Oxygen and hydrogen atoms on the diamond's surface

AI Thread Summary
Hydrogen and oxygen atoms on diamond surfaces contribute to a low coefficient of friction by passivating dangling bonds, as evidenced by spectroscopic studies. This passivation occurs through a balance of bond-breaking during sliding and the adsorption of gaseous species like water vapor. The effectiveness of this mechanism is influenced by factors such as contact stress, sliding rate, temperature, relative humidity, and reciprocation frequency. The findings support the hypothesis that surface chemistry plays a critical role in friction properties. Overall, the presence of these atoms significantly enhances the performance of ultrananocrystalline diamond in reducing friction and wear.
PatrickP2
Messages
16
Reaction score
2
Is it true that hydrogen and oxygen atoms on the surface of diamond make it have such a low coefficient of friction?
 
Engineering news on Phys.org
From the paper "Origin of ultralow friction and wear in ultrananocrystalline diamond" by AR Konicek, DS Grierson, P Gilbert, WG Sawyer, AV Sumant, RW Carpick (Physical review letters, 100, 235502 (2008)):

“The mechanism of low friction supported by this spectroscopy is passivation of dangling bonds [1,3,4,35]. This is the first definitive spectroscopic evidence supporting the passivation hypothesis. This mechanism hinges on a balance between the processes of bond breaking during each sliding pass (which depends on contact stress, sliding rate, and temperature) and passivation by dissociative adsorption of gaseous species, in particular, water vapor (which depends on RH and reciprocation frequency [36,37]).”
 
Thread 'What type of toilet do I have?'

Thread 'What type of toilet do I have?'

I was enrolled in an online plumbing course at Stratford University. My plumbing textbook lists four types of residential toilets: 1# upflush toilets 2# pressure assisted toilets 3# gravity-fed, rim jet toilets and 4# gravity-fed, siphon-jet toilets. I know my toilet is not an upflush toilet because my toilet is not below the sewage line, and my toilet does not have a grinder and a pump next to it to propel waste upwards. I am about 99% sure that my toilet is not a pressure assisted...
View full post »

Thread 'Thread No-Go plug gage allows 3 turns to enter. That's too many!'

After over 25 years of engineering, designing and analyzing bolted joints, I just learned this little fact. According to ASME B1.2, Gages and Gaging for Unified Inch Screw Threads: "The no-go gage should not pass over more than three complete turns when inserted into the internal thread of the product. " 3 turns seems like way to much. I have some really critical nuts that are of standard geometry (5/8"-11 UNC 3B) and have about 4.5 threads when you account for the chamfers on either...
View full post »
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'

Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'

Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...
View full post »

Similar threads

Loss of atoms from the surface of the material: How does it work?
Replies
15
Views
1K
What are the implications of tetrahedral stacking in diamond cubic arrangements?
Replies
1
Views
1K
I Collision of anti-hydrogen with matter
Replies
13
Views
2K
A Transition frequency -> Rydberg oxygen atoms
Replies
10
Views
3K
B Why don't solids always stick together?
Replies
5
Views
4K
How is this diagram of the structure of diamond correct?
Replies
14
Views
4K
Atomic density of Oxygen in a composite
Replies
6
Views
2K
A Metallic Hydrogen as a knife blade
Replies
10
Views
3K
Can a diamond's color be simulated by only a surface coloring?
Replies
1
Views
1K
I What is the Average Angle of Infrared Emission from a Flat Diamond Surface?
Replies
1
Views
983

Hot Threads

Recent Insights

Back
Top