A general and robust strategy for in-situ templated synthesis of patterned inorganic nanoparticle assemblies

Precisely controlling the spatial organization of inorganic nanoparticles is essential for many applications, such as sensing, catalytic, and optical/electronic systems. Here, we describe a general and robust strategy to fabricate arbitrary quasi-two-dimensional (quasi-2D) nanoparticle assembly structures with tunable size and thickness on a substrate by using block copolymer brushes as the templates. To achieve this, patterned amphiphilic block copolymer brushes were first grown via light-mediated surface-initiated atom transfer radical polymerization. The hydrophilic polymer blocks could interact and enrich the inorganic precursors, and thus accelerate the in-situ growth of nanoparticles within the patterned hydrophilic polymer domains. In our method, the block copolymer template could strictly limit the vertical growth of quasi-2D nanoparticle assemblies to achieve thickness control in the nanometer scale. By changing the design of the photomask and experimental conditions for the light-mediated polymerization, quasi-2D inorganic nanoparticle assemblies with controllable shape and dimension can be feasibly obtained. Moreover, this method is also generally applicable to prepare various patterned inorganic nanoparticle assemblies with different compositions.