Polymer-grafted nanoparticle superlattice monolayers over 100 cm2 through a modified Langmuir-Blodgett method

Abstract

Two-dimensional polymer/nanoparticle (NP) composite superlattice monolayers have attracted great attention, due to their applications in flexible optical, sensing, and electronic devices. The large-scale fabrication of these devices requires large-area superlattice monolayers. However, the preparation of large-area superlattice monolayers of polymer-grafted NP still faces great challenges. Herein, we report a modified Langmuir-Blodgett method for preparing large-area superlattice monolayers of polystyrene-grafted gold NPs (AuNP@PS). This method involves two key steps: pre-assembling the AuNP@PS on a liquid surface using mixed high/low-boiling-point solvent as the spreading solvent and then compressing the pre-assembled film in low-boiling-point solvent vapor. The discrete monolayer islands of AuNP@PS are formed in the pre-assembly process. During the surface compression process, the introduction of solvent vapor facilitates the fusion of AuNP@PS islands to form the continuous superlattice monolayers. Otherwise, discrete films with nonuniform thickness are obtained by compression without solvent vapor. This strategy enables the preparation of large superlattice monolayer films over 100 cm 2 , which are useful in the manufacture of microelectronic devices. • A modified Langmuir-Blodgett method for preparing superlattice films is reported. • Superlattice films of polymer-grafted nanoparticles over 100 cm 2 can be obtained. • Mixed solvent and solvent vapor facilitate the formation of superlattice monolayers.