Langmuir–Blodgett Transfer of Nanocrystal Monolayers: Layer Compaction, Layer Compression, and Lattice Stretching of the Transferred Layer

TL;DR

This study uses X-ray scattering to analyze how nanocrystal layers change during compression and transfer to a solid surface.

Contribution

The paper reveals stretching of nanocrystal layers during Langmuir–Blodgett transfer, a previously unobserved structural change.

Findings

Lateral compression at the air–water interface reduces interparticle spacing in nanocrystal monolayers.

Langmuir–Blodgett transfer causes stretching of the nanocrystal layer, increasing interparticle spacing.

GISAXS provides detailed structural insights into nanocrystal arrangement during transfer.

Abstract

Grazing incidence small angle X-ray scattering (GISAXS) was used to study the structure and interparticle spacing of monolayers of organic ligand-stabilized iron oxide nanocrystals floating at the air–water interface on a Langmuir trough, and after transfer to a solid support via the Langmuir–Blodgett technique. GISAXS measurements of the nanocrystal arrangement at the air–water interface showed that lateral compression decreased the interparticle spacing of continuous films. GISAXS also revealed that Langmuir–Blodgett transfer of the nanocrystal layers to a silicon substrate led to a stretching of the film, with a significant increase in interparticle spacing.

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