A Piston-Rotaxane with Two Potential Stripes: Force Transitions and Yield Stresses

Molecules

Edith M. Sevick¹ 

[1] ¹Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia ²Department of Applied Mathematics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200, Australia

关键词: rotaxane;    piston-rotaxane;    one-dimensional gas;    stripes;    stations;   

DOI  :  10.3390/molecules181113398

来源: mdpi

【 摘 要 】

We examine a rod piston-rotaxane system, where the positions of several mobile rings on the axle are controlled by an external force acting on one of the rings. This allows us to access the translational entropy of the rings. For a simple rotaxane molecule with an axle that has uniform ring-axle interactions along its length, the molecule behaves like a miniature piston filled with a one-dimensional ideal gas. We then examine the effect of two stripes on the axle, having different ring-axle interactions with the mobile rings, so that one section is of high energy (repulsive) for the rings and another section is of lower energy (or attractive). This kind of rotaxane can exhibit rapid changes in displacement or force, and in particular, this molecule can exhibit a yield stress in which the piston suddenly compresses under a small increase in the applied force.

【 授权许可】

CC BY   
This is an open access article distributed under the Creative Commons Attribution License (CC BY) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.