Facile Amine Termination of Nanodiamond Particles and Their Surface Reaction Dynamics

Abstract

Nanodiamond synthesized by the detonation method is a composite of sp3/sp2 carbon structures; amorphous and disordered-sp2 carbons populate the surface of a sp3 diamond core lattice. Because of the production process, various elemental impurities such as N, O, H, and so forth are inherent in interstitial sites or the surface carbon (sp2/amorphous) network. Herein, the reaction dynamics on the surface of ultradisperse diamond (UDD) due to the surface transformation or reconstruction during annealing in vacuum with temperatures ranging from ambient to 800 °C is described. In situ measurement of Fourier transform infrared spectroscopic analysis shows that low-temperature (<500 °C) annealing of UDD in vacuum results in isonitrile/isocyanide (−N=C:) and nitrile functionalization (−C≡N) on the surface. At temperatures ∼500 °C, the surface hydrogenation of UDD is initiated. During annealing at 780–800 °C, the nitrile group (−C≡N) is reduced to the primary amine (NH2), and isonitrile (−N=C:) turns it to be in the saturated () structure. On exposure to air, the obtained isonitrile is transformed to an N-formyl derivative (Aryl/R–NH–CHO) structure via hydrolysis. This study provides a fundamental insight into the surface reactive profile of UDD which could lead to facile surface functionalization properties and their applications in various fields such as biomedical, biosensing, drug delivery, epoxy materials process, tribology, and possibly in cyano (−C≡N/–N=C:) chemistry.

Valorization of Diamond Polishing Industry Waste: A Cost-Effective Reservoir for Nanodiamonds and Synthesis of Advanced Epoxy-Diamond Composites

“…Further, presence of other absorption bands, 3324 (N-H), 1718 (-C=O), 1665 (-C=O) and 1127 (-OH) cm -1 in the spectrum show the complexity of diamond surface. [22,23] We treated the raw dust with an oxidising mixture of conc. H 2 SO 4 and conc.…”

“…A careful comparison of the FTIR spectra of both the materials indicates the integration of the additives D-NH2 (1400, 1116 and 602 cm -1 ) in epoxy (Figure 4). [22,23] Further, XRD analysis of E and ED was also performed. It indicates two phases of epoxy, amorphous (broader peak at 2θ = 17.9°) and crystalline phase (2θ = 42°).…”

“…[18] Generally, the surfaces of nanodiamonds are decorated with several organic functional groups, C-H, C-N, C = O, C-O and many more, however, the surface chemistry largely depends on the chemical process applied during puri cation. [22,23] This surface functionality is used to graft the amide chain to achieve uniform dispersion, to maximise covalent integration and to minimise the interfacial failures in polymers. [19,21,24] Epoxy resins are a very important thermosetting coating materials with excellent mechanical and chemical resistance.…”

Designing functionalized nanodiamonds with hyaluronic acid–phospholipid conjugates for enhanced cancer cell targeting and fluorescence imaging capabilities

“…1 As a result, a wide variety of methods for their production has been developed, encompassing both top-down approaches, like detonation of carbon-containing explosives 1,2 and grinding of High-Pressure High-Temperature (HPHT) microdiamond powders, 3 and bottom-up techniques, such as Chemical Vapor Deposition (CVD) 4 and synthesis from adamantane derivatives. 5 Similarly, an extensive array of post-synthetic procedures, including treatments with microwave plasma, 6,7 high-temperature thermal processes in controlled environments [8][9][10] and wet chemistrybased strategies, [11][12][13] have been established. This combined spectrum of synthesis methods and subsequent modifications enables the creation of NDs with diverse sizes, covering the 5-300 nm range, morphologies, and surface characteristics.…”