基于高分子单晶模板的二维无机纳米片晶的可控构造研究

Since the discovery of graphene, ultrathin two-dimensional (2D) nanomaterials have attracted increasing interests, mainly due to their extraordinary electronic, photonic, magnetic, and catalytic properties compared to those of the bulk counterparts with different dimensionality. By exploiting both the “top-down” and “bottom-up” strategies, various kinds of synthetic methods, including exfoliation, chemical vapor deposition and wet-chemical synthesis, have been developed to prepare such 2D nanomaterials. However, in general, these known methods suffer from poor control over product morphology and lack of universality, which can be attributed to the distinctly different chemical compositions and properties of different bulk materials and the ultrahigh specific surface areas of 2D nanomaterials. As a result, it remains a grand challenge to develop a robust, efficient, and widely applicable method for the preparation of 2D nanomaterials. In this project, following the templated synthesis strategy, we propose a general and robust approach to prepare various 2D nanomaterials by using polymer single crystals of designed block copolymers as the 2D “nano-reactors” to provide the confinement for the formation of 2D inorganic nanocrystals. Through changing the molecular parameters and conditions for solution crystallization, 2D nano-reactors with tunable size, thickness, morphology, and surface chemistry could also be obtained. We anticipate that this project would provide a powerful platform for controlled preparation and diverse applications of novel 2D nanomaterials.

自从石墨烯被发现以来，这类超薄二维纳米材料因其独特的电学、光学、磁学和催化性能引起了广泛的研究兴趣。目前，基于“自上而下”和“自下而上”的策略，人们已经发展了包括剥离、气相沉积、湿化学法等方法用于制备各类超薄二维纳米材料。然而这些方法在通用性和可控性等方面仍然存在较多问题。考虑到不同本体材料的组分和性质的多样性，以及二维纳米材料较大比表面的形貌特点，寻找一种高效、通用、易重复的二维纳米材料的制备方法依旧是当前研究领域内的一项重大挑战。在本项目中，我们提出以二维高分子单晶作为纳米反应器，结合模板合成策略，期望发展出一种具有广泛适用性和可控性的二维纳米材料的制备方法。通过调节嵌段共聚物的组成和结晶条件，我们还预期能够实现对二维纳米材料的形状、尺寸、结构和表面化学性质的精确可控调节。此项目的顺利开展将为实现二维纳米材料的可控制备、扩展二维纳米材料的广泛应用提供重要的技术平台。

二维纳米材料的可控制备和性能研究是近年来一个研究热点，然而，由于其较大的比表面特性，寻找一种高效、通用、易重复的二维纳米材料的制备方法依旧是当前研究领域内的一项重大挑战。在本项目中，我们利用可控自由基聚合制备了聚乙二醇-聚丙烯酸-聚苯乙烯三嵌段共聚物，利用聚乙二醇嵌段的结晶性，在溶液中成功生长了该三嵌段共聚物的高分子片晶。通过加入小分子二胺与聚丙烯酸嵌段中的羧基形成酰胺化反应，在溶液中将聚丙烯酸嵌段交联，得到了结构稳定的二维高分子纳米片。其中的亲水性聚丙烯酸嵌段具有与金属离子配位的能力，因此有望提供一种二维纳米反应器，通过原位的氧化还原或沉淀反应，制备不同组分的二维纳米材料。本项目的顺利实施为模板法合成二维纳米结构提供了一种新的思路。