Transforming clay minerals into solvent-free nanofluids via an interfacial interaction: An experimental and simulation study

The emergence of solvent-free nanofluids (SFNs) has solved the problem of aggregation of conventional nanoparticles, resulting in better compatibility and dispersion of nanoparticles, and has led to the rapid development of their applications in various fields. However, at present, clay mineral-based SFNs (Clay-F) are rarely reported, and the general preparation method of clay mineral-based SFNs has not been investigated. Therefore, we report a general strategy for the construction of Clay-F. Clay-F have good flow properties at room temperature, and have higher dispersion stability under the steric hindrance effect of the long chain of the corona-canopy species. We demonstrated the universality of this method by grafting a corona-canopy species onto various clay minerals (montmorillonite, kaolinite, and attapulgite). At the same time, based on the lack of current research on the synthesis mechanism of Clay-F by simulation, the interaction mechanism between montmorillonite and corona-canopy species was finally confirmed and verified at the molecular level by quantum chemistry and molecular dynamics simulation, and the formation mechanism of Clay-F was further determined. Finally, to verify the concept, the adsorption performance of Clay-F for CO₂ was investigated. This work expands the family of solvent-free nanofluids and provides new ideas for the application of clay minerals.