Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Single chain structure in thin polymer films: Corrections to Flory's and
  Silberberg's hypotheses   Conformational properties of polymer melts confined between two hard
structureless walls are investigated by Monte Carlo simulation of the
bond-fluctuation model. Parallel and perpendicular components of chain
extension, bond-bond correlation function and structure factor are computed and
compared with recent theoretical approaches attempting to go beyond Flory's and
Silberberg's hypotheses. We demonstrate that for ultrathin films where the
thickness, $H$, is smaller than the excluded volume screening length (blob
size), $\xi$, the chain size parallel to the walls diverges logarithmically,
$R^2/2N \approx b^2 + c \log(N)$ with $c \sim 1/H$. The corresponding bond-bond
correlation function decreases like a power law, $C(s) = d/s^{\omega}$ with $s$
being the curvilinear distance between bonds and $\omega=1$. % Upon increasing
the film thickness, $H$, we find -- in contrast to Flory's hypothesis -- the
bulk exponent $\omega=3/2$ and, more importantly, an {\em decreasing} $d(H)$
that gives direct evidence for an {\em enhanced} self-interaction of chain
segments reflected at the walls. Systematic deviations from the Kratky plateau
as a function of $H$ are found for the single chain form factor parallel to the
walls in agreement with the {\em non-monotonous} behaviour predicted by theory.
This structure in the Kratky plateau might give rise to an erroneous estimation
of the chain extension from scattering experiments. For large $H$ the
deviations are linear with the wave vector, $q$, but are very weak. In
contrast, for ultrathin films, $H<\xi$, very strong corrections are found
(albeit logarithmic in $q$) suggesting a possible experimental verification of
our results.

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The categories of this paper are: stat
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics