A fully extended PBd22-PEO14 polymer is estimated to have a maximum bilayer thickness of approximately 209 Å, and a hydrophobic core of 111 Å. Although polymers can form an extended, segregated brush conformation, this conformation is entropically highly unfavourable. The polymer block chains can also collapse to protect the hydrophobic region, and the hydrophobic polymer chains can become entangled and interdigitate, thus decreasing the bilayer thickness. Hence, the fully extended bilayer and hydrophobic core thickness provide physical limits for the underlying system. The collapsed polymer conformation can be modelled using a polymer random walk model (freely jointed chain), where the root mean squared end-to-end distance of the polymer is given by