Fabrication of highly ordered microporous thin films by PS-b-PAA self-assembly and investigation of their tunable surface properties
- 1 January 2008
- journal article
- Published by Royal Society of Chemistry (RSC) in Journal of Materials Chemistry
- Vol. 18 (6), 683-690
- https://doi.org/10.1039/b715520d
Abstract
A facile approach is presented to fabricate three-dimensional ordered microporous thin films by self-assemblyvia an amphiphilic block polymer, polystryene-b-polyacrylic acid (PS-b-PAA). The highly ordered microporous thin films were formed by casting a PS-b-PAA tetrahydrofuran (THF) solution onto a glass slide under high humidity conditions. The condensed water droplets act as sacrificial templates on the air–polymer solution interface based on thermocapillary convection. Some critical influencing factors, such as the concentration of the block polymer solution, the relative humidity of the atmosphere, the properties of the solvent, the spreading volume and the substrates, were investigated to control micropore size and tune film surface properties. The surface composition and wettability of the film were found to be dramatically changed in aqueous solution, and the contact angle of the film surface was interestingly reduced from nearly hydrophobic to super-hydrophilic, which was shown by optical contact angle measurements. The influence of porosity and the ionization degree of PAA on the above properties was investigated. Micropore diameters of the films determine the initial contact angle, while the PAA ionization degree determines the transformation time of the wettability behavior and the final contact angle. The microporous thin films, as potential functional materials, are expected to play an important role in future applications.Keywords
This publication has 37 references indexed in Scilit:
- Single-Step Fabrication of Transparent Superhydrophobic Porous Polymer FilmsChemistry of Materials, 2005
- Water-Assisted Fabrication of Polyaniline Honeycomb Structure FilmThe Journal of Physical Chemistry B, 2004
- Self-Organized Networks Based on Conjugated PolymersAdvanced Materials, 2001
- Honeycomb-patterned thin films of amphiphilic polymers as cell culture substratesMaterials Science and Engineering: C, 1999
- Self-Assembly of Ordered Microporous Materials from Rod-Coil Block CopolymersScience, 1999
- Infrared filters using metallic photonic band gap structures on flexible substratesApplied Physics Letters, 1997
- Self-organized honeycomb morphology of star-polymer polystyrene filmsNature, 1994
- PATTERN-FORMATION OUTSIDE OF EQUILIBRIUMReviews of Modern Physics, 1993
- Low-dimensional systems: quantum size effects and electronic properties of semiconductor microcrystallites (zero-dimensional systems) and some quasi-two-dimensional systemsAdvances in Physics, 1993
- Electrochemical Characterization of Electrodes with Submicrometer DimensionsJournal of the Electrochemical Society, 1986