Next Article in Journal
Significantly Enhanced Electrical Performances of Eco-Friendly Dielectric Liquids for Harsh Conditions with Fullerene
Previous Article in Journal
Antagonistic Interactions between Benzo[a]pyrene and Fullerene (C60) in Toxicological Response of Marine Mussels
Article Menu

Export Article

Open AccessArticle

Controlled Preparation of Nanoparticle Gradient Materials by Diffusion

Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
Department of Applied Science (Materials Science & Engineering), Fontys University of Applied Science, 5612 MA Eindhoven, The Netherlands
Author to whom correspondence should be addressed.
Nanomaterials 2019, 9(7), 988;
Received: 20 June 2019 / Revised: 4 July 2019 / Accepted: 4 July 2019 / Published: 9 July 2019
PDF [3637 KB, uploaded 9 July 2019]


Nanoparticle gradient materials combine a concentration gradient of nanoparticles with a macroscopic matrix. This way, specific properties of nanoscale matter can be transferred to bulk materials. These materials have great potential for applications in optics, electronics, and sensors. However, it is challenging to monitor the formation of such gradient materials and prepare them in a controlled manner. In this study, we present a novel universal approach for the preparation of this material class using diffusion in an analytical ultracentrifuge. The nanoparticles diffuse into a molten thermoreversible polymer gel and the process is observed in real-time by measuring the particle concentrations along the length of the material to establish a systematic understanding of the gradient generation process. We extract the apparent diffusion coefficients using Fick’s second law of diffusion and simulate the diffusion behavior of the particles. When the desired concentration gradient is achieved the polymer solution is cooled down to fix the concentration gradient in the formed gel phase and obtain a nanoparticle gradient material with the desired property gradient. Gradients of semiconductor nanoparticles with different sizes, fluorescent silica particles, and spherical superparamagnetic iron oxide nanoparticles are presented. This method can be used to produce tailored nanoparticle gradient materials with a broad range of physical properties in a simple and predictable way. View Full-Text
Keywords: composites; diffusion; functional materials; gradients; nanoparticles composites; diffusion; functional materials; gradients; nanoparticles

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Supplementary material


Share & Cite This Article

MDPI and ACS Style

Spinnrock, A.; Martens, M.; Enders, F.; Boldt, K.; Cölfen, H. Controlled Preparation of Nanoparticle Gradient Materials by Diffusion. Nanomaterials 2019, 9, 988.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Nanomaterials EISSN 2079-4991 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top