Laboratory of Materials and Interface Chemistry & Centre for Multiscale Electron Microscopy Department of Chemical Engineering and Chemistry, Eindhoven University of Technology , Eindhoven 5600 MB, The Netherlands.
Institute for Complex Molecular Systems, Eindhoven University of Technology , Eindhoven 5600 MB, The Netherlands.
Acc Chem Res. 2017 Jul 18;50(7):1495-1501. doi: 10.1021/acs.accounts.7b00107. Epub 2017 Jun 30.
Morphology plays an essential role in chemistry through the segregation of atoms and/or molecules into different phases, delineated by interfaces. This is a general process in materials synthesis and exploited in many fields including colloid chemistry, heterogeneous catalysis, and functional molecular systems. To rationally design complex materials, we must understand and control morphology evolution. Toward this goal, we utilize cryogenic transmission electron microscopy (cryoTEM), which can track the structural evolution of materials in solution with nanometer spatial resolution and a temporal resolution of <1 s. In this Account, we review examples of our own research where direct observations by cryoTEM have been essential to understanding morphology evolution in macromolecular self-assembly, inorganic nucleation and growth, and the cooperative evolution of hybrid materials. These three different research areas are at the heart of our approach to materials chemistry where we take inspiration from the myriad examples of complex materials in Nature. Biological materials are formed using a limited number of chemical components and under ambient conditions, and their formation pathways were refined during biological evolution by enormous trial and error approaches to self-organization and biomineralization. By combining the information on what is possible in nature and by focusing on a limited number of chemical components, we aim to provide an essential insight into the role of structure evolution in materials synthesis. Bone, for example, is a hierarchical and hybrid material which is lightweight, yet strong and hard. It is formed by the hierarchical self-assembly of collagen into a macromolecular template with nano- and microscale structure. This template then directs the nucleation and growth of oriented, nanoscale calcium phosphate crystals to form the composite material. Fundamental insight into controlling these structuring processes will eventually allow us to design such complex materials with predetermined and potentially unique properties.
形态学在化学中起着至关重要的作用，通过将原子和/或分子分离到不同的相中，并通过界面来描绘。这是材料合成中的一个普遍过程，在胶体化学、多相催化和功能分子体系等许多领域都得到了应用。为了合理设计复杂材料，我们必须理解和控制形态演变。为此，我们利用低温透射电子显微镜（cryoTEM），它可以以纳米空间分辨率和<1 秒的时间分辨率跟踪溶液中材料的结构演变。在本述评中，我们回顾了我们自己的研究中的一些例子，其中 cryoTEM 的直接观察对于理解大分子自组装、无机成核和生长以及杂化材料的协同演变中的形态演变至关重要。这三个不同的研究领域是我们材料化学方法的核心，我们从自然界中无数复杂材料的例子中汲取灵感。生物材料是使用有限数量的化学组分在环境条件下形成的，它们的形成途径在生物进化过程中通过大量的试错方法进行了自我组织和生物矿化的改进。通过结合自然界中可能的信息，并专注于有限数量的化学组分，我们旨在提供对材料合成中结构演变作用的基本认识。例如，骨骼是一种分层和杂化材料，它重量轻，但强度高、硬度大。它是通过胶原的分级自组装形成的，具有纳米和微尺度结构的大分子模板。然后，这个模板指导取向的、纳米级磷酸钙晶体的成核和生长，形成复合材料。对这些结构过程进行控制的基本认识最终将使我们能够设计出具有预定的、潜在独特性能的复杂材料。
