Adv Mater 2005, 17:1045–1047.CrossRef 30. Chartier C, Bastide S, Lévy-Clément C: Metal-assisted chemical etching of silicon in HF-H 2 O 2 . Electrochim Acta 2008, 53:5509–5516.CrossRef 31. Lee CL, Tsujino K, Kanda Y, Ikeda S, Matsumura M: Pore formation in silicon by wet etching using micrometer-sized metal particles as catalysts. J Mater Chem 2008, 18:1015–1020.CrossRef 32. Rykaczewski K, Hildreth O, Wong C, Fedorov A, Scott J: Guided three-dimensional catalyst folding during metal-assisted

chemical etching of silicon. Nano Lett 2011, 11:2369–2374.CrossRef Competing interests The authors declare that they have no competing interests. Authors’ contributions HA and SO conceived the idea and designed the experiments. KF carried out all the experiments and data analysis under the instruction of SO. All the authors contributed to the preparation and revision of the manuscript and read and PF-02341066 cell line approved its final version.”
“Background

Polymer-based monoliths which emerged in the early 1990s have attracted significant attention during about 20 years of progress. Up to now, they have been applied for various fields such as chromatography, biomolecule immobilization, and support catalysis, because of their predominant pH stability, nonspecific interaction, EX 527 supplier and fast mass transfer performance [1–4]. However, their main drawbacks include the limit of small surface area for the pore walls and the new lack of functional groups on the pore surface [5, 6]. Stimuli-responsive porous materials have aroused special interest not only for their pore structures, but also because they

can go through the visible changes in their property to respond to environmental variation [6]. Some efforts have been made to introduce functional groups onto the pore surface of polymer monoliths, providing stimuli-responsive properties [7]. In most cases, such monoliths should be fabricated by polymerization of monomers and subsequent surface functionalization. For both processes, time-consuming procedures for precise control of the monolith structure and introduction ratio of the functional group are often involved. Recently, we developed a novel method for preparation of the polymer-based monolith directly from a polymer by means of either thermally induced phase separation or non-solvent induced phase separation (NIPS). This phase separation technique represents a very simple and straightforward approach to the formation of a monolith having a uniform nanoscale porous structure (mesoporosity) without assistance of any templates in comparison with conventional fabrication methods from monomers. In NIPS, the addition of non-solvent into a homogeneous polymer solution with appropriate ratio of solvent and non-solvent affords the monolith with a uniform pore structure. So far, we have fabricated monoliths of hydrophobic polymers such as polyacrylonitrile, polycarbonate, and polymethacrylates through this method [8, 9].