Self-Assembled Ag-MXA Superclusters with Structure-Dependent Mechanical Properties

Abstract

The low elastic modulus and time-consuming formation process represent the major challenges that impede the penetration of nanoparticle superstructures into daily life applications. As observed in the molecular or atomic crystals, more effective interactions between adjacent nanoparticles would introduce beneficial features to assemblies enabling optimized mechanical properties. Here, a straightforward synthetic strategy is showed that allows fast and scalable fabrication of 2D Ag-mercaptoalkyl acid superclusters of either hexagonal or lamellar topology. Remarkably, these ordered superstructures exhibit a structure-dependent elastic modulus which is subject to the tether length of straight-chain mercaptoalkyl acids or the ratio between silver and tether molecules. These superclusters are plastic and moldable against arbitrarily shaped masters of macroscopic dimensions, thereby opening a wealth of possibilities to develop more nanocrystals with practically useful nanoscopic properties.

The Ag-mercaptoalkyl acid superclusters with different architectures exhibit structure-dependent mechanical properties. Inspired by molecular or atomic crystal, whose mechanical properties are dramatically different between various packing modes, the nanoparticle assemblies' mechanical properties can be tuned by controlling the crystal structure. Assembly of hexagonal, lamellar, and random structures of superclusters through hydrogen bonds between the tether molecules is reported.

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