Generation of high concentrations of respirable solid-phase aerosols from viscous fluids

• Published in: Aerosol science and technology Vol. 52; no. 8; pp. 933 - 952
• Main Authors: Heng, Xin, Yeates, Donovan B.
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 01.01.2018; Taylor & Francis Ltd
• Subjects: Aerosol particles; Aerosol research; Aerosols; Compressed air; Dilution; Dimpling; Flow rates; Flow velocity; Fluid dynamics; Fluid flow; Fluids; Gamma globulin; Infrared radiation; Molecular weight; Orifices; Polyvinylpyrrolidone; Radiation; Solid phases; Surface tension; Surfactants; Viscosity; Viscous fluids; Warren Finlay; macromolecules; aerosol drug delivery; proteins; antibodies; spray drying; ARDS; surfactant
• ISSN: 0278-6826; 1521-7388
• DOI: 10.1080/02786826.2018.1488078

High outputs of respirable solid-phase aerosols were generated from viscous solutions or suspensions of low- and high-molecular weight polyvinylpyrrolidone (PVP) solutions, 10% (w/v) albumin and, gamma globulin solutions as well as 10.3% (w/v) surfactant suspensions. A central fluid flow was aerosolized by coaxial converging compressed air. The water was evaporated from the droplets using warm dilution air and infrared radiation. The resulting aerosol particles were concentrated using a virtual impactor. The aerosols were generated at fluid flow rates between 1 and 3 ml/min and delivered at a flow rate of 44 l/min as 2.6-3.6 μm MMAD aerosols with geometric standard deviations between 1.5 and 2. Increases in viscosity over the range of 4-39 cSt caused a modest increase in MMAD. Increases in aerosol exit orifice diameter were associated with a decrease in aerosol diameter. Increases in compressed air pressure caused a decrease in aerosol diameter. Increases in fluid flow rate resulted in modest increases in MMAD together with proportional increases in output mass. Aerosolizing 10% 8 kDa PVP at 3 ml/min resulted in the delivery of 193 mg/min of PVP at 64% efficiency enabling 1.2 g to be collected in 7 min. Aerosolizing 10.3% surfactant suspensions at 3 ml/min resulted in the delivery of up to 163 mg/min with 59% efficiency. The surface tension of the surfactant was not changed by these processes. SEM showed dimpled particles of PVP, albumin, and gamma globulin indicating that their aerodynamic diameter was less than their morphometric diameter. Copyright © 2018 American Association for Aerosol Research