixed with organic dyes for preparing Maya Blue-like pigments [25].…”