Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Orienting Ion-Containing Block Copolymers Using AC Electric Field   We consider orientation mechanisms for block copolymers in an electric field.
Theoretical and experimental studies have shown that nonuniformity of the
dielectric constant gives rise to a preferred orientation of the melt with
respect to the applied field. We show that the presence of ions, as found in
anionically prepared copolymers, may increase the alignment effect markedly.
Time-varying (ac) and static (dc) fields are considered within a unified
framework. We find that orientation of block copolymers can in principle be
achieved without a dielectric contrast if there is a mobility contrast. The
presence of ions is especially important at small field frequencies, as is in
most experiments. Unlike the no-ions case, it is found that orienting forces
depend on the polymer chain lengths. The mobile-ions mechanism suggested here
can be used to reduce the magnitude of orienting fields as well as to
discriminate between block copolymers of different lengths.

13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol