Laterally patterned magnetic nanoparticles

Abstract

Laterally patterning magnetic nanoparticles (MNPs) through self-assembly and simple solution processing constitutes an important step toward inexpensive nanoparticle-based devices. In this work, MNPs were laterally patterned on metal thin films using laterally patterned self-assembled monolayers (SAMs) as a template. SAMs of inactive molecules were first patterned on an Au thin film using the soft-lithographic technique, microcontact printing. The active, bifunctional molecules, 1,10decanedithiol or 4-(11-mercaptoundecyl)benzene-1,2-diol, were then patterned through backfilling. The MNPs selectively bind to the terminal thiols or modified catechols when the substrates are submerged into a solution of MNPs. By adjusting the deposition conditions, both monolayers and partial multilayers were controllably formed. Co, Ni, Fe 3 O 4 , and FePt MNPs, as well as Au nonmagnetic nanoparticles were successfully patterned by this process. This generalized approach is anticipated to be adaptable to many other kinds of nanoparticles via judicious selection of the substrates, surfactant ligands (on the nanoparticle), and/or surface-bound monolayers.

Self-Assembled Monolayer of Mixed Gold and Nickel Nanoparticles

“…When we reserve the soaking sequence, densities of both the Ni and Au particles are higher. This observation may be ascribed to the relative reactivity of ligand exchange for different nanoparticles towards the surface bound thiols [9]. For the nanofiber growth, a relatively higher Au density is preferred since the Ni nanoparticles can be spaced apart from each other by the vast amount of Au nanoparticles.…”

“…The Au nanoparticles with oleyamine ligands and Ni nanoparticles with oleic acid and TOP ligands can be covalently attached to the organic molecular monolayer surface functionalized with thiol (-SH) (MPTS-SAMs) via the ligand exchange [9], as shown in Fig. 2(c).…”

Plasmon-Coupled Gold Nanoparticles in Stretched Shape-Memory Polymers for Mechanical/Thermal Sensing

“…Spherical Au NPs with an average diameter of 15 nm were synthesized according to an established procedure. , Chemicals used for synthesizing Au NPs included HAuCl 4 · x H 2 O (Alfa Aesar, 99.999%, where x was estimated as 3), oleylamine (OA, Sigma Aldrich, ≥98% primary amine), anhydrous toluene (EMD, DriSolv), tetrahydrofuran (THF, EMD, OmniSolv, Non-UV), and methanol (MeOH, Macron, ChromAR). The Au NPs are stabilized by OA and are dispersed in THF after purification.…”

Tuning Deposition of Magnetic Metallic Nanoparticles from Periodic Pattern to Thin Film Entrainment by Dip Coating Method

“…6 On the other hand, the control could also permits to study the influence of dimensionality and structural disorder on transport mechanism and therefore on the resulting magneto-transport properties. 9,10 One way to integrate the NPs into patterned devices is based on physical and/or chemical templates, obtained by lithography, 11,12 microcontact printing, [13][14][15][16] micro-injection molding in capillaries, 17 dip pen lithography, 18,19 elimination lithography on self-assembled monolayers 20 or a combination of such approaches. 21,22 Nevertheless, the one-step self-assembly of NPs on solid substrates directly from colloidal solution is highly desirable.…”