Carnegie Mellon University

Flat Surfaces

There are several factors determining structure of the polymer layertethered to a flat surface.  One is anchor distance, or distribution of tethering sites on the surface and another is polymer molecular weight.  There is a direct dependence of polymer conformation on grafting density. 

D = Distance between attachment points and RF = Flory radius = aNν  

(RF = Flory radius, a = monomer dimension, N = degree of polymerization, ν = Flory exponent, n = 0.6 (PEO in good solvent)

Four different topologies have been described depending on relationship between density of grafting sites and Flory radius.(1)



(1)          Unsworth, L. D.;  Tun, Z.;  Sheardown, H.; Brash, J. L. J. Colloid Interface Sci. 2005, 281, 112-121.