Mechanical nanodiamond

The ability to synthesize carbon nanostmctures, such as fullerenes, carbon nanotubes, nanodiamond, and mesoporous carbon functionalize their surface or assemble them into three-dimensional networks has opened new avenues for material design. Carbon nanostructures possess tunable optical, electrical, or mechanical properties, making them ideal candidates for numerous applications ranging from composite structures and chemical sensors to electronic devices and medical implants. 

A modification of functional groups already attached to the nanodiamond surface is of considerable interest for the development of new diamond materials for biomedical or mechanical applications. 

Owing to its properties, nanodiamond like the classical diamond is an attractive material for many applications. For the time being, however, just a limited number of industrial scale processes has really been established due to its inhomogeneity and the variable quality available from different suppHers. Pioneers in this area are the countries of the former Soviet Union where by now access has been made to various fields of applicahon. The examples given herein comprise processes developed to an industrial scale already as weU as such stUl operahve on a laboratory scale. They include the preparation of composites and coatings, mechanical apphcations to reduce friction or to modify surfaces, uses in electro-deposition or biomedical apphcahons. 

The preparation of composite materials in general is a very important appHca-tion of the mechanical properties of nanodiamond. With many polymers like caoutchouc, polysiloxanes, fluoroelastomers polymethacrylates, epoxy resins, etc., composites with markedly improved mechanical characteristics have already been obtained from the noncovalent incorporation of nanodiamond by simple admixing during polymerization. The modulus of elasticity, the tensile strength, and the maximal elongation of the material all increase upon this modification. Depending on the basic polymer, just 0.1-0.5% (w/w) of nanodiamond are required to achieve this effect (Table 5.3). Polymer films can also be reinforced by the addition of nanodiamond. For a teflon film with ca. 2% of nanodiamond added, for example, friction is reduced at least 20%, and scratches inflicted by mechanical means are only half as deep as in neat teflon. 

Furthermore, nanodiamond is suitable to applications in liquid chromatography. A directed modification of surface polarity and adsorptive properties is feasible here by functionalization of the particles. Apart from this versatility, the nanodiamond material also stands out for another advantage the large mechanical resistance and the small particle size allow a use in high-pressure applications, which is where the best separating power is achieved. 

In this paper we present the results of the quantum-chemical modeling of the structure, electronic and spin density distribution for a nanodiamond with [NV] -center, passivated by hydrogen atoms. The ab initio calculations of the isotropic and anisotropic HFSC for such the systems were performed for the first time. The information about these constants and spin density formation mechanisms is very important for practical applications in quantum computers based on [NV] -centers. 

Zhang Q, Mochalin VN, Neitzel 1, Hazeli K, Niu J, Kontsos A, et al. Mechanical properties and biomineralization of multifunctional nanodiamond-PLLA composites for bone tissue engineering. Biomaterials 2012 33 5067-75. 

Carbon-based polymer nano composites represent an interesting type of advanced materials with structural characteristics that allow them to be applied in a variety of fields. Functionalization of carbon nanomaterials provides homogeneous dispersion and strong interfacial interaction when they are incorporated into polymer matrices. These features confer superior properties to the polymer nanocomposites. This chapter focuses on nanodiamonds, carbon nanotubes and graphene due to their importance as reinforcement fillers in polymer nanocomposites. The most common methods of synthesis and functionalization of these carbon nanomaterials are explained and different techniques of nanocomposite preparation are briefly described. The performance achieved in polymers by the introduction of carbon nanofillers in the mechanical and tribological properties is highlighted, and the hardness and scratching behavior of the nanocomposites are also discussed. 

Keywords Nanodiamonds, carbon nanotubes, graphene, functionalization, polymer nanocomposites, mechanical properties, tribological properties... 

U. Maitra, K.E. Prasad, U. Ramamurty, and C.N.R. Rao Mechanical properties of nanodiamond-reinforced polymer-matrix composites. Solid State Communications, 149 (39-40), 1693-1697, 2009. 

A.-Y. Jee, and M. Lee, Thermal and mechanical properties of alkyl-functionalized nanodiamond composites. Current Applied Physics, 11 (5), 1183-1187, 2011. 

Y.-J. Zhai, Z.-C. Wang, W. Huang, J.-J. Huang, Y.-Y. Wang and Y.-Q. Zhao, Improved mechanical properties of epoxy reinforced by low content nanodiamond powder, Materials Science and Engineering A, 528 (24), 7295-7300, 2011. 

MR Ayatollahi, E Ahshahi, S Doagou-R, and S. Shadlou, Tribological and mechanical properties of low content nanodiamond/epoxy nanocomposites. Composites Part B Engineering, 43 (8), 3425-3430, 2012. 

Hoffman, A., Mechanism and properties of nanodiamond films deposited by the DC-GD-CVD process, in Synthesis, Properties and Applications of Ultrananocrystalline Diamond, Gruen, D., Shenderova, O., VuT A.Ya., eds., NATO Science Series II Mathematics, Physics and Chemistry. Springer, Dordrecht, 192, 125, 2005. 

The purpose of providing a brief overview on recent reviews of nanocomposite materials that discuss synthesis, structure properties, and applications is to bring to the reader s attention the nascence of this field and justify the rare availability of degradation studies of these materials when we have only recently embarked on our journey to understanding the fundamentals about them. Nevertheless, a few examples of degradation studies of nanocomposite materials are provided with the hope of advances towards mechanistic aspects of degradation with nanomaterials components. Chrisaffis et al [56, 57] report studies on the decomposition mechanisms of syndiotactic polystyrene (sPS) nanocomposites with two different types of nano fillers multi-walled carbon nanotubes (MWCNTs) and carbon nanodiamonds (NDs). sPS is a semicrystalline polymer considered to be a... 

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