Nanodiamond: Synthesis, Properties, and Applications

   Nanomaterials hold tremendous potential enabling new unexpected applications and pushing the horizons of attainable properties and environments amenable to exploration to the extreme limits. Graphene (2D), carbon nanotubes (1D), and fullerene (0D) are commonly known, but the nanomaterials world has many more treasures to offer. The talk will give an overview and discuss our recent progress in nanodiamond (0D sp3 carbon).
   Nanodiamond powder made of ~5nm diamond particles with large accessible surface and tailorable surface chemistry delivers extreme optical, mechanical, electronic, and thermal properties of diamond on the nanoscale. It is being developed for many applications ranging from lubrication to advanced composites, to drug delivery and biomedical imaging. The superior mechanical and thermal properties of diamond core, its stability in harsh environments on one hand, as well as rich and tailorable surface chemistry on the other, make nanodiamond the material of choice for design of super-strong composites, where the nanodiamond particles in effect become part of the molecular structure of the matrix. In biomedical applications nanodiamond offers small size with large accessible surface and tailorable surface chemistry, unique optical properties in combination with biocompatibility. To fully exploit the potential of nanodiamond in drug delivery, biomedical imaging, and nanocomposites, attention must be paid to its purity, surface chemistry, and dispersion quality. Surface modification of nanodiamond for composite and biomedical applications will be discussed. Reactions of nanodiamond functional groups with polymers bring the nanocomposite design to a conceptually new level, allowing for creation of covalent nanofiller-matrix interface with designed properties. For tissue engineering scaffolds, the non-toxic fluorescent nanodiamond introduced into biodegradable polymers provides increased strength, visual monitoring, enhanced biomineralization, and release of growth factors and antibiotics attached to its surface. The mechanisms of drug adsorption on nanodiamond surface will be discussed. In drug delivery, rational surface modification allows for enhanced adsorption and chemical binding of the drugs for sustained or triggered release. The role of nanodiamond surface chemistry in the delivery of drugs via their adsorption/de-sorption will be analyzed.