weak confinement where $R=49>\langle R_{\rm g}\rangle$, Fig. \[fig:N\_dens\](a), positioning of the segments near the boundary is not favorable as it increases the non-bonded interaction which is accompanied by higher entropic loss of peripheral conformation for longer segments; longer segments lose more translational and orientational entropies close to the boundary than other chains. Therefore we can see in figures \[fig:N\_dens\](a,b) that longer segments avoid the periphery, instead, the flexible chain with less entropic penalty cost moves towards the boundary.

In contrast, the more strongly confined state in Fig. \[fig:N\_dens\](c) drives the system to the point that the entropic competition forces the longer segments to start relocating to the periphery where they have less bending energy cost. Further confinement, Fig. \[fig:N\_dens\](d), shows segregation of longer segment chain; all the longer segments congregate at the periphery where they adopt the nematic orientation. It is disentangled from the rest of the chains and forms a clump of segments where they can move together with less bending energy cost and relatively lower [*translational*]{} entropy loss. This characteristic entropy-driven segregation and differentiation is something that we could call [*entropic chromatography*]{} [@ent_chro]. A short video of the simulation trajectory is also included as Supplementary Video.

Experiments on 