The Role of Citric Acid in the Stabilization of Nanoparticles and Colloidal Particles in the Environment: Measurement of Surface Forces between Hafnium Oxide Surfaces in the Presence of Citric Acid
| Autor: | Kaoru Tamada, Drew F. Parsons, Vincent S. J. Craig, Shuhei Shinohara, Namsoon Eom, E-Jen Teh |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Flocculation
Oxide Nanoparticle 02 engineering and technology 010402 general chemistry complex mixtures 01 natural sciences Metal chemistry.chemical_compound Adsorption Electrochemistry General Materials Science Dissolution Spectroscopy fungi Surface force Surfaces and Interfaces 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences chemistry Chemical engineering visual_art visual_art.visual_art_medium 0210 nano-technology Citric acid |
| Zdroj: | Langmuir. 34:2595-2605 |
| ISSN: | 1520-5827 0743-7463 |
| Popis: | The interactions between colloidal particles and nanoparticles determine solution stability and the structures formed when the particles are unstable to flocculation. Therefore, knowledge of the interparticle interactions is important for understanding the transport, dissolution, and fate of particles in the environment. The interactions between particles are governed by the surface properties of the particles, which are altered when species adsorb to the surface. The important interactions in the environment are almost never those between the bare particles but rather those between particles that have been modified by the adsorption of natural organic materials. Citric acid is important in this regard not only because it is present in soil but also as a model of humic and fulvic acids. Here we have studied the surface forces between the model metal oxide surface hafnia in the presence of citric acid in order to understand the stability of colloidal particles and nanoparticles. We find that citric acid stabilizes the particles over a wide range of pH at low to moderate ionic strength. At high ionic strength, colloidal particles will flocculate due to a secondary minimum, resulting in aggregates that are dense and easily redispersed. In contrast, nanoparticles stabilized by citric acid remain stable at high ionic strengths and therefore exist in solution as individual particles; this will contribute to their dispersion in the environment and the uptake of nanoparticles by mammalian cells. |
| Databáze: | OpenAIRE |
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