Intercrystolecular interactions
This page is about basic interaction modes between crystolecules.
This goes beyond mere nonbonded forces and van der Waals forces
as there are effects of redirection involved too. Indirect forces. Thus a dedicated page.
This page does not cover snaps between crystolecules.
For snaps see page: Intercrystolecular snapping modes
(TODO: Some questions need better answering with simulations and eventually experiments.)
Vand der Waals sticking
Attractive van der Waals force flat on flat force along the surface normal.
❓Q: What is the sticking energy per unit area?
❓Q: What is the maximal attractive force per unit area?
Energy minimum (zero force)
Statically stable "surface contact".
- Energy: Is minimal and can be quantified per unit area relative to energy at infinite distance.
- Force: Is zero, (otherwise it would not be the statically stable energy minimum)
- Stiffness: is a nonzero characteristic value per area.
Force maximum (zero stiffness)
Maximally attractive distance.
- Energy: Is a certain characteristic value per area.
- Force: Is maximally attractive per definition
- Stiffness: is zero as an infinitesimal change in distance does not change the force
Stiffness maximum
There is no limit to stiffness on the compressive side but
there is a maximal stiffness on the attractive side
This value might be of interest in some cases.
Interdigitation sticking
Energy minimum (zero force)
- Energy: Reference: Full energy barrier height between interdigitation and anti-interdigitating alignments
- Force: zero local shear force (as this is the statically stable minimum)
- Stiffness: shear stiffness (zero due to symmetry?)
❓Q: How big are the energy barriers between commensural snap in locations?
Especially compared to kT thermal energy.
In other terms a contact area dependent "corrugation equivalent temperature".
Force maximum (zero stiffness)
- Energy: Is a certain characteristic value per area.
- Force: maximal shear force
- Stiffness: zero shear stiffness
❓Q: How is the maximal shear force (and characteristic energy)
at the critical zero shear-stiffness point.
Stiffness maximum
???
Superlubric limits
❓Q: Same two questions for self suggesting superlubric cases like 1/sqrt(2) ratios and such.
Nonbonded forces for assembly
See main page: Assembly from atomically precise nanoscale and microscale parts
(wiki-TODO: add more details here)
Related
- Intercrystolecular interactions < you are here
- Intercrystolecular snapping modes
- Intercrystolecular levitation