Vecchio Drew A, Hammig Mark D, Xiao Xiongye, Saha Anwesha, Bogdan Paul, Kotov Nicholas A
Department of Chemical Engineering, BioInterfaces Institute, University of Michigan, 2800 Plymouth Rd, Ann Arbor, MI, 48109, USA.
Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Blvd, Ann Arbor, MI, 48109, USA.
Adv Mater. 2022 Jun;34(23):e2201313. doi: 10.1002/adma.202201313. Epub 2022 Apr 27.
Gels self-assembled from colloidal nanoparticles (NPs) translate the size-dependent properties of nanostructures to materials with macroscale volumes. Large spanning networks of NP chains provide high interconnectivity within the material necessary for a wide range of properties from conductivity to viscoelasticity. However, a great challenge for nanoscale engineering of such gels lies in being able to accurately and quantitatively describe their complex non-crystalline structure that combines order and disorder. The quantitative relationships between the mesoscale structural and material properties of nanostructured gels are currently unknown. Here, it is shown that lead telluride NPs spontaneously self-assemble into a spanning network hydrogel. By applying graph theory (GT), a method for quantifying the complex structure of the NP gels is established using a topological descriptor of average nodal connectivity that is found to correlate with the gel's mechanical and charge transport properties. GT descriptions make possible the design of non-crystalline porous materials from a variety of nanoscale components for photonics, catalysis, adsorption, and thermoelectrics.
由胶体纳米颗粒（NP）自组装而成的凝胶将纳米结构的尺寸依赖性特性转化为具有宏观体积的材料。NP链的大型跨越网络在材料内部提供了高互连性，这对于从导电性到粘弹性的广泛特性来说是必要的。然而，此类凝胶的纳米级工程面临的一个巨大挑战在于能够准确且定量地描述其结合了有序和无序的复杂非晶态结构。纳米结构凝胶的中尺度结构与材料特性之间的定量关系目前尚不清楚。在此，研究表明碲化铅NP会自发地自组装成一种跨越网络水凝胶。通过应用图论（GT），利用平均节点连通性的拓扑描述符建立了一种量化NP凝胶复杂结构的方法，发现该描述符与凝胶的力学和电荷传输特性相关。GT描述使得从各种用于光子学、催化、吸附和热电学的纳米级组件设计非晶态多孔材料成为可能。
