Synthesis and Dispersions of Nanoparticles

Nanotechnologies itself are already today of enormous scientific, technical, and thus also of economical interest. By far the most important field today is the development of novel materials based on nanoscaled precursors, such as zero-dimensional nanoparticles, one-dimensional nanorods, and nanotubes, or two-dimensional nanoplatelets, such as graphene, just to name a few [10]. 

Again there are some interesting combinations of properties that also can be tuned to specific purposes making I Ls ideal candidates for the synthesis of inorganic nanoscaled materials. The most important properties for the control of size and 

The fact that some ILs may also form supramolecular structures opens the door to the synthesis of one-dimensional structures such as nanorods. But in addition other properties of ILs may be useful The often high thermal stability, which can reach for some ILs the value of250 °C, enables the synthesis at higher temperatures than in common solvents, without the need of an autoclave, because they have no significant vapor pressure. In addition, the use of hydrophobic ILs enables the use of precursors that are sensitive to moisture. Finally, once the nanoparticles are synthesized in the ILs, they can be removed easily, as long as weakly or better non-coordinating anions are used [12]. 

The overall handling of nanoparticles in terms of safety becomes also more and more an important issue. Thus, the preparation of safe and easy to handle dispersions is of great technical importance. Those particles being synthesized in I Ls may be used direcdy, being inherently safe [13]. On the other hand, nanoparticles that are manufactured by other chemical bottom-up-techniques or via top-down techniques can be dispersed by using specific ILs, also because of their generally versatile surface active properties [14]. 

A general understanding how ILs have to be designed to fit best at different particle surfaces is still at a very early stage. Recently published simulations from Padua et al. demonstrated, in which way side chains of cation interacted with metal surfaces [15], As a consequence, more measurements, but also simulations concerning the interaction between the ILs and the particle surfaces has to be made, to quantify them more accurate, resulting in a model and finally in an overall quantitative theory, similar to the Hehnholtz-double-layer and its extensions. 

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