Characterisation and rational design of porous conjugated polymers for solar energy conversion

共轭微孔聚合物（CMP）作为传感器、发光二极管等具有令人兴奋的应用，但也作为将太阳能转化为直接使用的电力或用于能量存储的化学燃料（如氢）的潜在材料，化学燃料可以在稍后阶段转化为电力。由于这些材料的高可用性和低成本，我建议将重点放在最后两种应用上，它们有可能加速向“低碳”能源的能源转型。CMP由构建块（“砖”）组成，这些构建块组装成复杂的3D骨架，形成纳米颗粒（“房子”）。这些“房子”将有不同的形状，并根据形状，或多或少的功能。这些“房子”又可以相互作用，组合成一个“城市”。以与“房屋”可以呈现更大或更小的体积并且“城市”可以或多或少地密集相同的方式，CMP可以具有宽的孔径分布。最终，“房屋”的组织和连接方式将影响“城市”的交通和效率。同样，CMP的三维骨架和孔网络也会影响光电化学性能和器件效率。元素“砖”的化学设计几乎是无限的，因此，它们的组合不可能通过试错法筛选。此外，合成某些组合可能是一个真实的挑战，甚至是不可能的。因此，化学直觉是最终指导合成化学家的东西。然而，即使在最先进的实验室中，合成新的CMP，然后对其进行表征也是一个缓慢的过程。在这个奖学金，我建议开发一个计算筛选工具，可以用来补充组合化学，以加快材料的发现。在奖学金的时间内达到预测阶段可能过于乐观，但定义一套新的设计规则来指导新CMP的合成是可以实现的。该计算工具旨在将化学设计与材料的电子特性联系起来。CMP的所有结构特性都必须通过计算工具来掌握。为了应对这一挑战，不同的计算技术将不得不结合在一个多尺度建模方案，其中较大尺度模型的参数是从较短尺度模型中提取的。这些模型必须经过实验验证，才能用于计算光电化学性质。CMP是以随机方式构建的，不具有长程有序性。因此，结构表征具有挑战性。因此，该项目的一部分致力于通过光谱技术的组合来验证模型。CMP到目前为止是不溶性的，因此将其加工成薄膜是具有挑战性的。薄膜将是我想要研究的应用的理想选择，并将进一步实现光学和电学特性。我建议进一步研究从这种不溶性CMP到薄膜的加工路线，以及使用我的计算工具来提出可溶性CMP的新化学设计。

Conjugated microporous polymers (CMPs) have exciting applications as sensors, emitting diodes but also as potential materials for transforming solar energy to either electricity for direct use or to chemical fuels such as hydrogen for energy storage, the chemical fuel could be transformed to electricity in a later stage. I propose to concentrate on these last two applications that have the potential to accelerate the energetic transition to "low-carbon" energies due to the possible high availability and low costs of those materials.CMPs are formed of building blocks ("bricks") that are assembled into complex 3D skeletons that form nanoparticles ("houses"). These "houses" will have different shapes and depending on the shape, be more or less functional. The "houses" can in turn interact and assemble into a "city". In the same way as "houses" can present larger or smaller volumes and "cities" can be more or less dense, CMPs can have a broad distribution of pore sizes. Ultimately, the way "houses" are organised and connected will impact transport and efficiency of the "city". Similarly, CMPs 3D skeleton and pore network will impact photo-electrochemical properties and device efficiency.The chemical design of the elemental "bricks" is almost infinite and thus, their combinations impossible to screen by trial and error method. Furthermore, synthesizing some combinations might be a real challenge or even impossible. Therefore, chemical intuition is what ultimately guides synthetic chemists. However, even in state-of-the-art labs, synthesizing new CMPs, and then characterizing them is a slow process. In this fellowship, I propose to develop a computational screening tool that can be used complementary to combinatorial chemistry to speed up materials discovery. Reaching the prediction stage within the time of the fellowship would be over-optimistic but defining a set of new design rules to guide synthesis of new CMPs can be achieved. The computational tool will aim to link chemical design with electronic properties of the material. All the structural properties of CMPs have to be grasped by the computational tool. In order to answer the challenge, different computational techniques will have to be combined in a multiscale modelling scheme where parameters for the larger scale model are extracted from the shorter scale model Such models must be experimentally validated to be useful for calculating photo-electrochemical properties. CMPs are built in a random manner and possess no long-range order. Thus, structural characterization is challenging. Part of the project is therefore dedicated to the validation of the model by a combination of spectroscopic techniques.CMPs are so far insoluble and thus processing them into thin film is challenging. Thin films would be ideal for the applications I want to investigate and would further enable optical and electrical characterization. I propose to further investigate processing routes to thin films from this insoluble CMPs as well as using my computational tool to propose new chemical design for soluble CMPs.