Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Multilayer nanofibre face mask helps to combat pollution

14.05.2014

Researchers at the Hong Kong Polytechnic University have developed a ground-breaking filter technology that guards against the finest pollutants in the air.

Haze is usually composed of pollutants in the form of tiny suspended particles or fine mists/droplets emitted from vehicles, coal-burning power plants and factories. Continued exposure increases the risk of developing respiratory problems, heart diseases and lung cancer. Can we avoid the unhealthy air?


Professor Wallace Woon-Fong Leung, a renowned filtration expert, and his team from the Department of Mechanical Engineering at PolyU have successfully developed a simple face mask which can block out suspended particles.

Copyright : The Hong Kong Polytechnic University

A simple face mask that can block out suspended particles has been developed by scientists from the Department of Mechanical Engineering at the Hong Kong Polytechnic University (PolyU). The project is led by Professor Wallace Woon-Fong Leung, a renowned filtration expert, who has spent his career understanding these invisible killers.

In Hong Kong, suspended particles PM 10 and PM 2.5 are being monitored. PM 10 refers to particles that are 10 microns (or micrometres) in size or smaller, whereas PM 2.5 measures 2.5 microns or smaller. At the forefront of combating air pollution, Professor Leung targets ultra-fine pollutants that have yet been picked up by air quality monitors – particles measuring 1 micron or below, which he perceived to be a more important threat to human health.

“In my view, nano-aerosols (colloid of fine solid particles or liquid droplets of sub-micron to nano-sizes), such as diesel emissions, are the most lethal for three reasons. First, they are in their abundance by number suspended in the air. Second, they are too small to be filtered out using current technologies. Third, they can pass easily through our lungs and work their way into our respiratory systems, and subsequently our vascular, nervous and lymphatic systems, doing the worst kind of harm.”

However, it would be difficult to breathe through the mask if it were required to block out nano-aerosols. To make an effective filter that is highly breathable, a new filter that provides high filtration efficiency yet low air resistance (or low pressure drop) is required.

According to Professor Leung, pollutant particles get into our body in two ways – by the airflow carrying them and by the diffusion motion of these tiny particles. As the particles are intercepted by the fibres of the mask, they are filtered out before reaching our lungs.

Fibres from natural or synthetic materials can be made into nanofibres around 1/500 of the diameter of a hair (about 0.1 mm) through nanotechnologies. While nanofibres increase the surface area for nano-aerosol interception, they also incur larger air resistance. Professor Leung’s new innovation aims to divide optimal amount of nanofibres into multiple layers separated by a permeable space, allowing plenty of room for air to pass through.

A conventional face mask can only block out about 25% of 0.3-micron nano-aerosols under standard test conditions. Professor Leung said: “The multi-layer nanofibre mask can block out at least 80% of suspended nano-aerosols, even the ones smaller than 0.3 micron. In the meantime, the wearer can breathe as comfortably as wearing a conventional face mask, making it superb for any outdoor occasions. Another option is to provide a nanofiber mask that has the same capture efficiency as conventional face mask, yet it is at least several times more breathable, which would be suitable for the working group.”

The new filtration technology has been well recognized. Recently, Professor Leung and his team won a Gold Medal and a Special Merit Award from the Romania Ministry of National Education at the 42nd International Exhibition of Inventions of Geneva held in Switzerland.

If the breakthrough is turned into tightly-fit surgical masks, they are just as effective against bacteria and viruses whose sizes are under 1 micron. “In the future, medical professionals at the frontline can have stronger protection against deadly bacteria and viruses,” added Professor Leung.

In addition, a new gas purifying technology is under development to convert harmful pollutant gases, such as NOx and volatile organic compound, to harmless substances including acids, carbon dioxide and water vapour.

Going beyond personal protection, the filtration and purifying technologies when combined can also clean the air in buildings and improve indoor air quality. Professor Leung said they could make air-purifying filters that are easily fitted into old and new buildings, without any extra supporting structures or additional costs. Therefore, the potential is limitless; air-purifying filters can also be installed in the cabins of airplanes, vehicles, trains and ships. Such a handy solution can be the way of future for “cleaner and healthier” air.

Associated links

The Hong Kong Polytechnic University | Research SEA News
Further information:
http://www.polyu.edu.hk/ife/corp/en/publications/tech_front.php?tfid=8167
http://www.researchsea.com

Further reports about: Multilayer Polytechnic bacteria conventional droplets lungs micron particles pollutant resistance vehicles viruses

All articles from Innovative Products >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Self-assembling nano inks form conductive and transparent grids during imprint

Transparent electronics devices are present in today’s thin film displays, solar cells, and touchscreens. The future will bring flexible versions of such devices. Their production requires printable materials that are transparent and remain highly conductive even when deformed. Researchers at INM – Leibniz Institute for New Materials have combined a new self-assembling nano ink with an imprint process to create flexible conductive grids with a resolution below one micrometer.

To print the grids, an ink of gold nanowires is applied to a substrate. A structured stamp is pressed on the substrate and forces the ink into a pattern. “The...

Im Focus: The Glowing Brain

A new Fraunhofer MEVIS method conveys medical interrelationships quickly and intuitively with innovative visualization technology

On the monitor, a brain spins slowly and can be examined from every angle. Suddenly, some sections start glowing, first on the side and then the entire back of...

Im Focus: Newly discovered material property may lead to high temp superconductivity

Researchers at the U.S. Department of Energy's (DOE) Ames Laboratory have discovered an unusual property of purple bronze that may point to new ways to achieve high temperature superconductivity.

While studying purple bronze, a molybdenum oxide, researchers discovered an unconventional charge density wave on its surface.

Im Focus: Mapping electromagnetic waveforms

Munich Physicists have developed a novel electron microscope that can visualize electromagnetic fields oscillating at frequencies of billions of cycles per second.

Temporally varying electromagnetic fields are the driving force behind the whole of electronics. Their polarities can change at mind-bogglingly fast rates, and...

Im Focus: Continental tug-of-war - until the rope snaps

Breakup of continents with two speed: Continents initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. The final speed can be up to 20 times faster than in the first, slow extension phase.phases

Present-day continents were shaped hundreds of millions of years ago as the supercontinent Pangaea broke apart. Derived from Pangaea’s main fragments Gondwana...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2016: 7th Conference on the Art, Technology and Theory of Digital Games

29.07.2016 | Event News

GROWING IN CITIES - Interdisciplinary Perspectives on Urban Gardening

15.07.2016 | Event News

SIGGRAPH2016 Computer Graphics Interactive Techniques, 24-28 July, Anaheim, California

15.07.2016 | Event News

 
Latest News

Vortex laser offers hope for Moore's Law

29.07.2016 | Power and Electrical Engineering

Novel 'repair system' discovered in algae may yield new tools for biotechnology

29.07.2016 | Life Sciences

Clash of Realities 2016: 7th Conference on the Art, Technology and Theory of Digital Games

29.07.2016 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>