Hydrophobic diamond films

Ostrovskaya, L. Yu.; Ralchenko, V.G.; Власов, И. И.; Khomich, А.А.; Bolshakov, A. P.

doi:10.1134/s2070205113030118

Cited by 15 publications

(15 citation statements)

References 33 publications

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“…Compared with the WCA results of diamond films mentioned in Section 1, the WCA value of diamond powders grown with 2% Ar shows larger values than either single-crystal diamond (93 ) or nanocrystal diamond films (124 ). [7,11] The hydrophobic properties of the as-grown diamond powders are partly due to their aggregation and mixed micro-/nanoscale structure, [27] as well as to their hydrogen termination.…”

Section: Resultsmentioning

confidence: 99%

“…The standard test for wettability is to measure the contact angle made by a water droplet placed onto the surface. [ 10,11 ] A water contact angle (WCA) of <90° means the droplet spreads on the surface, so the surface is hydrophilic. Complete wetting is when the WCA = 0°, and the droplet forms a flat liquid layer on the surface.…”

Section: Introductionmentioning

confidence: 99%

“…The WCA of single crystalline diamond is ≈93° [ 11,12 ] ; i.e., it is reasonably hydrophilic; however, this value depends greatly upon the surface termination and its morphology. [ 13,14 ] Different chemical species terminating a diamond surface may either attract or repel water molecules, influencing both the surface hydrophilicity and adhesion properties.…”

Section: Introductionmentioning

confidence: 99%

“…For example, Ostrovskaya et al grew ultrananocrystalline diamond (UNCD) films on silicon substrates in a microwave plasma CVD system. [ 7,11 ] The UNCD films exhibited a higher WCA of 124° compared with that of a smooth single‐crystalline diamond. This was ascribed to the high nanoporosity and passivated surface of the UNCD film.…”

Section: Introductionmentioning

confidence: 99%

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Hydrophobicity and Adhesion of Aggregated Diamond Particles

Yao

Dai

May

et al. 2020

Physica Status Solidi (a)

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Diamond powders with high hydrophobicity are prepared by etching graphite plates using a hydrogen/argon (H2/Ar) plasma. The morphology and size of the diamond powders are found to vary with the proportion of Ar in H2 from 0% to 50%. Wettability is measured using water contact angle (WCA) measurements giving values between 129.7° and 146.9°. The high hydrophobicity can be ascribed to the aggregated structure of the as‐grown diamond powders. To check this assumption, the aggregated diamond powders are separated into individual particles by mechanical grinding; then, the WCAs of separated as‐grown diamond powders and commercial dispersed diamond powders are compared. The separated diamond surfaces show the lower WCAs of 99.68° and 96.96°. The surface of the aggregated diamond powders also exhibits high adhesion to water. The diamond surface grown in 2% Ar suspends 40 μL of water under a tilt angle of 180°. Such aggregated diamond powders are promising for no‐loss liquid transportation.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Hydrophobicity and Adhesion of Aggregated Diamond Particles

Yao

Dai

May

et al. 2020

Physica Status Solidi (a)

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“…Normally this can be observed only when the surfaces are a few nanometers apart. Considering the mild hydrophobicity of B-UNCD [34] and the particular conditions of an unprotected environment, it is possible that a meniscus is formed between the approaching asperities, dragging the surfaces towards each other. In the adhesion measurements shown in Fig.…”

Section: Experiments Of Adhesion Between B-uncd Sidewalls In Uncontromentioning

confidence: 99%

Studies on measuring surface adhesion between sidewalls in boron doped ultrananocrystalline diamond based microelectromechanical devices

Buja

Kokorian

Sumant

et al. 2015

Diamond and Related Materials

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a b s t r a c tIn this study, we have investigated the adhesion phenomena between two sidewalls in boron-doped ultrananocrystalline diamond (B-UNCD) micro-electro mechanical systems (MEMS) in a humid and dry environment. We have developed and built B-UNCD MEMS test devices, in order to assess the tribological properties of diamond micro devices in-situ. Using these devices, we have been able to measure the adhesion force with approximately 15 nN resolution, by monitoring the displacement optically with a precision of 4 nm. In the case of testing in a dry atmosphere, virtually no adhesion (b 18 nN) was observed between the sidewalls. After testing in humid air over 55,000 cycles, increased adhesion force up to 128 nN was measured. A rare observation of capillary neck formation between sidewalls at high contact force, in humid air is observed which is most probably caused by the precipitation of carbon contamination. This contamination layer can be easily removed by oxygen plasma exposure but thereafter highest adhesion force of 260 nN adhesive force was measured. Our studies demonstrate that micromechanical devices fabricated based on diamond represent a great alternative over polysilicon based devices in terms of reduced adhesion and thus long term reliability, which is a significant step forward in developing diamond based MEMS.

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