Highly Conductive Ribbons Prepared by Stick–Slip Assembly of Organosoluble Gold Nanoparticles

Abstract

Precisely positioning and assembling nanoparticles (NPs) into hierarchical nanostructures is opening opportunities in a wide variety of applications. Many techniques employed to produce hierarchical micrometer and nanoscale structures are limited by complex fabrication of templates and difficulties with scalability. Here we describe the fabrication and characterization of conductive nanoparticle ribbons prepared from surfactant-free organosoluble gold nanoparticles (Au NPs). We used a flow-coating technique in a controlled, stick-slip assembly to regulate the deposition of Au NPs into densely packed, multilayered structures. This affords centimeter-scale long, high-resolution Au NP ribbons with precise periodic spacing in a rapid manner, up to 2 orders-of-magnitude finer and faster than previously reported methods. These Au NP ribbons exhibit linear ohmic response, with conductivity that varies by changing the binding headgroup of the ligands. Controlling NP percolation during sintering (e.g., by adding polymer to retard rapid NP coalescence) enables the formation of highly conductive ribbons, similar to thermally sintered conductive adhesives. Hierarchical, conductive Au NP ribbons represent a promising platform to enable opportunities in sensing, optoelectronics, and electromechanical devices.

Functionalized gold nanoparticles for topical delivery of methotrexate for the possible treatment of psoriasis

“…Among others, gold nanoparticles (AuNPs) exhibit a range of chemical-physical properties suitable for advanced applications such as sensing, [1][2][3] optoelectonics [4][5][6] biotechnology and nanomedicine from diag- hyper proliferative keratinocytes effect in thick epidermis clinically appears as thick, silvery scales and itchy, dry, salmon pink patches, mostly on elbows, knees and scalp but also in other cutaneous sites [19,20] giving rise to tiresome diseases; for example, a 5-8% of patients complains from psoriatic arthritis, which can be painful and greatly limits mobility [21].…”

Controlled evaporative self‐assembly of polymer nanoribbons using oscillating capillary bridges

“…Among the different possible structures that can be made, our focus is on the fabrication of nanoribbons, a straight‐line segment of assembled nanoparticles and/or polymers with nanoscale thickness, microscale width, and macroscale length. As demonstrated in recent publications, such flexible, mesoscale structures offer highly tunable mechanical properties and are potential building blocks for higher order hierarchical structures …”

“…As demonstrated in recent publications, such flexible, mesoscale structures offer highly tunable mechanical properties and are potential building blocks for higher order hierarchical structures. 1,29,30 A combination of a uniform meniscus shape and a programmed meniscus depinning is required to deposit homogeneous nanoribbons with controlled dimensions. 1,29,31,32 Uniform meniscus shape and height provides a consistent nanoribbon cross section, and meniscus depinning controls the duration of particle assembly and nanoribbon spacing.…”

Nanomanufacturing: A Perspective

“…Additionally, once assembled onto a templating substrate, the nanoparticle structures can readily be transferred to a different material. 392,393 Unfortunately, the maximum linear contact line speeds achieved so far are only ~ 1 µm·s −1 to mm·s −1,394,395,396,397 which, even if used in a roll-to-roll process with a meter wide web, translate into an areal throughput of 10 −6 m 2 ·s −1 to 10 −3 m 2 ·s −1 . The limiting factors are the overall concentration of nanoparticles, which cannot be increased indefinitely without causing deposition in un-patterned areas, and the evaporation rate of the carrier fluid, which also cannot be increased dramatically.…”