Our core aerosol science training provide a focal point for engaging with the public on topics in aerosol science that affect our daily lives (consumer products, materials) through to our health (inhalation therapeutics, disease transmission and impacts of pollution) and the future of our planet (geoengineering).
Follow our students leading debates on all of these societal and technological challenges.
Video Shorts Introducing Aerosols
“Fry-up” for breakfast?
Aerosols are all around us and we meet them from the moment we get up in the morning. Olivia takes us through her morning and all of the aerosols she meets before she even gets to work at the University.
See how aerosols are generated from a deodorant can, to boiling your kettle for a cup of tea, to frying-up your cooked breakfast.
On the journey into work, Olivia looks at the clouds in the sky, the aerosol particles emitted by petrol cars and by vehicle brakes, finishing off with a walk in the park.
Particles of all sizes and shapes…
Aerosol particles span from the nanometre to the millimetre scale, from clusters of molecules to rain drop size. They come in a wide range of shapes from spherical droplets to irregular ice crystals and carrier particles in inhalation therapeutics. They may occur naturally in the environment or could be designed and fabricated through processes such as spray drying.
Aerosol science deals with all of the fundamental concepts and their application to aerosols in consumer products, disease transmission, pharmaceutical aerosols or the atmosphere.
How far do particles travel in indoor air? How are they produced when you sneeze or cough? What particle sizes deposit in the lung when inhaled? How are aerosol processes used in the production of solar panels, fine powders or thin films?
Why don’t clouds fall out of the sky?
What do the transport of Saharan dust around the globe, virus spread within a room and the delivery of drugs to the lungs all have in common? The motion of the airborne particles is governed by drag in all cases.
Unlike the ballistic trajectories for large particles (e.g. missiles) acting under the action of gravity, Stokes’ drag is an important concept that plays a crucial role in understanding the motion of aerosol particles. Put simply, large particles fall more quickly than small ones.
So, clouds don’t fall from the sky because cloud droplet sizes are so small that they sediment only very slowly. Over time, the cloud droplets meet each other and coalesce becoming larger and eventually leading to rain.
Inhalation of the bad and the good
The inhalation of aerosols can impact our health for the bad and the good. Particles inhaled through the mouth and the nose can be transported deep to the furthest recesses of the lung, the alveoli, only if they are sufficiently small. So, inhaled pathogens in exhaled aerosol, such as bacteria and viruses, may only reach certain regions of the respiratory tract depending on the size of the particle that carries them.
Of course, aerosols may be intentionally inhaled to treat respiratory and systemic diseases. Drug delivery to the lung requires careful consideration of both the device use to generate the aerosol and the size distribution it produces, as well as the efficacy of the active pharmaceutical ingredient.
Once inhaled, the aerosol-lung interactions must consider the innate immune response and adaptive immunity.
Moving particles with light
Using light to move objects around always sounds like science fiction, but intense light beams from lasers can be used to capture and manipulate aerosol particles. Once they are isolated, they can be studied in detail exploring how aerosols behave.
Optical tweezers rely on a steep gradient in light intensity, rather than just a high light intensity, and can be thought of as trapping particles in a deep valley with the particles needing considerable energy to escape the laser beam.
Aerosol particles can also be trapped using sound waves in acoustic traps or by charging them in an electrodynamic field.
EPSRC CDT in Aerosol Science
University of Bristol
School of Chemistry
Bristol, BS8 1TS
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