Current issues and challenges in surface chemistry of nanodiamonds

Krueger, Anke

doi:10.1016/b978-0-32-343029-6.00008-8

Cited by 23 publications

(23 citation statements)

References 194 publications

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“…The structure of a DND particle is usually represented in the core-shell model [ 8 ] as a diamond core ( sp 3 hybridization) in the form of a polyhedron [ 37 ] surrounded by a non-crystalline C shell (with sp 3 - sp 2 hybridization of C atoms). The shell contains C–H x , C–C–H, C–OH, C–O, C=C [ 26 ]. The shell thickness is 0.4–1.0 nm [ 38 , 39 , 40 ].…”

Section: Methodsmentioning

confidence: 99%

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Fluorination of Diamond Nanoparticles in Slow Neutron Reflectors Does Not Destroy Their Crystalline Cores and Clustering While Decreasing Neutron Losses

et al. 2020

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If the wavelength of radiation and the size of inhomogeneities in the medium are approximately equal, the radiation might be intensively scattered in the medium and reflected from its surface. Such efficient nanomaterial reflectors are of great scientific and technological interest. In previous works, we demonstrated a significant improvement in the efficiency of reflection of slow neutrons from a powder of diamond nanoparticles by replacing hydrogen located on the surface of nanoparticles with fluorine and removing the residual sp2 amorphous shells of nanoparticles via the fluorination process. In this paper, we study the mechanism of this improvement using a set of complementary experimental techniques. To analyze the data on a small-angle scattering of neutrons and X-rays in powders of diamond nanoparticles, we have developed a model of discrete-size diamond nanospheres. Our results show that fluorination does not destroy either the crystalline cores of nanoparticles or their clustering in the scale range of 0.6–200 nm. This observation implies that it does not significantly affect the neutron scattering properties of the powder. We conclude that the overall increase in reflectivity from the fluorinated nanodiamond powder is primarily due to the large reduction of neutron losses in the powder caused by the removal of hydrogen contaminations.

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Section: Methodsmentioning

confidence: 99%

“…= 108 ± 2 b at room temperature) that consists of inelastic and elastic contributions depending on the temperature [ 24 ]. In DNDs, H atoms are involved in C-OH, C-H, CH 2 , and COOH groups [ 25 , 26 ].…”

Section: Introductionmentioning

confidence: 99%

Fluorination of Diamond Nanoparticles in Slow Neutron Reflectors Does Not Destroy Their Crystalline Cores and Clustering While Decreasing Neutron Losses

et al. 2020

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“…If a vinyl-containing silane is used, it is reported that the dispersion is improved both in nonpolar and polar organic media [22]. However, an increase in the agglomerate size can be observed after silanization due to the condensation reaction between treated particles [23] or a self-condensation of the silane [24]. Owing to the self-condensation reaction, a siloxane shell is formed around the ND particle, which can further bond particles into very large aggregates.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, a probability of the reaction between carboxylated nanodiamond and hydrolyzed silane needs to be evaluated. Another direct functionalization of carboxylated NDs through the reaction with the epoxy group can be applied [24,32] based on the esterification reaction discussed in the literature [33,34]. However, such modification has been performed on NDs at 140 °C, which is still relatively high temperature.…”

Section: Introductionmentioning

confidence: 99%

Influence of Surface Modified Nanodiamonds on Dielectric and Mechanical Properties of Silicone Composites

et al. 2019

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Detonation nanodiamonds, also known as ultradispersed diamonds, possess versatile chemically active surfaces, which can be adjusted to improve their interaction with elastomers. Such improvements can result in decreased dielectric and viscous losses of the composites without compromising other in-rubber properties, thus making the composites suitable for new demanding applications, such as energy harvesting. However, in most cases, surface modification of nanodiamonds requires the use of strong chemicals and high temperatures. The present study offers a less time-consuming functionalization method at 40 °C via reaction between the epoxy-rings of the modifier and carboxylic groups at the nanodiamond surface. This allows decorating the nanodiamond surface with chemical groups that are able to participate in the crosslinking reaction, thus creating strong interaction between filler and elastomer. Addition of 0.1 phr (parts per hundred rubber) of modified nanodiamonds into the silicone matrix results in about fivefold decreased electric losses at 1 Hz due to a reduced conductivity. Moreover, the mechanical hysteresis loss is reduced more than 50% and dynamic loss tangent at ambient temperature is lowered. Therefore, such materials are recommended for the dielectric energy harvesting application, and they are expected to increase its efficiency.

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“…1,3 Recently, it has been shown that annealing UDD in vacuum/gas phase yields catalytic activity. 7−9 Various studies suggested that the surface elemental bonding–rebonding and desorption processes during annealing which lead to the structural transformation or reconstruction of the surface non-diamond carbon structures are the key factors of the surface reactivity of UDD. 7,8,10 Thus, the analysis of surface signatures during vacuum annealing/post-treatment of UDD is crucial to uncover their reactive profile.…”

Section: Introductionmentioning

confidence: 99%

Facile Amine Termination of Nanodiamond Particles and Their Surface Reaction Dynamics

et al. 2019

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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.

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Current issues and challenges in surface chemistry of nanodiamonds

Cited by 23 publications

References 194 publications

Fluorination of Diamond Nanoparticles in Slow Neutron Reflectors Does Not Destroy Their Crystalline Cores and Clustering While Decreasing Neutron Losses

Fluorination of Diamond Nanoparticles in Slow Neutron Reflectors Does Not Destroy Their Crystalline Cores and Clustering While Decreasing Neutron Losses

Influence of Surface Modified Nanodiamonds on Dielectric and Mechanical Properties of Silicone Composites

Facile Amine Termination of Nanodiamond Particles and Their Surface Reaction Dynamics

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