Non-Close-Packed Breath Figures via Ion-Partitioning-Mediated Self-Assembly

Author(s)
Jia En Aw, Glen Tai Wei Goh, Shengnan Huang, Michael R. Reithofer, Aaron Zhenghui Thong, Jia Min Chin
Abstract

We report a one-step method of forming non-close-packed (NCP) pore arrays of micro- and sub-micropores using chloroform-based solutions of polystyrene acidified with hydrogen bromide for breath figure (BF) patterning. As BF patterning takes place, water vapor condenses onto the polystyrene solution, forming water droplets on the solution surface. Concurrently, preferential ion partitioning of hydrogen bromide leads to positively charged water droplets, which experience interdroplet electrostatic repulsion. Self-organization of charged water droplets because of surface flow and subsequent evaporation of the droplet templates result in ordered BF arrays with pore separation/diameter (L/D) ratios of up to 16.5. Evidence from surface potential scans show proof for preferential ion partitioning of HBr. Radial distribution functions and Voronoi polygon analysis of pore arrays show that they possess a high degree of conformational order. Past fabrication methods of NCP structures typically require multi-step processes. In contrast, we have established a new route for facile self-assembly of previously inaccessible patterns, which comprises of only a single operational step.

Organisation(s)
External organisation(s)
Agency for Science, Technology and Research A*STAR, University of Hull, Imperial College London
Journal
Langmuir
Volume
31
Pages
6688-6694
No. of pages
7
ISSN
0743-7463
DOI
https://doi.org/10.1021/la504656j
Publication date
06-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
104017 Physical chemistry, 205019 Material sciences
ASJC Scopus subject areas
General Materials Science, Condensed Matter Physics, Surfaces and Interfaces, Spectroscopy, Electrochemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/331b1838-e3f7-4f96-aad2-8eaf85ff2a84