Prolonged reorganization of thiol-capped Au nanoparticles layered structures

Abstract

Prolonged reorganization behaviour of mono-, di-, tri- and multi-layer films of Au nanoparticles prepared by Langmuir-Blodgett method on hydrophobic Si(001) substrates have been studied by using X-ray scattering techniques. Out-of-plane study shows that although at the initial stage the reorganization occurs through the compaction of the films keeping the layered structure unchanged but finally all layered structures modify to monolayer structure. Due to this reorganization the Au density increases within the nanometer thick films. In-plane study shows that inside the reorganized films Au nanoparticles are distributed randomly and the particle size modifies as the metallic core of Au nanoparticles coalesces.

The fate of organic species upon sintering of thiol-stabilised gold nanoparticles under different atmospheric conditions

“…15,16 There remains considerable debate about whether stabilising ligands should first be released from the gold surface [17][18][19] or if sintering can proceed with the surface layer intact. [20][21][22][23] Although the thermal stability and desorption of thiol-based monolayers on flat gold surfaces has been reasonably well investigated, few reports have examined this behaviour on the surfaces of AuNPs. [24][25][26][27][28][29][30] Such knowledge is important as the desorption behaviour directly affects the sintering temperatures of AuNPs.…”

Contact angle and adsorption energies of nanoparticles at the air–liquid interface determined by neutron reflectivity and molecular dynamics

“…13,14 Although it can be used to measure the contact angle of NPs deposited on substrates, it is not suitable for in situ measurements at fluid interfaces. The measurements performed on deposited NPs are influenced by the transfer process, 15,16 by the rearrangement of NPs and their shell on the substrate, by low coverage and roughness. Pinning and humidity are also major issues as they play a role in contact angle measurement.…”

Directed self-assembly of inorganic nanoparticles at air/liquid interfaces

“…16,17 However, measurements performed on these systems are influenced by the transfer process on the arrangement of NPs. 18,19 The following phenomena might take place during the transfer: dragging of NPs by the water droplet, chemical reactions of the cross-linkers added to fix NPs to the substrate, rearrangement of the NP capping ligands, low coverage and roughness on the substrate. Pinning and humidity are also major issues in contact angle measurement.…”