Organoclay

Organoclay is an organically modified phyllosilicate, derived from a naturally occurring clay mineral. By exchanging the original interlayer cations for organocations (typically quaternary alkylammonium ions) an organophilic surface is generated, consisting of covalently linked organic moieties. The lamellar structure remains analogous to the parent phyllosilicate.

Separation of the layers due to ion exchange, from the initial interlayer spacing of as little as 3 Å in the case of Na+ cations to the distances in the range of 10–40 Å as well as the change of chemical character of the clay surface, allows the in-situ polymerization or mixing with certain polymers to obtain what is known as nanocomposite. When ordered aluminasilicate sheets are lying parallel to each other, separated with polymer chains of certain type, the system is classified as intercalated nanocomposite. If separation of the layers is so significant, that they are no longer lying opposite to one another, but randomly ordered, then one get the exfoliated nanocomposite.[1]

Applications

Owing to its large surface area together with hydrophobic chains emerging from the clay surface, organoclay can be used to remove oil from water. It is also applied as a component in paint formulations or as a viscosifier for oil-based drilling fluids.

It can be used in polymer chemistry as a nucleating agent.[2]

References

Józef Bardziński, Piotr (2014). "On the impact of intermolecular interactions between the quaternary ammonium ions on interlayer spacing of quat-intercalated montmorillonite: A molecular mechanics and ab-initio study". Applied Clay Science. 95: 323–339. doi:10.1016/j.clay.2014.04.035.
Preschilla, Nisha; Rasheed, A. S. Abdul; Sahadevan, Swayajith; Biswas, Amit; Bellare, Jayesh R.; Shyamroy, Subarna (2010). "Study of layered silicate clays as synergistic nucleating agent for polypropylene". Journal of Polymer Science Part B: Polymer Physics. 48: 1786–1794. Bibcode:2010JPoSB..48.1786P. doi:10.1002/polb.22044.

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[1] Józef Bardziński, Piotr (2014). "On the impact of intermolecular interactions between the quaternary ammonium ions on interlayer spacing of quat-intercalated montmorillonite: A molecular mechanics and ab-initio study". Applied Clay Science. 95: 323–339. doi:10.1016/j.clay.2014.04.035.

[2] Preschilla, Nisha; Rasheed, A. S. Abdul; Sahadevan, Swayajith; Biswas, Amit; Bellare, Jayesh R.; Shyamroy, Subarna (2010). "Study of layered silicate clays as synergistic nucleating agent for polypropylene". Journal of Polymer Science Part B: Polymer Physics. 48: 1786–1794. Bibcode:2010JPoSB..48.1786P. doi:10.1002/polb.22044.