Hybrid materials based on clays for environmental and biomedical applications

Hybrid and biohybrid silicate based materials: molecular vs. block-assembling bottom–up processes

“…43,44 However, new tendencies in organoclays preparation focus on the use of non-toxic modifiers of biological origin such as lecithin based tensioactives 45 or diverse biopolymers 46 instead of the conventional surfactant quaternary ammonium based agents because their ''bio-friendly'' character may enlarge their applications to the food, pharmaceutical and biomedical fields. 41 Some examples of these materials are discussed in sections below.…”

“…Thus, organoclays based on smectites have been extensively studied for industrial and environmental applications, such as rheology controlling agents in paints, greases and cosmetics, nanofillers in the preparation of clay-polymer nanocomposites, adsorbents for poorly water soluble species, hosts for electrochemical reactions, as matrices for photofunctional species and catalytically active species, as well as in the so-called environmentally-oriented pesticide formulations that avoid or reduce the loss of bioactivity due to volatility or photodegradation of insecticides and herbicides. 41 The surfactant in the interlayer space can be regarded as an aggregate, since phase transition of the dioctadecyldimethylammonium ion intercalated in smectites has been reported and the phase transition between the gel and liquid-crystalline phases affected the diffusion and reaction of solute molecules. 43,44 However, new tendencies in organoclays preparation focus on the use of non-toxic modifiers of biological origin such as lecithin based tensioactives 45 or diverse biopolymers 46 instead of the conventional surfactant quaternary ammonium based agents because their ''bio-friendly'' character may enlarge their applications to the food, pharmaceutical and biomedical fields.…”

“…34 Recent studies and model calculations reveal more detailed description on the alkyl-chains organization in the interlayer space 39,40 though Lagaly's conceptual model is still useful to explain the interactions and spatial arrangements and distances measured. 41 Electrostatic interactions between the silicate surface and the cationic head group are the driving force for the molecular intercalation, while the intercalated surfactant can interact with adjacent surfactant (intermolecular interactions) to form a unique assembly under the effects of the cooperative van der Waals forces. 37 Therefore, host-guest interactions and guest-guest interactions play a dominant role for the nanostructure formation in this type of silicate based hybrids.…”

Morphology control and interlayer pillaring of swellable Na-taeniolite mica crystals

“…Clay-based intercalation compounds and hybrid materials attract much attention because of their interesting properties, for example, adsorption and catalysis, as well as environmental preservation and remediation [9,10]. The host clays most extensively studied are smectite group minerals, such as a naturally occurring montmorillonite.…”

Thermal stability and pollutant adsorption efficiency of nanocomposites consisted of clay and polymeric quaternary ammonium salts

“…These materials are mainly used for car and packaging production, but they are also tested as drug carriers [1] and water pollutant adsorbents [2]. In industrial effluent dyes are particularly harmful substances [3] and cresol red is one of their examples [4].…”