Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ion Distributions at the Nitrobenzene-Water Interface Electrified by a
  Common Ion   Synchrotron x-ray reflectivity is used to study ion distributions at the
liquid-liquid interface between a nitrobenzene solution of tetrabutylammonium
tetraphenylborate (TBATPB) and a water solution of tetrabutylammonium bromide
(TBABr). The concentration of TBABr is varied to alter the ion distribution.
Our x-ray measurements are inconsistent with several commonly used theories of
ion distributions, including Gouy-Chapman, modified Verwey-Niessen, and the
MPB5 version of the Poisson-Boltzmann equation. These structural measurements
are described well by ion distributions predicted by a version of the
Poisson-Boltzmann equation that explicitly includes a free energy profile for
ion transfer across the interface when this profile is described by a simple
analytic form or by a potential of mean force from molecular dynamics
simulations. These x-ray measurements from the liquid-liquid interface provide
evidence for the importance of interfacial liquid structure in determining
interfacial ion distributions.

7
The categories of this paper are: hep-th
19
The categories of this paper are: eess
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
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The categories of this paper are: nlin
0
The categories of this paper are: hep-ph