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

共轭微孔聚合物(CMPS)在传感器、发光二极管等方面有着令人兴奋的应用，也可以作为潜在的材料，将太阳能转化为直接使用的电能，或者转化为化学燃料，如用于储能的氢气，这些化学燃料可以在以后的阶段转化为电能。我建议将重点放在后两种应用上，由于这些材料可能具有高可用性和低成本，因此有可能加速能量向“低碳”能源的转变。CMPS由积木(“砖”)组成，这些积木被组装成复杂的3D骨架，形成纳米颗粒(“房屋”)。这些“房子”会有不同的形状，根据形状的不同，或多或少会有一些功能。这些“房子”可以相互作用，并聚集成一座“城市”。就像“房子”可以呈现更大或更小的体积，“城市”可以或多或少地密度一样，CMP可以有广泛的孔尺寸分布。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，CMPS的三维骨架和孔道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进行筛选。此外，合成一些组合可能是一个真正的挑战，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，合成新的中药并对其进行表征也是一个缓慢的过程。在这项研究中，我建议开发一种计算筛选工具，该工具可用于补充组合化学，以加快材料发现。在研究员的时间内达到预测阶段将是过于乐观的，但定义一套新的设计规则来指导新中医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性质联系起来。CMPS的所有结构性质都必须通过计算工具来掌握。为了应对这一挑战，必须将不同的计算技术结合到一个多尺度模型方案中，其中较大尺度模型的参数是从较短尺度模型中提取的，这样的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，没有长程有序。因此，结构表征是具有挑战性的。因此，该项目的一部分致力于通过组合光谱技术来验证模型。到目前为止，CMPS是不可溶的，因此将它们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表征。我建议进一步研究从这种不溶性中药制备薄膜的工艺路线，并使用我的计算工具来提出新的可溶性中药的化学设计。

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.