Borromean Interprenetration

Borromean interpenetration occurs when networks interpenetrate such that any two nets are not themselves interpenetrating (i.e. they can be separated topologically), and the entanglement only becomes inseparable upon addition of a third (and possibly further) nets. This is analogous to the entanglement shown by Borromean rings, where if any ring was omitted, the other two rings would be separable without bonds breaking. Term coined by Carlucci, Ciani and Proserpio in CrystEngComm 2003, 5, 269-279.

Borromean rings

Borromean interpenetration in 2D → 3D parallel interpenetration of (6,3) sheets

Borromean interpenetration in 2D → 3D parallel interpenetration of (6,3) sheets