Physics – Condensed Matter – Soft Condensed Matter
Scientific paper
2007-10-29
Physics
Condensed Matter
Soft Condensed Matter
35 pages, 2 figures
Scientific paper
10.1103/PhysRevE.76.061802
Attempts to use coarse-grained molecular theories to calculate corrections to the random-phase approximation (RPA) for correlations in polymer mixtures have been plagued by an unwanted sensitivity to the value of an arbitrary cutoff length, {\it i.e.}, by an ultraviolet (UV) divergence. We analyze the UV divergence of the inverse structure factor $S^{-1}(k)$ predicted by a `one-loop' approximation similar to that used in several previous studies. We consider both miscible homopolymer blends and disordered diblock copolymer melts. We show, in both cases, that all UV divergent contributions can be absorbed into a renormalization of the values of the phenomenological parameters of a generalized self-consistent field theory (SCFT). This observation allows the construction of a UV convergent theory of corrections to SCFT phenomenology. The UV-divergent one-loop contribution to $S^{-1}(k)$ are shown to be the sum of: (i) a $k$-independent contribution that arises from a renormalization of the effective $\chi$ parameter, (ii) a $k$-dependent contribution that arises from a renormalization of monomer statistical segment lengths, (iii) a contribution proportional to $k^{2}$ that arises from a square-gradient contribution to the one-loop fluctuation free energy, and (iv) a $k$-dependent contribution that is inversely proportional to the degree of polymerization, which arises from local perturbations in fluid structure near chain ends and near junctions between blocks in block copolymers.
Grzywacz Piotr
Morse David C.
Qin Jian
No associations
LandOfFree
Renormalization of the one-loop theory of fluctuations in polymer blends and diblock copolymer melts does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Renormalization of the one-loop theory of fluctuations in polymer blends and diblock copolymer melts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Renormalization of the one-loop theory of fluctuations in polymer blends and diblock copolymer melts will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-364582