Fabrication of complex free-standing nanostructures with concave and convex curvature via the layer-by-layer approach.
Fabrication of complex free-standing nanostructures with concave and convex curvature via the layer-by-layer approach.
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DOI：
10.1021/la500007x
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发表时间：
2014-02
期刊：
影响因子：
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通讯作者：
Mohammad Raoufi;H. Schönherr
中科院分区：
文献类型：
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作者：
Mohammad Raoufi;H. Schönherr
我们报告了前所未有的独立的复杂的聚合物纳米物体的制造，具有凹和凸曲率，通过利用逐层（LBL）沉积的聚电解质。采用自上而下/自下而上相结合的复制方法制备了孔径调制阳极氧化铝（AAO）模板，并将其与聚苯乙烯磺酸盐（PSS）和聚烯丙基胺盐酸盐（PAH）多层膜进行了复制，得到了直径分别为210 nm和150 nm的宽段和窄段开放式纳米管。为了获得稳定的孔径调制的纳米孔，其在窄孔部分和宽孔部分中分别具有1 μm和5 μm以及5 μm和10 μm之间的段长度，铝的常规硬质阳极化之后是随后的温度调制阳极化。在去除背侧铝电极、使氧化铝硅烷化并且用金薄层钝化暴露的膜表面之后，交替地沉积PSS和PAH以产生LBL多层。对于优化的LBL多层厚度和紧凑性，在硅基板和具有直孔的纳米多孔AAO的单独实验中建立，获得了具有凹曲率和凸曲率的独立聚合物纳米物体。壁厚与孔径比≥0.08时，这些值稳定。
We report on the fabrication of unprecedented free-standing complex polymeric nanoobjects, which possess both concave and convex curvatures, by exploiting the layer-by-layer (LBL) deposition of polyelectrolytes. In a combined top-down/bottom-up replication approach pore diameter-modulated anodic aluminum oxide (AAO) templates, fabricated by temperature modulation hard anodization (TMHA), were replicated with multilayers of poly(styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) to yield open nanotubes with diameters in the wide and narrow segments of 210 and 150 nm, respectively. To obtain stable pore diameter-modulated nanopores, which possess segment lengths between 1 and 5 μm and 5 and 10 μm in the narrow and wide pore portion, respectively, conventional hard anodization of aluminum was followed by a subsequent temperature-modulated anodization. After removing the backside aluminum electrode, silanizing the aluminum oxide, and passivating the exposed membrane surface with a thin layer of gold, PSS and PAH were deposited alternatingly to yield LBL multilayers. For optimized LBL multilayer thicknesses and compactness, established in separate experiments on silicon substrates and nanoporous AAO with straight pores, free-standing polymeric nanoobjects with concave and convex curvatures, were obtained. These were stable for wall thickness to pore diameter ratios of ≥0.08.