posted on 2016-12-21, 00:00authored byTianchan Luo, Hua Bai, Lei Li
A breath
figure (BF)-inspired method for preparing ordered porous
films has attracted more and more attention because of its simplicity,
low cost, and easy implementation. However, it remains a challenge
to use this method to fabricate nanoscale porous structures without
designed polymer architecture and auxiliary. Herein, we first report
a facile method to fabricate BF arrays with nanopores (nanoBFAs) in
reactive vapor. Depending on the chemical reaction between the formic
acid (FA) droplet template and the polyvinylpyridine (PVP) segments
in copolymer, we successfully create nanoBFAs by casting a PVP-containing
copolymer solution in CS2 in FA vapor. The condensed FA
droplets can be instantly fixed by the PVP composition, and thus the
growth and the aggregation of adjacent droplets are effectively restricted.
Eventually, nanoBFAs are achieved in wide range solution concentration.
In addition, binary porous structures with both nano- and microscale
topology can be formed by using a FA/water mixed vapor with a one-step
BF process. The produced nanoBFA films exhibit excellent antireflection
performance with 0.5% reflectance, which is well-preserved even after
hydrophobic treatment. This modified BF technique not only facilitates
the elucidation of BFA formation mechanism but also opens a new way
of fabricating nanoporous structures, which may have potential applications
in electronic and optical devices.