Detonation nanodiamonds dispersed in polydimethylsiloxane as a novel electrorheological fluid: Effect of nanodiamonds surface

• Published in: Carbon (New York) 2021-04, Vol.174, p.138-147
• Main Authors: Kuznetsov, Nikita M., Belousov, Sergey I., Kamyshinsky, Roman A., Vasiliev, Alexander L., Chvalun, Sergei N., Yudina, Elena B., Ya. Vul, Alexander
• Format: Article
• Language: English
• Subjects: Anisotropy; Colloids; Detonation; Detonation nanodiamonds; Diamonds; Effects; Electric fields; Electrophoresis; Electrorheological fluid; Electrorheological fluids; Functional groups; Low concentrations; Nanostructure; Polydimethylsiloxane; Rheological properties; Rheology; Sedimentation; Sedimentation & deposition; Sedimentation stability; Smart materials; Studies; Yield strength; Yield stress
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2020.12.014

Using deagglomerated nanodiamond particles of 4–5 nm suspended in polydimethylsiloxane (PDMS) we have fabricated fluids demonstrated pronounced electrorheological effect. It has been revealed that the type of functional groups on nanodiamond particle surface plays a crucial role in the behavior of the suspensions under electric field. Suspension of hydrogenated nanodiamonds has demonstrated the most powerful electrorheogical effect. The high values of yield stress of the order of 80–90 Pa have been detected at extremely low concentrations of nanodiamond particles (3–4 wt%). The suspensions has outstanding sedimentation stability: the sedimentation ratio is more than 90% after 30 days. A power law dependence of the yield stress on the electric field, τ ∼ E1.0-1.5 indicates mainly the conduction mechanism of the effect. Suspensions of carboxylated nanodiamonds in PDMS reveal qualitatively different behavior and the electrophoresis occurs. The paper discusses the reasons of different rheological behavior depending on nanodiamond surface functionalization. The prospects of nanodiamonds application as filler for electrorheological fluids have been shown. [Display omitted] •Fluids of 4–5 nm nanodiamond particles suspended in polydimethylsiloxane demonstrate pronounced electrorheological effect.•The functionalization of detonation nanodiamonds plays a crucial role in the behavior of suspensions under electric field.•The nanoscale of diamond particles result in high sedimentation stability of suspensions.•Detonation nanodiamonds in polydimethylsiloxane form percolation network at very low concentrations.•Electrorheological fluids filled by detonation nanodiamonds well effective for operation in on/off mode.