Fluorescent Nanodiamonds

4Surface Chemistry of Nanodiamonds

We discuss surface modification chemistry of nanodiamonds (NDs) in this chapter. The chemistry of a substance is ultimately determined by its molecular structure and physical conditions surrounding it. A quick look over the three allotropes of nanocarbon material reveals some subtle differences between the sp² endcaps of fullerenes, the sp² sidewalls of carbon nanotubes (CNTs), the sp² sheets of graphenes, and their dangling carbon bonds along the edges (Figure 1.1–1.3). Both CNT and graphene have mixed chemical reactions as discussed in Section 1.2 and, depending where on a CNT or graphene, different chemical reactions may occur at different locations. Now with the ND’s sp³ saturated carbon bonds, it is the most stable bond configuration of carbon and therefore is expected to be chemically inert. Why would anyone care for the chemistry of such an inert material? Well, it is precisely because of the inertness (chemical stability) and other trademark properties (Table 2.1) that make ND an excellent nanomaterial for a diversified array of applications, ranging from laboratories to industries and from cosmetics to lubrications, including as a supporting medium for biomolecules. Similar to CNTs and graphenes, all chemical activities if/when occurs with NDs must happen on their surface. Fortunately, for a given amount, ND is equipped with a large surface area and a deep loading capacity perfectly for a nano‐sized carrier. But, the question is: ...