Directly probing surfactant adsorption on nanoscopic trenches and pillars
| Autor: | Rico F. Tabor, Brian P. Grady, Joshua J. Hamon, Alberto Striolo |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Morphology (linguistics)
Materials science 02 engineering and technology Adhesion 010402 general chemistry 021001 nanoscience & nanotechnology Cetylpyridinium chloride 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Biomaterials Molecular dynamics chemistry.chemical_compound Colloid and Surface Chemistry Adsorption Pulmonary surfactant Chemical engineering chemistry Molecule 0210 nano-technology Nanoscopic scale |
| Zdroj: | Journal of Colloid and Interface Science. 579:128-139 |
| ISSN: | 0021-9797 |
| Popis: | Hypothesis Confinement causes a change in the amount of surfactant adsorbed and in the adsorption morphology. Experiments Two cationic surfactants, tetradecyltrimethylammonium bromide (TTAB) and cetylpyridinium chloride (CPC) were adsorbed at the silica-water interface. Atomic force microscopy (AFM) force curves were measured on 50 nm and 80 nm wide trenches. Force curves were also measured on silica pillars, and the results were quantified based on distance from the edge. Findings Trenches: Adsorbed surfactants films in 50 nm and 80 nm trenches showed the same break-through values. However, compared to unconfined values, TTAB in trenches had decreased break-through and adhesion forces while CPC in trenches had increased break-through and adhesion forces, indicating that surfactant identity varies the confinement effect. Pillars: Near the edge, few surfactants adsorb, and those that do extend in the direction normal to the surface. While the experimental data agree qualitatively with previous coarse-grained molecular dynamic simulations, the length scales at which the phenomena are detected differ by ~ half-order of magnitude. Specifically, experimental data show measurable effects on adsorbed surfactant morphology at a distance from the edge 10–20 times the length of a surfactant molecule after accounting for the ~8 nm size of the probe. |
| Databáze: | OpenAIRE |
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