Carboxylic Anchoring Dye p-Ethyl Red Does Not Adsorb Directly onto TiO2 Particles in Protic Solvents
| Autor: | Zachary Zander, Michael J. Wilhelm, Brendan G. DeLacy, Danielle L. Kuhn, Jianqiang Ma, Hai-Lung Dai, Yi Rao, Hui Fang |
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| Rok vydání: | 2019 |
| Předmět: |
Chemistry
Hydrogen bond 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Light scattering 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Gibbs free energy Solvent chemistry.chemical_compound symbols.namesake General Energy Adsorption symbols Molecule Particle Physical and Theoretical Chemistry 0210 nano-technology Protic solvent |
| Zdroj: | The Journal of Physical Chemistry C. 123:8265-8272 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/acs.jpcc.8b08513 |
| Popis: | Adsorption of the carboxylic anchoring dye, p-ethyl red (p-ER), onto TiO2 nanoparticles in protic vs aprotic solvents was studied in situ using the surface-specific technique, second harmonic light scattering (SHS). Two different adsorption schemes were proposed to account for p-ER interactions with TiO2 under different solvent environments. In aprotic solvents, p-ER adsorbs directly onto TiO2. Conversely, in protic solvents, in which solvent molecules bind stronger than p-ER with TiO2, the dye molecules adsorb onto the solvent shell around the particle but not directly to the TiO2 surface. In addition, a portion of the p-ER molecules form hydrogen bonds with the protic solvent molecules. The two different adsorption models reproduce the measured adsorption isotherms detected by SHS. Specifically, the p-ER molecules adsorb with a smaller free energy change and a larger density in protic solvents than in aprotic solvents. Our results indicate that protic solvents are undesirable for administering adsorptio... |
| Databáze: | OpenAIRE |
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