Structure and stability of kaolinite/TiO2 nanocomposite: DFT and MM computations

Abstract

The adhesion of TiO(2) (anatase structure) nanoparticles to kaolinite substrate was investigated using molecular modeling. Universal force field computation, density function theory computation, and a combination of both two approaches were used. This study enabled the adhesion energy for the TiO(2)/kaolinite nanocomposite to be estimated, and revealed the preferred orientation of the TiO(2) nanoparticles on the kaolinite substrate. The results of all three levels of computation were compared in order to show that the accuracy of universal force field computations is sufficient in this context. The role of nanoparticle size and the importance of the nanoparticle-substrate bonding contribution are presented here and discussed. A comparison of the molecular modeling results with scanning electron microscopy observations showed that the results of the modeling were consistent with the experimental data, and that this approach can be used to help characterize nanocomposites of the nanoparticle/phyllosilicate substrate type.

α-Fe2O3 Nanoparticles/Vermiculite Clay Material: Structural, Optical and Photocatalytic Properties

“…This result does not necessarily mean a lower occurrence of α-Fe 2 O 3 nanoparticles at the vermiculite edges in the real sample, because nanoparticles on the edges tend to be smaller than on the surface, so the contact area between nanoparticle and edge increases. This problem was discussed in our earlier study focused on a similar nanocomposite system of metal oxide/phyllosilicate-type TiO 2 /kaolinite [43]. The optimized structures of all four models, the energies of which are listed in Table 2, are displayed in Figure 5.…”

Moving into advanced nanomaterials. Toxicity of rutile TiO2 nanoparticles immobilized in nanokaolin nanocomposites on HepG2 cell line

“…In the past years, TiO 2 NPs have been extensively studied to investigate their potential toxicological effects due to their increased environmental and occupational exposure (Tucci et al, 2013). In order to monitor and control the release of TiO 2 NPs, the technique of immobilization of these nanoparticles into crystalline substrates, such as inorganic clay minerals, was developed to facilitate their manipulation, restraining their release and diminishing their threat into the environment and human health (MODENA, 2012;Tokarsky et al, 2012;Tokarčíková et al, 2014).…”

Fate and Bioavailability of Engineered Nanoparticles in Soils: A Review

“…The scale bar corresponds to 250 nm (Buffle et al, 1998); (b) TiO 2 nanoparticle aggregated at the edges of a kaolinite clay crystal. A single TiO 2 nanoparticle can be seen in the upper left corner (Tokarsky et al, 2012); (c) TiO 2 ENM deposited on soil grains of an eutric cambisol (Nickel et al, 2013); and (d) CeO 2 nanoparticle heteroaggregate from a spiked loamy soil suspension (Cornelis et al, 2011). Values from Illes and Tombacz (2006), Kosmulski (2009), Stumm and Morgan (1996), Tombacz and Szekeres (2004), and Tombacz and Szekeres (2006).…”