Subramanian Ashwanth, Doerk Gregory, Kisslinger Kim, Yi Daniel H, Grubbs Robert B, Nam Chang-Yong
Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, USA.
Nanoscale. 2019 May 16;11(19):9533-9546. doi: 10.1039/c9nr00206e.
Three-dimensional (3D) nanoarchitectures can offer enhanced material properties, such as large surface areas that amplify the structures' interaction with environments making them useful for various sensing applications. Self-assembled block copolymers (BCPs) can readily generate various 3D nanomorphologies, but their conversion to useful inorganic materials remains one of the critical challenges against the practical application of self-assembled BCPs. This work reports the vapor-phase infiltration synthesis of optoelectrically active, 3D ZnO nanomesh architectures by combining hierarchical successive stacking of self-assembled, lamellar-phase polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) BCP thin films and a modified block-selective vapor-phase material infiltration protocol. The 3D ZnO nanomesh exhibits optoelectrical functionality, featuring stack-layer-number-dependent electrical conductance resembling the percolative transport originating from the intrinsic morphological network connectivity of the lamellar BCP pattern with symmetric block ratio. The results not only illustrate the first demonstration of electrical functionality based on the ZnO nanoarchitecture directly generated by the infiltration synthesis in self-assembled BCP thin films but also present a new, large-area scalable, metal oxide thin film nanoarchitecture fabrication method utilizing industry-compatible polymer solution coating and atomic layer deposition. Given the large surface area, three-dimensional porosity, and readily scalable fabrication procedures, the generated ZnO nanomesh promises potential applications as an efficient active medium in chemical and optical sensors.
三维（3D）纳米结构可以提供增强的材料性能，例如大表面积，这会增强结构与环境的相互作用，使其适用于各种传感应用。自组装嵌段共聚物（BCP）能够轻松生成各种3D纳米形态，但其转化为有用的无机材料仍然是自组装BCP实际应用面临的关键挑战之一。这项工作报道了通过将自组装的层状聚苯乙烯-嵌段-聚（2-乙烯基吡啶）（PS-b-P2VP）BCP薄膜的分层连续堆叠与改进的块选择性气相材料渗透方案相结合，气相渗透合成具有光电活性的3D ZnO纳米网结构。3D ZnO纳米网具有光电功能，其电导取决于堆叠层数，类似于源自具有对称嵌段比的层状BCP图案的固有形态网络连通性的渗流传输。这些结果不仅首次展示了基于自组装BCP薄膜中渗透合成直接生成的ZnO纳米结构的电功能，还提出了一种利用与工业兼容的聚合物溶液涂层和原子层沉积的新型大面积可扩展金属氧化物薄膜纳米结构制造方法。鉴于其大表面积、三维孔隙率和易于扩展的制造工艺，所生成的ZnO纳米网有望作为化学和光学传感器中的有效活性介质具有潜在应用。
