Armoured nanobubbles; ultrasound contrast agents under pressure
| Autor: | Vincent S. J. Craig, Muidh Alheshibri |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
education.field_of_study
Materials science Bubble Population Nanoparticle 02 engineering and technology engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Biomaterials Colloid and Surface Chemistry Coating Chemical engineering Dynamic light scattering Pulmonary surfactant engineering Laplace pressure 0210 nano-technology education Dissolution |
| Zdroj: | Journal of Colloid and Interface Science. 537:123-131 |
| ISSN: | 0021-9797 |
| Popis: | Hypothesis Robust methods for differentiating long-lived nanobubbles from other nanoparticles are required. Evaluation of the density and compressibility of nanoparticles should enable nanobubbles to be differentiated from other nanoparticles, although the response of nanobubbles to pressure can be strongly influenced by a coating of insoluble surfactant. Here we evaluate the response of nanobubbles armoured with a coating of insoluble surfactants in order to determine if they can be differentiated from other nanoparticles. Experiments Dynamic light scattering was used to size candidate nanoparticles under the influence of external pressure and resonant mass measurements were employed to assess the density of candidate nanoparticles. Findings The resonant mass measurement revealed a significant population of lipid-coated gas nanobubbles. These nanobubbles are proven to be gas entities, by their response to application of pressure. The pressure at which the gas within the nanobubbles condenses is shifted to higher pressure due to the mechanical resistance of the lipid shell, which shields the bubble contents from up to ∼0.8 atm. of the external pressure The presence of lipids of low solubility at the nanobubble-solution interface effectively results in a negative Laplace pressure, which stabilizes these nanobubbles against dissolution. |
| Databáze: | OpenAIRE |
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