or partially removed, superhydrophobicity properties vanish easily. Such 2D surfaces provide a metastable superhydrophobic state since the limited entrapped air in such surfaces disappears quickly in contacting with water and the surface gets completely wetted within a short time. In contrast, 3D structures maintain trapped air at the surface and through whole bulk. [7] These kinds of structures may provide a stable and long-running superhydrophobicity since penetrating water will meet continuously with a fresh trapped-air barrier. It is essential to extend the surface topographies responsible for superhydrophobicity into the bulk by creating both roughness and low surface energy to achieve superhydrophobic 3D materials.Herein, a commercially available polyurethane (PU) foam was utilized as the sacrificial hard template to infiltrate TiO 2 nanoparticles in its interstitial pores. By simply burning out PU template and sintering at 850-900 °C, a 3D TiO 2 skeleton (forming inner and outer macropores) was achieved by 2D assembling of TiO 2 nanoparticles through the whole bulk. By combining macrolevel pores and the micro-/nanostructured topography, a 3D high surface roughness was achieved (Figure 1a; Figure S1, Supporting Information). The prepared TiO 2 slurry was also applied to planar quartz substrates by double-doctor blade coating technique to achieve micro-/nanostructured 2D TiO 2 (Figure 1a; Figure S2, Supporting Information). Afterward, initiated chemical vapor deposition (iCVD) was carried out to coat 2D and 3D TiO 2 homogenously with a thin layer of polytetrafluoroethylene (PTFE) while conserving the inner micro-and nanotopography (as shown schematically in Figure 1b). iCVD allows coating various types of substrates varying from simple 2D to complex 3D structures with a high conformity (without altering topographic details of the pristine structure). [8] After coating a thin layer of PTFE, 3D TiO 2 showed an extraordinary superhydrophobicity.3D TiO 2 has a porous structure with the pore size of ≈100-150 µm (Figure 2a) and exhibits approximately the same micro-and nanoscale structures with 2D TiO 2 surface prepared for the comparison by the well-established doctor blade technique. [9] While 2D surface was composed of micro/nano hierarchical porous texture, 3D surface consists additionally macropores (Figure 2a). Clearly micro-and nanoscale roughness was provided through the whole bulk in 3D TiO 2 . Following the iCVD step, we did not observe any significant change in the morphology of both 2D and 3D TiO 2 . This indicates that the deposited PTFE layer was extremely thin and highly conformal. Figure 2b shows the X-ray photoelectron spectroscopy (XPS) survey spectra of the uncoated and coated 3D TiO 2 . Simply Combining hard-templating and infiltration processes, micro-and nanoscale topography induced by 2D assembling of TiO 2 nanoparticles is extended to 3D TiO 2 . By applying an ultrathin and highly conformal polytetrafluoroethylene (PTFE) layer on prepared 3D TiO 2 via initiated chemical vapor deposition (iC...

The tuning of wetting over an extreme range, from superhydrophilic to superhydrophobic, was demonstrated on 1D Al/AlO nanostructures. While chaotic and tangled 1D Al/AlO nanostructures exhibited complete wetting, they became water repellent (with a water contact angle (CA) ≥173°) after the infiltration of poly[bis(2,2,2-trifluoroethoxy)phosphazene] (PTFEP) solution. This simple strategy allows the achievement of two extreme wetting regimes, perfect wetting and non-wetting, without altering the nanostructured surface topography. The same surface was also found to exhibit repellency towards artificial blood and hexadecane.

No abstract

Cell responses to surface and contact cell guidance are of great interest in bio-applications especially on nano- and micro scale features. Recently we showed selective cell responses on Al/Al2O3, bi-phasic nanowires (NWs). In this context, Al/Al2O3 NWs were synthesized by the chemical vapor deposition of (tBuOAIH2)2. Afterwards, linear periodic nano- and micro structured NWs were formed using laser interference lithography (LIL) technique to study the contact guidance of neurons from rat dorsal root ganglion (DRG), human umbilical vein smooth muscle cells (HUVSMC), human umbilical vein endothelial cells (HUVEC) and human osteoblast (HOB). LIL treatment did not alter surface chemistry of NWs. From our preliminary research LIL patterned NWs lead to alignment of axons contrary to non-patterned NWs. Morphology of HUVSMC changed from poly- to linear shapes and strong alignment was observed while HUVEC and HOB were not affected.