Chemistry of Single‐Nano Diamond Particles

Ōsawa, Eiji

doi:10.1002/9780470660188.ch17

Cited by 6 publications

(4 citation statements)

References 31 publications

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“…3a), the higher ND concentration also exhibits a 50% lower CoF relative to no nanoparticle additives, with several possible mechanisms contributing to the friction reduction. First, nanodiamonds are known to reduce friction, including against a hydrogel surface [67], most commonly through a rolling, or ball-bearing, mechanism [68][69][70]. It should be noted that particle entrapment in the hydrogel mesh is unlikely.…”

Section: Effect Of Nanoparticle Composition and Concentration On In S...mentioning

confidence: 99%

Influence of Nanoparticle Chemical Composition on <i>In Situ</i> Hydrogel Friction

Bovia,

Gleeson,

Buckley

et al. 2023

Tribology Online

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Nanoparticles are promising candidates as direct therapeutics and delivery systems for osteoarthritis treatments, primarily via intraarticular injection, but little is known about the impact on sliding behavior for a soft material surface like cartilage that would be encountered in a joint. Nanoparticle additives have primarily been studied in the context of hard material interfaces, such as metals or metal oxides, where different lubricating or anti-wear mechanisms depend sensitively on chemical composition, size, and concentration.To understand what nanoparticle parameters influence in situ (in a fluid environment) frictional behavior of soft materials, polyacrylamide (PAM) hydrogels were used as a model soft material platform. Friction tests were conducted in a rheometer with a tribology adapter, with PAM hydrogels molded in a petri dish and immersed in different nanoparticle containing fluid environments. A range of nanoparticle compositions were selected to compare broad categories: gold (metal) with a citrate capping ligand, nanodiamond (carbon), and zirconium dioxide (metal oxide). Comparing surface chemistry, concentration, and degree of aggregation, both nanoparticle surface chemistry and nanoparticle solution viscosity were found to modulate in situ hydrogel friction.

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Section: Effect Of Nanoparticle Composition and Concentration On In S...mentioning

confidence: 99%

Influence of Nanoparticle Chemical Composition on <i>In Situ</i> Hydrogel Friction

Bovia,

Gleeson,

Buckley

et al. 2023

Tribology Online

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show abstract

“…The TG plot clearly shows the substantial weight loss of the nonthermally treated nanodiamonds below 750 K that is higher than the weight loss observed for nanodiamonds heated at 423 K. This weight loss is associated with the removal of the water contained in nonthermally treated nanodiamonds. The nanodiamond hydrogel contains water that can be removed by heating at 473 K for 10 h [11]. Weakly adsorbed water desorbs from nanodiamonds below 373 K, while strongly adsorbed water desorbs between 373 and 573 K [20].…”

Section: Chemical and Structural Changes Of Nanodiamond Aggregates Upon Heatingmentioning

confidence: 99%

“…However, the samples heated for a long time, such as 52 h, must have narrow micropores among the nanodiamond aggregates that are produced by long-term heating through the evolution of surface oxygen-containing functional groups. Such surface functionalities should be produced under intensive sonication and mechanical milling treatment in aqueous dispersions of nanodiamond particles during the stage of synthesis [11,[28][29][30].…”

Section: Effect Of Heating Time On the Pore Structure Of Nanodiamond Aggregatesmentioning

confidence: 99%

“…Ji et al reported the strong adsorption of water molecules even at a relative humidity (RH) lower than 35% [6]. Water contained in nanodiamonds can be removed by long-term thermal treatments in vacuo, such as 423 K for 15 h under high vacuo [10] or at 473 K under 15 hPa (10 3 Pa) for 10 h for the determination of water contents in nanodiamond gels (stable gels of extremely small diamond crystals 2 nm in diameter) [11]. The removal of tightly bound water produces a large number of pores that are available for the further adsorption of water or target molecules.…”

Section: Introductionmentioning

confidence: 99%

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Pore-Mouth Structure of Highly Agglomerated Detonation Nanodiamonds

et al. 2021

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Detonation nanodiamond aggregates contain water that is removed by thermal treatments in vacuo, leaving available pores for the adsorption of target molecules. A hard hydrogel of detonation nanodiamonds was thermally treated at 423 K for 2 h, 10 h, and 52 h in vacuo to determine the intensive water adsorption sites and clarify the hygroscopic nature of nanodiamonds. Nanodiamond aggregates heated for long periods in vacuo agglomerate due to the removal of structural water molecules through the shrinkage and/or collapse of the pores. The agglomerated nanodiamond structure that results from long heating periods decreases the nitrogen adsorption but increases the water adsorption by 40%. Nanodiamonds heated for long times possess ultramicropores <0.4 nm in diameter in which only water molecules can be adsorbed, and the characteristic mouth-shaped mesopores adsorb 60% more water than nitrogen. The pore mouth controls the adsorption in the mesopores. Long-term dehydration partially distorts the pore mouth, decreasing the nitrogen adsorption. Furthermore, the nitrogen adsorbed at the pore mouth suppresses additional nitrogen adsorption. Consequently, the mesopores are not fully accessible to nitrogen molecules because the pore entrances are blocked by polar groups. Thus, mildly oxidized detonation nanodiamond particles can show a unique molecular sieving behavior.

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Identification of non‐agglomerated nanodiamonds inside metal matrix composites by synchrotron radiation

Попов

Többens

Prosviryakov

2014

Physica Status Solidi (a)

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Identification of non-agglomerated nanodiamonds in an aluminum matrix at a content of 3-10 vol% was performed on compacted specimens using KMC-2 beamline at the BESSY II synchrotron. Composites were produced by a mechanical alloying process that allowed a uniform distribution of individual non-agglomerated primary nanodiamond particles in the metal matrix, as verified by scanning electron microscopy investigation of the composite granule's surface. The study demonstrated for the first time that the application of synchrotron radiation could effectively identify nanodiamond particles in the matrix at a volume fraction as low as 3%. The obtained results are in complete agreement with the theoretical predictions.

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Chemistry of Single‐Nano Diamond Particles

Cited by 6 publications

References 31 publications

Influence of Nanoparticle Chemical Composition on <i>In Situ</i> Hydrogel Friction

Influence of Nanoparticle Chemical Composition on <i>In Situ</i> Hydrogel Friction

Pore-Mouth Structure of Highly Agglomerated Detonation Nanodiamonds

Identification of non‐agglomerated nanodiamonds inside metal matrix composites by synchrotron radiation

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