基于大分子的“软”纳米偶联技术

Nano-particle, the critical object in nanotechnology, raised great interest in the areas of academia and application in the recent decade. Manipulation on the scale of nano-meter is the core part of nanotechnology, and one of the most important question concerned by scientists of nano-science. The current proposal aims at filling the vacancy of manipulation between different types of nano-particles by using a novel "soft-nano-coupling" technique based on macromolecules to connect heterogeneous nano-particles to fabricate "soft" hybrid nano-object. It is known that conventional "hard-coupling" method is based on complicated inorganic synthetic chemistry usually by using harmful solvents and highly toxic organometallic reagents, which requires great expertise and patience in methodology design. In contrast, "soft-coupling" takes advantage of the well-developed science of advanced controlled radical polymerization, synthesizing multi-functional block copolymers which selectively anchor onto different types of mono-functional nano-particles acting as isolated "modules". In this way, nano-particle hybrid can be fabricated by playing "modules" environmentally friendly and with low cost, which is beneficial to the booming applications recently. It is not hard to see that the "soft" hybrid of nano-particle possesses unique property of controlled compactness compared to the "hard" hybrid. Behind the idea of "module building up" is the widely-adapted methodology of "soft-coupling" to simplify the synthesis of hybrid nano-object using functional block copolymers made from monomers of specific preferential anchoring effects to targeting typical mono-functional nano-particles, such as gold, silica, and iron oxide. It is noted that "soft-coupling" provides an exceptional novel platform for the study of the combination of nano-objects. It combines with "hard-coupling", comprising the solid body of modern nano-manipulation, enriching the synthetic techniques of nano-science. Promisingly, new area and knowledge should be explored and obtained in this study. It is believed that new frontier of advanced nano-manipulation technique would be extended greatly.

近几年来，纳米粒子作为纳米技术的重要研究对象，在学术和应用领域引起了非常广泛的兴趣。纳米尺度上的控制是纳米技术的核心，是纳米科学关心的主要问题之一。课题针对目前国际上对于不同种纳米粒子关联控制研究的不足，以基于大分子的偶联思想为基础，首次提出"软纳米偶联"的方法，在不同纳米微粒之间构筑起一座高分子的桥梁，从而制备新型"软复合"纳米粒子体系。"软复合"是基于纳米尺度的一种新型控制思想的尝试，它构建在现代高分子科学的基础上，通过设计新型具有特异"锚化"作用的功能型嵌段大分子，以"模块化"的方式把功能单一的普通纳米粒子联系起来，组成一个复合体。与传统"硬复合"方法相比，"软复合"设计灵活，易于制备，方法具有普适性，有利于降低复合粒子的成本。更重要的是，纳米"软"偶联得到的复合体既"松散"又"统一"，完全不同于"硬"复合体，它提供给人们一个全新的纳米研究平台，极大地拓展了纳米控制技术的研究前沿。

材料在纳米尺度上的控制是纳米技术的核心，是纳米科学关心的主要问题之一。课题中首次提出“软纳米偶联”的方法，在官能团特异性锚化的基础上，设计和制备了一系列两嵌段、三嵌段及无规共聚物，利用化学基团的在不同纳米微粒表面的锚化，在纳米粒子之间构筑起一座高分子的桥梁，从而制备新型“软复合”纳米粒子体系。“软复合”是基于纳米尺度的一种新型控制思想的尝试，以“模块化”的方式把功能单一的普通纳米粒子联系起来，组成一个复合体。研究中主要以二氧化硅和纳米金为研究对象，利用嵌段共聚物对其进行偶联，制备出二氧化硅/纳米金复合杂化纳米粒子。研究中发现，对于合成目标聚合物，合成顺序和策略非常重要，比如利用环氧基团的开环引入硫辛酸基团可能造成交联，因此需要在后期进行，或者待大分子偶联在一个纳米粒子上之后，再进行化学修饰。制备出的复合纳米粒子经TEM观察，呈现出纳米金“点缀”在二氧化硅表面上的形貌特点。此外，在探索各种新型软纳米偶联聚合物结构的过程中，研究还在高分子合成领域和面向应用的大分子设计中取得了不少意外的成果和发现。例如，得到一系列含磷均聚和共聚物，它们的玻璃化转变温度可以在很大的范围内调控，同时还具备阻燃和光刻性能。通过对高分子纳米胶束粒子的研究，得到了一种高效的自由基纳米捕获器。在聚合方法学上，首次得到同时含有降冰片烯和叠氮结构的AB型单体，它可以在常温下自发的进行3+2反应，得到含有三唑啉机构的大分子，该三唑啉结构进而还能在光照等条件下失去一分子氮气，得到氮杂环丙烷结构，这为新型反应性树脂的制造提供了思路。