The Role of Substrate Wettability in Nanoparticle Transfer from Wrinkled Elastomers: Fundamentals and Application toward Hierarchical Patterning

Abstract

We report on the role of surface wettability during the printing transfer of nanoparticles from wrinkled surfaces onto flat substrates. As we demonstrate, this parameter dominates the transfer process. This effect can further be utilized to transfer colloidal particles in a structured fashion, if the substrates are patterned in wettability. The resulting colloidal arrangements are highly regular over macroscopic surface areas and display distinct pattern features in both the micrometer and nanoscale regime. We study the obtained structures and discuss the potential of this approach for creating hierarchical particle assemblies of high complexity. Our findings not only contribute to a better understanding of technologically relevant colloidal assembly processes, but also open new avenues for the realization of novel materials consisting of nanoparticles. In this regard, the presented structuring method is especially interesting for the design of optically functional surface coatings.

Optically anisotropic substrates via wrinkle-assisted convective assembly of gold nanorods on macroscopic areas

“…Previous work has shown that wrinkle-assisted assembly requires strongly hydrophilic (ideally, completely wetting) substrates. 19 Thus, as-received nanorods are not appropriate, as they are only colloidally stable in the presence of an excess of CTAB. The amphiphilic character of CTAB however strongly influences the wetting behaviour of the nanoparticle solution on the substrate and results in a contact angle of 32 ± 0.8° for hydrophilised PDMS.…”

Strongly Coupled Plasmonic Modes on Macroscopic Areas via Template-Assisted Colloidal Self-Assembly

“…41 Template-assisted organization imposes several requirements on the colloidal interactions of the employed particles; long-range electrostatic attraction between the template and the particles has to be avoided and at the same time, the particles should maintain colloidal stability at elevated concentrations and possess hydrophilic surfaces. 42 As prepared, the particles are coated by a layer of cetyltrimethylammonium bromide (CTAB), of which a large excess present in solution is necessary in order to ensure colloidal stability. During template-assisted assembly, this surfactant strongly adsorbs onto the surface of the used silica substrate, changing the wettability in an unfavorable fashion.…”

Colloidal Surface Assemblies: Nanotechnology Meets Bioinspiration

“…Furthermore, Hanske and co‐workers used a combined approach of chemical patterning and template assisted in combination with microcontact printing to organize nanoparticles in complex structures achieving a selective adsorption of particle lines in concrete regions of the substrate. This technique leads not only to linear assemblies, but also to grid like structures 186…”