Surface Tensions of Picoliter Droplets with Sub-Millisecond Surface Age.
J Phys Chem A
; 123(13): 3021-3029, 2019 Apr 04.
Article
em En
| MEDLINE
| ID: mdl-30864798
ABSTRACT
Aerosols are key components of the atmosphere and play important roles in many industrial processes. Because aerosol particles have high surface-to-volume ratios, their surface properties are especially important. However, direct measurement of the surface properties of aerosol particles is challenging. In this work, we describe an approach to measure the surface tension of picoliter volume droplets with surface age <1 ms by resolving their dynamic oscillations in shape immediately after ejection from a microdroplet dispenser. Droplet shape oscillations are monitored by highly time-resolved (500 ns) stroboscopic imaging, and droplet surface tension is accurately retrieved across a wide range of droplet sizes (10-25 µm radius) and surface ages (down to â¼100 µs). The approach is validated for droplets containing sodium chloride, glutaric acid, and water, which all show no variation in surface tension with surface age. Experimental results from the microdroplet dispenser approach are compared to complementary surface tension measurements of 5-10 µm radius droplets with aged surfaces using a holographic optical tweezers approach and predictions of surface tension using a statistical thermodynamic model. These approaches combined will allow investigation of droplet surface tension across a wide range of droplet sizes, compositions, and surface ages.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Phys Chem A
Assunto da revista:
QUIMICA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Reino Unido