Confinement to a pore of diameter D sets the length scale of the blob, in the sense that on smaller length scales than D, the monomers or segments do not feel the confinement, and may execute an unperturbed random walk. We write equations for the size of the pore in terms of the number of segments in the blob, and then estimate the length that the polymer occupies in the tube, L, as that resulting from a random walk of the blobs in the tube.
The energetic penalty due to confinement is again kT per blob, so
 | (10) |