两亲性嵌段共聚物导向合成有序介孔金属氧化物半导体材料

Amphiphilic Block Copolymer Directed Synthesis of Ordered Mesoporous Metal Oxide Semiconductors

有序介孔材料作为一种结构稳定、高比表面积、孔径可调、孔壁易于修饰的新型纳米结构材料在基础研究与应用开发方面都引起了人们的关注.有关有序介孔材料的文献中,无定型介孔材料(如二氧化硅、碳材料等)报道占据了大约70%,主要是由于传统软模板剂(如小分子表面活性剂或者聚环氧乙烷-b-聚环氧丙烷基嵌段共聚物)能够胜任无定型介孔材料的合成.相比而言,常规软模板剂在合成具有独特物化性能(光、电、磁以及催化、气敏等特性)的晶态半导体金属氧化物介孔材料方面面临很大的挑战.近年来,随着学科交叉发展以及高分子界研究人员加入无机多孔材料领域,一系列新型嵌段共聚物模板剂(例如具有高残碳率、高玻璃化转变温度和络合能力的嵌段共聚物)相继被合成并用于合成新型多孔材料,特别是这些模板剂在诱导组装合成有序介孔金属氧化物材料方面的研究取得了突出进展.本文从聚合物模板剂的制备与组装出发,围绕金属氧化物前驱体与模板剂之间的相互作用,系统综述了两者组装的作用机理和组装行为.深入探讨并总结了常见的三大组装方式:金属无机盐-聚合物模板、金属簇化合物-聚合物模板、金属纳米晶-聚合物模板组装,详细阐述了聚合物模板在合成有序介孔金属氧化物中的组装机理以及微观结构调控规律,并分析了聚合物模板诱导合成有序介孔金属氧化物未来宏量制备面临的机遇与挑战.鉴于其丰富的物化特性和新颖的介孔结构,有序介孔金属氧化物将逐步成为纳米光电器件、纳米催化载体以及化学传感的核心材料.

Ordered mesoporous materials, a family attentions of many researchers in various fields due to of highly porous nanomaterials, have attracted extensive their stable structure, high specific surface area, adjustable pore size, and easily modifiable pore wall. Over 70% reports on mesoporous materials are about amorphous mesoporous materials （e.g., silica）, because the traditional templates are widely commercially available and can be used readily for synthesis of amorphous mesoporous materials. However, conventional soft templates are not favorable for the synthesis of crystalline ordered mesoporous metal oxide semiconductors （OMMSs） with unique physical and chemical properties （i.e., light, electricity, magnetism, catalysis, gas sensitivity, etc）. Fortunately, this issue is well tackled by the development of interdisciplinary research along with more involvement of polymer researchers into the field of inorganic porous materials. In recent years, various novel block copolymers, particularly those with high carbon residue, high glass transition temperature, and complex-ability, have been synthesized and applied for fabricating porous materials. Remarkable progress has been achieved in using these templates to direct the co-assembly of various precursors for OMMSs synthesis. Starting from the preparation and assembly of polymer templates, this review elucidates systematically the mechanism and assembly behavior between metal oxide precursor and polymer templates. In addition, in-depth discussion is developed on the common three assembly processes, i.e. the metal inorganic salt-polymer template assembly, the metal cluster compounds-polymer template assembly, and the metal nanocrystals-polymer template assembly. Future opportunities and challenges faced by the synthesis and applications of OMMSs based on these novel block copolymer templates are foreseen in the last section.