Adsorption of a semiflexible wormlike chain.
Adsorption of ideal polymers with stiff backbone onto a flat surface is considered theoretically. Both scaling approach and quantitative theory are developed. We predict a self-similar monomer concentration profile c(x) approximately x(-4/3) near the surface (when the distance to the surface x is much smaller than the chain persistence length l /2). The typical conformation of a weakly adsorbed chain can be viewed as a sequence of alternating flat (2-dimensional) trains of wormlike short loops (flat blobs) and coil-like (3-dimensional) loops forming a triple-layer structure: contact layer (x < Delta) of adsorbed fragments virtually laid on the surface, proximal layer (Delta < x < l) of flat blobs, and more dilute distal corona layer (x > l). Here Delta defines the range of monomer/surface attraction, Delta << l. The adsorption transition is continuous. However, its relative width Delta(T) is divided by T* is small (T(*) is the adsorption temperature, Delta T is the relevant temperature interval): Delta(T) is divided by T* approximately (Delta is divided by l)(4/3), i.e. a discontinuous transition in the limit Delta/ l --> 0.
Semenov
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Institut Charles Sadron, 6 rue Boussingault, 67083 Strasbourg Cedex, France. semenov@polly.phys.msu.ru