Photoacoustics of single laser-trapped nanodroplets for the direct observation of nanofocusing in aerosol photokinetics
Cremer, Johannes W.
Thaler, Klemens M.
- Journal Article
Rights / licenseCreative Commons Attribution 4.0 International
Photochemistry taking place in atmospheric aerosol droplets has a significant impact on the Earth’s climate. Nanofocusing of electromagnetic radiation inside aerosols plays a crucial role in their absorption behaviour, since the radiation flux inside the droplet strongly affects the activation rate of photochemically active species. However, size-dependent nanofocusing effects in the photokinetics of small aerosols have escaped direct observation due to the inability to measure absorption signatures from single droplets. Here we show that photoacoustic measurements on optically trapped single nanodroplets provide a direct, broadly applicable method to measure absorption with attolitre sensitivity. We demonstrate for a model aerosol that the photolysis is accelerated by an order of magnitude in the sub-micron to micron size range, compared with larger droplets. The versatility of our technique promises broad applicability to absorption studies of aerosol particles, such as atmospheric aerosols where quantitative photokinetic data are critical for climate predictions Show more
Journal / seriesNature Communications
Pages / Article No.
PublisherNature Publishing Group
SubjectChemical sciences; Physical chemistry; Atmospheric science; Optical physics
Organisational unit03961 - Signorell, Ruth / Signorell, Ruth
159205 - Interaction of Light with Ultrafine Aerosol Particles II (SNF)
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