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Elasticity of Cross-Linked Titania Nanocrystal Assemblies Probed by AFM-Bulge Tests

In order to enable advanced technological applications of nanocrystal composites, e.g., as functional coatings and layers in flexible optics and electronics, it is necessary to understand and control their mechanical properties. The objective of this study was to show how the elasticity of such comp...

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Autores principales: Hensel, Andreas, Schröter, Clemens J., Schlicke, Hendrik, Schulz, Norbert, Riekeberg, Svenja, Trieu, Hoc Khiem, Stierle, Andreas, Noei, Heshmat, Weller, Horst, Vossmeyer, Tobias
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6780250/
https://www.ncbi.nlm.nih.gov/pubmed/31470667
http://dx.doi.org/10.3390/nano9091230
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author Hensel, Andreas
Schröter, Clemens J.
Schlicke, Hendrik
Schulz, Norbert
Riekeberg, Svenja
Trieu, Hoc Khiem
Stierle, Andreas
Noei, Heshmat
Weller, Horst
Vossmeyer, Tobias
author_facet Hensel, Andreas
Schröter, Clemens J.
Schlicke, Hendrik
Schulz, Norbert
Riekeberg, Svenja
Trieu, Hoc Khiem
Stierle, Andreas
Noei, Heshmat
Weller, Horst
Vossmeyer, Tobias
author_sort Hensel, Andreas
collection PubMed
description In order to enable advanced technological applications of nanocrystal composites, e.g., as functional coatings and layers in flexible optics and electronics, it is necessary to understand and control their mechanical properties. The objective of this study was to show how the elasticity of such composites depends on the nanocrystals’ dimensionality. To this end, thin films of titania nanodots (TNDs; diameter: ~3–7 nm), nanorods (TNRs; diameter: ~3.4 nm; length: ~29 nm), and nanoplates (TNPs; thickness: ~6 nm; edge length: ~34 nm) were assembled via layer-by-layer spin-coating. 1,12-dodecanedioic acid (12DAC) was added to cross-link the nanocrystals and to enable regular film deposition. The optical attenuation coefficients of the films were determined by ultraviolet/visible (UV/vis) absorbance measurements, revealing much lower values than those known for titania films prepared via chemical vapor deposition (CVD). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed a homogeneous coverage of the substrates on the µm-scale but a highly disordered arrangement of nanocrystals on the nm-scale. X-ray photoelectron spectroscopy (XPS) analyses confirmed the presence of the 12DAC cross-linker after film fabrication. After transferring the films onto silicon substrates featuring circular apertures (diameter: 32–111 µm), freestanding membranes (thickness: 20–42 nm) were obtained and subjected to atomic force microscopy bulge tests (AFM-bulge tests). These measurements revealed increasing elastic moduli with increasing dimensionality of the nanocrystals, i.e., 2.57 ± 0.18 GPa for the TND films, 5.22 ± 0.39 GPa for the TNR films, and 7.21 ± 1.04 GPa for the TNP films.
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spelling pubmed-67802502019-10-30 Elasticity of Cross-Linked Titania Nanocrystal Assemblies Probed by AFM-Bulge Tests Hensel, Andreas Schröter, Clemens J. Schlicke, Hendrik Schulz, Norbert Riekeberg, Svenja Trieu, Hoc Khiem Stierle, Andreas Noei, Heshmat Weller, Horst Vossmeyer, Tobias Nanomaterials (Basel) Article In order to enable advanced technological applications of nanocrystal composites, e.g., as functional coatings and layers in flexible optics and electronics, it is necessary to understand and control their mechanical properties. The objective of this study was to show how the elasticity of such composites depends on the nanocrystals’ dimensionality. To this end, thin films of titania nanodots (TNDs; diameter: ~3–7 nm), nanorods (TNRs; diameter: ~3.4 nm; length: ~29 nm), and nanoplates (TNPs; thickness: ~6 nm; edge length: ~34 nm) were assembled via layer-by-layer spin-coating. 1,12-dodecanedioic acid (12DAC) was added to cross-link the nanocrystals and to enable regular film deposition. The optical attenuation coefficients of the films were determined by ultraviolet/visible (UV/vis) absorbance measurements, revealing much lower values than those known for titania films prepared via chemical vapor deposition (CVD). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed a homogeneous coverage of the substrates on the µm-scale but a highly disordered arrangement of nanocrystals on the nm-scale. X-ray photoelectron spectroscopy (XPS) analyses confirmed the presence of the 12DAC cross-linker after film fabrication. After transferring the films onto silicon substrates featuring circular apertures (diameter: 32–111 µm), freestanding membranes (thickness: 20–42 nm) were obtained and subjected to atomic force microscopy bulge tests (AFM-bulge tests). These measurements revealed increasing elastic moduli with increasing dimensionality of the nanocrystals, i.e., 2.57 ± 0.18 GPa for the TND films, 5.22 ± 0.39 GPa for the TNR films, and 7.21 ± 1.04 GPa for the TNP films. MDPI 2019-08-29 /pmc/articles/PMC6780250/ /pubmed/31470667 http://dx.doi.org/10.3390/nano9091230 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Hensel, Andreas
Schröter, Clemens J.
Schlicke, Hendrik
Schulz, Norbert
Riekeberg, Svenja
Trieu, Hoc Khiem
Stierle, Andreas
Noei, Heshmat
Weller, Horst
Vossmeyer, Tobias
Elasticity of Cross-Linked Titania Nanocrystal Assemblies Probed by AFM-Bulge Tests
title Elasticity of Cross-Linked Titania Nanocrystal Assemblies Probed by AFM-Bulge Tests
title_full Elasticity of Cross-Linked Titania Nanocrystal Assemblies Probed by AFM-Bulge Tests
title_fullStr Elasticity of Cross-Linked Titania Nanocrystal Assemblies Probed by AFM-Bulge Tests
title_full_unstemmed Elasticity of Cross-Linked Titania Nanocrystal Assemblies Probed by AFM-Bulge Tests
title_short Elasticity of Cross-Linked Titania Nanocrystal Assemblies Probed by AFM-Bulge Tests
title_sort elasticity of cross-linked titania nanocrystal assemblies probed by afm-bulge tests
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6780250/
https://www.ncbi.nlm.nih.gov/pubmed/31470667
http://dx.doi.org/10.3390/nano9091230
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