Silver nanocrystals capped with

Short alkanes such as decane and dodecane are completely miscible in sc-CO2 at moderate pressures and temperatures. Based on the earlier simulations, it would seem that nanocrystals capped with dodecanethiol should disperse in sc-CO2 at moderate conditions however, this is not the case. Gold and silver nanocrystals capped with dodecanethiol ligands were exposed to SC-CO2 at pressures as high as 483 bar and temperatures up to 80 C without any visible dispersibility. This indicates that ligands with better CO2 compatibility need to be developed to allow for effective dispersibility. The dodecanethiol capped nanocrystals were dispersible in sc-ethane, as the solvent-ligand interactions were much more compatible. 

Figure 5. Representative TEM images of silver nanocrystals capped with perfluorodecanethiol synthesized in sc-CO2. (Reproduced from reference 19. Copyright 2002 American Chemical Society.)...

A good example of particles stabilized by a monolayer of organic capping ligands is that of silver nanocrystals capped with dodecanethiol. 

Tao et al. [214] reported the synthesis of monodispersed silver NPs capped by PVP with regular polyhedral shapes with solely (100) and (111) facets on the fee crystal lattice. Initially, small silver particles (<10 nm) nucleate and develop into nanocubes bound by (100) planes. As the reaction continues, silver deposits selectively onto the (100) nanocrystal facets and various polyhedral shapes capped with (100) and (111) faces can be obtained, depending on the reaction duration (Figure 15.4). It was suggested that the driving force for the selective (100) planes growth is not the adsorption of the capping polymer (PVP) to the (111) planes, but rather the inherent increased stability of the (100) planes [215]. 

---