Controlling the Interaction and Non-Close-Packed Arrangement of Nanoparticles on Large Areas

Abstract

In light of the importance of nanostructured surfaces for a variety of technological applications, the quest for simple and reliable preparation methods of ordered, nanometer ranged structures is ongoing. Herein, a versatile method to prepare ordered, non-close-packed arrangements of nanoparticles on centimeter sized surfaces by self-assembly is described using monodisperse (118-162 nm Ø), amino-functionalized silica nanoparticles as an exploratory example. It is shown that the arrangement of the particles is governed by the interplay between the electrostatic repulsion between the particles and the interaction between particles and surfaces. The latter is tuned by the properties of the particles such as their surface roughness as well as the chemistry of the linkage. Weak dispersive interactions between amino groups and gold surfaces are compared to a covalent amide linkage of the amino groups with carboxylic acid functionalized self-assembled monolayers. It was shown that the order of the former systems may suffer from capillary forces between particles during the drying process, while the covalently bonded systems do not. In turn, covalently bonded systems can be dried quickly, while the van der Waals bonded systems require a slow drying process to minimize aggregation. These highly ordered structures can be used as templates for the formation of a second, ordered, non-close-packed layer of nanoparticles exemplified for larger polystyrene particles (Ø 368 ± 14 nm), which highlights the prospect of this approach as a simple preparation method for ordered arrays of nanoparticles with tunable properties.

Self-assembled colloidal arrays for structural color

“…When high-charge-density colloidal particles in the dispersion medium reach a certain volume fraction, the colloidal particles can self-assemble into a 3D-ordered periodic structure because of the minimized electrostatic repulsion between the electric double layers on the surface of the colloidal particles. [65][66][67] Moreover, as the high volume fraction can compress the electric double layer, the crystal lattice and structural color of the colloidal crystals can be obtained by changing the particle concentration. However, because of the low elastic modulus, the crystal structure is easily damaged by forces such as weak shear, gravity, electric elds, and thermal shock from the surrounding materials, which results in an unstable system.…”

Conformal Nanocoatings with Uniform and Controllable Thickness on Microstructured Surfaces: A General Assembly Route

“…SEM image (Figure i) displays that some NPs sparsely deposit on the chip surface, indicating the unmodified chip cannot adsorb the negatively charged NPs. However, amines can bind to gold with a binding energy between 14.2 and 38.5 kJ mol −1 in solutions . Therefore, the NPs can gradually assemble on the chip.…”

Plasma-based processes for planar and 3D surface patterning of functional nanoparticles

“…Surfaces covered with non-close-packed 2D arrangement of NPs are attractive for applications such as optical devices, bio-medical sensors, and catalysis. Several methods have been reported for preparation of such functional surfaces including colloidal lithography and atomic layer deposition (ALD) (Dendooven et al 2017;Schmudde et al 2016;Hou et al 2018). Interestingly, our plasma sputtering method is capable of rapid and largearea deposition of such non-close-pack arrays of NPs.…”

“…A variety of devices have been reported using NP assembly techniques including novel optoelectronic devices (e.g., light-emitting diodes, sensors, solar cells, photodetectors, and transistors), optical and plasmon sensing devices, electrodes in nanoscale electrochemistry, printable chips, nano-pore biosensors, and transparent electrodes (Grzelczak et al 2010;Yang et al 2016;Flauraud et al 2017;Gwo et al 2016;Huang et al 2016;Su et al 2014;Lewis and Ahn 2015;Choi et al 2016;Xie et al 2015;Ellis et al 2014;Momotenko et al 2016;Blasco et al 2016). In response to the growing demand in the field, diverse techniques have been developed for 3D self-assembly of ligand-protected colloidal NPs including lithographic patterning, template-based methods, DNA-mediated assembly, dip-pen processes, and capillary assembly (Su et al 2014;Xie et al 2015), and also for 2D surface patterning such as etching of close-packed structures and atomic layer deposition (ALD) (Wang et al 2018;Dendooven et al 2017;Schmudde et al 2016;Hou et al 2018). In 3D printing technology, NPs are now widely used for 3D printing in ink-jet printers that are compatible with printing polymer and metals using colloidal inks (Hirt et al 2017).…”