event thumbnail image
SLONANO2007

Some topics in theoretical nanofriction

author: Erio Tosatti, ICTP - International Centre for Theoretical Physics

Description

As is natural for all properties determined by surfaces and interfaces rather than by bulk, adhesion and friction increase in importance when the objects that come into contact  and move relative to one another are nanosized. In this talk I propose to review some theory and simulation work recently done in our group on topics and models that are inspired by nanofriction. Among them are: * Some strange phenomena determined by the sliding of periodic but incommensurate systems. * The effect of high temperatures and surface melting on the friction felt by an AFM tip. * The negative differential friction predicted for high-speed sliding coaxial nanotubes. * The diffusive-ballistic crossover predicted for the frictional slip time of gold nanoclusters on graphite.

You might be experiencing some problems with Your Video player.
Slides
0:00 (NANO)FRICTION SOME THEORETICAL SURPRISES
1:05 Rferences
1:29 1. MOVING MOIRE' PATTERNSAROUND
3:03 Lubricated Friction
3:42 Harmonic Chain Among Two Periodic Sliding Substrates[4]
4:26 The system dynamicsis described by
4:51 Length ratios: commensurability
5:08 Lubricant sliding velocity: surprise!
7:07 Solitions: kinks and anti-kinks
9:29 Consequences of kinks
9:31 Animations: kinks
10:14 Animations: anti-kinks
10:27 Animations: the Golden Mean
10:34 MOIRE' PATTERNS: THEY ARE THE REAL OBJECTS THAT CAN BE DRAGGED!
11:19 2. NANOFRICTION CLOSE TO THE MELTING TEMPERATURE
11:28 Animations: the Golden Mean
12:17 2. NANOFRICTION CLOSE TO THE MELTING TEMPERATURE
13:06 FRICTION DROPS AT HIGH TEMPERATURE...
13:37 ....LIKE IN ICE SKATING.
14:04 ...BUT FRICTION MAY ALSO DECREASE AT HIGH TEMPERATURE!
14:49 A POLYCRYSTALLINE SURFACE
14:56 NANOFRICTION: A (RARE) WELL DEFINED FRICTION EXPERIMENT
15:08 ON A NORMAL SURFACE YOU'D LOSE YOUR TIP
16:01 TRY A NONMELTINGSURFACE:
16:18 THEORY + SIMULATION
16:46 HIGH TEMPERATURE FRICTION SIMULATIONS
17:02 HIGH T PLOWING SIMULATIONS
17:04 HIGH TEMPERATURE FRICTION SIMULATIONS
17:12 HIGH T PLOWING SIMULATIONS
17:31 PLOWING FRICTION
18:06 PLOWING FRICTION: FORCES
18:40 FRICTIONAL DROP!
19:15 ....JUST LIKE IN ICE SKATING!
19:20 TIP CARRIES LIQUID CLOUD, AS IN SKATING
19:40 PLOWING FRICTION
20:08 WEARLESS, GRAZING FRICTION (1)
20:16 FRICTIONAL DROP!
20:56 WEARLESS, GRAZING FRICTION (1)
21:07 WEARLESS, GRAZING FRICTION (2)
21:52 WEARLESS, GRAZING FRICTION (3)
22:40 ANALOG: IMPURITY PINNING OF THE FLUX LATTICE
23:37 THE “PEAK EFFECT” IN SUPERCONDUCTORS (1)
24:40 THE “PEAK EFFECT” IN SUPERCONDUCTORS (2)
24:47 LINEAR RESPONSE THEORY (1)
25:51 LINEAR RESPONSE THEORY (2)
26:08 CONCLUSIONS (1)
26:28 CONCLUSIONS (2)

Lecture rating

People found this lecture:
Worth seeing
because it is:
 Valuable and informative
Well presented
Easily understandable
Acceptably recorded
You need to login to cast your vote.

Report a problem or upload files

If you have found a problem with this lecture or would like to send us extra material, articles, exercises, etc., please use our ticket system to describe your request and upload the data.
Enter your e-mail into the 'Cc' field, and we will keep you updated with your request's status.

Link this page

Would you like to put a link to this lecture on your homepage?
Go ahead! Copy the HTML snippet !

Write your own review or comment:

make sure you have javascript enabled or clear this field: