Two-dimensional metal gels: from fundamentals to applications

在最近成功地制备了二维、纳米厚和平方厘米宽的金网络之后，我们打算在这个新的研究领域的两端进行工作：对形成机理的更深入的理解和选择的应用。理解驱动的第一场是关于影响胶体金属颗粒界面凝胶化的因素以及将合成路线扩展到多金属结构的可能性的问题。这两个子领域的答案将有助于学习评估新制造路线的局限性，并开辟可能的加工选择，如扩大规模和可印刷性。在应用驱动的第二个领域，我们首先将自己限制在网络在电催化和生物医学中的潜在用途。对于第一个子领域，我们将尝试使用在三维凝胶方面获得的知识(例如，将PtNi凝胶用作燃料电池中高活性和坚固的阴极)，通过逐层堆积2D凝胶来实现减少材料使用量的同时保持活性和稳定性。第二个应用将是制造用于神经科学的柔性电极。对于由非常软的物质组成的大脑的研究，需要生物兼容的机械软电极，以避免损害被应用程序研究的组织。我们对三维金属凝胶的力学性质的研究表明，对于二维凝胶来说，这些条件以及生物相容性都是通过选择形成网络的(贵金属)来满足的。

Following the recent successful fabrication of two-dimensional, nanometer-thick and square centimeter-wide gold networks, we intend to work on both ends of this new research field: the deeper understanding of the formation mechanism and on selected applications. The understanding-driven first field is governed by questions about the factors influencing the interfacial gelation of colloidal metal particles and the possibility of extending the synthesis route to multimetallic structures. The answers from both subfields will help to learn to assess the limitations of the new fabrication route and open up possible processing options such as upscaling and printability. In the application-driven second field, we will initially limit ourselves to the potential use of the networks in electrocatalysis and biomedicine. For the first subfield, we will try to use the knowledge gained on three-dimensional gels (for example, the use of PtNi gels as highly active and robust cathodes in fuel cells) to achieve reduced material usage while maintaining activity and stability through layer-by-layer stacking of 2D gels. The second application will be in the fabrication of flexible electrodes for neuroscience. For investigations on the brain, which consists of very soft matter, biocompatible, mechanically soft electrodes are needed to avoid damaging the tissue under investigation by the application. Our studies on mechanical properties of three-dimensional metal gels suggest that these conditions are fulfilled for two-dimensional gels as well as the biocompatibility by the choice of (noble) metals from which the networks are formed.