Bachelor Thesis

FZJ-2025-03916

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Controlled Organization of Silica Nanospheres into Highly Ordered Monolayers on a Substrate

Seidel, N.FZJ*

2024

Abstract: The study of nanoparticle self-assembly has been of interest in the field ofnanotechnology due to their broad range of potential applications. It allowsfor the creation of new nanomaterials with unique properties that differfrom bulk materials. The distinctive properties of nanoparticles, such astheir high surface area relative to their volume and enhanced quantum effects,facilitate the development of new technology across various industries.However, nanoparticles must be organized into ordered structures to be ableto exhibit their characteristics in practical applications. Therefore, producingstructures with long-range ordering is needed to utilize the functionalproperties of nanoparticles. To achieve this, nanoparticle self-assembly is away to arrange nanoparticles into defined structures using interparticle andparticle-substrate interactions.In this thesis, the self-assembly of silica (SiO2) nanoparticles with a diameterof 200 nm into ordered monolayers on a silicon substrate is investigated.Silica nanoparticles in particular offer great tunability of their physical,chemical, and optical properties, in addition to their low toxicity andgood biocompatibility. They can be derived from biomass, making them notonly cost-effective but also environmentally friendly. Fabricating monolayersfrom silica nanoparticles allows them to serve as a modulating substratefor the subsequent deposition of thin films, thereby enabling the tuning ofproperties such as optical, mechanical, and magnetic characteristics. Forthis, an improved version of drop-casting is used to fabricate the monolayersthat includes the addition of stearyl alcohol to the nanoparticle dispersion.Then, a drop volume series investigation is conducted to determine the idealdrop volume as it is a key factor in the self-assembly process. This is followed by an additional heat treatment step to improve the monolayer quality.The structural characterization of the SiO2 was done by Scanning ElectronMicroscopy (SEM) to obtain local information, and by X-ray Reflectivity(XRR) and Grazing-Incidence Small-angle X-ray Scattering (GISAXS) forglobal average information.

Note: Bachelorarbeit, Heinrich Heine Universität Düsseldorf, 2024

---

Contributing Institute(s):

1. Streumethoden (JCNS-2)
2. JARA-FIT (JARA-FIT)

Research Program(s):

1. 632 - Materials – Quantum, Complex and Functional Materials (POF4-632) (POF4-632)
2. 6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ) (POF4-6G4) (POF4-6G4)

---