Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Molecular Weight Dependence of Spreading Rates of Ultrathin Polymeric
  Films   We study experimentally the molecular weight $M$ dependence of spreading
rates of molecularly thin precursor films, growing at the bottom of droplets of
polymer liquids. In accord with previous observations, we find that the radial
extension R(t) of the film grows with time as R(t) = (D_{exp} t)^{1/2}. Our
data substantiate the M-dependence of D_{exp}; we show that it follows D_{exp}
\sim M^{-\gamma}, where the exponent \gamma is dependent on the chemical
composition of the solid surface, determining its frictional properties with
respect to the molecular transport. In the specific case of hydrophilic
substrates, the frictional properties can be modified by the change of the
relative humidity (RH). We find that \gamma \approx 1 at low RH and tends to
zero when RH gets progressively increased. We propose simple theoretical
arguments which explain the observed behavior in the limits of low and high RH.

15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas